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Fenders - Best practice examples
With a clear sense of responsibility and a commitment to high-performance products, we see it as our mission to share our knowledge and best practice cases with the industry and our clients.
Fender design is a complex subject. We therefore take it in small bites and explain selected cases for you in detail in this section: FENDERS - BEST PRACTICE EXAMPLES
Learn more about rubber compound, fender testing, load cases, maintenance, and get tips from a fender expert. Enjoy ⤵️
Learn from the leading fender manufacturer.
We share selected best practice cases and present our technical knowledge in small bites.
Stay tuned for more to come.
🔧 Only tensioned weight chains ensure a top performance of fender systems
[29.08.2023]
This is valid for the moment of installation, but also for re-tensioning weight chains after some years in service. Did you know that the weight chain of a fender system is the only chain working 24/7 ⏰ 📅 ? It is therefore of utmost importance that weight chains are 𝗽𝗿𝗼𝗽𝗲𝗿𝗹𝘆 𝗶𝗻𝘀𝘁𝗮𝗹𝗹𝗲𝗱 𝗮𝗻𝗱 𝗽𝗿𝗼𝗽𝗲𝗿𝗹𝘆 𝘁𝗲𝗻𝘀𝗶𝗼𝗻𝗲𝗱. As easy as the process is, as 𝗰𝗿𝘂𝗰𝗶𝗮𝗹 it is for the 𝗽𝗲𝗿𝗳𝗼𝗿𝗺𝗮𝗻𝗰𝗲 𝗮𝗻𝗱 𝘀𝗲𝗿𝘃𝗶𝗰𝗲 𝗹𝗶𝗳𝗲 𝗼𝗳 𝗮 𝗳𝗲𝗻𝗱𝗲𝗿 𝘀𝘆𝘀𝘁𝗲𝗺.
Get to know the details:
① The fender panel needs to be lifted slightly by a crane, to properly tighten the chain tensioners of the weight chain – it is not possible adjusting the tensioners without crane support.
② When the panel is fully supported by the crane, the chain tensioners need to be tightened as much as needed.
③ With re-tensioned weight chains, the fender panel can be lowered and released from the crane.
🚫 Without properly tensioned weight chains, the full fender panel weight is supported by the rubber unit only – 𝗮 𝘀𝗶𝘁𝘂𝗮𝘁𝗶𝗼𝗻 𝘁𝗵𝗮𝘁 𝘀𝗵𝗼𝘂𝗹𝗱 𝘀𝗵𝗮𝗹𝗹 𝗮𝘃𝗼𝗶𝗱𝗲𝗱, as otherwise it can lead to cracks in the fender, especially at the top flange areas. Such failure modes, which we see in the industry more often than you think, is typically not the result of low-quality rubber compounds, but rather a flawed design of the fender system.
✔️ A holistic approach to fender system design considers the 𝗯𝗮𝗹𝗮𝗻𝗰𝗲 𝗼𝗳 𝗮𝗹𝗹 𝗰𝗼𝗺𝗽𝗼𝗻𝗲𝗻𝘁𝘀 𝗮𝗻𝗱 𝗶𝘁𝘀 𝗶𝗻𝘁𝗲𝗿𝗮𝗰𝘁𝗶𝗼𝗻 𝘁𝗼 𝗮𝗰𝗵𝗶𝗲𝘃𝗲 𝗮 𝗵𝗶𝗴𝗵-𝗾𝘂𝗮𝗹𝗶𝘁𝘆 𝗳𝗲𝗻𝗱𝗲𝗿 𝘀𝘆𝘀𝘁𝗲𝗺 – an approach advocated by the SFT Group since 2017, and which we see more and more applied within the industry, especially in the new PIANC WG211 ‘Guideline for the design of fender systems’.
How to properly install fender systems – p. 12-19 of our 𝗜𝗻𝘀𝘁𝗮𝗹𝗹𝗮𝘁𝗶𝗼𝗻, 𝗢𝗽𝗲𝗿𝗮𝘁𝗶𝗼𝗻 𝗮𝗻𝗱 𝗠𝗮𝗶𝗻𝘁𝗲𝗻𝗮𝗻𝗰𝗲 𝗠𝗮𝗻𝘂𝗮𝗹 give a step-by-step instruction
How ⏩pressure⏪ during heat lamination of foam fenders ensures a high quality
[08.08.2023]
The energy absorbing component of the fenders, the foam core, is manufactured by wounding two-meter-wide foam sheets around a mandrel. The proven and most successful bonding technology is 🔥 heat lamination. Why?
➡️ to achieve a strong bonding between the foam layers
➡️ to create the solid and homogeneous fender core.
𝗪𝗵𝗮𝘁 𝗶𝘀 𝗶𝗺𝗽𝗼𝗿𝘁𝗮𝗻𝘁 𝘁𝗼 𝗸𝗻𝗼𝘄?
⚠️ Heat lamination is superior compared to adhesives which could break down over time and therefore, could lead to bonding failure in a short period of time.
🔁 The heat lamination process ensures an increased life cycle and a reliable performance of foam fenders.
⏩ ⏪ The lamination has to be done correctly: Pressure is key, and without adequate pressure, the performance and life cycle of the product is impaired.
↪️ The 𝗰𝗼𝗿𝗿𝗲𝗰𝘁 𝗽𝗿𝗲𝘀𝘀𝘂𝗿𝗲 𝗱𝘂𝗿𝗶𝗻𝗴 𝗺𝗮𝗻𝘂𝗳𝗮𝗰𝘁𝘂𝗿𝗶𝗻𝗴 𝗶𝘀 𝘃𝗶𝘁𝗮𝗹 to basically all high performance fenders in the market, both to rubber and foam fenders.
SFT with its own manufacturing facility for foam products in Germany combines pure craftsmanship 🔧 of our skilled workers with the right equipment and long-standing know-how 💡.
For more information on Foam Fenders #MadeInGermany or a visit to our manufacturing facility, please get in touch with our sales offices around the world 🌍.
🚩 𝗪𝗮𝘁𝗰𝗵 𝗼𝘂𝘁 𝘄𝗵𝗮𝘁’𝘀 𝗶𝗻𝘀𝗶𝗱𝗲 𝘆𝗼𝘂𝗿 𝗳𝗼𝗮𝗺 𝗳𝗲𝗻𝗱𝗲𝗿 🔎
[18.07.2023]
“𝘐𝘧 𝘺𝘰𝘶 𝘴𝘦𝘦 𝘷𝘰𝘪𝘥𝘴 𝘪𝘯 𝘢 𝘧𝘰𝘢𝘮 𝘧𝘦𝘯𝘥𝘦𝘳 𝘣𝘰𝘥𝘺 𝘵𝘩𝘢𝘵 𝘢𝘳𝘦 𝘭𝘢𝘳𝘨𝘦 𝘦𝘯𝘰𝘶𝘨𝘩 𝘵𝘰 𝘴𝘵𝘪𝘤𝘬 𝘺𝘰𝘶𝘳 𝘩𝘢𝘯𝘥 𝘪𝘯 👋 , 𝘵𝘩𝘦𝘯 𝘵𝘩𝘦𝘳𝘦 𝘪𝘴 𝘴𝘰𝘮𝘦𝘵𝘩𝘪𝘯𝘨 𝘷𝘦𝘳𝘺 𝘸𝘳𝘰𝘯𝘨 𝘸𝘪𝘵𝘩 𝘵𝘩𝘦 𝘧𝘦𝘯𝘥𝘦𝘳 𝘰𝘳 𝘵𝘩𝘦 𝘮𝘢𝘯𝘶𝘧𝘢𝘤𝘵𝘶𝘳𝘪𝘯𝘨 𝘮𝘦𝘵𝘩𝘰𝘥.”
❓ How can that happen?
The foam core of a foam fender is manufactured by winding foam sheets around a mandrel until the required outer diameter is reached.
As there is no industry standard, these foam sheets have different widths, ranging from ↔️ 0.15m up to 2m. Foam Fenders with lengths of several meters would need a massive amount of these small strips, compared to a couple of 2m wide sheets.
As these large sheets are more difficult to handle and considered the state-of-the-art design, smaller ones are used in the industry based on legacy processes with 𝟬.𝟭𝟱𝗺 𝘀𝘁𝗿𝗶𝗽𝘀 𝗵𝗮𝘃𝗶𝗻𝗴 𝗺𝗮𝗷𝗼𝗿 𝘀𝗵𝗼𝗿𝘁𝗰𝗼𝗺𝗶𝗻𝗴𝘀:
① Increased risk of voids and overlapping areas between strips
➡️ Voids have no energy absorbing material, and therefore the performance of the fender is limited
② Increased risk of water ingress into the fender body
➡️ During operation, especially for ship-to-ship, the water ingress into the fender could be so massive, that the fender might reach the limit of the vessels deck equipment for pulling the fender back on board.
𝗪𝗮𝘁𝗰𝗵 𝗼𝘂𝘁 𝘄𝗵𝗮𝘁’𝘀 𝗶𝗻𝘀𝗶𝗱𝗲 – the foam core provides the energy absorption, and this is what you pay for.
Foam Fenders being manufactured with wide sheets substantially reduce the number of voids and overlapping areas, 𝗿𝗲𝘀𝘂𝗹𝘁𝗶𝗻𝗴 𝗶𝗻 𝗮 𝘀𝘁𝗿𝗼𝗻𝗴𝗲𝗿 𝗳𝗲𝗻𝗱𝗲𝗿, ensuring full energy absorption capacity.
SFT with its own manufacturing facility for foam products in Germany combines pure craftsmanship of our skilled workers with the right materials and equipment, based long-standing know-how.
For more information about Foam Fenders #MadeInGermany or if you are interest to visit our manufacturing facility, please get in touch with our sales offices around the world.
◀️🔄▶️ Why inverted cone fenders should be avoided.
[27.06.2023]
𝔹𝕒𝕔𝕜𝕘𝕣𝕠𝕦𝕟𝕕:
Cone Fenders have different flange sizes on each side: a wider bottom flange and a smaller head flange. 𝗧𝗵𝗲𝗿𝗲 𝗮𝗿𝗲 𝘁𝘄𝗼 𝗱𝗶𝗳𝗳𝗲𝗿𝗲𝗻𝘁 𝘄𝗮𝘆𝘀 𝗼𝗳 𝗶𝗻𝘀𝘁𝗮𝗹𝗹𝗶𝗻𝗴 𝘁𝗵𝗲𝗺: 𝗮 𝘀𝘁𝗮𝗻𝗱𝗮𝗿𝗱 𝗼𝗻𝗲, 𝗮𝗻𝗱 𝘁𝗵𝗲 𝗶𝗻𝘃𝗲𝗿𝘁𝗲𝗱 𝗼𝗻𝗲. Designers often pay only little attention to the installation of these fenders, and some projects end up with the smaller flange installed to the substructure (inverted).
𝕋𝕙𝕖 𝕡𝕣𝕠𝕓𝕝𝕖𝕞:
This ‘inverted’ Cone Fender (small flange to substructure) 𝗶𝗺𝗽𝗮𝗰𝘁𝘀 𝘁𝗵𝗲 𝗱𝘂𝗿𝗮𝗯𝗶𝗹𝗶𝘁𝘆 𝗮𝗻𝗱 𝘀𝘁𝗮𝗯𝗶𝗹𝗶𝘁𝘆 𝗼𝗳 𝘁𝗵𝗲 𝗳𝗲𝗻𝗱𝗲𝗿 𝘀𝘆𝘀𝘁𝗲𝗺 and the safety at the berth. It means that the weight of the steel panel and rubber unit introduce a large moment into the small head section of the fender over the full stand-off distance, leading to irregular compression and more stress.
𝔼𝕩𝕔𝕖𝕡𝕥𝕚𝕠𝕟𝕒𝕝 𝕦𝕤𝕖:
Inverted fenders might be suitable when deflection and weight of the panel is guided, e.g. 𝘄𝗶𝘁𝗵 𝗣𝗮𝗿𝗮𝗹𝗹𝗲𝗹 𝗠𝗼𝘁𝗶𝗼𝗻 𝗼𝗿 𝗣𝗶𝗹𝗲/𝗣𝗶𝘃𝗼𝘁 𝗙𝗲𝗻𝗱𝗲𝗿 𝗦𝘆𝘀𝘁𝗲𝗺𝘀 𝗼𝗿 𝘄𝗵𝗲𝗿𝗲 𝘀𝗲𝘃𝗲𝗿𝗮𝗹 𝘂𝗻𝗶𝘁𝘀 𝗮𝗿𝗲 𝗰𝗼𝗺𝗯𝗶𝗻𝗲𝗱 𝗶𝗻 𝗼𝗻𝗲 𝘀𝘆𝘀𝘁𝗲𝗺, but typically not for conventional fender systems.
