MDL custom solution for North Sea tie-back campaign

Maritime Developments MDL has completed a North Sea tie-back, which included delivery of solution for handling reels of 12-metre diameter.


The work scope covered installation of 3 reels of flowlines, jumpers and an umbilical using MDL Third-generation Reel Drive System.

The reels measured from 9.2 metres to 12 metres diameter – the largest reel handled by the MDL RDS to date.

To accommodate the larger diameter, MDL designed and manufactured a set of 12-metre cradles to integrate with its T&C System.

As standard, the MDL RDS track system comes with integrated cradles, supplied with boltable inserts to accommodate varying diameter reels.

As a result, mobilisation time reduces by eliminating sea fastening of the reels and cradles.

The system’s lashing points fasten the reels to the tracks instead of welding multiple fixing points to the vessel deck.

This also saves time and engineering costs, MDL explains.

A further time efficiency comes from the RDS design, where the HPU is built into one of the towers.

Specifically, this cuts the space taken up by the system on deck and the associated sea-fastening design and execution requirements.

The RDS was also a benefit as the towers can engage with the smallest 9.2-metre reel and stroke to the largest 12-metre reel without the need for any packers or interim mobilisation.

On this project the RDS had already been mobilised on the vessel.

Namely, the tie-back was a follow-up scope in a multi-project campaign.

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Dave Gardiner, MDL VP UK & Europe, said:

“We take up a partnership approach with every client, where we jointly discuss their upcoming campaigns and identify possible time and cost efficiencies.

“That was the case on this project – part of a larger campaign with the client using the same vessel.

“By keeping the RDS and track system on board in between projects, we reduced the design and engineering workloads pre-mission and optimised the mobilisation times for the equipment and product across the campaign to date.

“MDL was also the most cost-effective option to deliver the cradles for the client’s 12-metre reel.

“We combined our 20-year track record in equipment design and manufacture with the in-house data on our track system, to safely and efficiently integrate the new cradles with the spread already on board the vessel.