HMS DASHER underway.

DASHER was originally laid down at the yard of the Sun Shipbuilding & Dry Dock Company, Chester Pennsylvania, on March 14th 1940 as a 9,100 ton C3 type passenger-cargo vessel the RIO DE JANEIRO. She was Maritime Commission hull number 62, Sun number 189; One of four sister ships of the “Rio” class, RIO HUDSON, RIO PARANA, RIO DE LA PLATA, RIO DE JANEIRO ordered from the Sun Shipbuilding & Dry Dock Company for the US operator Moore-McCormack Lines to operate on the lines South American routes. The “Rio” ships had 17,500 tons loaded displacement, and loaded draft of 27 feet 4 inches. Each ship was designed to accommodate 196 passengers and have 440,000 bales cubic feet cargo space, including 40,000 cubic feet for refrigerated cargo. .

The RIO DE JANEIRO was launched on April 12th 1941 and christened by her sponsor Senhora Alzira do Amaral Peixoto, daughter of the President of Brazil. All four “Rio” ships were to be purchased by the US Navy for conversion into a modified 'Long Island' class Auxiliary Aircraft Carrier; RIO DE JANEIRO was requisitioned on May 20th 1941 while still fitting out, and was delivered 80% complete to the US Navy on November 22nd 1941 at the Tietjen and Lang Dry Dock Co., shipyard, Hoboken, New Jersey for conversion.
 

Conversion to a warship: May 1941 - November 1941

Her conversion consisted of installing a lightweight wooden flight deck on a truss work superstructure which covered 70% of the ships' length, fitting a small enclosed hangar beneath the aft of the flight deck to be serviced by a single lift. Like her sister ship BITER, DASHER was completed with a small island superstructure.

She arrived at US Navy Yard New York at 12:00 on July 1st 1942 and was officially delivered to the USN at Hoboken Navy Yard, where she was to complete her fitting out, dry-docking for the installation of Asdic gear, installation of radar and completion of outstanding contractor items. She was also to receive repairs and alterations to her main engines. She was transferred to Admiralty custody on July 2nd and commissioned into the Royal Navy as HMS DASHER (D37), retired Vice Admiral R. B. Davies CB, DSO, and AFC, RN in command.

Vice Admiral Davies had been appointed to the ship in February 1942 and was tasked overseeing her completion and accepting her on behalf of the Admiralty. Once commissioned he was to oversee her work up in preparation for her assuming operational duties.

On completion of her builders and Admiralty Sea trials DASHER put to sea on the morning of July 24 for live gunnery firing followed by flying exercises in Long Island Sound early on the 25th. The four Swordfish of 837 Torpedo, Bomber, Reconnaissance squadron flew out to the ship from the U.S. Naval Air Station at Floyd Bennett Field, Brooklyn in New York to do a period of Deck Landing Training (DLT); this was to give both the pilots and ship’s departments involved in flying operations experience of landing and taking off from the carrier. The squadron had formed at RNAS Palisadoes, Jamaica on May 1st and had departed for USNAS Floyd Bennett Field on July 7th to join the ship. The DLT session did not go well the squadron had only two serviceable aircraft by the end of flying; Swordfish DK763 crashed on landing and went over the side intro the sea, the pilot was rescued OK. A second (unidentified) machine, hit rounddown knocking off its undercarriage, and broke in two on hitting the deck, the pilot Sub-Lt J. L. Newman, RNVR was unhurt.

While alongside at Pier 2, Hoboken on the 29th, an explosion occurred in DASHER’s engine room injuring two men. On completion of her work-up command passed to Captain C. N. Lentaignes RN on August 6th 1942.

At New York she embarked 20 Grumman Wildcats from the RN Aircraft Storage Unit at USNAS Floyd Bennett Fieldfor delivery to the UK. She anchored in the harbour on August 18th to await the ships of Convoy AT.20 which was due to sail for the Clyde, via Halifax the next day. At 04:30 on the 19th DASHER experienced more engine trouble and did not sail with the convoy.

She did not sail until August 25th and proceeded to Boston to join convoy BX.35B on the 28th. She arrived at Halifax on August 30th and joined convoy HX.205 for passage to Liverpool. DASHER detached from the convoy off Ireland and proceeded to fly off a837 squadron to RNAS Campbeltown on September 10th. She arrived on the Clyde on September 11th to unload her ferry load of aircraft.

HMS DASHER at anchor, there are two Swordfish parked on her flight deck, The aft lift is down for ventilation.

Working up and Operation TORCH

DASHER spent the next month exercising in the Clyde training areas. On October 15th she embarked the 6 Sea Hurricanes Mk.IIc of 891 squadron which transferred from ARGUS after three days of DLT on the training carrier. She now began flying training to work up both ship and squadron. DASHER left the Clyde on the 27th in company with the Carrier ARGUS, Cruisers JAMAICA and DELHI, and four destroyers bond for Gibraltar for Operation TORCH. She embarked another 6 Sea Hurricane Mk.IIc of 804 squadron from RNAS Belfast making her aircraft complement up to 12.

