Ahoy - Mac's Web Log

Introduction.
Cammel Laird had built the 1,290 ton HM Submarine Thetis ( her motto" I bide my time." ) launching her on the 29th. of June 1938. The initial trials were delayed because the forward hydroplanes had jammed, but on the 1st. of June 1939, under the command of Lieutenant Commander G. H. Bolus. R.N. trials were finally due to commence. But the submarine was too light to dive, and a survey of water within her various compartments was made, one check was to ascertain if the internal torpedo tubes were flooded.

A submarine slides down the slipway at its launching

A TRAGEDY WAS ABOUT TO UNFOLD.

Thetis' diving trials.
On her trial day, Thetis carried 103 people, some 50 above her normal crewing level. There were 8 Naval Officers extra, some of them commanding their own submarines, coming along for the ride, to observe a new class of boat put through her paces. The other extra personnel were technical people from her builders Cammel Laird, and from Vickers Armstrong, two from a catering company who were to arrange the " After Trials party." and finally, the Mersey Pilot, Norman Wilcox.

At 0940 ( 9.40 AM ) her Captain, headed his new command from Birkenhead out to Liverpool Bay, escorted by the Tug Grebecock, its additional duty, to remove the passengers from Thetis, prior to the dive, and transport them back to shore. But at 1330 ( 1.30 PM ) a signal indicated that all on board had decided to stay and witness the first dive. Indeed a fatal decision.

At 1400 ( 2 PM ) air rushed out of the tanks with a WOOSH, and then for the next 50 minutes those aboard the tug watched as the submarine very, very, slowly dived below the surface, but it did appear to be " a very slow time dive." The bow of the submarine was at a slight angle, she seemed having trouble in diving, but finally at 1458 ( 2.58 PM ) she had disappeared.

Trouble in diving.
As I indicated in my intoduction, Thetis was too light to dive, and a survey was made of water in various tanks on board. As part of this process, the Torpedo Officer, Lieutenant Frederick Woods opened test cocks on each of the torpedo tubes, these were designed to allow a small amount of water to flow if indeed a particular torpedo tube had had its bow door inadvertently left open. Woods opened up the test cock for Number 5 tube, but unbeknown to him it was blocked up by enamel paint,and no water flowed, indicating to him that this tube was empty of water, and its bow door shut. ( when a dockyard workman was about to paint with enamel paint, he had not first plugged this test hole, so promptly filled it up with paint, negating its safety role )

To further compound the problem, the layout of the bow door indicators was unusual, they were arranged vertically, 1, 2, 3, 4, 6, with 5 at the bottom. The shut position for the Bow Door of Number 5 tube was in a different position to that of all the other torpedo tubes, this led to the rear door of Number 5 tube being opened. ( all appeared to be in order, no water dripping out when the test cock was opened, and the bow door appeared to be closed ) Alas, not so, as a result of opening No 5 tube rear door, water flooded in from the open sea, causing the bow of Thetis, to plunge into the sea bed 160 feet below the surface. This left her stern stuck above the surface some 18 feet.

Thetis bow down, stuck in the mud of Liverpool Bay

It was now dark, and the attending tug had drifted about four miles away from the dive site. Thetis was now on her own for a long and lonely night. Thetis found an increased level of carbon dioxide in the boat.

At 0745 ( 7.45 AM ) the next morning, the sunken submarine was found by a searching aircraft, and surface craft rushed to the scene, it was now 18 hours since she went down. A destroyer, HMS Brazen arrived, to hammer on the hull to indicate help was at hand. The level of carbon dioxide in the boat was at a critical level, in all, but four trapped men escaped, Oram,Woods, Arnold and Shaw, the poisionous atmosphere putting the remainder to sleep before the 99 men on board died.

Memorial Service.
The Archbishop of Canterbury led a memorial service on the 8th. of June at St Martins in the Fields.

Thetis at the bottom of Liverpool Bay.
The hawsers securing the stern of the submarine parted when the sheer weight of water exceeded their breaking strain, the boat disappeared to sink to the muddy bottom of Liverpool Bay. There she lay from the 3rd. of June, on the 23rd. of August, one of the salvage divers, Petty Officer Henry Perdue was claimed by the "bends" and this accident chalked up its 100th. victim.

The crew of Thetis were in the main, buried here at Holyhead,
but her Captain, Lt. Cdr. Bolus was buried at sea.

Back to the surface 12 weeks after Thetis sank.
Thetis finally saw the light of day once more 12 weeks after her first and only tragic dive. She was towed towards Anglesey, but beached on a sandbank in foul weather, there she stayed for the next 8 days, until the weather moderated.

On the 10th. of September, Thetis made it to Moelfre , but again shocking weather again intervened, and it was 68 days before all the bodies of the dead crew could be recovered, for a mass burial at Holyhead.

Note, in our story about the "Golden Shipwreck Steam Clipper Royal Charter Comes To Grief." that tragedy also took place at Moelfre, but back in 1859.

Thetis beached after recovery

Thetis returns to her birth place.
Now, on the 18th. of November 1939, designated as Job Number 1027, Thetis went back to her birth place at the Cammel Laird Yard, but as a battered hulk. She was stripped completely, waiting for an Admiralty decision to scrap or refit her, but as Submarines were at a premium to prosecute the war, it was decided to refit, and rename this ill fated submarine.

All traces of her old identity were removed, and on the 26th. of October 1940 she commissioned as HM Submarine Thunderbolt, her new Captain, Lieutenant Cecil Crouch, R.N. The new crew were all volunteers, but they all were well aware they sailed in the old Thetis.

The old Thetis, rebuilt, and sailing as Thunderbolt.

The Thetis Clip.
As a result of this accident, on the rear doors of all torpedo tubes was fitted a" Thetis Clip" a single dog clip, which stopped the door being opened more than a fraction, it allowed a very reduced flow of water, should the bow door be opened, once it became evident that the tube was empty of water, this safety clip could be overridden and the rear door safely opened.

Success as Thunderbolt.
Under her new name and command, this submarine achieved success, sinking an Italian submarine Tarantini, seven ships by torpedoes, and another six by gunfire.

Sixth patrol in the Mediterranean.
On the sixth patrol in the Mediterranean, on the night of the 12th. of March 1943, Thunderbolt lookouts sighted a large Italian convoy, protected by a single Sloop Cicogna, and the submarine Captain must have smacked his lips in anticipation of a slaughter. But, the sloop was commanded by a wily Capitano diCorvetta Augusto Migliorini, himself an ex submariner.

At 0854 ( 8.54 AM ) on the morning of the 14th. the sloop still had Thunderbolt pinned down and dived, Augusto knew she would soon have to surface, and his sound equipment told him he was immediately on top of the enemy submarine. Then, only a few yards away on his starboard bow, a periscope appeared. 24 depth charges were soon sent on their way, the British boat rose from the depths, briefly hung in the air, tipped to almost a vertical position. For the second time, this submarine's stern was thrust into the air, and then she plunged down, down, to a depth of 3,000 feet to the bottom of the Mediterranean. No one survived.

It was exactly four years to the day that the four men, Oram, Woods, Arnold and Shaw had escaped from Thetis in Liverpool Bay.

An Admiralty announcement.
"The Admiralty regrets to announce that HM Submarine Thunderbolt must now be considered lost."

Conclusion.
Thus, the curtain fell on an ill fated submarine that had carried two different names, Thetis and Thunderbolt, but in all, claimed 162 lives.

The crest of Thetis