WRECKTOUR:139 HMS Whirlwind

I CAN ONLY INTRODUCE this month's Wreck Tour as something really special and inspiring - a wreck that is unique. HMS Whirlwind was the Type 15 frigate F187, rebuilt for the Cold War from the hull of World War Two emergency-build destroyer R87.
As a wreck, it is not only one of a kind, but it is also at a comfortably accessible depth of 36m, though a bit out of the way for many divers, in Cardigan Bay.
Our tour begins at the highest point of the wreck, 6m above the 36m seabed, on the starboard side of the bow by a large pair of bollards (1).
The bow rests 90° over on its port side, as I would guess the whole ship did when it initially sank in the Cardigan firing range.
Following the tapering bow forwards and deeper, chain mooring cables extend from hawse pipes on the port and starboard side (2), and lead off to the north and west.
Above deck, the cables stretch back beneath a range target platform (3), a light latticework tower welded to the deck after HMS Whirlwind was decommissioned and handed over to the firing range in 1974.
Behind the target platform, a square of four large bollards is mounted across the centre-line, with loops on the mooring cables hooked over them. The bow deck now comes to an abrupt end where the bridge would have been located (4). Here the wreck is considerably broken, and the debris is closer to the seabed.
The bridge of the Whirlwind was low, only one deck above the forecastle and the superstructure extending aft at a similar level, putting it two decks above the main deck. This was one of the first fully enclosed bridges fitted to a Royal Navy frigate,
a welcome change from open bridges in the North Atlantic winter.
A truncated pyramid (5) with a small hatch in one side may have been an ammunition locker for the twin 40mm Bofors anti-aircraft gun (6). A heavy tube among the debris towards the hull could have been part of the bracing and support for the gun position.
Immediately aft of the anti-aircraft gun, a small raised deck-house would have been the observation position, with an optical range-finder mounted on the roof (7).
Another lattice structure is the ship's main mast (8). This is considerably taller than the range target platforms, and tapers towards the top.
When you look closely, the construction is much stronger than that of the range target platforms, with additional cross-bracing to support the weight of radio and radar antennae through whatever stresses heavy seas could inflict on the frigate.
On the seabed behind the mast, a small anchor (9) is probably nothing to do with HMS Whirlwind, but one lost here or dumped by trawlermen on a known "foul ground".
The wreckage now gets a bit confused where the hull has collapsed, partly covering the remains of the deck and superstructure. The reinforced tube from the centre of the funnel lies between two mushroom-style ventilator covers (10).
About here, the extended forecastle would have ended, the sides of the hull dropping to main deck level, though none of this detail is apparent on the wreck.
The next big structure is another fire-control position with a rotating mechanism on top that would have supported the Whirlwind's radar (11). This would have been covered by a lightweight dome.
Immediately behind it is the twin 4in gun turret (12), though this could be easy to miss because the gun barrels point forwards and are largely obscured by wreckage. The turret has an open back, revealing the breeches of the guns and gun-training mechanisms inside.
Behind the turret, HMS Whirlwind's deck opened out to provide wells for two Mark 10 Limbo anti-submarine mortars.
These three-barrelled mortars were developments of the wartime Squid system, launching a spread of three depth charges in any direction about the ship. A turned-over section of the upper deck, with steps "descending" (13), would have led into one of the Limbo positions.
The stern of the ship has twisted almost completely over. A chain runs across and partly through the wreck, then off to the west. It's hard to tell whether this was another mooring-chain from the firing range, or arises from an anchor fouled on the wreck after it sank.
Looking beneath the overturned deck, a wide tube may have been part of one of the Limbo anti-submarine mortars.
Standing away from the wreck, by some miracle upright on the sand, is the aft range target platform (14), identical in every way to the forward platform. I suspect that to land upright like this it must have broken away from the deck as the ship capsized, and then fell independently to the seabed.
A section of deck with a pair of bollards has broken from the hull and stands just off the side (15).
Beneath the overturned hull, the deck is held up from the seabed by an enclosed winch-housing (16). This may have been used for towing a sonar array behind the ship when searching for submarines.
The upturned hull is relatively flat at the stern, typical of a ship built for speed.
In the centre is a single large rudder, and there would have been propeller-shafts to either side.
The A-frame supporting the starboard shaft is truncated (17), while that supporting the port shaft is intact (18).
Both propeller-shafts broke away from the A-frames before the stern twisted over, and now rest on the seabed, slightly out from the wreck.
The propellers are missing, and would either have been removed when HMS Whirlwind was decommissioned, or were salvaged from the wreck. After it sank, the Hydrographic Office reported: "Salvage work not expected for some time".
Perhaps there has never been any salvage; there is little sign of it, and the Royal Navy may well have had other uses for a pair of bronze high-speed propellers. The hull of HMS Whirlwind could have been towed to the range by tugs.
Following the shafts forward, one disappears beneath the hull, and the other leads into the casing of a gearbox (19).
The steam turbines that powered HMS Whirlwind turned at high speed, and the gearboxes would have reduced this to a rate more suitable for a ship's propellers.
Although overturned and even caved in, the hull is relatively intact (20), so other machinery such as the turbines themselves and the boilers are inaccessible - assuming, that is, that the turbines were not removed when HMS Whirlwind was decommissioned.
With a seabed at 36m, seeing this much of the wreck in a single dive could put you well into decompression, so it is probably time to ascend, either on a delayed SMB or, with a larger group, to rendezvous at a decompression station and cast off from the shotline.

Thanks to Mark Dean, Bob Lymer, Dave Wakeham and Jim Hopkinson.

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