.gif)
HMS Thetis (N25)
Encyclopedia
HMS Thetis (N25) was a Group 1 T-class
submarine
of the Royal Navy
which served under two names. Under her first identity, HMS Thetis, she commenced sea trials on 4 March 1939. She sank during trials on 1 June 1939 with the loss of 99 lives. She was salvaged, repaired and recommissioned as HMS Thunderbolt serving in the Atlantic and Mediterranean theatres until she was lost with all hands on 14 March 1943.
This makes Thetis one of the few military vessels that have been lost twice with her crew in their service history.
in Birkenhead
, England and launched on 29 June 1938. After completion, trials were delayed because the forward hydroplane
s jammed, but eventually started in Liverpool Bay
under Lieutenant Commander
Guy Bolus. Thetis left Birkenhead for Liverpool Bay to conduct her final diving trials, accompanied by the tug
Grebecock. As well as her normal complement of 59 men she was carrying technical observers from Cammell Laird and other naval personnel, a total of 103 men. The first dive was attempted at about 14:00 on 1 June 1939. The submarine was too light to dive, so a survey of the water in the various tanks on board was made. One of the checks was whether the internal torpedo tubes were flooded.
Lieutenant
Frederick Woods, the torpedo
officer, opened the test cocks on the tubes. Unfortunately, the test cock on tube number 5 was blocked by some enamel paint
so no water flowed out even though the bow cap was open. Prickers to clear the test cocks had been provided but they were not used. This combined with a confusing layout of the bow cap indicators — they were arranged in a vertical line with 5 at the bottom - 1,2,3,4,6, and then 5; and the shut position for tube 5 on the dial was in a different position from those of the other torpedo tubes — led to the inner door of the tube being opened. The inrush of water caused the bow of the submarine to sink to the seabed 150 ft (45.7 m) below the surface.
An indicator buoy was released and smoke candle fired. By 16:00, Grebecock was becoming concerned for the safety of Thetis and radioed HMS Dolphin submarine base at Gosport
. A search was immediately instigated. Although the stern remained on the surface, only four crew escaped before the rest were overcome by carbon dioxide
poisoning caused by the crowded conditions, the increased atmospheric pressure and a delay of 20 hours before the evacuation started. Ninety-nine lives were lost in the incident. In addition to the normal crew of 53, there were 26 Cammell Laird employees, another 9 naval officers, 4 Vickers-Armstrong employees and 2 caterers. The crew waited before abandoning the vessel until it had been discovered by the destroyer
, which had been sent to search for it and which indicated her presence by dropping small explosive charges into the water.
The incident attracted legal action from one of the widows, who brought a claim of negligence against the shipbuilders, for not removing the material blocking the valve. Unfortunately for her the Admiralty successfully invoked Crown Privilege (now termed Public Interest Immunity
) and blocked the disclosure of, amongst other items, 'the contract for the hull and machinery of Thetis as evidence in court, on the basis that to do so would be 'injurious to the public interest'. The case is one of interest in English law, as the judges in this case accepted the Admiralty's claim on face value with no scrutiny, a ruling later overturned.
The Liverpool & Glasgow Salvage Association
were commissioned to salvage the sunken submarine. On completion of the salvage operation the bell from Thetis was presented to the Liverpool & Glasgow Salvage Association by the Admiralty. The inscribed bell is now on display at the Mersey Maritime Museum.
One further fatality occurred during salvage operations, when Diver Petty Officer
Henry Otho Perdue died from "the bends"
on 23 August 1939. On Sunday 3 September, Thetis was intentionally grounded ashore at Red Wharf Bay, Anglesey
. It was the same day that war was declared. Human remains that had not already been removed by the salvage team were now brought out to a Naval funeral, with full honours.
The loss went beyond that of a submarine's crew. Among the dead were two naval constructors and several of the submarine team from Cammell-Laird; experienced designers and builders of submarines who would have been needed during the war.
The Thetis disaster was in marked contrast to the successful rescue of the survivors of , which had sunk off the coast of New Hampshire
just a week previously.
The submarine was successfully salvaged and repaired, being commissioned in 1940 as under the command of Lt. Cdr. Richard Crouch.