𝕀𝕕𝕖𝕒𝕝 𝕤𝕠𝕝𝕦𝕥𝕚𝕠𝕟:
𝗖𝗼𝗻𝗲 𝗙𝗲𝗻𝗱𝗲𝗿𝘀 𝗮𝗿𝗲 𝗺𝗼𝗿𝗲 𝘀𝘁𝗮𝗯𝗹𝗲, 𝗱𝘂𝗿𝗮𝗯𝗹𝗲 𝗮𝗻𝗱 𝗿𝗼𝗯𝘂𝘀𝘁, 𝘄𝗵𝗲𝗻 𝗶𝗻𝘀𝘁𝗮𝗹𝗹𝗲𝗱 𝘄𝗶𝘁𝗵 𝘁𝗵𝗲 𝘄𝗶𝗱𝗲𝗿 𝗳𝗹𝗮𝗻𝗴𝗲 𝘁𝗼 𝘁𝗵𝗲 𝘀𝘂𝗯𝘀𝘁𝗿𝘂𝗰𝘁𝘂𝗿𝗲. ‘Inverted’ cone fender designs should be avoided and challenged, to not compromise the operation and, above all, the safety at the terminal.
Some examples of world-class Cone Fender solutions, all individually designed and manufactured for our clients.
𝗪𝗵𝗮𝘁 𝘆𝗼𝘂 𝘀𝗲𝗲 𝗮𝘁 𝗳𝗶𝗿𝘀𝘁 𝘀𝗶𝗴𝗵𝘁, 𝗺𝗶𝗴𝗵𝘁 𝗻𝗼𝘁 𝗯𝗲 𝘁𝗵𝗲 𝗳𝘂𝗹𝗹 𝗽𝗶𝗰𝘁𝘂𝗿𝗲 🎨
[23.05.2023]
① 𝗧𝗶𝗹𝘁𝗶𝗻𝗴 𝗮𝗻𝗱 𝗱𝗿𝗼𝗼𝗽𝗶𝗻𝗴
② 𝗣𝗲𝗮𝗸 𝗽𝗿𝗲𝘀𝘀𝘂𝗿𝗲 𝗼𝗻 𝘁𝗵𝗲 𝗵𝘂𝗹𝗹
Tilting is especially a problem with long panels 📐, as the cantilever and dead weight of the panel will cause the rubber unit to deflect slightly, resulting in a tilted panel.
As shown in the sketch below, when the rubber unit is installed in the upper third of the panel, a peak hull pressure occurs 📈, as the lower part is ineffective.
↔️ If you are striving for a good and 𝗯𝗮𝗹𝗮𝗻𝗰𝗲𝗱 𝗳𝗲𝗻𝗱𝗲𝗿 𝘀𝘆𝘀𝘁𝗲𝗺, we recommend to position the rubber unit in the middle third of the steel panel, or even symmetrically, if hull pressure is a significant factor, as for LNG carriers.
📧 📞 Our fender experts are happy to share further recommendations about the 𝗰𝗼𝗿𝗿𝗲𝗰𝘁 𝗽𝗼𝘀𝗶𝘁𝗶𝗼𝗻 𝗼𝗳 𝘁𝗵𝗲 𝗿𝘂𝗯𝗯𝗲𝗿 𝘂𝗻𝗶𝘁𝘀 𝗼𝗻 𝘀𝘁𝗲𝗲𝗹 𝗽𝗮𝗻𝗲𝗹𝘀. Please contact our local office for information.
🔍 𝗪𝗵𝗮𝘁 𝗶𝘀 𝘀𝗵𝗲𝗮𝗿 𝗰𝗼𝗺𝗽𝗿𝗲𝘀𝘀𝗶𝗼𝗻 𝘁𝗲𝘀𝘁𝗶𝗻𝗴?🔎
[09.05.2023]
A combined shear compression testing is an alternative to a simple compression testing. This durability test combines axial deflection with 𝘀𝗵𝗲𝗮𝗿 𝗱𝗲𝗳𝗹𝗲𝗰𝘁𝗶𝗼𝗻.
⚠️ Keep in mind that fenders typically experience compression and shear at the same time when being used at the berth. ⚠️
At SFT, the 𝗰𝗼𝗺𝗯𝗶𝗻𝗲𝗱 𝘀𝗵𝗲𝗮𝗿 𝗰𝗼𝗺𝗽𝗿𝗲𝘀𝘀𝗶𝗼𝗻 𝘁𝗲𝘀𝘁 𝗲𝗾𝘂𝗶𝗽𝗺𝗲𝗻𝘁 allows for almost any fender size to be tested, yet the number of compression cycles is inherently limited for the largest fenders. For scale models, 25,000 and more test cycles are possible and have already been successfully 𝘁𝗲𝘀𝘁𝗲𝗱 𝘂𝗻𝗱𝗲𝗿 𝗳𝘂𝗹𝗹 𝘁𝗶𝗺𝗲 𝗲𝘅𝘁𝗲𝗿𝗻𝗮𝗹 𝗮𝘂𝗱𝗶𝘁𝗶𝗻𝗴.
Full scale testing with max. 3 cycles is recommended for demanding and sensitive projects.
Ｅｘｐｅｒｔ ａｄｖｉｃｅ：Durability tests could be surprisingly expensive. Before this test protocol is required in specifications, we suggest to consult with the manufacturer for details and prices to be aware of the additional cost.
SFT compiled all the “need-to-know” information about Fender Testing in its 𝗪𝗵𝗶𝘁𝗲 𝗣𝗮𝗽𝗲𝗿 ‘𝗧𝗲𝘀𝘁𝗶𝗻𝗴 - 𝗔 𝗯𝗲𝘀𝘁-𝗽𝗿𝗮𝗰𝘁𝗶𝗰𝗲 𝗮𝗽𝗽𝗿𝗼𝗮𝗰𝗵’
♐️ 𝗔𝗻𝗰𝗵𝗼𝗿𝘀 – 𝗢𝗻𝗲 𝘀𝗶𝘇𝗲 𝗳𝗶𝘁𝘀 𝗮𝗹𝗹. 𝗢𝗿?
[25.04.2023]
📏 The size of anchors for fenders is determined during the development of the rubber unit and applied according to the fender manufacturer’s catalogue data.
In contrast, 𝗮𝗻𝗰𝗵𝗼𝗿𝘀 𝗳𝗼𝗿 𝗰𝗵𝗮𝗶𝗻 𝗯𝗿𝗮𝗰𝗸𝗲𝘁𝘀 𝗵𝗮𝘃𝗲 𝗮 𝗱𝗶𝗳𝗳𝗲𝗿𝗲𝗻𝘁 𝗮𝗽𝗽𝗿𝗼𝗮𝗰𝗵: It is important that the anchor size and length is calculated individually according to the occurring 𝗹𝗼𝗮𝗱 𝗰𝗮𝘀𝗲s.
💬 Typically, these main load cases exist:
① Full face contact by vessel with ship list
② Line load contact e.g. by belting
③ Low level impact / Bow flare contact
It is therefore of utmost importance that the fender manufacturer is aware of the anticipated load cases. 𝗜𝗳 𝘁𝗵𝗲 𝗮𝗰𝘁𝘂𝗮𝗹 𝗹𝗼𝗮𝗱 𝗰𝗮𝘀𝗲 𝗱𝗶𝗳𝗳𝗲𝗿𝘀 𝗳𝗿𝗼𝗺 𝘁𝗵𝗲 𝘀𝗽𝗲𝗰𝗶𝗳𝗶𝗰𝗮𝘁𝗶𝗼𝗻, 𝘃𝗮𝗿𝗶𝗼𝘂𝘀 𝗽𝗿𝗼𝗯𝗹𝗲𝗺𝘀 𝗮𝗻𝗱 𝗿𝗶𝘀𝗸𝘀 𝗰𝗼𝘂𝗹𝗱 𝗼𝗰𝗰𝘂𝗿 𝗱𝘂𝗿𝗶𝗻𝗴 𝗼𝗽𝗲𝗿𝗮𝘁𝗶𝗼𝗻.
Applying loads on a fender system other than specified, could not only imply monetary consequences for the terminal operator and costly downtimes, but also a safety risk for port personnel.
🔁 Share the information of the anticipated load case with your fender manufacturer to make sure that anchors for chain brackets are calculated correctly, to avoid damages, unnecessary cost and safety risks ⛔️.
📧 If you need any further #advice on the topic of anchors for chain brackets, please contact your local ShibataFenderTeam experts via email or our contact form.
🔩 𝗛𝗼𝘄 𝘁𝗼 𝗮𝘃𝗼𝗶𝗱 𝘁𝗵𝗮𝘁 𝗯𝗼𝗹𝘁𝘀 𝗮𝗿𝗲 𝗹𝗼𝗼𝘀𝗲𝗻𝗶𝗻𝗴?
[11.04.2023]
❗️ Bolt tightening is an extremely important topic for the safety in ports. If bolts of a fender system are not tight enough, they will become undone; if they are too tight, they may damage the fender system.
Here is some best practice advice for you, to be on the safe side:
① 𝗖𝗵𝗲𝗺𝗶𝗰𝗮𝗹 𝘁𝗵𝗿𝗲𝗮𝗱 𝗹𝗼𝗰𝗸𝗲𝗿 is recommended for all bolted connections 𝘁𝗼 𝘀𝘁𝗼𝗽 𝗳𝗶𝘅𝗶𝗻𝗴𝘀 𝗳𝗿𝗼𝗺 𝗹𝗼𝗼𝘀𝗲𝗻𝗶𝗻𝗴 due to vibrations from moored ships or wave movements. Our recommendation is to apply the thread locker (e.g. Loctite) during assembly 𝗯𝘂𝘁 𝗿𝗲𝗺𝗼𝘃𝗲 𝘁𝗵𝗲 𝗴𝗿𝗲𝗮𝘀𝗲 from inside the sockets of rubber fenders or steel panels before. The thread locker (medium grade) shall be applied according to manufacturer’s recommendations, it cures by being exposed to oxygen. Connections can be untightened by applying reasonable force.
We furthermore recommend to 𝗮𝗹𝘄𝗮𝘆𝘀 𝘂𝘀𝗲 𝘁𝗵𝗿𝗲𝗮𝗱 𝗹𝗼𝗰𝗸𝗲𝗿 𝗼𝗻 𝗮𝗹𝗹 𝘁𝗵𝗿𝗲𝗮𝗱𝘀 𝘁𝗼 𝗽𝗿𝗲𝘃𝗲𝗻𝘁 𝗹𝗼𝗼𝘀𝗲𝗻𝗶𝗻𝗴. Any loose bolts identified during inspection or maintenance should be fixed to prevent further damages to the systems.
② Other possible locking methods include 𝘁𝗮𝗯 𝘄𝗮𝘀𝗵𝗲𝗿𝘀, 𝗹𝗼𝗰𝗸𝗶𝗻𝗴 𝗽𝗶𝗻𝘀 𝗮𝗻𝗱 𝘁𝗮𝗰𝗸-𝘄𝗲𝗹𝗱𝗶𝗻𝗴. It needs to be taken into account, however, that especially tack-welding might lead to damages during loosening and some components might need to be replaced.
📧 If you need any further #advice on the topic of bolt loosening, please contact your local ShibataFenderTeam experts.
⚓️ How to avoid that a Chemical Anchor is pulled out of the concrete?
[28.03.2023]
𝗔𝗻𝗰𝗵𝗼𝗿𝘀 for fender systems secure the fender system and its components to the substructure.
To avoid being pulled out of the concrete is all about being threaded and a strong bonding.