On October 30th while on passage her port main engine failed, her speed was reduced to 13 knots but she continued in company because there were no escorts spare to allow her to detach. The reduction in speed delayed their arrival at Gibraltar until November 3rd, two days behind schedule It is unclear whether repairs could be made at Gibraltar before DASHER was due to sail in company with Destroyers AMAZON, ACHATES, ANTELOPE, BRILLIANT, BOADICEA and WIVERN, at 21:30 on November 5th (D -2) to rendezvous with assault Convoy KMF0.1 at 22:30 on passage into the Mediterranean.

On November 7th the convoys, now in the Mediterranean began to form up into their assault groups. There were three Task Forces involved in Operation TORCH; Western Task Force, aimed at Casablanca, Centre Task Force, aimed at Oran and Eastern Task Force aimed at Algiers DASHER was allocated for duty with Central Naval Task Force to provide cover for landings at Oran on November 8th. The carrier force comprised of BITER (800 15 x Sea Hurricanes), DASHER (804 & 891 12 x Sea Hurricanes) and FURIOUS (801 & 807 12 x Seafire each, 822 9 x Albacore.)

At Oran landings by the Central Task Force were to made along a 52 mile stretch of coast line divided into four sectors; ‘R’, ‘X’, ‘Y’ and ‘Z’. The Carrier Force was to focus on Landing sector ‘Z’. FURIOUS, BITER and DASHER were on station at position CF, 25 nautical miles north of Oran on the morning of November 8th and flying operations began at 05:00.

The primary mission was a strike by eight of Albacores launched from FURIOUS, escorted by six Hurricanes from 804 Sqn, DASHER as top cover, and six from 800 Sqn, BITER as close escort, to attack the airfield at La Senia. The strike force departed at 06:00 The Albacores were attacked by Dw520 fighters over La Senia as they began their attack dive, but they destroyed 46 aircraft on the ground despite the leader, going down in flames in his first dive. Three Albacores failed to return, but two of the crews were safe; two others returned with damage from French fighters. At 06:30 10 Seafires from 807 Sqn launched from FURIOUS to strafe the Vichy French airfields at Tafraoui and La Senia, despite heavy flak and enemy fighter they set fire to several aircraft at each and damaging many more.

The loss of the Albacores was blamed on the pilots of 804 Sqn; as Top cover for the strike they failed to spot the French fighters and so took no part in the dog fights that ensued with the low cover. It was later reported that they were not sufficiently worked up before joining DASHER for the operation. This lack of training was further highlighted on their return leg from the strike; 8 of her 12 aircraft failed to return to DASHER; 3 from 891 Sqn, AM288 (was shot down by a Dw520 over La Senia airfield and JS332 failed to return, both pilots were safe; JS226 crashed killing the pilot Sub-Lt D. C. Greenhill, RNVR. 5 aircraft from 804 failed to find DASHER on completion of the strike, although they found FURIOUS they failed to contact her for directions and eventually flew back inland, one, AM277 crashed on beach at St. Leu, Algeria the other 4 safely landed on a flat Salt lake, they were flown off later when fuel was found. DASHER now had only 4 serviceable Sea Hurricanes and was assigned to fly Combat Air Patrols (CAP) over the force and the beach. BITER too switched to CAP over the beaches while Seafires from FURIOUS flew CAP over the airfields at Tafraoui and La Senia.

The lift bringing down a Hawker Sea Hurricane from the flight deck. The Sea Hurricane did not have folding wings so took up considerably more hangar space and limiting the number embarked. (Picture taken on sister ship AVENGER)

One of BITER’s 800 squadron Sea Hurricanes, AG334 flown by Sub-Lt R. M. Crosley, RNVR was ordered to land on DASHER on returning to the carrier force from a Beach Patrol sortie as BITER had a fouled deck; on landing he entered the barrier. A flight of five aircraft from 800 Sqn was launched from BITER to conduct patrols over the beach at Arzeu; after 2 hours of fruitless patrolling they headed back to BITER, all but one were ordered to land on DASHER, the five aircraft were to remain on her in lieu of 804 and 891 aircraft which had all failed to return from the strike mission.

Flying ceased on D-Day at 17:00, DASHER had 9 Sea Hurricanes on-board, 1 from 804 Sqn, 3 from 891 Sqn. And 5 from 800 Sqn; on withdrawing from the area maintenance crews worked overnight to maximise the number available for operation on D +1.