During the next 18 months, she saw service in the Atlantic: In December 1940 she was on patrol in the Bay of Biscay
and on 15 December she encountered and sank the Italian submarine Tarantini.
In the autumn of 1942, Thunderbolt was converted with her sister ships and to carry two "Chariots"
(a type of manned torpedo) and their crews for operations against Axis shipping in harbour, and was transferred with them to the Mediterranean in December 1942.
Their first mission, Operation Principal
, was undertaken in December 1942, the three boats taking their charges to targets around the Mediterranean. Thunderbolts objective was shipping in Cagliari, but the operation was not a success, and P311 was lost at La Maddalena
, her intended target.
A second operation against Palermo
harbour in January 1943 was more successful. On 2-3 January, the manned torpedoes entered the harbour and mined the ships there, sinking the cruiser Ulpio Traiano
and the freighter .
A further mission to Tripoli
harbour took place on 18 January. This was to prevent the Axis using blockships to neutralize Tripoli harbour, which was about to be occupied by the British Eighth Army.
Thunderbolt was sunk on 14 March 1943 off Sicily by the Italian corvette
Cicogna
, which had detected her and attacked with depth charges. All hands were lost and Thunderbolt settled to the bottom in 1,350 m of water.
broadcast a radio play about the Thetis disaster. The play was called Close Enough To Touch and was written by Liverpool writer Fred Lawless
. The play was also broadcast on BBC Radio Merseyside
and the BBC World Service
. In 1999, a play entitled HMS Thetis by Mark Gee in association with David Roberts, was performed at the Liverpool Bluecoat Chambers and at Birkenheads Pacific Road Theatre. The Play Starred John McArdle and also the newly employed First Year Apprentices from Cammell Laird Shipyard, (Paul Gillies, Dave Gill, Alan Lane, Chris Motley, Mike Jebb, Steve Taylor, Ollie Dodson, Stuie Dicken, Mark Poland, Ben McDonald, Tony Cummins, Barry Hayes, Chris Hall, Martin King, Graham Crilly, Billy Coburn, Matty Brassey,)
The cause of the loss of Thetis was also used in the 1968 film Ice Station Zebra
, where the character played by Patrick McGoohan
describes a method of sabotaging a submarine by blocking the tube test cocks, allowing the inner door to be opened with the outer door also open. In the film Ernest Borgnine
's character does sabotage the submarine using epoxy resin to block the test tube; the submarine, being American, has no Thetis Clip and is nearly sunk.
British T class submarine
The Royal Navy's T class of diesel-electric submarines was designed in the 1930s to replace the O, P and R classes. Fifty-three members of the class were built just before and during the Second World War, where they played a major role in the Royal Navy's submarine operations...
submarine
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...
of the Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...
which served under two names. Under her first identity, HMS Thetis, she commenced sea trials on 4 March 1939. She sank during trials on 1 June 1939 with the loss of 99 lives. She was salvaged, repaired and recommissioned as HMS Thunderbolt serving in the Atlantic and Mediterranean theatres until she was lost with all hands on 14 March 1943.
This makes Thetis one of the few military vessels that have been lost twice with her crew in their service history.
HMS Thetis
Thetis was built by Cammell LairdCammell Laird
Cammell Laird, one of the most famous names in British shipbuilding during the nineteenth and twentieth centuries, came about following the merger of Laird, Son & Co. of Birkenhead and Johnson Cammell & Co. of Sheffield at the turn of the twentieth century.- Founding of the business :The Company...
in Birkenhead
Birkenhead
Birkenhead is a town within the Metropolitan Borough of Wirral in Merseyside, England. It is on the Wirral Peninsula, along the west bank of the River Mersey, opposite the city of Liverpool...
