DLM’s subsea cable holdback tensioner debuts on NKT Victoria

UK-based Dynamic Load Monitoring (DLM) has unveiled a new device for measuring tension and creating holdback force on a single piece of subsea cable.

The Saddleback Holdback Tensioner (SB-HBT), which combines the Saddleback product with an additional Hold Back Tension element, is being primarily used by the vessel NKT Victoria.

The 450 kg product works by creating additional line tension on the subsea cable running through it, specifically for bundled cable lays.

According to DLM, a Saddleback can measure line tension from 0 to 5,000kg and is suited for more delicate cable. Moreover, a twin pair of Dunlop 18 x 7 SMO LCE tyres are connected to a hydraulic cylinder to clamp the two wheels together, and a disc braking system is used to control the rotational speed of the wheels on the SB-HBT.

The device can create 750 kg of clamping force between the wheels and hold back 500 kg of line tension. On the top wheel there is an encoder to measure speed and distance, the company added.

“This is the first requirement we have had [for the SB-HBT] but we have discussed it with other potential customers; this seems to be a reoccurring problem aboard vessels,” said Chris Scrutton, technical manager at DLM.

“It can be used when a cable laying vessel is completing a new lay project, and needs to control the departure speed to small diameter cables being bundled alongside larger cable diameters. The reason for doing this is that the small diameter cable often does not bundle tightly enough with the larger diameter cables and can run free of the bundle when departing off of the vessel.”