First of all, we distinguish between Cast-in Anchors and Chemical Anchors:
▶️ Cast-In Anchors for a new concrete structure
▶️ Chemical Anchors for existing concrete structures
𝖠 𝗌𝗉𝖾𝖼𝗂𝖺𝗅 𝗇𝗈𝗍𝖾 𝗈𝗇 𝖢𝗁𝖾𝗆𝗂𝖼𝖺𝗅 𝖠𝗇𝖼𝗁𝗈𝗋𝗌: The threaded rod of the anchor is bonded with special high-strength resin-grout into a drilled hole. It is therefore essential that the chemical anchor is 𝘁𝗵𝗿𝗲𝗮𝗱𝗲𝗱 so that the grout can set in the threads and 𝗱𝗲𝘃𝗲𝗹𝗼𝗽 𝗮 𝘀𝘁𝗿𝗼𝗻𝗴 𝗯𝗼𝗻𝗱𝗶𝗻𝗴 with the concrete 🔄 - especially when the selected anchors deviate from standard 8.8 Chemical Anchors (e.g. as stainless steel).
➡️ 𝗜𝗳 𝘁𝗵𝗶𝘀 𝗶𝘀 𝗺𝗶𝘀𝘀𝗶𝗻𝗴, 𝘁𝗵𝗲𝗿𝗲 𝗶𝘀 𝗮 𝘃𝗲𝗿𝘆 𝗵𝗶𝗴𝗵 𝗰𝗵𝗮𝗻𝗰𝗲 𝘁𝗵𝗮𝘁 𝘁𝗵𝗲 𝗮𝗻𝗰𝗵𝗼𝗿 𝗺𝗮𝘆 𝗯𝗲 𝗽𝘂𝗹𝗹𝗲𝗱 𝗼𝘂𝘁 𝗼𝗳 𝘁𝗵𝗲 𝗰𝗼𝗻𝗰𝗿𝗲𝘁𝗲 𝗱𝘂𝗿𝗶𝗻𝗴 𝘁𝗵𝗲 𝗯𝗲𝗿𝘁𝗵𝗶𝗻𝗴 𝗽𝗿𝗼𝗰𝗲𝘀𝘀.
Our international experts in the different SFT offices around the world are very happy to be in touch with you for further questions about anchors.
📧 You can reach them via email or our contact form.
🔬 𝗩𝗲𝗿𝗶𝗳𝗶𝗰𝗮𝘁𝗶𝗼𝗻 𝘁𝗲𝘀𝘁𝗶𝗻𝗴 𝗱𝗲𝘁𝗲𝗿𝗺𝗶𝗻𝗲𝘀 𝘁𝗵𝗮𝘁 𝘆𝗼𝘂 𝘁𝗿𝘂𝗹𝘆 𝗿𝗲𝗰𝗲𝗶𝘃𝗲 𝘄𝗵𝗮𝘁 𝘆𝗼𝘂 𝗼𝗿𝗱𝗲𝗿𝗲𝗱
[14.03.2023]
❓ What is the best way for you to ensure that the final fender and the material used are compliant with your individual project requirements before the fenders are shipped to their new home ⚓️?
Once the specific parameters and requirements for your project have been determined, the manufacturer starts with the manufacturing of your customized fenders.
Ensuring compliance with your requirements is done via the so-called 𝗩𝗲𝗿𝗶𝗳𝗶𝗰𝗮𝘁𝗶𝗼𝗻 𝗧𝗲𝘀𝘁𝗶𝗻𝗴 - the most relevant fender testing procedure as it confirms the performance and material quality of the product.
Verification testing consists of:
☑️ material testing
☑️ traceability
☑️ performance testing
☑️ verification of dimensions
☑️ visual checking
The first one is done on the actual rubber compound used for the production of the fender, whereas the other test procedures are performed on the final fender that has been produced for your individual project.
All of them are covered in more depth in our 𝗪𝗵𝗶𝘁𝗲 𝗣𝗮𝗽𝗲𝗿 #𝟰 ‘𝗧𝗲𝘀𝘁𝗶𝗻𝗴 – 𝗔 𝗯𝗲𝘀𝘁-𝗽𝗿𝗮𝗰𝘁𝗶𝗰𝗲 𝗮𝗽𝗽𝗿𝗼𝗮𝗰𝗵’. ⬅️ Download it from our website and Join The Safe Side.
📕 What does British Standard 6349-1-4-2021 really say about rubber compounds? And what doesn’t it?
[28.02.2023]
The newest British Standard, 𝗕𝗦 𝟲𝟯𝟰𝟵-𝟭-𝟰-𝟮𝟬𝟮𝟭, a ‘Code of practice for materials’, gives recommendations for the materials used in the design and construction of maritime environment structures with specific provisions for use in seawater.
💬 What does it tell us? And more important, what doesn’t it ❌?
𝟭 It is specifically mentioned that this code of practice takes the form of 𝗿𝗲𝗰𝗼𝗺𝗺𝗲𝗻𝗱𝗮𝘁𝗶𝗼𝗻 𝗮𝗻𝗱 𝗴𝘂𝗶𝗱𝗮𝗻𝗰𝗲 and is 𝗻𝗼𝘁 to be quoted as if it was a specification (see Foreword V).
𝟮 If a 𝗱𝗲𝘀𝗶𝗴𝗻𝗲𝗿 plans to specify a compound including semi-reinforcing fillers, specialist advice should be obtained from the manufacturer – it is 𝗻𝗼𝘁 the obligation of the manufacturer to detail the components of their compounds (see 16.1.3/16.1.4).
𝟯 It introduces a 𝟱% 𝗹𝗶𝗺𝗶𝘁 to fillers in rubber compounds – don’t let yourself be fooled here: the 5% limit is for inert and extending fillers, 𝗻𝗼𝘁 for common semi-reinforcing fillers with very small particle sizes (see 16.1.3).
𝟰 It explains that if a 𝗧𝗚𝗔 testing (Thermogravimetric Analysis) is performed on a test sample and the finished fender, and results are then compared, that 𝗱𝗲𝘃𝗶𝗮𝘁𝗶𝗼𝗻𝘀 𝗰𝗮𝗻 𝗼𝗰𝗰𝘂𝗿, even between samples from the same batch, especially if different laboratories are used and if solvent extraction is not performed on both parts. It does 𝗻𝗼𝘁 say that a TGA test gives an indication of quality or durability – this can only be done by physical property and durability testing (see 16.1.5).
International standards and guidelines are usually very comprehensive documents and not easy to be analyzed.
📱 📧 If you have further questions about the new British Standard BS 6349-1-4-2021, 𝗴𝗲𝘁 𝗶𝗻 𝘁𝗼𝘂𝗰𝗵 𝘄𝗶𝘁𝗵 𝗼𝘂𝗿 𝗳𝗲𝗻𝗱𝗲𝗿 𝗲𝘅𝗽𝗲𝗿𝘁𝘀 who are available for you worldwide 🌎
💫 Fender design is not about beliefs; it is about facts ❗️
[14.02.2023]
❗️ Fenders are of paramount importance in securing port infrastructures and creating a safe environment for ships and crews – they need to perform as expected throughout their entire service life, even in the most remote locations and under harshest conditions.
❗️ Fender Design builds on the foundation of engineering excellence and skilled specialists with a long proven track record in the maritime construction industry.
❗️ All steps of fender design go hand in hand and influence each other - all the components of a fender system must be designed in the correct balance and work together properly.
❗️ This concept, a ‘holistic approach to fender system design’, considers a fender system as a whole, taking into account the project conditions, its different components as well as its manufacturing process.
💫 What is about beliefs, is the 𝗲𝘁𝗵𝗶𝗰𝘀 𝗼𝗳 𝗮 𝗺𝗮𝗻𝘂𝗳𝗮𝗰𝘁𝘂𝗿𝗲𝗿.
A durable fender is the physical evidence of a corporate culture that puts the performance requirements of the customer first in determining product quality, and not the company’s own need for market differentiation.
SFT believes in more 𝘁𝗿𝗮𝗻𝘀𝗽𝗮𝗿𝗲𝗻𝗰𝘆 in fender production in order to ensure quality standards that are driven by a commitment to high-performance products and a clear sense of responsibility.
🔃 Cyclic load cases - Part II
[31.01.2023]
𝗜𝗳 𝗻𝗼𝘁 𝗱𝗲𝘀𝗶𝗴𝗻𝗲𝗱 𝗳𝗼𝗿 𝗰𝘆𝗰𝗹𝗶𝗰 𝗼𝗿 𝗰𝗼𝗻𝘀𝘁𝗮𝗻𝘁 𝗹𝗼𝗮𝗱𝘀 𝗯𝘂𝘁 𝗯𝗲𝗶𝗻𝗴 𝗲𝘅𝗽𝗼𝘀𝗲𝗱 𝘁𝗼 𝘀𝘂𝗰𝗵, 𝗮𝗻𝘆 𝗳𝗲𝗻𝗱𝗲𝗿 𝘄𝗶𝗹𝗹 𝗳𝗮𝗶𝗹.
Unlike berthing loads, which are individual impacts isolated over time, cyclic loads have a certain constant period of oscillation, while constant loads are permanent. These loads can cause cyclic or permanent deflections. The consequences are severe!
If a fender is not designed for cyclic or constant loads but then being exposed to it, e.g. 10 deflections per minute, there are two components that could lead to failures:
①one is the heat build-up in the fender (fatigue)
② and the other is the overstress of the rubber, leading to early deterioration of materials and a premature failure
What makes a difference is a thorough mooring and berthing analysis and a customized design of the fender system, taking into account all project requirements – a holistic approach to fenders system design. This is also addressed and picked up by industry guidelines and standards to improve the safety and efficiency in the industry.
Summing up:
☑️ Choose a fender manufacturer who focuses on a holistic approach
☑️ Make sure all conditions of the cyclic and constant loads are analyzed and well known before the fender design phase starts
☑️ Receive a customized fender system for your requirements to protect your quay wall, avoid accidents and downtime
Join the safe side – Work with ShibataFenderTeam.
🔃 Cyclic load cases - Part I
[17.01.2023]
What are 𝗰𝘆𝗰𝗹𝗶𝗰 𝗮𝗻𝗱 𝗰𝗼𝗻𝘀𝘁𝗮𝗻𝘁 𝗹𝗼𝗮𝗱𝘀 and how do they affect the design of a fender? To find out, we need to go back one step, to the 𝗱𝗶𝗳𝗳𝗲𝗿𝗲𝗻𝗰𝗲 𝗯𝗲𝘁𝘄𝗲𝗲𝗻 𝗮 𝗯𝗲𝗿𝘁𝗵𝗶𝗻𝗴 𝗮𝗻𝗮𝗹𝘆𝘀𝗶𝘀 𝗮𝗻𝗱 𝗮 𝗺𝗼𝗼𝗿𝗶𝗻𝗴 𝗮𝗻𝗮𝗹𝘆𝘀𝗶𝘀.
Where the berthing analysis focuses on the kinetic energy of the vessel during berthing, the mooring analysis focuses on forces on the berthed vessel, that are due to wind, current, tension lines and others. A thorough mooring analysis can prevent the fender from damages and failure. Here is how:
The mooring analysis might reveal that load cases need to be considered that include 𝗰𝘆𝗰𝗹𝗶𝗰 𝗮𝗻𝗱 𝗰𝗼𝗻𝘀𝘁𝗮𝗻𝘁 𝗹𝗼𝗮𝗱𝘀. The main difference here is that with cyclic loads, there is an oscillation motion, whereas constant loads deflect the fender permanently until release of the vessel. Both loads could also occur simultaneously, which poses potential design challenges to the fender and its life cycle.
Examples for cyclic and constant load cases are permanent mooring situations, like
➡️ FSRU’s
➡️ floating docks
➡️ stationary vessels, like museum vessels (e.g. the barque ‘Peking’ in Hamburg)
Taking into account cyclic and constant loads during the design process, the designer needs to focus on the 𝗳𝗲𝗻𝗱𝗲𝗿’𝘀 𝗿𝗲𝗮𝗰𝘁𝗶𝗼𝗻 𝗳𝗼𝗿𝗰𝗲, to make sure that wind and other loads do not exceed the load limits of a fender. But most important, the 𝗱𝗲𝗳𝗹𝗲𝗰𝘁𝗶𝗼𝗻 𝗼𝗳 𝘁𝗵𝗲 𝗳𝗲𝗻𝗱𝗲𝗿 under cyclic and constant loads should be limited.
That could be achieved by
☑️ a correct mooring arrangement, and/or
☑️ an oversized fender where the expected loads correspond to a 5-10% deflection of the fender.