, England and launched on 29 June 1938. After completion, trials were delayed because the forward hydroplane
Diving plane
A diving plane, also known as a hydroplane, is a control surface found on submarines which allow the vessel to pitch its bow and stern up or down to assist in the process of submerging or surfacing the boat, as well as controlling depth when submerged....
s jammed, but eventually started in Liverpool Bay
Liverpool Bay
Liverpool Bay is a bay of the Irish Sea between northeast Wales, Cheshire, Lancashire and Merseyside to the east of the Irish Sea. The bay is a classic example of a region of freshwater influence...
under Lieutenant Commander
Lieutenant Commander
Lieutenant Commander is a commissioned officer rank in many navies. The rank is superior to a lieutenant and subordinate to a commander...
Guy Bolus. Thetis left Birkenhead for Liverpool Bay to conduct her final diving trials, accompanied by the tug
Tugboat
A tugboat is a boat that maneuvers vessels by pushing or towing them. Tugs move vessels that either should not move themselves, such as ships in a crowded harbor or a narrow canal,or those that cannot move by themselves, such as barges, disabled ships, or oil platforms. Tugboats are powerful for...
Grebecock. As well as her normal complement of 59 men she was carrying technical observers from Cammell Laird and other naval personnel, a total of 103 men. The first dive was attempted at about 14:00 on 1 June 1939. The submarine was too light to dive, so a survey of the water in the various tanks on board was made. One of the checks was whether the internal torpedo tubes were flooded.
Lieutenant
Lieutenant
A lieutenant is a junior commissioned officer in many nations' armed forces. Typically, the rank of lieutenant in naval usage, while still a junior officer rank, is senior to the army rank...
Frederick Woods, the torpedo
Torpedo
The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...
officer, opened the test cocks on the tubes. Unfortunately, the test cock on tube number 5 was blocked by some enamel paint
Enamel paint
Enamel paint is paint that air dries to a hard, usually glossy, finish, used for coating surfaces that are outdoors or otherwise subject to hard wear or variations in temperature; it should not be confused with decorated objects in "painted enamel", where vitreous enamel is applied with brushes and...
so no water flowed out even though the bow cap was open. Prickers to clear the test cocks had been provided but they were not used. This combined with a confusing layout of the bow cap indicators — they were arranged in a vertical line with 5 at the bottom - 1,2,3,4,6, and then 5; and the shut position for tube 5 on the dial was in a different position from those of the other torpedo tubes — led to the inner door of the tube being opened. The inrush of water caused the bow of the submarine to sink to the seabed 150 ft (45.7 m) below the surface.
An indicator buoy was released and smoke candle fired. By 16:00, Grebecock was becoming concerned for the safety of Thetis and radioed HMS Dolphin submarine base at Gosport
Gosport
Gosport is a town, district and borough situated on the south coast of England, within the county of Hampshire. It has approximately 80,000 permanent residents with a further 5,000-10,000 during the summer months...
. A search was immediately instigated. Although the stern remained on the surface, only four crew escaped before the rest were overcome by carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
poisoning caused by the crowded conditions, the increased atmospheric pressure and a delay of 20 hours before the evacuation started. Ninety-nine lives were lost in the incident. In addition to the normal crew of 53, there were 26 Cammell Laird employees, another 9 naval officers, 4 Vickers-Armstrong employees and 2 caterers. The crew waited before abandoning the vessel until it had been discovered by the destroyer
Destroyer
In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from...
, which had been sent to search for it and which indicated her presence by dropping small explosive charges into the water.
The incident attracted legal action from one of the widows, who brought a claim of negligence against the shipbuilders, for not removing the material blocking the valve. Unfortunately for her the Admiralty successfully invoked Crown Privilege (now termed Public Interest Immunity
Public Interest Immunity
Public-interest immunity is a principle of English common law under which the English courts can grant a court order allowing one litigant to refrain from disclosing evidence to the other litigants where disclosure would be damaging to the public interest...
) and blocked the disclosure of, amongst other items, 'the contract for the hull and machinery of Thetis as evidence in court, on the basis that to do so would be 'injurious to the public interest'. The case is one of interest in English law, as the judges in this case accepted the Admiralty's claim on face value with no scrutiny, a ruling later overturned.
