Thetis returned as a battered hull. She was stripped completely as soon as the salvage crews had left her on her return from Anglesey. For several weks they waited for an Admiralty decision as to whether Thetis should be scrapped. Had it been peacetime this would very probably have happened. But events were dictated by a wartime economy. Submarines were needed fast. If refitted the submarine could be back in service within the year.
All traces of the boats previous identity were erased.
In November 1939 she joined the 3rd Submarine Flotilla bearing a new name. Thunderbolt. Commanded by Lieutenant Cecil Crouch, every man on board was a volunteer, and all knew she was the old Thetis.
One modification in Thunderbolts torpedo tubes / equipment regularly called to mind her previous identity. On the rear doors of each of the tubes was fitted a "Thetis Clip" - as it became universally known in the submarine service. This was a single dog clip which prevented the door opening more than a fraction when the original lever moved from "Shut" to "Open". This safeguard would reduce the inflow of water in any mishap in manageable proportions.
The most nagging reminder of Thetis came from the dirty, rusty brown high water mark which persisted in showing through in certain compartments, no matter how many coats of paint were administered.
Thunderbolt went into action when the Battle of the Atlantic was at its height. On 3rd December, 1940 she proceeded in the company of her fellow submarines Tribune and Cachelot, escorted by the armed yacht Cutty Sark. Some forty hours later the ships parted company with Thunderbolt heading south into her designated patrol area. On the morning of December 15th, she had made her first 'kill'. An Italian submarine Tarantini was hit by Thunderbolt's torpedoes.
More successes followed, and by 1943 Thunderbolt had notched up seven sinkings by torpedo, six by gun action and had served on two special assignments. All on board had forgotten the Thetis and it was in a spirit of high confidence that they set out on their sixth Mediterranean patrol.
On the night of March 12th Thunderbolt sighted a large convoy escorted by a single Italian sloop. Picking out the largest freighter in the group Crouch made a torpedo attack. Minutes later the target - the steamer Esterel was sinking rapidly, Thunderbolt turned away to escape the attentions of the pursuing sloop - Cicogna, commanded by Capitano di Corvetta Augusto Migliorini. He was an ex-submariner, and his ability to predict the movements of his quarry made him a dangerous adversary.
A grim cat-and-mouse game developed with the Italian sweeping the area in the knowledge that the submarine would have to surface before long. Methodically he patrolled back and forth waiting for the tell-tale echo on his sounding equipment that would locate his enemy. His patience was rewarded. At 8.54 am on March 14th a strong signal told him that he was immediately above the submarine and as he turned to go into his attack thunderbolt's periscope emerged a mere ten feet away on the starboard bow.
Twenty four depth charges hurtled from their racks, the sea erupted and before the water settled Thunderbolt's stern rose drunkenly from the sea, hung there for a moment, tipped to almost 90 degrees from horizontal, and then disappeared.
For the second time in her life the old Thetis had thrust her stern into the air before plunging 3000 feet to the bottom of the Mediterranean. But this time she had gone for ever.
The men who had survived the Thetis disaster, Arnold, Oram, Shaw and Woods must have relived their experience when they heard of the loss of Thunderbolt. The admiralty announcement was made on June 2nd 1943, exactly four years after they had escaped from their steel tomb.
"The Admiralty regrets to announce that His Majesties Submarine Thunderbolt must now be considered lost...." The curtain had finally fallen.
His Majesties Submarine Thetis
Secrets & Scandal.
The men who lost their lives aboard HMS Thetis / Thunderbolt