📝 𝘍𝘦𝘯𝘥𝘦𝘳𝘴 𝘰𝘧 𝘢𝘭𝘭 𝘵𝘺𝘱𝘦𝘴, 𝘨𝘳𝘢𝘥𝘦𝘴, 𝘲𝘶𝘢𝘭𝘪𝘵𝘪𝘦𝘴, 𝘱𝘳𝘪𝘤𝘦𝘴 𝘢𝘯𝘥 𝘧𝘳𝘰𝘮 𝘢𝘭𝘭 𝘮𝘢𝘯𝘶𝘧𝘢𝘤𝘵𝘶𝘳𝘦𝘳𝘴 𝘸𝘪𝘭𝘭 𝘧𝘢𝘪𝘭 𝘪𝘧 𝘯𝘰𝘵 𝘥𝘦𝘴𝘪𝘨𝘯𝘦𝘥 𝘧𝘰𝘳 𝘤𝘺𝘤𝘭𝘪𝘤 𝘰𝘳 𝘤𝘰𝘯𝘴𝘵𝘢𝘯𝘵 𝘭𝘰𝘢𝘥𝘴 𝘣𝘶𝘵 𝘣𝘦𝘪𝘯𝘨 𝘦𝘹𝘱𝘰𝘴𝘦𝘥 𝘵𝘰 𝘴𝘶𝘤𝘩.
🔑 3 Maintenance Levels to follow 🔍
[13.12.2022]
🔧 Maintenance is an important topic but also extensive and not always easy to grasp. So where to start? A maintenance checklist is already a helpful tool – if this is even topped up by a list of 𝗺𝗮𝗶𝗻𝘁𝗲𝗻𝗮𝗻𝗰𝗲 𝗹𝗲𝘃𝗲𝗹𝘀 and detailed instructions, you are ready to go.
We recommend these three maintenance levels:
𝗟𝗲𝘃𝗲𝗹 𝟭: 𝗖𝗹𝗼𝘀𝗲 𝘃𝗶𝘀𝘂𝗮𝗹 𝗶𝗻𝘀𝗽𝗲𝗰𝘁𝗶𝗼𝗻
Every 6 months or 1 year, depending on component
𝗟𝗲𝘃𝗲𝗹 𝟮: 𝗜𝗻𝘁𝗲𝗿𝗶𝗺 𝗺𝗮𝗶𝗻𝘁𝗲𝗻𝗮𝗻𝗰𝗲
For most components every 4-6 years
𝗟𝗲𝘃𝗲𝗹 𝟯: 𝗠𝗮𝗷𝗼𝗿 𝗺𝗮𝗶𝗻𝘁𝗲𝗻𝗮𝗻𝗰𝗲 𝗼𝗿 𝗼𝘃𝗲𝗿𝗵𝗮𝘂𝗹
For most components every 15-25 years
👉 If you like to get assistance on how to approach the maintenance of your installations, feel free to get in touch with your local SFT office - we offer 𝗶𝗻𝘀𝗽𝗲𝗰𝘁𝗶𝗼𝗻 𝘃𝗶𝘀𝗶𝘁𝘀 𝘆𝗲𝗮𝗿 𝗿𝗼𝘂𝗻𝗱. In some cases, these are done in cooperation with our local agents.
Rely on our expertise and receive a customized maintenance schedule to prevent wear and tear and possible costly damages. Further information on maintenance levels – download our IOM (maintenance manual) for free.
▶️ Join the safe side – Work with ShibataFenderTeam ◀️
🔨 Maintenance Inspection Periods. 4 reasons why preventive maintenance should not be ignored 🔦
[29.11.2022]
⛵️Where no maintenance of your fender systems can lead to...
The 𝗴𝗼𝗮𝗹 𝗼𝗳 𝗮𝗻𝘆 𝗺𝗮𝗶𝗻𝘁𝗲𝗻𝗮𝗻𝗰𝗲 𝗽𝗿𝗼𝗴𝗿𝗮𝗺 is to avoid or reduce the consequences of failure of equipment whilst maintaining safety at all times with a low financial impact.
With a preventive maintenance program in place, your equipment is regularly checked for wear and tear – and it is possible to replace or repair worn components before they cause a failure.
𝗧𝗵𝗲𝘀𝗲 𝗮𝗿𝗲 𝘁𝗵𝗲 𝟰 𝗿𝗲𝗮𝘀𝗼𝗻𝘀 𝘄𝗵𝘆 𝗽𝗿𝗲𝘃𝗲𝗻𝘁𝗶𝘃𝗲 𝗺𝗮𝗶𝗻𝘁𝗲𝗻𝗮𝗻𝗰𝗲 𝘀𝗵𝗼𝘂𝗹𝗱 𝗻𝗼𝘁 𝗯𝗲 𝗶𝗴𝗻𝗼𝗿𝗲𝗱:
✔️ Enable safe and efficient operations at the port
✔️ Reduce the potential for accidents
✔️ Increase the operational life of marine fenders
✔️ Reduce operational costs
Remember: The cost for downtime of the berth, liability claims and the cost to repair potential damages is always higher than carrying out a preventive maintenance program or repair equipment/order spare parts.
An ideal and well executed maintenance program would ensure 𝘇𝗲𝗿𝗼 𝗱𝗼𝘄𝗻𝘁𝗶𝗺𝗲.
For more information on maintenance, visit our website to download our 𝗜𝗻𝘀𝘁𝗮𝗹𝗹𝗮𝘁𝗶𝗼𝗻, 𝗢𝗽𝗲𝗿𝗮𝘁𝗶𝗼𝗻 𝗮𝗻𝗱 𝗠𝗮𝗶𝗻𝘁𝗲𝗻𝗮𝗻𝗰𝗲 𝗠𝗮𝗻𝘂𝗮𝗹 and our free 𝗺𝗮𝗶𝗻𝘁𝗲𝗻𝗮𝗻𝗰𝗲 𝗰𝗵𝗲𝗰𝗸𝗹𝗶𝘀𝘁 (available in 7 languages).
🍎 3 technical details in specifications you should not miss when comparing quotations with specifications
[15.11.2022]
“Compare apples with apples” – this has always been a wise counsel and still is when speaking about high-quality durable fender systems.
Quotations are based on project specifications – or at least they should be. ❌ But what if not?
Project specifications allow clients to detail their specific project needs and to ensure a common basis for expected quotations, and at the same time they give guidance for equipment suppliers/manufacturers to prepare their quotations.
❌ But what if quotations aren’t based on specifications and it is therefore not possible to compare them? Not quoting to specifications usually goes along with a lower price, making it difficult for the client to compare apples with apples 🍎.
When it comes to high-quality durable fender systems, the following 3 technical details should not be missed:
𝟭. 𝗠𝗮𝘁𝗲𝗿𝗶𝗮𝗹 𝘀𝗽𝗲𝗰𝗶𝗳𝗶𝗰𝗮𝘁𝗶𝗼𝗻𝘀
𝟮. 𝗦𝗽𝗲𝗰𝗶𝗳𝗶𝗲𝗱 𝗹𝗼𝗮𝗱 𝗰𝗮𝘀𝗲𝘀
𝟯. 𝗖𝗼𝗮𝘁𝗶𝗻𝗴 𝗿𝗲𝗾𝘂𝗶𝗿𝗲𝗺𝗲𝗻𝘁𝘀
If you are in doubt, it is better to double check with the suppliers and get detailed written confirmation for any item with ambiguity.
The SFT Group is your partner and you can rely on us – always.
🔶 Why fender selection cannot be automated ◀️
[01.11.2022] 💦
⚡️ Fender manufacturers offer a wide range of fender types suitable for different requirements. The purpose of fenders is to 𝗮𝗯𝘀𝗼𝗿𝗯 the kinetic energy of berthing vessels 🚢, and on the other hand, to 𝘁𝗿𝗮𝗻𝘀𝗳𝗲𝗿 the reaction force via different components of the fender system onto the vessel hull and into the berth substructure.
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High energy absorption while having acceptable reaction forces is key to a good fender system design. However, simply calculating 📐 the berthing energy requirements results in a long list of suitable fender types and sizes
❓ How to select the right fender?
There are many other factors which need to be considered ✔️, like: vessel details (e.g. vessel type, hull pressure, beltings), berthing information (e.g. berthing mode, type of substructure, fender spacing, stand-off requirements), project conditions 🌊, preferences of the client 📝, and more. Selecting the right fender for your specific project needs a unique approach and cannot be done by an automated tool. The topic of fender selection again shows why it is beneficial to rely on 𝗽𝗲𝗿𝘀𝗼𝗻𝗮𝗹 𝗲𝘅𝗽𝗲𝗿𝘁𝗶𝘀𝗲 𝗮𝗻𝗱 𝗲𝘅𝗽𝗲𝗿𝗶𝗲𝗻𝗰𝗲.
Contact us 📞 📧 for a 𝗳𝗿𝗲𝗲 𝗰𝗼𝗻𝘀𝘂𝗹𝘁𝗮𝘁𝗶𝗼𝗻 – we are available already at the design stage of your project.
➰ Holistic Approach Part III
[18.10.2022]
A complex route lies ahead to get a high-quality and durable fender system to protect vessels 🚤, port infrastructure ⚓️ and people 👷.
Three aspects need to be taken into account when following 𝗮 𝗵𝗼𝗹𝗶𝘀𝘁𝗶𝗰 𝗮𝗽𝗽𝗿𝗼𝗮𝗰𝗵 𝘁𝗼 𝗳𝗲𝗻𝗱𝗲𝗿 𝘀𝘆𝘀𝘁𝗲𝗺 𝗱𝗲𝘀𝗶𝗴𝗻.
PART III explains why the manufacturing process makes a difference.
The 𝙢𝙖𝙣𝙪𝙛𝙖𝙘𝙩𝙪𝙧𝙞𝙣𝙜 𝙥𝙧𝙤𝙘𝙚𝙨𝙨 of the rubber unit plays a vital part in the ultimate performance of a fender system, same as for steel parts and PE. A holistic approach ensures that all manufacturing steps are interconnected, from compounding to mixing, molding/manufacturing, curing and de-molding.
There is a common misconception in the industry that good raw material alone will ensure a high-quality fender – this is not the full story 🔬. Of course, good raw material is very important and the foundation, but there is a lot more. If a rubber unit is produced from the best raw material and with a balanced compounding, a wrong mixing process or low-quality equipment can still harm the final quality of the rubber unit.
The lack of this holistic approach concept in industry standards 📑 and the many examples of poor fender system design around the world emphasize the need for more attention to this topic. Already in a first step, the awareness of all the aspects and their interconnection will increase the understanding in the industry about potential problems with fender system design.
SFT owns and operates first class 𝗺𝗮𝗻𝘂𝗳𝗮𝗰𝘁𝘂𝗿𝗶𝗻𝗴 𝗳𝗮𝗰𝗶𝗹𝗶𝘁𝗶𝗲𝘀 for rubber fenders, steel panels, foam fenders and PE plates. All SFT fenders are designed and manufactured following a holistic approach. Join the safe side – Work with ShibataFenderTeam.
💭 Holistic Approach Part II🔑
[04.10.2022]
➰ A complex route lies ahead to get a high-quality and durable fender system to protect vessels 🚤, port infrastructure ⚓️ and people 👷.
A holistic approach to fender system design ensures that a fender system performs as expected and that the safety in marine operations is not at stake. PART II deals with the question ‘What is so important about the different components of a fender system and their interaction?’
A fender system is made of 𝙙𝙞𝙛𝙛𝙚𝙧𝙚𝙣𝙩 𝙘𝙤𝙢𝙥𝙤𝙣𝙚𝙣𝙩𝙨: rubber unit, steel panel, chains, anchors, fixings and PE plates. A holistic approach makes sure they are all designed in the correct balance 🔄 and work together properly. Since the rubber units are mostly standardized in the industry, the main engineering and design challenge is with the steel panels, chains and the corresponding anchorage.
Typical problems in poor fender system design are:
▶️ the rubber fender position on the panel,
▶️ chain layout,
▶️ the steel panel’s internal structure,
▶️ UHMW-PE protection pads, and
▶️ coating system.
The picture above gives a good example of three typical problems of poor fender system design: Unfavorable panel position (P1), chains with incorrect angle (P2) and low rubber quality with incorrect design (P3).