The Liverpool & Glasgow Salvage Association
Liverpool & Glasgow Salvage Association
The Liverpool & Glasgow Salvage Association was formed on 1 January 1924 from the merger of the Liverpool Salvage Association and the Glasgow Salvage Association....
were commissioned to salvage the sunken submarine. On completion of the salvage operation the bell from Thetis was presented to the Liverpool & Glasgow Salvage Association by the Admiralty. The inscribed bell is now on display at the Mersey Maritime Museum.
One further fatality occurred during salvage operations, when Diver Petty Officer
Petty Officer
A petty officer is a non-commissioned officer in many navies and is given the NATO rank denotion OR-6. They are equal in rank to sergeant, British Army and Royal Air Force. A Petty Officer is superior in rank to Leading Rate and subordinate to Chief Petty Officer, in the case of the British Armed...
Henry Otho Perdue died from "the bends"
Decompression sickness
Decompression sickness describes a condition arising from dissolved gases coming out of solution into bubbles inside the body on depressurization...
on 23 August 1939. On Sunday 3 September, Thetis was intentionally grounded ashore at Red Wharf Bay, Anglesey
Anglesey
Anglesey , also known by its Welsh name Ynys Môn , is an island and, as Isle of Anglesey, a county off the north west coast of Wales...
. It was the same day that war was declared. Human remains that had not already been removed by the salvage team were now brought out to a Naval funeral, with full honours.
The loss went beyond that of a submarine's crew. Among the dead were two naval constructors and several of the submarine team from Cammell-Laird; experienced designers and builders of submarines who would have been needed during the war.
The Thetis disaster was in marked contrast to the successful rescue of the survivors of , which had sunk off the coast of New Hampshire
New Hampshire
New Hampshire is a state in the New England region of the northeastern United States of America. The state was named after the southern English county of Hampshire. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Atlantic Ocean to the east, and the Canadian...
just a week previously.
HMS Thunderbolt
During the next 18 months, she saw service in the Atlantic: In December 1940 she was on patrol in the Bay of Biscay
Bay of Biscay
The Bay of Biscay is a gulf of the northeast Atlantic Ocean located south of the Celtic Sea. It lies along the western coast of France from Brest south to the Spanish border, and the northern coast of Spain west to Cape Ortegal, and is named in English after the province of Biscay, in the Spanish...
and on 15 December she encountered and sank the Italian submarine Tarantini.
In the autumn of 1942, Thunderbolt was converted with her sister ships and to carry two "Chariots"
Human torpedo
Human torpedoes or manned torpedoes are a type of rideable submarine used as secret naval weapons in World War II. The basic design is still in use today; they are a type of diver propulsion vehicle....
(a type of manned torpedo) and their crews for operations against Axis shipping in harbour, and was transferred with them to the Mediterranean in December 1942.
Their first mission, Operation Principal
British commando frogmen
Britain's commando frogman force is now the Special Boat Service , which is part of the Royal Marines. They perform various operations on land as well as in the water....
, was undertaken in December 1942, the three boats taking their charges to targets around the Mediterranean. Thunderbolts objective was shipping in Cagliari, but the operation was not a success, and P311 was lost at La Maddalena
La Maddalena
La Maddalena is a town and comune located on the island with the same name, in northern Sardinia, part of the province of Olbia-Tempio, Italy.-The town:...
, her intended target.
A second operation against Palermo
Palermo
Palermo is a city in Southern Italy, the capital of both the autonomous region of Sicily and the Province of Palermo. The city is noted for its history, culture, architecture and gastronomy, playing an important role throughout much of its existence; it is over 2,700 years old...
harbour in January 1943 was more successful. On 2-3 January, the manned torpedoes entered the harbour and mined the ships there, sinking the cruiser Ulpio Traiano
Capitani Romani class cruiser
Capitani Romani was a class of light cruisers of the Italian navy. They were essentially designed to out-run and out-gun the large new French destroyers of the Fantasque and Mogador classes. Twelve hulls were ordered in late 1939, but only four were completed, just three of these before the...
and the freighter .
A further mission to Tripoli
Tripoli
Tripoli is the capital and largest city in Libya. It is also known as Western Tripoli , to distinguish it from Tripoli, Lebanon. It is affectionately called The Mermaid of the Mediterranean , describing its turquoise waters and its whitewashed buildings. Tripoli is a Greek name that means "Three...
harbour took place on 18 January. This was to prevent the Axis using blockships to neutralize Tripoli harbour, which was about to be occupied by the British Eighth Army.
