WRECKTOUR:167 The Scotia

SKETCHING THIS MONTH’S Wreck Tour of the bucket-dredger Scotia began as a near-impossible task, then suddenly became easier.
Skipper Iain Easingwood had dropped the shot well ahead of slack, and we had impatiently dropped in as soon as it was slack enough to dive.
As I descended, it got darker to the point of being black, with less than 2m visibility. I had begun working my way round as much by feel as observation, and attempted some photographs.
It was only after 15 minutes, round about when I was deciding to call it a day, that the vis suddenly improved, as the water slackened fully and stopped dragging up silt from the seabed.
The wreck became a different dive, so I decided to do another lap. The visibility had risen to 5m by the time I had finished, and it was just about bright enough to see by natural light.
The shot had dropped against a box-section of hull (1), the only obvious target for an echo, and what I would later work out to be the port pontoon of the hull.
Working aft, the deck-beams of the pontoon soon break up, and an upright boiler (2) has fallen forward.
Dredging-buckets (3) rest on the back of the boiler, with another bucket propped against the inside of the port side of the hull.
Behind the boiler is the massive flywheel (4) of an old beam-engine oriented across the deck. The Scotia was a dredger of 1848 vintage, and I believe it was a simple unpowered iron pontoon barge with an industrial beam-engine mounted on the deck.
Attached to the aft side of the wheel is a connecting rod leading to the remains of a piston and rocker-valve assembly (5).
The aft of the barge is cleanly semi-circular, with ribs changing from a transverse to a radial pattern. Just off the starboard side is an Admiralty-pattern anchor (6).
As a dredger, I expect the Scotia would have carried anchors in each corner to secure and manoeuvre the hull while dredging.
Level with the flywheel on the starboard side is a massive shaft attached to an equally massive gear-wheel (7).
This would have pulled the bucket-chain, with the rotation of the engine transferred and geared down by a set of bevelled gears immediately behind it (8). Inboard of this are a few more dredging-buckets (9) piled over the machinery.
The starboard part of the hull (10) is a box pontoon like the port side, with an initially open area soon superseded by ribs from the deck.
Between the split pontoons, a rectangular hole (11) provides a long gap through which the dredging-buckets would have been lowered and rotated to dredge the harbour silt below.
A pair of shafts with disc-shaped ends rest into this gap. Perhaps this is a mystery part of the dredging machinery – or maybe nothing to do with it.
The term “dredger” covers a huge scope in ship design, all the way from a flat raft just big enough to float a JCB through to sizeable ships with steam-powered bucket systems, such as the St Dunstan off Dorset.
The split twin-pontoon layout of the Scotia’s hull suggests that it could have had a solid bucket-chain arm as on the St Dunstan, but there is no sign of such an arm, only a litter of buckets.
The rest of the machinery is iron, so if such an arm ever existed it would have been iron too. Could it have been removed to transport? Could it have been torn loose by the storm and lost away from the main body of the wreck? Could it be buried deep in the silt underneath?
Or perhaps there never was an arm. The Scotia may have worked by dragging buckets on a cable in a rotating loop.
A little further forward, the port pontoon breaks up. Just off the port side is a simple A-frame anchor-winch (12), not unlike the kind found on many steam trawlers. Next to this is a hull-plate with a small porthole (13).
Heading back into the wreck, we pass a small fairlead and then just general debris of iron plates and ribs.
At the forward extent of this debris is an obvious bow (14), and perhaps the folded tubular structure behind it (15) was another part of the dredging machinery – or perhaps that is wishful thinking, and it was a simple tripod base for a mast.
If you delayed starting your dive until well into slack water to allow time for the silt to settle out, the current will be beginning to pick up by now. The best method of ascent will likely be a DSMB.

Thanks to Iain Easingwood and Jim Easingwood.

DEPTH -20m 20m-35m 35m-45m 45m+ DIFFICULTY RATING