Poor fender system design has many faces with severe consequences for ports, ships and people. These are often a dramatic reduction in the operational life of the system. Several measures help to prevent failures and minimize risks and they all follow 𝗮 𝗵𝗼𝗹𝗶𝘀𝘁𝗶𝗰 𝗮𝗽𝗽𝗿𝗼𝗮𝗰𝗵 𝘁𝗼 𝗳𝗲𝗻𝗱𝗲𝗿 𝘀𝘆𝘀𝘁𝗲𝗺 𝗱𝗲𝘀𝗶𝗴𝗻. It is of vital importance for your project to have a partner at your side who has a proven track record and experience with the design and manufacturing of high-quality fender systems.
All SFT fenders are designed and manufactured following a holistic approach. Join the safe side – Work with ShibataFenderTeam.
Our video shows how a fender system comes to life 🚀.
💡Holistic Approach Part I 📐
[20.09.2022]
💡 What is a holistic approach to fender system design and how do ports benefit from it? 📐
➰ A complex route lies ahead to get a high-quality and durable fender system to protect vessels 🚤, port infrastructure ⚓️ and people 👷.
Many different aspects need to be taken into account when designing a fender system. If the focus is only on a few of those aspects, the quality, durability and the guaranteed safety that is expected from a fender are lacking. This is why a 𝗵𝗼𝗹𝗶𝘀𝘁𝗶𝗰 𝗮𝗽𝗽𝗿𝗼𝗮𝗰𝗵 is needed, taking these three aspects into account and treating a fender system as one:
- 𝙥𝙧𝙤𝙟𝙚𝙘𝙩 𝙘𝙤𝙣𝙙𝙞𝙩𝙞𝙤𝙣𝙨
- 𝙙𝙞𝙛𝙛𝙚𝙧𝙚𝙣𝙩 𝙘𝙤𝙢𝙥𝙤𝙣𝙚𝙣𝙩𝙨 𝙤𝙛 𝙖 𝙛𝙚𝙣𝙙𝙚𝙧 𝙨𝙮𝙨𝙩𝙚𝙢 𝙖𝙣𝙙 𝙩𝙝𝙚𝙞𝙧 𝙞𝙣𝙩𝙚𝙧𝙖𝙘𝙩𝙞𝙤𝙣
- 𝙢𝙖𝙣𝙪𝙛𝙖𝙘𝙩𝙪𝙧𝙞𝙣𝙜 𝙥𝙧𝙤𝙘𝙚𝙨𝙨.
Only when all of these aspects are valued equally, are interconnected and seen as one single process, will the fender system perform as expected.
PART I: What is so important about project conditions?
𝙋𝙧𝙤𝙟𝙚𝙘𝙩 𝙘𝙤𝙣𝙙𝙞𝙩𝙞𝙤𝙣𝙨, such as berthing energy or local weather, are very individual and have a tremendous impact on the fender design. If something goes wrong with the berthing energy calculation of vessels, the entire waterfront design could be at risk.
Those aspects, and the different characteristics of various fender types are to be incorporated in the fender design process. Our in-house engineering team relies on years of experience in the maritime industry and considers all the many conditions to design a unique fender system.
All SFT fenders are designed and manufactured following a holistic approach. Join the safe side – Work with ShibataFenderTeam.
💡 Why is low compression set so important for foam fenders?
[06.09.2022]
⚠️Compression set is an important metric for foam fenders and can have significant impacts on their performance. But first of all, what is compression set?
𝗖𝗼𝗺𝗽𝗿𝗲𝘀𝘀𝗶𝗼𝗻 𝘀𝗲𝘁 is the amount of permanent deformation of a material after it had been compressed. Or seeing it from another perspective, it is the percentage that a material fails to recover of its original height after being compressed. 🏈
Or seeing it from another perspective, it is the percentage that a material fails to recover of its original height after being compressed. For example, a compression set for foam fenders of 20% indicates that the foam fender only regained 80% of its uncompressed diameter.
There are several reasons for that:
▶️ overloading
▶️ insufficient foam density for the application
▶️ manufacturing method
Fenders which are laminated with small strips of foam are more prone to that, due to the higher probability of gaps in-between the layers and potential bonding failures between layers. This can be avoided by using wide sheets of 1.5m – 2m, which is the SFT standard.
Co𝗻sequences are simple but severe. If a foam fender’s compression set is too high, it’s diameter is smaller than before. This can lead to
▶️ Clearance issues especially for ship-to-ship operations
▶️ Reduced energy absorption of the fender
▶️ Smaller deflection as the fender only recovers to a smaller amount of its original diameter
▶️ Reduced life time, higher cost of ownership to the early replacements
▶️ Fender is less sustainable as the foam core is permanently damaged and the fender needs to be replaced
Manufacturing and designing foam fenders requires longstanding expertise and skills – something where you can truly rely on us. We manufacture foam fenders of various sizes at our own production facility in Germany, from Ocean Guard Fenders, to Donut Fenders, to Buoys.
have a look on our website and learn more about Foam Fenders
🔬 Why a fender system without chains is not recommended
{09.08.2022]
The very same fender system at exactly the opposite stage of its life cycle 🔁
A fender system needs several types of chains to perform as expected – weight chains, tension chains, and sometimes also shear chains. Each chain type has its own responsibility:
The very same fender system at exactly the opposite stage of its life cycle 🔁
A fender system needs several types of chains to perform as expected – weight chains, tension chains, and sometimes also shear chains. Each chain type has its own responsibility:
The 𝘄𝗲𝗶𝗴𝗵𝘁 𝗰𝗵𝗮𝗶𝗻 of a fender system supports the weight of the panel and avoids sagging and is providing support in cases of vertical shear. It is the only chain that works 24/7, the other chains are only active when the fender is being compressed.
An incorrect 𝘁𝗲𝗻𝘀𝗶𝗼𝗻 𝗰𝗵𝗮𝗶𝗻 design could diminish the energy absorption of the fender system at low level contact.
𝗦𝗵𝗲𝗮𝗿 𝗰𝗵𝗮𝗶𝗻𝘀 are recommended for applications where large horizontal shear forces are expected, e.g. at ferry terminals or when vessels are winched along the quay.
Incorrect or even missing chains can have several negative impacts.
📷 ① It shows an Element Fender System that was installed without chains, following the requirements of the designer, against our strict recommendations. It is clearly visible that the rubber fender is sagging, as tension and weight chains are missing – the panel’s dead weight is only supported by the rubber unit. This leads to more stress in the rubber unit, resulting in cracks, and ultimately lowering its performance and service life. Some might say, that would not happen with a “good” rubber fender, but the laws of physics are what they are, so don’t fall for that.
📷 ② Later, chains were installed as the user pushed for that – the result is obvious: a fender system with a supportive chain, all in all a high-quality and durable system. Some of the rubber units needed to be replaced though, following their damage by the incorrect design.
Correctly designed chains will protect the rubber unit against excessive weight introduction and premature failure.
This high-quality design ensures a long service life, high performance and no additional maintenance cost. Our #engineering team has a long proven track record in the design of marine fender systems - Join the safe side and partner with SFT for your next project.
You will find more information about chains on our website.
🔁 What is important when designing fender systems for oil, gas and LNG terminals? PART II -
[26.07.2022]
Ensuring the highest safety level is the most important consideration when designing high performance fender systems for #oil, #gas and #LNG terminals. Already the smallest incident like a spark could results in major and sometimes fatal accidents.
So what is important? Part II ❗️
𝗣𝗿𝗼𝘁𝗲𝗰𝘁 𝘀𝘁𝗲𝗲𝗹 𝗽𝗮𝗿𝘁𝘀
▶️ Flying sparks are a sensitive issue in such an environment, making it mandatory to protect all steel parts. The steel panels of the fender systems are protected with UHMW-PE pads, while there are several solutions for the accessories: protective sleeves, chains embedded in rubber or covered in Polyurethane, and a special coating.
𝗖𝘆𝗰𝗹𝗶𝗰 𝗹𝗼𝗮𝗱𝘀
Besides shore based LNG plants, FSRUs (Floating Storage and Regasification Units) are a common alternative to import and transfer LNG.
▶️ Typically, FSRUs are permanently moored at a dedicated berth. The fenders for such a berth are normally not designed for a berthing loads, as this usually only occurs only once when the FSRU arrives at the berth and the conditions during berthing are very controlled and maneuvering is performed with extreme caution. The design focus is on the permanent mooring situation. The FSRUs do not remain in a steady and stable position, as winds and currents have an influence on the vessel, causing a slight but enduring movement. This movement results in frequent small deflections of the fenders – so-called cyclic loads. During the design process, the designer need to focus on the fender’s reaction force, to make sure that wind and other loads do not overcompress the fender. But most important, the deflection of the fender under cyclic loads should be limited to about 5-10%, which could be achieved by the correct mooring arrangement, and/or an oversized fender where the expected loads correspond to a 5-10% deflection of the fender.
Reliability, durability and safety are always of utmost importance for the design of fender systems, but a spark more important when it comes to fender systems for oil, gas and LNG terminals. Join the safe side and partner with SFT for your next project.
SFT reference projects for oil, gas and LNG terminals.
🔍 What is important when designing fender systems for oil, gas and LNG terminals? PART I
[12.07.2022]
Oil, gas and LNG terminals have one thing in common: the highest safety levels in the industry, since just the smallest incident could results in major and sometimes fatal accidents. Therefore, ensuring the highest safety level is the most important consideration when designing high performance fender systems for #oil, #gas and #LNG terminals. 💫
So what is important? PART I
📖
Hull Pressure
A Low hull pressure is required for oil and gas carrier, but especially for LNG carriers, which is why these terminals need fender systems which reliably ensure low hull pressure during berthing. This can be achieved by using fenders with a linear increase of energy absorption and reaction force – such as Foam Fenders or Pneumatic fenders.
A back-to-back fender solution in a Parallel Motion Fender configuration could be another suitable option. Here, two rubber cone fenders are mounted “back-to-back” between the substructure and the steel panel using different rubber hardness grades – this can ensure a soft landing especially if smaller vessels berth at the terminal as the reaction force will not be that high during the initial deflection of the softer fender.
Reaction force to substructure
Usually, oil, gas and LNG terminals are constructed using dolphins as their substructure. Dolphins are very different compared to bulkhead concrete substructures which is why the reaction force plays a vital role. As dolphins are pile structures, they are more load sensitive than concrete bulkheads, therefore the reaction forces introduced into the structure is typically limited. Using an appropriate fender type being designed exactly for such a berthing situation is mandatory to prevent damages or accidents.
Fender Type
The following fender types are very suitable for oil, gas and LNG terminals:
▶️ Foam Fenders with their linear increase in energy and reaction and their characteristic of adapting to the shape of different types of vessels
▶️ Parallel Motion Fenders with their characteristic of low hull pressure and their ability to provide the same energy absorption at any impact level, together with the advantage of reduced reaction forces for the substructure. Additionally, Parallel Motion Fenders avoid a second contact on the hull of the vessel, limiting the risk of damages to the vessel.
Reliability, durability and safety are always of utmost importance for the design of fender systems, but a spark more important when it comes to fender systems for oil, gas and LNG terminals. Join the safe side and partner with SFT for your next project.
SFT reference projects for oil, gas and LNG terminals.
In Part II you will learn why cyclic loads are a special topic for FSRUs and what the protection of steel parts is all about.
Example of a world-class fender solution by SFT
LNG Terminal | Kitimat, BC | Canada
See more best practice cases below
Amongst others, we write about:
➡️ Open panel vs. closed box panel
➡️ Best drainage system for hydraulic lock-up of submerged fender units
➡️ Industry practice for calculating hull pressure?
🔎 Corrosion protection and coating systems.
[17.05.2022]
🔁 The life cycle of a fender system, especially the steel panel is only as good as its corrosion protection, mainly the panel coating system.
There are several different coating systems all covered by ISO12944 which is the adopted coating standard for the marine and off-shore environment:
> The typical coating system which consists of 2-3 epoxy layers has a service life of up to 15 years in the marine environment
> There are additional layers of corrosion protection that can be added, especially if the fender system is used in a highly corrosive area. > There are duplex systems that combine epoxy coating systems with metalizing, which is the process of spraying molten zinc or aluminum on the sandblasted panel before the application of the epoxy coating
If you require a duplex coating system for your project, be aware that some companies on the market try to convince you that a #zinc rich primer is the same as metalizing, just because it contains the word zinc. Zinc rich primers are just part of a standard #epoxy coating system and have nothing in common with metalizing. It’s just a simple wet primer that is applied on the panel before the other layers of epoxy paint are added. Metalizing on the other hand is a much more complex and expensive process where zinc or aluminum is molten in a spray gun and then applied to the steel panel where it then cools off and cures. If two companies offer you a duplex system, and there is a price difference of 20-30% between the systems, you can be sure that one of them is not quoting you the correct materials.
