Two next-generation deepwater pipeline plows designed and built by UK-based IHC Engineering Business (EB) recently left EB’s Hadrian Riverside workshops on Tyneside for extensive offshore commissioning and installation on the owner’s vessels.
The new-build PL3 and BPL3 Plows are the largest subsea plows EB has developed. Designed to handle pipeline diameters of up to 1.55 meters in water depths of 1,000 meters, they will be used for burial of main pipeline trunk routes. Their design follows the theme of plows being specified for ever-larger pipe diameters to match technological developments.
“We’re truly passionate about plows,” says EB’s managing director Tony Trapp. “We were genuinely excited to have been challenged to deliver a game changing plow system. Our design focused on increasing levels of performance, productivity, reliability and safety and will allow our client to trench the largest and longest subsea pipelines. During the whole process of design and build we took maximum advantage of the proven North East of England supply chain.”
“We were asked to design a trenching spread matched to the exceptional capabilities of the vessel,” said Mike Crosby, senior engineer for the plows. “The new PL3 Plow weighs 200 tons, is 22 meters long, has 100-ton capacity pipe-handling equipment front and back, and can create a 2.5-meter deep multipass trench, and a 2.3-meter maximum single-pass trench. The control system will be built into the ship bridge module, and this together with the use of a buoyant control umbilical, will greatly increase productivity in comparison to previous spreads.
“BPL3 is unlike any previous backfill plow. Aimed at reducing the risk of damage to the trenched pipeline, it offers front skids that run outside the trench. It has been designed to fold into itself, rather like a spider, for launch and recovery. Its design ensures it is possible to launch the plow in the correct orientation to save time during deployment.”
“The larger the pipe diameter, the more technical the issues the designers face,” said Andrew Stevenson, EB’s Director of Sales. He said the PL3 and BPL3 took two years from concept to delivery.