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Monthly Archives: March 2013


Our rubber testing whitepaper “Fenders: why it’s not so black and white” highlights some interesting results from the comparison of the compositions of low cost and high quality fenders – results that clearly highlight dramatically different performance characteristics between the two.

The low cost fenders contained larger amounts of recycled rubber and filler, and were found to be heavier and denser than those that used virgin rubber.

Further chemical and physical analysis revealed some further important results, including:

  • Tensile strength and the value of elongation at break were found to be lower in the low cost fender than in the high quality fender, which was made with higher quantities of virgin rubber.

    Crucially, the low cost fender was not in compliance with the specification.

  • Rubber to filler ratio for the high quality fender was 1.23, for the low cost fender, just 0.88.
  • Overall, the low cost fender contained 28.45% less rubber than the high quality product, explaining the difference in the physical properties of the two and justifying the higher purchase price of the high quality fender.

It’s essential that decision makers are aware of the key performance differences and varying quality being sold as one and the same thing, when they procure fenders based on up front price alone.

These tests provide a reliable analytical method that can be made available to buyers so that they can assess the composition of recently procured fenders prior to delivery, simply by taking a small sample from the surface of the fender.

For more information, download the full rubber testing white paper here.


As discussed in my last blog, there’s a trend across the industry of procuring mission critical fenders on the basis of upfront outlay – rather than the cost over the fender’s entire lifecycle.

Industry body, PIANC, set out the leading design guidelines for fender systems in 2002, but I remain concerned that these aren’t working in practice.  PIANC have neither the authority nor mandate to enforce these regulations, and this is allowing some of the more unscrupulous suppliers to use higher percentages of recycled rubber, to supply fenders at a cheaper upfront cost – without transparency around the composition of the fender.

PIANC’s guidelines state that robust material testing is a necessity, but laboratory and full scale testing is not routinely performed by all suppliers as part of their quality assurance process.  This is a serious concern, as specifiers need assurance that both sets of testing have been conducted on mission critical equipment.

We’ve developed new analytical tests to help stakeholders across the industry determine the quality and performance characteristics of the fenders they procure, so that buyers can understand and substantiate the makeup of their fenders and subsequently, the performance characteristics they can expect.

We conducted a series of physical and chemical tests on one high quality and a low cost fender – to really understand how much performance between the two differs.  To learn more about the tests and see the results, download the rubber testing whitepaper here.


Mission critical equipment such as fender systems need to be bespoke, fit for purpose and considered, from the design stage, on the merits of the specific project.

Designing a fender system requires engineers to determine the berthing energy of a vessel, or range of vessels, that are likely to be docked against the system, then determine the necessary capacity of the fender system to absorb that energy.  Finally, engineers need to find ways to avoid creating too much force both when a ship comes to berth and whilst it continues to bear against the system, to avoid damage to both the port infrastructure and the vessel.

Commercially, high quality fendering systems can add value to port operations by minimising maintenance requirements and reducing the risk of incidents. Custom made, high quality fenders also offer a longer service life and, reduced maintenance requirements ensure fewer “lost” days for ports and subsequently, minimise lost revenue.

In addition to these commercial concerns, and most importantly, fenders provide the first line of defence for ports and play a key role in protecting the safety of port personnel, vessel crew, cargo and infrastructure.

We’ve frequently discussed the worrying trend within the industry of specifiers procuring this mission critical equipment on the basis of upfront cost and subsequently, only short term cost savings – without taking into account the fact that over the fenders lifecycle, costs will be higher.

Some suppliers have been able to take advantage of this trend by supplying lower cost, but lower quality fenders.  These fenders have been found to contain a higher percentage of recycled rubber, as opposed to virgin rubber, and replace carbon black filler with non-reinforcing white filler.

We decided to put our money where our mouth is on this issue and conduct some independent testing, comparing the physical and chemical properties of a high quality and low cost fender.

Our rubber testing whitepaper discusses this trend in more depth and reveals the results of this testing.  Download it for free here.