Project Overview

The Project – Subsea Engineering

Umbilical cable reels used in Subsea engineering, are complex constructions. Manufacturing these reels in multiple sizes would be incredibly expensive. Getting their name from an umbilical cord, they supply consumables such as air, hydraulic or electrical power to subsea equipment and divers. These cables require large reels to carry and extend them when necessary. In an ideal world the umbilical cable reel sizes would be as variable as the cables. However in reality, reels are expensive items. Meeting requirements for specific jobs can be costly. A common problem – resizing reels.

Typically this has been done by using either wooden or steel partitions to narrow the reel. Our client, an umbilical cable manufacturer also had weight constraints on the project. Polystyrene is lightweight at 98% air. Therefore, installing polystyrene partitions is much easier and efficient opposed to typically used materials.

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  • EPS can be cut to fit specific umbilical cable reel sizes, making reel alterations a possibility.
  • Polystyrene easily bolts on to the umbilical cable reels – no requirement for external contractors.
  • The polystyrene pieces are easy to remove and can be re-used if required.
  • Polystyrene provided lower cost than wood or steel. Material costs were comparable but big savings on installation time and cost made this a lower cost solution.
  • Molygran have no tooling costs and short lead times.
  • Molygran were able to provide the EPS expertise required.

The brief The brief

For the job pictured the weight of the umbilical cable reel was a critical factor.
This is a 12m reel and a wood or steel partition would have added an extra 7-8 tonnes to the total reel weight. This was sufficient to take the total reel weight beyond the job tolerances so a different solution was needed.
Polystyrene sections used to provide an alternative method of narrowing the reel width. These were custom made from heavy density EPS and designed to bolt to the reel structure. The sections were chamfered on the outside to take the cable and were also cut to allow a cable entry point to the centre of the reel.
The polystyrene came in at less than 1 tonne. Hardly surprising since polystyrene is over 90% air so the weight saving was considerable.

The solution The solution

The Senior Engineer reported that some of his team were a little sceptical about the new solution at the outset but the polystyrene bolted easily to the reel and the winding operations were straightforward.

EPS is an extremely durable and versatile material – particularly in heavier densities. The polystyrene took the cable tension easily and performed exactly as expected. The complex shapes and designs were easily created with polystyrene and the lightweight properties made it extremely easy to handle in comparison with previous materials used.

EPS can also be cut to provide a cost effective way of increasing reel core diameters at a much lower cost than using a wooden or steel alternative.

I didn't have a single phone call when we put this together...

C.B - Senior Engineer