AC-6/FC Pontoon
The following presents new data collected as part of a recent Historic Scotland funded project – the Scapa Flow 2013 Marine Archaeology Survey – which aimed to assess the extent and condition of some of the sites around Scapa Flow.
Vessel History
A British barge used to facilitate salvage activities by Metal Industries Ltd it is unclear whether the remains present are from the Floating Crane (FC) Pontoon or the remains of the AC-6 Barge as descriptions of both these vessels are the same.
The ADM report of blockships requisitioned during World War II available from the Public Record Office, Kew refer to the AC-6, but make no mention of the FC Pontoon. It is possible that the AC-6 is the name of the FC Pontoon. The Undermarine Operations surveys completed in 1972 do not record any protruding remains which is incongruous in light of the scale of the visible superstructure, which is likely to have been more extensive in the 1970s. There is no UKHO report for FC Pontoon
Diver Surveys
The midsection of the barge sits out of water and is visible at all states of tide measuring 12m long by 10m beam. The remains are oriented east to east but it is unclear which way the bow would have pointed as this is no long visible. There are four steam winches on the top of the barge and a small Scotch boiler submerged within the box section which would have been used to operate the barge machinery not for propulsion. The block stands on lattice work support legs that drop to the seabed.
East and west of the visible wreckage the submerged remains lie on a sand and rock bottom in 5m - 7m of water. The well scattered broken down wreckage includes rib fragments, sections of hull plating, a winch and some bitts.
Side Scan Data
The site was not side scanned as most of the remains sit above the water at all states of the tide.