EPS300 GeoFoam Bears the Load of 2000 Tonne Undersea Umbilical

With a very challenging lead time Engineered Foam Products helped the client to rapidly source 1000M³ of EPS blocks to securely pack undersea umbilical’s due for international shipment from their manufacturing site in the North East of the UK. Heavy duty umbilical’s provide a critical link supplying hydraulic power, electrical power and control signals as well as consumables such as anti-corrosion or anti-waxing chemicals to isolated subsea wells from fixed platforms or floating production systems (FPSO).

The Challenge

The client was seeking a cost-effective solution for a new time-sensitive project which required the shipment of two umbilical’s measuring a staggering 26km total length with heavy and bulky termination heads, aboard a single vessel.

Typically, with delivery usually close to the pickup point there is rarely a need to ship more than one umbilical on the same vessel, however in instances where international delivery is required the cost and practicality of shipping just one cable per voyage can be astronomical with multiple vessels required to ship multiple umbilicals.

To facilitate the shipment of the 11.5km and 14.5km long umbilicals weighing approx. 2000 tonnes total aboard a single vessel, the umbilicals would be fed into a carousel aboard the ship and a voidfill material used to keep these securely in place during transit. The material would need to withstand heavy loads whilst also be relatively quick and easy to install within the confines of the carousel.

Previous material trials included high density extruded polyethylene which was found to be too narrow and brittle making it unsuitable for the weight-dependant application. Timber was also considered but required more onsite labour to over engineer the material to make it structurally sound enough to withstand heavy loads.

Our Approach

Expanded polystyrene has excellent compressive strength but the selection of the correct density is key in any given application. Engineered Foam Products Design and Technical team reviewed detailed drawings and structural calculations and ran some load bearing physical trials to determine EPS300^* as the optimum density to securely ship the umbilical’s.

Supplied in block form measuring 2000x1200x1000mm, EPS 300 is a medium to high density foam suited to void fill applications with excellent structural strength. The lightweight blocks can be manoeuvred by hand and can be easily sliced down to size on site using the recommend hotwire cutting equipment on site. This allows for the creation of channels for routing of umbilical around the carousel, resulting in uniform coiling across the cables full length.

The Results

The EPS 300 blocks performed well during carousel packing for transport, acting as spacers allowing the guided uniform coiling of the umbilical’s length preventing any kinks and cuts whilst also protecting the heavy and large cable head terminations from damage.

The use of EPS blocks reduced the complexity of the pack out design and the engineering calculations required, simplifying the behavioural analysis when loaded as the compressibility only needed to be analysed on two planes (the x and y axis), no additional bracing was required either.

EPS is incredibly cost effective and easier to cut and shape on site when compared to other packing and void filling materials such as timber. This unique application highlights the versatility and incredible weight bearing potential of EPS.

*EPS300 refers to the compressive stress of the material, in this case 300 Kilopascals (kPa) at 10% deformation.