If you have any questions on coating and corrosion protection, our fender experts are pleased to assist you!
🔎 Open Panel vs. Closed Box Panel
[03.05.2022]
⬛️ Using closed box or open steel panels depends often on the region of the world and local preferences as well as the thought that open panels are cheaper than closed box panels. Looking that the full story and based on current PIANC recommendations, closed box panels are not necessarily more expensive, especially if you consider the full life cycle cost. As per PIANC, if steel plate are exposed on two surfaces, the min. steel thickness is 12 mm. That would be applicable to open panel, as all plates are exposed on two surfaces. Even if the plate could structurally be thinner, a 12 mm plate for the entire system is a must.
♋️ Looking at closed box panel, here the plates are only exposed on one surface, with the advantage that these plate only need a min. thickness of 9-10 mm and inside members could even be 8 mm, as they would never be exposed. You could argue that an open panel does not need a back-plate and therefore the savings compensate for the thicker steel plates. Often, that is not the case, as the back-plate provides a lot of strength to the fender panel, i.e. you can use less or thinner (min. 8 mm) inside leading to an overall lighter panel design. Even if the closed box is heavier, which can be the case in certain design, clients’ needs to consider the maintenance aspect as well, over the typical life cycle of 15-20 years.
Open panels have a much larger surface for potential corrosion, trapped water, debris getting stuck on or behind the panel – all leading to higher maintenance and service cost. Also the rehab of such a panel is more difficult due to the larger and uneven surface area. Closed panels on the other hand, have only 4 exposed surfaces, which are even, easy to access and easy to clean, sandblast and coat during life extending full scale maintenance works.
If you are unsure which way to go, check with the SFT Group to get a comparison and recommendation of the way forward for your particular project.
🔍 Hydraulic lock-up of submerged fender units – What is the best drainage system?💧
[19.04.2022]
✔️ When cone or cell fenders are submerged, it is recommended to provide a water drainage system that effectively drains water from the inner cavity of the fender. There are several systems on the market, where some companies simply add small recesses in the rubber unit to drain the water. Considering the amount of water in a fender cavity, the only way to sufficiently drain the water is with a custom designed drainage system through the substructure or steel fender panel.
💬 Another issue to consider is marine growth that could clog-up the drainage system, especially if there are only small rubber recesses. It is therefore recommended that the drainage system is considered in the initial design of the fender system and substructure. Especially for fender systems on mono-steel piles, there are some very simple and economical drainage solutions that can be integrated into the connecting flange between pile and fender. For further questions or design suggestions, please contact your local SFT office.
What needs to be considered when designing chain lugs on steel panels. 🔍
[05.04.2022]
✖️ Not only the design of weight, tension and shear chains are most important, also the attachment of these chains to the panel needs detailed attention. The chain lugs have to be designed to withstand major forces when chains are engaged during berthing. Therefore, not only the lug must be designed with sufficient capacity, but also the interface to the panel.
❗️If chain lugs are just welded to the backplate of the panel, the interface is not providing the needed strength and the lug could pull of the back plate from the panel, like a can opener❗️
✔️ Only if the lug design incorporates the interface and welding to the internal structural members of the panel, the lug has sufficient strength to accept the high forces during berthing ✔️
Pay attention to this detail when reviewing designs and drawings to avoid steel panel failure and downtime at the terminal. Only engage with fender manufacturers that live a holistic approach to fender design, only then you can be sure that the fenders will perform as intended. Contact your SFT experts for more detailed information.
💡What is common industry practice for calculating hull pressure?
[22.03.2022]
🔴 Theoretically, hull pressure (HP) is distributed evenly if the fender reaction into the panel is symmetrical. For some designs however, that is not always possible, and an off-center peak reaction needs to be tolerated, while the average HP remains the same. For such design cases, the rubber unit is positioned below the upper third of the panel, so that the peak HP is no more than double the average HP.
Rubber fender positions above the upper third of the panel should be avoided, as peak/average hull pressures could be very high, as the lower part of the steel panel is ineffective for hull pressure. But, how is HP calculated at low contact then? Assuming a single fender unit system, there is actually no hull pressure, there is only a line load as the panel rotates at contact, introducing a line load into the panel and the vessel.
Typically, vessels can only resist a limited pressure on their hull, therefore it is crucial to determine the fender contact pressure, based on the vessels draft and freeboard in connection with tides and mounting elevations, to ensure allowable limits are not exceeded.
When it comes to HP, be aware that there are several load cases and scenarios to consider for your project. If you are not sure about the right approach, contact your nearest SFT office for support.
🔧 Why fender deflection is not a criterion for passing or failing performance testing.
[09.03.2022]
💢 Each type of fender has a specific design deflection, which is the point to which the fender can be safely deflected. Therefore it is a must for any performance test to be executed up the to the design deflection. Therefore it is a must for any performance test to be executed up the to the design deflection. The percentage of design deflection may vary from manufacturer to manufacturer.
To determine if a fender passes or fails a performance test as per PIANC2002 and ASTM F2192, the deflection at which the min. E/A and max. R/F occurs, does not matter, as long as the required values are achieved prior to the design deflection. That means, the fender must be deflected to its design deflection, but the minimum E/A and max. R/F may be achieved earlier along the performance curve. In that case, the fender has actually some reserved capacity which might be a welcome ⛔️ buffer in case of an accidental berthing, like berthing speeds over the operational limits.
🔍 Why we perform 𝒄𝒐𝒎𝒃𝒊𝒏𝒆𝒅 shear compression testing. 🔎
[08.02.2022]
♠️ In our post from a couple of months ago, we explained shear compression testing as an alternative to standard durability testing.
In order to fully utilize this test approach for your project, we have introduced a new test protocol for high performance fenders like Cone or Cell Fenders, a combined shear compression test.
Only a combined and simultaneous shear compression testing provides the information you need to make sure your fender is up for the job. More and more clients realize that and start implementing this into their test requirements.
Model testing with 25k cycles and full scale testing with typical 1-3 cycles is possible. Due to the cost and time involved, full scale testing with max. 3 cycles is recommended for your demanding and sensitive projects.
⚠️ Keep in mind that fenders typically experience compression and shear at the same time when being used at the berth. ⚠️
Bollard selection - which cast material is most suitable for your application? PART III 🔨
[14.12.2021]
💬 When comparing the two materials, it can be noted that the use of the respective material has advantages and disadvantages, depending on external conditions and requirements. Therefore cast-iron as well as 🔲 cast steel bollards have their place in the industry, for example.
🔶 Ductile Iron Bollard:
Ductile iron bollards have a high impact strength and high corrosion resistance, that ensures a long service life. Due to its typical material properties, this type of bollard material is recommended in moderate climate conditions. This material is commonly used throughout the industry and provides a good combination of performance, strength and longevity. Ductile Cast Iron bollards can be installed with cast-in or resin anchors. It is important to determine the anchors of the bollard based on the design of the concrete reinforcement.
🔶 Cast Steel Bollard:
Cast Steel bollards have a high impact strength and can especially be used in cold climate areas down to -20°. Moreover, the bollard material can be welded to a steel substructure without compromising the material strength. Additionally to the safety of people, the correct dimensioning ✅ of bollards secures the integrity of the quay wall / . (welded connection to the plate) on cast steel bollards can be integrated, which acts as a predetermined breaking point above the quay substructure to avoid any damage in the event of an overload (detailed design needs to be checked with the project requirements). However, it should be noted that cast steel bollards are more prone to corrosion (if painting is damaged) and therefore require more frequent maintenance compared to ductile iron bollards.
If you are interested in bollards and need further information, please reach out to our experts
Bollard selection - which cast material is most suitable for your application? PART II 🔨
[30.11.2021]
📖 The below table compares the most commonly used material properties of cast steel and ductile iron for bollards.
Comparing both materials which are commonly used for bollard manufacturing, Cast Steel as well as Ductile Iron have a similar Yield Strength (point that indicates the limit of elastic behavior and the beginning of plastic deformation – pulling of a mooring rope). Comparing the Tensile Strength of Cast Steel and Ductile Iron, it can be stated that Cast Steel has a higher value 🔲 (point of fracture of the material).
However, the use of stronger material does not imply a stronger bollard, as the overall working capacity is relevant for the overall design of the bollard. 🏥 For this reason, Cast Steel bollards require a thinner wall thickness and have a good cost to weight ratio.
At the next Technical Tuesday, we will explain which cast material is most suitable for which application. Stay tuned!
If you are interested in bollards and need further information, please reach out to our experts.
|
Material |
Grade |
Yield Strength (MPa) |
Tensile Strength (MPa) |
Elongation (%) |
|
Cast Steel - EN10293 |
GE 300 |
>300 |
min. 520 – max. 750 |
>15 |
|
Ductile (SG) Cast Iron - EN1563 |
EN GJS-450 |
>310 |
>450 |
>10 |
Bollard selection - which cast material is most suitable for your application? PART I 🔧
[02.11.2021]
🔎 Various types of vessels are safely moored on bollards for a period of time during loading and off-loading conditions. The safety and reliability of the mooring equipment chosen, is extremely important. Thus, some aspects need to be considered for your bollard selection.
Bollards can typically be manufactured from 3 different types of cast material:
- Ductile Cast Iron (Spheroidal Graphite Cast Iron)
- Cast Steel
- Grey cast iron
Grey Cast Iron has excellent castability and provides long-term resistance to corrosion and wear.
However, nowadays, Ductile Iron and Cast Steel are usually preferred due to its superior strength to weight ratio.🔱 Therefore the below table focuses on Ductile Iron and Cast Steel, to provide a first comparison of the most important characteristics:
The selection of the ‘right’ bollard material depends on different factors and conditions (e.g. sub-structure, climatic conditions, application etc.) in the port.
At the next Technical Tuesday, we will compare the material properties of Cast Steel und Ductile Iron and explain which cast material is most suitable for which application. Stay tuned!
If you are interested in bollards and need further information, please reach out to our experts:
📝 3 technical details in specifications you should not miss 🔧
[19.10.2021]
📍 Project specifications serve to ensure a common basis for equipment suppliers/manufacturers, and for clients to detail their specific project needs.
Quotations are based on specifications – or at least they should be. Unfortunately, some companies try to cut corners of specifications, offering their products at lower prices as they are not quoting in accordance with the specification.
Make sure to compare apples with apples. When it comes to fender systems, the following 3 technical details should not be missed:
- ℹ️ Same coating system for steel panels
- ℹ️ Material specifications
- ℹ️ Specified load cases for the steel panels
If you are in doubt, it is better to double check with the suppliers and get detailed written confirmation for any item with ambiguity.
The SFT Group is your partner and you can rely on us – always.
🔍 Why the most efficient fender is not necessarily the most suitable fender for your project. ⚠️
[05.10.2021]
📍 Fender unit selection is about much more than efficiency, which is why only experienced and design-oriented marine fender manufacturers should select the most appropriate fender unit for each application.
The following factors should be considered when selecting a rubber unit for a fender system:
🔸 Minimum/maximum stand-off, deflected and undeflected.
🔸 Installation area on the substructure
🔸 Positioning of the rubber unit, based on the steel panel elevations and the rubber unit centerline
🔸 Type of substructure
🔸 Experience and preference of the user
🔸 Type of terminal
It is important to not only consider the rubber unit as a single component, but to apply a holistic approach to the entire fender system design. Therefore, generic online tools for fender selection could lead the designer on the wrong track.
For example, fenders for some naval vessels with large bow flares require systems with a larger stand-off, while container terminals aim for the smallest possible clearance to ensure that cranes can reach the last container row of the ship.
Why are chains for floating fenders always so large? ⛓
[21.09.2021]
🔔 Have you ever wondered why floating fender systems are often designed with oversized chains?
First of all, you need to keep in mind that floating fenders are in motion 24/7 as they float with water levels and are constantly moved by waves. This causes constant wear on the shackles and chain links due to friction.