Flying commenced at 07:00 on D +1 FURIOUS had 16 serviceable aircraft, BITER 7 and DASHER 6. The two CVEs were task to provide CAP sorties throughout the day over ‘Z’ beach and Arezu harbour while 10 Seafires from FURIOUS did a sweep of landing grounds at Mostaganem, Blanche, Reizana and Sidi Be lAbbes. No Vichy French aircraft were encountered. FURIOUS launched a strike of 3 Albacores escorted by 4 Seafires at 12:40 at the request of the command ship LARGs to attack a Vichy French Artillery position at a map reference passed to the ship by a forward air control officer. On arrival on target nothing was visible so the bombs were dropped on the co-ordinates and the aircraft returned to the ship. FURIOUS flew one last sortie, a 3 Seafire recognizance flight at 15:00, and when DASHER’s last CAP aircraft landed on at 17:00 the Carrier Force withdrew, their role in the landings complete. The three carriers arrived at Gibraltar on the evening of November 10th.

During Operation TORCH the Carrier Force had flown 141 sorties; FURIOUS flew 73 (62 Fighter and 11 Bomber), BITER 40, and DASHER 28. A total of 25 aircraft were lost; 5 Albacore, 7 |Seafire, 12 Sea Hurricane and 1 Fulmar. 6 Sea Hurricanes were seriously damaged in barrier crashes.
 

In Dockyard Hands November 20th 1942 – January 26th 1943

DASHER and BITER sailed for the UK as part of Convoy MKF.1X which depart Gibraltar on November 12th, DASHER detached and proceeded to Liverpool on the 19th to enter a commercial Dockyard on the 20th for engine repairs and modifications to be carried out.

On January 9th 1943 DASHER was transferred to Home Fleet Command. Modifications were primarily the fitting of an air defence operations room to improve her fighter capabilities. She remained there until mid-January 1943 when she put to sea to test her engines and to embarked 3 Swordfish of 837 Sqn 'D' flight which flew out to join her from RNAS Dunino on January 22nd. She sailed for the Clyde on January 26th, arriving there the following day top begin a work up period.
 

Allocated for Operation F E, escorting Russian convoy J W 53

A new squadron joined the ship on February 2nd, the 6 Swordfish of 816 Sqn flew out from RNAS Machrihanish. She conducted anti-submarine exercises with training submarine OBERON on February 5th before sailing for Scapa escorted by EGGESFORD on the 7th, arriving Scapa on the 9th.

DASHER was assigned to Force ‘A’ for Operation F E, part of the covering force for Russian bound Convoy J W 53 which sailed from Loch Ewe on February 15th. She left Scapa on the 16th screened by Destroyer BLANKNEY, IMPULSIVE and LEDBURY for Seidisfiord, Iceland to rendezvous with other elements of Force A. Once at sea she embarked a detachment of 5 Sea Hurricanes of 804 Sqn from RNAS Twatt to provide fighter cover.

DASHER off Akureyri, Iceland in February 1943 as part of Force 'A' to cover convoy JW53. Photo is taken from the deck of the cruiser BELFAST. Photo: From the collection of Sub-Lieutenant (A) John Vallely RNVR.

Bad weather plagued the ships on passage and on reaching Seidisfiord on the 18th only BLANKNEY and LEDBURY were able to enter the harbour, BLANKNEY with weather damage; DASHER and IMPULSIVE unable to enter Seidisfiord owing to a gale, proceeded north to Akureyri in company with SCYLLA and destroyers ECLIPSE, FURY, INTREPID, IMPULSIVE and ORKAN . They hove to off Akureyri to weather the gale on the 19th. They entered the harbour on the 20th many with weather damage. Owing to her weather damage, DASHER unable to take any further part in operation and she sailed for Scapa on the 22nd escorted by BLANKNEY and LEDBURY, arriving on the 25th. Both embarked squadrons were disembarked to RNAS Hatston on the 26th. DASHER was to go to Dundee for repairs and she sailed from Scapa on February 28th escorted by Destroyers NEWARK and WELLS.
 

Under repair and a new Commanding officer

On March 1st DASHER entered a Dundee Dockyard to receive repairs. The work took nearly three weeks to complete, during this time Captain L. A. K. Boswell, DSO, RN assumed command on the 12th.

On putting back to sea on the 20th she proceeded to Scapa escorted by Destroyers INGLEFIELD and ORWELL, arriving on the 21st were she re-embarked the 6 Swordfish of 816 squadron from RNAS Hatston. The next day she left Scapa escorted by BLANKNEY for the Clyde on temporary allocation to Western Approaches Command. She arrived at Greenock on March 23rd. She now embarked a detachment of 3 Sea Hurricanes of 891 Sqn from RNAS Machrihanish and began a programme of flying training and exercising in the Clyde area. One of the Sea Hurricane joining the ship, NF680, stalled over the deck and bounced into the barrier, the pilot Sub-Lt I. D. Scanes RNZNVR was unhurt.
 

