Foam filled fenders are widely used for jetties, shipyards, docks, boats and marine protection areas. They are lightweight, floating and practical for many small to medium berthing applications. However, if the fender size, end design or installation condition does not match the actual impact load, damage may occur during long-term use.
This article shares a real case from our Malaysian shipyard client. The client purchased several batches of small foam filled fenders from YT Marine. The regular size was 300 mm × 700 mm. After use, one fender was found broken near the flange area. Based on the pictures and application condition, we analyzed the possible reasons and provided design improvement suggestions.
Project Background
The client is a Malaysian shipyard that had purchased foam filled fenders from us for several batches. The regular fender size was 300 mm × 700 mm, which is a small-size foam fender used for light marine protection. According to the drawing, the fender was designed with an EVA foam core and SPUA outer coating.
Foam Filled Fender Structure
The inner material of this type of foam filled fender is EVA foam with a density of about 100 kg/m³. One fender weighs around 16 kg, making it easier to handle and install for small jetty, boat and shipyard applications. The outer layer uses SPUA coating, which helps improve seawater resistance, UV resistance and surface protection.
The fender in this order was produced in black, and other colors can also be customized according to project requirements.
Original Fender Design
The original drawing showed a cone-shaped fender body, but the produced fender had flat ends. A flat end provides a larger contact area during bumping, which can be useful in some applications. However, when the fender is installed close to a flange or hard metal edge, the end shape and contact position must be checked carefully.
Broken Area Near the Flange
From the pictures, the damage appeared near the flange area. The flange edge pressed into or cut the fender body during impact. When a hard flange repeatedly contacts the fender surface under load, it can create a concentrated cutting point instead of spreading the impact over a wider surface.
Possible Reason 1: Flange Cutting the Fender Body
The first possible reason is that the flange cut into the foam filled fender body. This is not simply a material problem. It is also related to the installation structure and how the fender contacts the metal part during compression. If the flange edge is sharp or the contact area is too concentrated, the SPUA coating and foam body may be damaged over time.
Possible Reason 2: Fender Diameter Too Small for the Impact Load
The second possible reason is that the fender diameter was too small for the actual bumping load. This type of small fender can work well for light protection, but if the vessel or working condition creates a heavier impact than expected, the fender may be compressed too much. Excessive compression can allow the flange or fixing area to contact and damage the fender body.
Design Improvement: Increase Fender Size
One solution is to increase the fender size according to the actual impact condition. Our foam filled fender design compression is normally considered around 50%. If the fender is too small for the real working load, a larger diameter or longer fender can provide more energy absorption and reduce the risk of the flange cutting into the body.
Design Improvement: Change Flat End to Cone Shape
Another solution is to change the flat end design back to a cone-shaped end. A cone end can help reduce direct interference between the flange and the fender body in certain installation conditions. The correct end shape should be selected according to the drawing, fixing structure, contact position and actual berthing condition.
Compression Recovery and Fender Quality
The broken area does not mean that the foam filled fender material is poor. Foam filled fenders with suitable EVA foam and SPUA coating can recover after compression when the application matches the design. Compression testing helps confirm the recovery performance and shows whether the fender can return close to its original shape after loading.
What Buyers Should Check Before Ordering
Before ordering foam filled fenders, buyers should confirm the fender size, installation structure, flange position, expected impact load, vessel size, contact area and fixing method. If the application includes a hard metal edge, flange or special bracket, photos and drawings should be reviewed before production to avoid concentrated cutting or over-compression.
Work with YT Marine
YT Marine manufactures foam filled fenders, EVA foam fenders and related marine fender products for shipyards, docks, jetties, boats and marine protection applications. Buyers can send drawings, application photos, installation details, fender size, expected load or damaged fender pictures. Our team will review the details and help recommend a suitable fender design for production and quotation.