Therefore, oversized chains are used to account for this constant wear and provide a kind of wear allowance for the chains and shackles. The weight of the large chain could also limit the movement of the fender.
Anchors for floating fender systems are usually designed for the characteristic load only, since designs based on MBL would result in an over-engineered anchorage and excessive edge distances.
Tack welds or half/full welds on the shackle pins are recommended for certain applications to prevent that shackle pins become loose, fall out and fenders drift away.
If you are interested in floating fenders and need more information, please contact our fender experts.
🔎 Why the velocity factor of reaction force and energy absorption cannot be the same.
[07.09.2021]
⏫ When testing fenders, the applied load is measured and a corresponding load-deflection 🅾️ curve is determined. This curve provides information on the reaction force and energy absorption of the fender.
❗️ The fundamental difference between determining the reaction force and energy absorption is that the maximum reaction force is a point along the curve, while the energy absorption considers an area ❗️
For buckling 🐪 type fenders, the highest reaction force usually occurs at the so-called first peak of the curve, i.e., at about 30% deflection. It is important to keep in mind that the decreasing velocity during berthing, leads to different R/F velocity factors at every % of deflection, i.e. that the max. reaction force represents one point along the curve. The energy absorption of the fender is not measured, but calculated by integral calculus based on the area under the load-deflection curve.
❗️ Furthermore, the difference in the reaction force curves for high and slow speed compression does not lead to a simple parallel shift of the curve, it rather results in a differently shaped curve ❗️
Comparing the reaction force curves of ‘CV R/F’ and ‘RF at 150mm’ in the figure, it is clear that the shapes differ, which is due to the higher initial compression speed of 150 mm/s compared to 1.33 mm/s. The viscoelastic property of the rubber leads to the phenomenon that a fender is stiffer when compressed at higher speeds, therefore the reaction force curve is steeper, especially in the beginning and overall at a higher level than the curve at slower speed. This steeper and higher ⤴️ curve results in a larger area under the curve and thus a higher energy absorption.
The differently shaped curve leads to a velocity factor for the reaction force, that must necessarily be different than the velocity factor for the energy absorption. The Japanese Society of Civil Engineering investigated that topic in their ‘Journal of structural engineering VOL. 55A’ and also reported such findings.
If you would like to learn more about this topic, please contact your SFT office.
Materials testing; why it is important to strictly adhere to the relevant testing standards. 📌
[24.08.2021]
➗ As part of verification testing, the material testing is of utmost importance for the client as it confirms the physical properties that ensure the durability and if the material is “fit for use” as a fender. Rubber compounds can have very different compositions, depending on their required performance criteria which have to comply with international standards and guidelines like PIANC2002, ASTM D2000, EAU 2004, ROM 2.0-11 (2012), or BS6349.
💡 These guidelines ensure that a fender performs as designed when installed at a berth.
• The rubber samples that are needed for the physical property testing are taken from the finalized compound. They are precisely prepared and then cured at a laboratory.
• Afterwards, they are tested under strict laboratory conditions, including tensile and bonding strength, compression set, hardness, elongation, tear and abrasion resistance, chemical and ozone resistance, and aging.
RPD vs. CV data and why using RPD values in designing substructures could avoid liability claims. 📝
[10.08.2021}
📏 The most significant difference between CV (constant slow velocity) and RPD (rated performance data) values is the compression/berthing speed and resulting reaction forces. Some designers use CV values only in their fender and substructure designs without the needed correction factors, and might underestimate these loads. The difference in reaction force or load into the substructure, between CV and RPD values is in the range of 20-40% and could therefore have a substantial impact. ♋️
Why is that?
🔸 CV compression speed is 0.33-1.33mm/s (2-8cm/min) which is the typical speed used for fender testing.
🔸 RPD is based on 150mm/s which is close to or the typical berthing speeds in today’s project specifications.
Due to the viscoelastic characteristics of rubber, fenders behave differently when compressed with different speeds: slow speeds lead to lower energy absorption and reaction forces, whereas high speeds lead to higher energy absorption and reaction force values. If RPD is used, both values are in the correct range, as different velocities around the 150mm/s typically have only about 5%ish impact on the loads.
What you need to know about type approval testing. 📚
[13.07.2021]
🔲 In order to obtain a product type approval or type examination certificate for a fender, the respective tests need to be witnessed or performed and verified by an independent and certified third party. 🔍
- The minimum test scope typically includes performance testing, durability testing, verification of correction factors and physical properties as published in the catalogue.
• A product type approval is usually valid for five years and needs to be renewed after the validity period or if any product specifics or the production location changes.
• It should be noted that only certificates that have been uploaded to the certifying body’s website, are true and valid.
• Throughout the validity period, periodical assessments needs to be carried out, to constantly review the manufacturing processes, ensuring that the product is still in compliance with the type approval base data.
➰ Type approval certificate is a main criterion for reliable fender manufacturers. ShibataFenderTeam strongly recommends to check a potential supplier for a valid type approval certificate. For example, our type approval certificates can be found at the type approval finder website of the certifier DNV.
Why makeshift or DIY test presses are no comparison to purpose-built frames. 🔎
[29.6.2021]
🌐 Fender testing is a complex and capital-intensive topic, not only in theory but also in practice. Even more important is a reliable and 'fit for us' testing equipment, as test frames are an elementary part of the performance testing process. It is necessary that calibration is performed per test equipment components, but it is most important that items are calibrated as a group as well. ⚠️
The load cell set-up, verification testing and other settings should be discussed and agreed before testing any fender. After the set-up and details are clarified, fenders are compressed up to their design deflection, while the reaction force is measured with load cells and/or pressure transducers. It is especially important for large fenders that the test frame has a sufficiently long stroke, in order to reach the required deflection of the fender.
⚠️There are test companies and institutes in the market that offer fender testing with makeshift test frames, that are by no means comparable to purpose built test frames of the manufacturer.
Get more insights into fender testing from our White Paper.
🔴 Why and when to perform fundamental testing?🔎
[18.05.2021]
🔶 WHY? Fundamental testing is carried out using a scale model to establish catalogue performance data and to determine correction factors which are the fundamental data for a product type approval.
💢 WHEN? Since these tests are designed to establish fundamental data during the development of a fender type or for a one-time specification, fundamental testing is not suitable to be performed for every fender project due to the high time and cost expenditure.
Published fundamental testing data includes standard performance, correction factors (e.g. temperature, velocity, angle) and test results, whereas any technological research and development results are used exclusively by the manufacturer for product improvement and remain confidential.
Read more about the different testing methods for rubber fenders in our new SFT White Paper ‘Testing. A Best-Practice Approach.
📏 Why physical property testing cannot be performed on the final product?. 📐
[04.05.2021]
✖️ It is sometimes asked within the industry why physical properties testing can typically not be performed on the final fender itself instead of preparing test samples from the compound before production.
🌀 Testing physical properties from final fenders is unusual and very difficult, since it would involve cutting larger pieces out of a final fender which could damage the fender. The reason for this is that a lot more material is needed for the physical properties testing than for the traceability testing. Also, deviations of 15-20% to the catalogue values need to be taken into account, because the preparation and vulcanization under laboratory conditions of the 2 mm test plates 🔺 differs from the preparation of test plates, cut from a finished fender.
The Japanese OCDI Guidelines on fender design and testing puts it this way when it comes to comparing results of test plate made in the lab vs. cut from the finished fender – “...it is impossible to match the physical properties to those on any section of the product”.
For more information, please refer to our new White Paper #4 on Testing which is available for free.
🔵 Edge distance – Choose the right clearance. 🔎
[06.04.2021]
‼️ The edge distance of the chain brackets and fender anchors, is a vital part of a fender system design. Especially existing structures pose challenges as modifications of the structure are often difficult. Sometimes, the edge distance is forgotten when designing 🎨 substructures for new constructions and issues could be avoided by consulting with fender manufacturers about general fender system layout including chain positioning. Therefore, we recommend to consider the following during the design stage of fender projects:
🔸 The edge distance is most critical for chain anchors, as these are under tension when the fender system is in use
🔸 Recommended edge distance for initial layout design is about 10x the anchors diameter in any direction, including the depth
🔸 Small edge distances are possible, but then the designer (not the fender manufacturer) needs to check the quay wall design and might incorporate additional rebar based on the forces provided by the fender manufacturer
Besides the edge distance, the thickness of the quay wall section at the fender location as well as the grade of the concrete should not be underestimated in the anchor design.
Tension Chains 🔗 Why are they important? 🔍
[23.03.2021]
🔺 Tension chains (or restraint) chains are an essential component of a panel fender system, and works in several ways:
🔸1) Balance the forces in the fender system, maintains position and alignment of the panel
🔸2) Prevent mooring lines being caught behind the panel (when installed at the top of the panel)
🔸3) For a cantilever fender system, preventing outward movement of the top/bottom of the panel, during low/high level contact. Lower tension chains are only applicable for special applications.
The location and angle of the chain will affect the fender systems performance. It is recommended that the chain is installed perpendicular to the wharf face, and when used in cantilever fender systems, should be at a practical distance above or below the centre-line of the rubber unit. This ensures sufficient compressed of the fender, providing the needed energy absorption for e.g. low impacts and avoids collision of the panel with the substructure.
If you want to learn more about optimising the use of tension chains in your design, please contact your local fender expert.
🔁 Fender shear chains, what to consider?
[09.03.2021]
🈸 Shear chains are recommended for applications where large shear forces are expected, e.g. at ferry terminals or when vessels are winched along the quay. 🚤
➡ Installed at an angle of 40° - 45° when fender is undeflected, resulting in about 30° under deflection
➡ Makes an arch movement during compression; therefore, small angle is required, otherwise chains would extent too much and not engage when needed
➡ Need to be installed in the fender center or above and below the fender for proper functioning
➡ Typically, biggest chain of the system, each side takes the full load
➡ Quay wall area and fender location need to allow enough space for shear chain installation and sufficient edge distance for brackets - particularly important for first and last fender position on a quay wall
Shear chains might not be needed for standard applications, leading to reduced maintenance cost.
For further information about chains and their layout in a fender system, please consult our Design Manual 📕 (free download in six languages ) – or for a personalized answer, call your local SFT office 📞!
🔲 Why the weight chain is the most important chain for a fender system.
[23.02 2021]
A panel fender system consists of the rubber unit, the steel panel, and the chain system, i.e. – tension and weight chains, and sometimes shear chains.
🔴 Did you know that the weight chain of a fender system is the only chain working 24/7? It supports the weight of the panel and avoids sagging – the other chains are only active when the fender is being compressed. ♒️
🎈 What you should know:
↪ The ideal angle between the substructure and the chain should be 30-35° to provide full support for the fender panel
↪️ If the angle is larger, like 50°, the chain cannot support the panel: all the weight and force of the panel is introduced into the rubber unit (P2)
↪️ The rubber unit might develop cracks, especially at the top flange areas (P3)
We often see fenders with these kinds of defects and make people aware that in a lot of cases, the failure is not the result of low-quality components, but rather a flawed design of the fender system.
A holistic approach to fender system design considers the balance of all components and its interaction to achieve a high-quality fender system.
‼️ Final clarification that chemical composition of rubber compound does not reveal the quality of a fender. 💬
[09.02.2021]
⏬ A lot has been discussed about compounding and chemical composition for rubber fenders within the maritime industry. PIANC Working Group 211, dealing with the new “Guidelines for the design of fender systems”, has achieved a breakthrough recently and can finally provide clarity for the industry:
Independent rubber experts stated:
- The chemical composition and density of rubber compound does not indicate the quality of a fender
- A TGA test is suitable for traceability between tested samples and the final product
- A TGA test will not reveal a high- or low-quality product
SFT’s member in the Working Group, Dominique Polte, is relieved that the ongoing discussion is solved once and for all: “The SFT Group is working towards more transparency in fender production and a clear sense of responsibility from fender manufacturers. We are advocating since many years that it’s the physical properties of a fender, that proof a high-quality product and not the chemical composition, as it has stated by independent rubber experts numerous times.“
🔧 Two Facts why a Thermogravimetric Analysis (TGA) for rubber compounds is useful 🔍
[01.12.2020]
🔶 TGA is a method of thermal analysis in which a sample of a rubber fender is continuously weighed during controlled heating. By performing a TGA, you are able to:
- Verify chemical composition of the rubber compound - As different components burn off at different temperatures, the loss in weight provides an indication of the sample’s composition.
