Shipbucket

HMS Challenger K07 was Commissioned in 1984 and was heralded as the navy’s Seabed Operations Vessel employing a team of Saturation divers, a Towed unmanned submersible (TUMS) and the capability to deploy the LR5 submarine rescue submersible. A great concept but with more than a few problems in delivering its claims.

The diving system. The diving system first installed during the build was woefully inadequate as it was designed by an engineering company that had had no previous diving system experience. When tenders were invited to bid for the contract the successful company would have any existing plans and concepts turned over to them. Consequently the successful firm figured that if plans existed then they could build it and won the contract with the lowest bid.
On requesting the existing plans and drawings they were shown some concept designs pretty much drawn on the back of a fag packet as to what the navy had in mind. This led to a system that was vastly over budget and never worked. Finally in 1986 the ship was refitted in Immingham by a company with a proven track record in building diving systems. On completion of her time in refit the ship had a working diving capability down to 300m.



The TUMS
The TUMS was a concept originally developed by the US but was never taken on by them because of many problems with the design. It was designed to deploy a depressor - a garage for the submersible about the size of an upturned skip. This depressor would tow the submersible behind and below the ship to great depths. From the depressor on a 30 m umbilical the submersible could be piloted from the ops room.

The problems with this concept was that the submersible could be up to 2 miles behind the ship navigating over rocks and cliffs that the ship had already passed over requiring a complex system of computer driven software to allow for the lag of the submersible passing over the same area and for the pilot to “fly” the submersible out of the way of the obstacle – the problem was that it didn’t always work. The whole thing was powered by 3 kilowatts of electricity which caused problems of its own the result was that the system was never successfully deployed. It was also vastly over budget.
It could not be used at the same time as the sat diving system so it was either or.

The LR5
The ship could within 24 hours be role changed and used to deploy the LR5 submarine rescue submersible, something she managed a few times. The problem was the original design was meant to allow the submersible to be able to lock onto the diving chamber complex to allow the rescued submariners to transfer under pressure into the chambers in the event of the rescuees being recovered from the sub under pressure – this system was never fitted.

The other snag was that although the ship was highly manoeuvrable as she was fitted with voith schnieder propulsers the top speed was only about 15 knots which meant if she was to be deployed to rescue a crashed submarine the time taken to reach the area was something that could become a problem.

Because of all of the ongoing problems and costs, indeed questions were asked in the house about the value of the ship to the navy so in a round of defence cuts the SOV was decommissioned in 1990 and sold off.

One of the casualties of these cuts and despite the saturation diving system actually finally being operational the navy also lost its saturation diving capability and withdrew the saturation diver qualification. Something that really upset us Sat divers.

I'm not sure how it can be handled with regards to standards compliance, but I think this is the prettiest and most clear representation of Voith-Schneider propulsors that I've seen on the bucket.