Thunderbolt was sunk on 14 March 1943 off Sicily by the Italian corvette
Corvette
A corvette is a small, maneuverable, lightly armed warship, originally smaller than a frigate and larger than a coastal patrol craft or fast attack craft , although many recent designs resemble frigates in size and role...
Cicogna
Gabbiano class corvette
The Gabbiano class corvettes were a group of 59 vessels built for the Regia Marina of Italy for service during the Second World War. They were built to a war-time design and intended for anti-submarine and escort duties.-Design:...
, which had detected her and attacked with depth charges. All hands were lost and Thunderbolt settled to the bottom in 1,350 m of water.
The Thetis clip
The torpedo tubes on British and Australian submarines were afterwards equipped with a "Thetis clip", one of the modifications introduced as a result of the accident. This is a latch which allows a torpedo tube door to be opened no more than a small amount in case it is open to the sea at the bow end. Once it is clear that no flooding will occur the latch can be released and the door fully opened.Appearance in the media
In 1997, BBC Radio 4BBC Radio 4
BBC Radio 4 is a British domestic radio station, operated and owned by the BBC, that broadcasts a wide variety of spoken-word programmes, including news, drama, comedy, science and history. It replaced the BBC Home Service in 1967. The station controller is currently Gwyneth Williams, and the...
broadcast a radio play about the Thetis disaster. The play was called Close Enough To Touch and was written by Liverpool writer Fred Lawless
Fred Lawless
Fred Lawless is a British writer from Liverpool who has written for television, radio and theatre.-Biography:Fred Lawless was born in Dingle Liverpool. He attended St Patrick's School in Toxteth before his family moved to Halewood. He later attended the Wade Deacon Grammar School in Widnes...
. The play was also broadcast on BBC Radio Merseyside
BBC Radio Merseyside
BBC Radio Merseyside is the BBC Local Radio service for the English metropolitan county of Merseyside and north Cheshire. It was the third BBC local radio station to launch on 22 November 1967 initially serving the south west of historic Lancashire....
and the BBC World Service
BBC World Service
The BBC World Service is the world's largest international broadcaster, broadcasting in 27 languages to many parts of the world via analogue and digital shortwave, internet streaming and podcasting, satellite, FM and MW relays...
. In 1999, a play entitled HMS Thetis by Mark Gee in association with David Roberts, was performed at the Liverpool Bluecoat Chambers and at Birkenheads Pacific Road Theatre. The Play Starred John McArdle and also the newly employed First Year Apprentices from Cammell Laird Shipyard, (Paul Gillies, Dave Gill, Alan Lane, Chris Motley, Mike Jebb, Steve Taylor, Ollie Dodson, Stuie Dicken, Mark Poland, Ben McDonald, Tony Cummins, Barry Hayes, Chris Hall, Martin King, Graham Crilly, Billy Coburn, Matty Brassey,)
The cause of the loss of Thetis was also used in the 1968 film Ice Station Zebra
Ice Station Zebra
Ice Station Zebra is a 1963 thriller novel written by Scottish author Alistair MacLean. This was the last of MacLean's classic sequence of first person narratives which began with Night Without End, and represented a return to that earlier novel's Arctic setting...
, where the character played by Patrick McGoohan
Patrick McGoohan
Patrick Joseph McGoohan was an American-born actor, raised in Ireland and England, with an extensive stage and film career, most notably in the 1960s television series Danger Man , and The Prisoner, which he co-created...
describes a method of sabotaging a submarine by blocking the tube test cocks, allowing the inner door to be opened with the outer door also open. In the film Ernest Borgnine
Ernest Borgnine
Ernest Borgnine is an American actor of television and film. His career has spanned more than six decades. He was an unconventional lead in many films of the 1950s, including his Academy Award-winning turn in the 1955 film Marty...
's character does sabotage the submarine using epoxy resin to block the test tube; the submarine, being American, has no Thetis Clip and is nearly sunk.