- Verify traceability between rubber test sheet and final product - TGA results of both should be similar but can deviate to some degree due to laboratory conditions.
What a TGA does not do, is verifying the quality of a product. There are no international standards giving guidance which chemical composition is favorable. This is plausible when considering the different reinforcement requirements of different rubber blends and the resulting varying amounts of other components.
Chemical composition is important in fender production, but not everything. It is the physical properties that ultimately determine the quality of a fender. ✅
Curious to learn more? Our White Paper on Compounding is available as a free download.
⛵️ Rubber Blend - why choosing a blend of natural and synthetic rubber is advantageous for high-quality rubber fenders.
[17.11.2020]
💡 Typically, rubber fenders are made from a blend of polymers. Most common polymers are natural rubber (NR), which is sourced in the form of latex from rubber trees and styrene-butadiene rubber (SBR), a synthetic rubber which is derived from petroleum byproducts. Using NR- and SBR-only compounds is not recommended.
🔩 SBR in its pure state is less sticky and has a higher density and glass transition temperature than NR. It also has a lower modulus and tear resistance and needs additional reinforcement. NR, by contrast, is already well-reinforced by nature. Thus, rubber compounds with either NR or SBR as the only polymer have strong limitations, and therefore the industry usually uses blends of NR and SBR to harness the advantageous properties of both:
▪️ good abrasion resistance
▪️ high resilience
▪️ good aging stability
▪️ reinforcement
The choice for – and the amount of – NR or SBR in the blend determines the amount of other components to be added to improve the properties of the compound, the best-known ones being carbon black (CB) and calcium carbonate (CC).
Are you interested to learn more? Download our free White Paper on Compounding.
🔲 Carbon Black – Three facts how Carbon Black influences the quality of rubber compound.
[03.11.2020]
◼️ Carbon Black (CB) is a well-known active filler which reinforces the rubber compound and has positive effects on physical properties such as tensile strength, tear resistance and abrasion resistance. The key 🎵is that an improvement of the properties is tied to the right use of the material.
1️⃣ A rubber compound which consists of more Natural Rubber than Synthetic Rubber needs a lower orcement, as Natural Rubber is already well reinforced by nature – less CB is needed. *𝗢𝗻𝗲 𝘀𝗶𝘇𝗲 𝗳𝗶𝘁𝘀 𝗮𝗹𝗹 𝗱𝗼𝗲𝘀 𝗻𝗼𝘁 𝘄𝗼𝗿𝗸*
2️⃣ If too much Carbon Black is used in the compound, the result will be a decrease in properties (see diagram below). The decrease results from overloading the compound with CB as there is not enough rubber left in the compound to disperse it. *𝗠𝗼𝗿𝗲 𝗶𝘀 𝗻𝗼𝘁 𝗮𝗹𝘄𝗮𝘆𝘀 𝗯𝗲𝘁𝘁𝗲𝗿*
3️⃣ The grade and particle size of Carbon Black plays an important role for the compound quality. Smaller particles have a larger specific surface area and therefore a higher ability to react with the other components in the rubber blend. *𝗦𝗺𝗮𝗹𝗹𝗲𝗿 𝗽𝗮𝗿𝘁𝗶𝗰𝗹𝗲𝘀 𝗺𝗮𝗸𝗲 𝗮 𝗱𝗶𝗳𝗳𝗲𝗿𝗲𝗻𝗰𝗲*
❗️ Why calculating the berthing energy of vessels is the first and most important step in the fender design process.
[20.10.2020]
🔨 If something goes wrong here, the entire waterfront design could be at risk.
We support our clients with our free Berthing Energy Calculation Tool.
⏬ Our tool considers all relevant parameters such as ship type, berthing mode or point of contact from bow, amongst others, and also offers the option to choose among different design methods, addressing the particulars of your project and or region.
The results should be seen as a guideline only. The list of suitable fender units based on the calculated energy is long, but typically there are only a few types and combinations that would work properly for your specific project. The subsequent step of choosing the suitable fender type and size should only be done together with an experienced fender manufacturer. Each project is unique, so our experts analyze every condition in detail to design the most suitable fender system. 🔷
Our experienced and highly skilled colleagues all around the globe are value engineers, in a sense, creating solutions that are ideal for our clients and on-site conditions.
Part I - 📐 Importance of specifying the load case for the fender panel
[06.10.2020]
It is important that the load case for the fender panel is specified exactly but more important: realistically.
Case ① ⬇️
A vessel contacts the steel panel with its full flat hull – the panel works as designed.
Part II - 📐 Importance of specifying the load case for the fender panel
[06.10.2020]
It is important that the load case for the fender panel is specified exactly but more important: realistically.
Case ② ⬇️
A vessel with beltings imparts a double contact. As the panel is not designed for this load case – the steel panel could get severely damaged and might need replacement.
Part III - 📐 Importance of specifying the load case for the fender panel
[06.10.2020]
It is important that the load case for the fender panel is specified exactly but more important: realistically.
Case ③ ⬇️
A vessel with beltings imparts a line load onto the panel; this concentrated load case is so severe, that the panel might break in the contact area.
Conclusion - 📐 Importance of specifying the load case for the fender panel
[06.10.2020]
Using a fender system for a load case other than specified, not only implies monetary consequences for the terminal operator and costly downtimes until it is replaced, but also a safety risk.
The three examples of load coases show in an easy but impressive way the consequences to a fender steel panel when the actual load case differs from the specification (for more information, check the posts from Part I-III).
Be informed about the anticipated load cases to avoid damages, unnecessary cost and safety risks.
Our colleagues around the world are experts in their field and happy to discuss any questions with you.
📧 You can reach them via email or our contact form.
Fender Design System – What has a dinner recipe 🍴 and fender design in common?
[22.09.2020]
Imagine a dinner recipe 📖 with the best organic ingredients, but the recipe is imbalanced. The result is that dinner will not be satisfactory.
The same principle applies to fender systems. 🔐
Incorrect fender system designs (recipe) have a costly impact on the operation. Even a high-quality, durable rubber unit (organic ingredient) cannot compensate for an imbalanced design. The chain layout for example is an important topic not to be scoffed at. The picture shows two fender systems-one with chains, one without:
Incorrect, or in this case, missing chains can have several negative impacts. It is clearly visible that the fender is sagging as tension and weight chains are missing – the panels dead weight is only supported by the rubber unit. This leads to more stress in the fender and cracks in the rubber unit, ultimately lowering its performance and service life.
The Cone Fender System was designed with weight and tension chains. Correctly designed chains will protect the rubber unit against excessive weight introduction and premature failure.
This high-quality design ensures a long service life, high performance and no additional maintenance cost.
RPD Values - Why using RPD values in designing fender panels could avoid liability claims. 👆
[08.09.2020]
👓 The most important difference between CV (constant slow velocity) and RPD (rated performance data) values, is that CV values are based on laboratory test values while RPD values reflect operational conditions.
🔷 When designers use CV values only for the selection of the fender units and for designing the size of the steel panel accordingly, forces will be underestimated.
Why is that? CV values are based on constant slow velocities of 0.0003-0.0013 m/s. Due to the viscoelastic characteristics of rubber, fenders behave differently when compressed with different speeds: slow speed leads to lower forces, high speed leads to higher forces. As the panels are designed for berthing speeds in operational conditions, operational speed needs to be used for the calculation to receive a realistic result. If done incorrectly with CV values only, panels will be too small and hull pressure will be too high, which could lead to vessel damages and heavy liability claims. ❌
If you want to learn more about the correct values to apply, contact us and don’t risk major liability claims by the final users.
Three technical details in specifications you should not miss. 🔍
[25.08.2020]
🔮 Project specifications serve to ensure a common basis for equipment suppliers/manufacturers, and for clients to detail their specific project needs.
Quotations are based on specifications – or at least they should be. Unfortunately, some companies try to cut corners of specifications, offering their products at lower prices as they are not quoting in accordance with the specification
Make sure to compare apples with apples.🍏
When it comes to fender systems, the following 3 technical details should not be missed:
1. Same coating system for steel panels
2. Material specifications
3. Specified load cases for the steel panels
If you are in doubt, it is better to double check with the suppliers and get detailed written confirmation for any item with ambiguity.
The SFT Group is your partner and you can rely on us – always.
❓ Fender Selection – why this cannot be automated. 💬
[11.08.2020}
🔨 Fender manufacturers offer a wide range of fender types suitable for different requirements. The purpose of fenders is to absorb the kinetic energy of berthing vessels, and on the other hand, to transfer the reaction force via different components of the fender system onto the vessel hull and into the berth substructure.
High energy absorption while having acceptable reaction forces is key 🔑 to a good fender system design.
However, simply calculating the berthing energy requirements results in a long list of suitable fender types and sizes.
How to select the right fender? There are many other factors which need to be considered, like: vessel details (e.g. vessel type, hull pressure, beltings), berthing information (e.g. berthing mode, type of substructure, fender spacing, stand-off requirements), preferences of the client, and more.
Selecting the right ✅ fender for your specific project needs a unique approach and cannot be done by an automated tool. The topic of fender selection again shows why it is beneficial to rely on personal expertise and experience.
Contact us for a free consultation.
🔧 Vessel’s Belting / Rub-rails – how can they damage fender panels.
[28.07.2020]
🔗 Beltings are like steel bumpers on vessel hulls. They are usually located just above the water line, and most used on ferries, cruise ships, and barges. 🚢
If vessels have beltings, it is essential that fender panels have been designed correctly with chamfers and corresponding load cases.
A chamfer is like a bevel, placed on certain sides of the fender panel. During tidal variations or un-/loading, vessels slide ⏫ up and down ⏬ or along the panel, and chamfers avoid snagging of beltings during these movements. In cases where panels have none or insufficient chamfers, beltings could get stuck on or below the panel and severe fender damages can occur. Therefore, the consideration of beltings and the corresponding design impacts should be clearly laid out in the project specifications. 📐
🔍 Additionally, changes in the operation at the berth should not be underestimated either. If a berth and its fenders were designed for vessels without beltings, a change to vessels with beltings could heavily damage the fender panels and will result in repair works and/or temporary closure of the berth.
Physical Properties Testing. 🔬
[30.06.2020]
🔦 Physical properties testing cannot be performed on the final product, which is why these properties have to be tested on conform sample rubber sheets. Testing can also be done by the customer themselves when a rubber sheet made from the same compound as used for their fenders is tested.
Each property and standard has their own conditioning parameters like storage conditions or timing of the test, and the testing processes have to strictly follow that. If tests are not done according to the mandated parameters, results could vary from the requirements. Always double check condition time and storing requirements with the respective standard or consult your fender manufacturer.
Customers can also test the composition of the rubber sheet to check for traceability by performing a TGA test. This is done to verify that the compound of the sample sheet used for physical property testing is the same compound that was used in the final product. Traceability verification is done by comparing TGA results of the final product with the results of the rubber sheet. The results should be similar but can deviate to some degree due to laboratory conditions.
For further details, please contact us.
⛵️ Pneumatic Fenders – What should you know.
[16.06.2020]
Pneumatic Fender can be produced with different methods and each has their own advantages when compared correctly. First of all, keep in mind, that no matter what the method is, both are fully compliant with ISO 17357-1:2014, as the standard does not indicate a production method, this is up to the manufacturer. 🏢
➰ The ISO 17357 focuses on materials used, the general design of the fender, its layers as well as the testing of the finished product only. How manufacturers achieve that, is fully up to them.
To give you an idea of the differences, molded fenders are made from several sections that are put together in the final steps of the manufacturing process, others like wrapped fenders typically consist of a homogeneous fender body with continuous nylon tired cord. If made from several sections, the tire cord is not continuous and only stitched at the critical connections of the sections.
In terms of certification, the fender should come with a third party prototype test, aka “type approval”, guaranteeing full compliance with ISO17357. Be aware, that this type approval is different than a type approval according to PIANC.
Last but not least, please also note that a ship launching airbag which is often mistaken as a fender, should not be compared to a Pneumatic Fender as both are different products and are produced differently.
Summarizing: Production method is not defined by ISO 17357 | Molded Pneumatic Fenders have weaknesses | Ship launch airbag is not the same as a Pneumatic Fender.
For further details, please contact your SFT expert.