Archaeology Notes
Event ID 758271
Category Descriptive Accounts
Type Archaeology Notes
Permalink http://canmore.org.uk/event/758271
NR16NE 8002 1955 6555
N55 48.1 W6 28.5
NLO: Campa [name: NR 200 658]
Coul Point [name: NR 188 644].
Formerly entered as Site no. 1.
(Location map and photographs).
S Blackburn 1986.
Horizontal Datum = OGB
General water depth = 5
Circumstances of Loss Details
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HMS GRAPH was captured on 28 August 1941 by HMS BURWELL and HM Trawler NORTHERN CHIEF in north Atlantic, after being depth-charged by the RAF aircraft of 269 squadron on the previous day. It was wrecked when the tow broke adrift while en-route from Chatham to the Clyde. It was scrapped in situ 1947.
Surveying Details
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10 October 1953. A certificate of purchase was issued to the Fixed Mortgage Trust Ltd.
9 February 1970. J R Scott esq of Ardbeg, Port Ellen, Islay now owns this wreck. He reports that the conning tower aft is still in one piece, but forward of this there is very little left.
Letter from J R Scott 6 February 1970
2 July 1981. The wreck is reported to lie at 55 48 06N, 006 28 30W in approximately 5 metres. It is well broken up, but easily located as large winch, which has been abandoned, overlooks the site.
Letter from D W Argood, 24 June 1981.
19 July 1982. The pennant number is believed to be N46 not P715.
Hydrographic Office, 1995.
The disadvantages of operating this exotic vessel are described on the basis of her single operational patrol (off northern Norway). The torpedo tubes were modified to fire British torpedoes and the valves were adapted to hydraulic working, rather than the manual working of German practice; many of the instruments retained their German labels and were calibrated in metric units.
German U-boats were designed to operate further from their bases than their British counterparts, being longer-ranged, deeper-diving, faster and more robust, with a consequent reduction in surface stability and crew comfort. Living conditions were primitive in the extreme and surface stability notably lacking, making surface watchkeeping uncomfortable. Crew efficiency deteriorated noticeably after about three weeks.
The surface speed of a U-boat was about 19kts, some 4kts faster than the British equivalent. Surface buoyancy was also reduced. The German high capacity batteries and MAN aluminium alloy engines had a comparatively short life, the batteries requiring annual replacement as against the British practice of having them last the life of the boat. Their diesel engines were, however, reversible. The electrical system was particularly complicated, while air bottles and fuel tanks were mounted outside the pressure hull. It was German practice to fit twin rudders for extra manoeuvrability and to use steel for periscopes and propellers, both being lighter and stronger than those in British service. U-boats never had a tight stern gland so their deep bilges needed constant pumping. Most U-boat machinery was mounted on buna (ersatz rubber). These differences provided enough spare weight to allow the use of steel 7/8in (22mm) thick for the hull, as against the 5/8in (16mm) of British practice.
Although the battery plates were replaced, the lack of compatible spares brought the operational use of this boat to an end. She was used for training and experimental duties in the Clyde before an unsuccessful attempt at a refit (in July 1943) resulted in her being taken out of service.
The capture of the vessel is also described, the name HMS/M Graph being taken from the code-name of the operation to recover the vessel from Canada to Britain.
P Durham 1996.
(Classified as submarine: former name cited as U-570, and date of loss as 20 March 1944). HMS [HMS/M] Graph: this vessel came ashore on the W side of Islay after breaking from tow.
Registration: London. Built 1941. 769 tons displacement. Length: 64m. Beam: 6m.
(Location of loss cited as N55 48.22 W6 28.48).
I G Whittaker 1998.
Plans and photographs of this vessel are held in the National Maritime Museum, Greenwich.
(For online catalogue of negatives, see www.nmm.ac.uk/historicphotographs).
Information from Ms G Fabri (NMM), 7 November 2003.