Catastrophic internal explosion sinks DASHER

On Saturday March 27th 1943 DASHER spent the day carrying out flying exercises. At 16:40 Captain Boswell, made an announcement over the ship's Tannoy system that flying for the day was completed and that shore leave would be granted on arrival back at Greenock. Shortly after this there was an explosion which shook the ship, followed almost immediately by a second tremendous explosion. The officers on the bridge witnessed the ship's two ton aircraft lift, fly about 60 feet into the air before it fell into the sea on the port side and the flight deck buckled along the length of the hanger below it.

DASHER lurched drunkenly before settling by the stern as she began to take on water. The now exposed lift shaft was belching thick black smoke and flames. The ship quickly lost head way as the engines had stopped, and all electrical power was lost. A fierce fire had broken out in the aft end of the hanger, another in the engine room, the Fleet Aim mess deck had been destroyed in the explosion and the ship was flooding fast. Men not part of the duty watch and in their mess decks were plunged into disorienting darkness were they stood. Those that could make tier way out of the ship began abandoning ship, jumping overboard from any point of exit they could reach as the fires in the hanger deck grew more intense and the ready use gun ammunition began to 'cook off', in addition she carried six torpedoes and 104 depth charges. By 16:48 DASHER had sunk by the stern, her flight deck almost vertical as she vanished beneath the waves 5 miles south off Cumbrae Island.

The closest vessels to the scene of the disaster were the minesweeping Trawler SIR GALAHAD, four miles to the north and the Radar Training Ship ISLE OF SARK, five miles to the south; both ships responded immediately in the knowledge that hundreds of men were swimming in the cold waters of the Clyde, many possibly injured. Other vessels were despatched from ports and harbours long the Clyde to assist. Two merchant vessels in the area at the time of the explosion, the SS CRAGSMAN and the SS LITHIUM, also made heroic rescue efforts; the CRAGSMAN rescued fourteen survivors while the LITHIUM picked up a total of sixty survivors. Burning fuel oil and aviation fuel had claimed the lives of many of those in the water, hypothermia yet others; in all 379 men out of the 528 men on board DASHER perished. 36 officers, including the C.O., and 113 ratings were rescued.

This disaster was not made public knowledge; the Admiralty deliberately put a black out on any press releases, next of kin were informed of hitter loss but the survivors were initially quarantined. The loss was promulgated in signals traffic classified as ‘most secret’, later on the 27th, and again on April 3rd. This secrecy was in part to stop the Germans learning of her loss – at his time she was one of only three ships of her kind in service with the RN, with ARCHER and BITER, a fourth AVENGER had been sunk the previous November. The first of the improved Attacker class CVEs was just about to reach the UK. And also to allow for an investigation into the cause of the explosions; enemy action was quickly discounted so the real cause had to be found. The suggestion that she had been sunk was raised in the U.S. three weeks later, a crew member had been incompact with a friend in New York mentioning casualties by name. It is not clear when, or if the news of the loss of DASHER was released.

A board of enquiry was quickly assembled and this convened on-board DASHER’s sister ship ARCHER on the morning of Tuesday March 30th. Twenty six survivors were also present on ARCHER to give evidence. The 5 board members toured ARCHER’s hangar, engine room, petrol stowage and petrol control room, as well as the add Depth Charge Magazines. After two days of hearing evidence the board departed ARCHER. The enquiry established that the initial explosion was caused by the ignition of petrol probably due to a cigarette or faulty light switch; at this time all 6 Swordfish and 2 Sea Hurricanes were in the hangar, 2 Swordfish were being refuelled, 1 Sea Hurricane remained on the flight deck the Petrol control Room was open and manned for fuelling aircraft, ‘No Smoking’ signs were correctly displayed but no sentry was posted. Evidence of petrol leakage into inaccessible and unsafe areas was given and it was established that access hatches to the FAA mess and engine room shaft tunnel were open. They concluded that the initial explosion occurred in either the Petrol stowage area or the aft Depth Charge Magazine (containing 68 Depth Charges) which ware adjacent to each other and was caused by a build-up of petrol vapour. [It is assumed, but not stated, that the second explosion was the petrol stowage tanks themselves going up; she carried up to 85,000 gallons of aviation petrol.

Further investigation into the standards for safety of both petrol and explosives storage on U.S. built CVEs found these were to be below those used on British Carriers. As a result all US built Escort Carriers which were in service and those under construction were to be modified. Particular attention was paid to the Aviation fuel distribution system, ammunition storage and hangar fire containment systems. The changes reduced the aviation petrol carried to 36,000 gallons. See Burrard Dry Dock modification page for details of these alteration]

Last modified: 30 June 2022

Primary information sources

Additional sources:
 

Fold3.com various documents including;

Admiralty War Diaries
Norfolk Navy Yard War Diaries
Mew York Navy Yard War Diaries
Miscellaneous documents