Catapults on RN WW2 Carriers

[MightyGem]

I've recently seen a documentary (Ch 4, I think) which stated that RN Aircraft Carriers were equipped with catapults by the end of WW2. Having always had an interest in carriers and read a few books, it's the first I've heard of catapults on WW2 carriers.

Anyone have any info?

[astir 8]

I've never heard of it - but I've heard a lot on Channel 4 which is b****cks.

What I find facinating is that it seemed to have taken so long to invent the steam catapult - given that someone (Stevenson/Brunel?) invented the "atmospheric railway" in the 1800's and that steam boilers had been around for even longer - all it needed was to put the two together!

[sycamore]

carrier catapults

The first US catapult shot was on Nov 18,1922 , by Lt. Cdr K. Whiting. It was a seaplane, so was probably fired off from the side. Early catapults were hydraulic, but the RN were using steam cats. to fire off Seafires in 1941.
I found the info on a " google" search, and it of course is US biased. I always believed that the RN were the first to use "cats", and steam driven ones too, but I can`t find a site.
Just like most good inventions , like angled decks, mirror landing -sights, ski -jump ramps, we pass them over the pond so history gets changed!!

[sycamore]

catapults

Sp.2

Apologies, you are probably correct,as I was looking at a picture of a Seafire 17 going off TRIUMPH and superimposed dates.First SPITFIRE arrested landings, free t/o, and catapult t/o were on Christmas 1941, by Lt-Cdr P Bramwell, Mk 5 b, BL676 off ILLUSTRIOUS,. 5b`s were then modified and became Seafire 1b

Sorry ,no further details on RN history.

[Out Of Trim]

The final, post war, carrier invention was the steam catapult. Aircraft had, up until this time, left the carrier’s flight deck by a number of different means, the most obvious being the free take off, which was still being employed by the Skyraider AEW1 in the 1950’s. Rocket assisted takeoffs (RATOG) was also used quite effectively by aircraft participating in Korean operations during 1950-1953.

Catapults had been around since the 1930’s (when they were fitted to the carriers Glorious and Courageous) however these early devices were powered either by compressed air or cordite. It was Commander C C Mitchell RNVR who first suggested taking steam from the ship’s main boiler to power the catapult. Trails on HMS Perseus during 1950-1952 showed an aircraft weighing 30,000lbs could be launched with a speed of over 90 knots, which was a considerable increase over the air hydraulic catapults then in service. The steam catapult also proved to be considerably more reliable. By the time the RN's last fixed wing carrier was retired in 1978 (HMS Ark Royal), the steam catapult was regularly launching aircraft weighing over 60,000lbs at 110+ knots.

It is only now that the Americans are looking to replace Steam Catapults, on their next generation carriers, with electromagnetic catapults.

[flyboy6876]

I seem to recall that there were Sea Hurricanes launched from catapults mounted on merchant ships as early as 1941 when on the Murmansk run. In fact, if I remember correctly some of the later merchantmen were modified with a short flight deck to allow these Hurricats to land back on, rather than lose the aircraft after one flight as happened with the originals. I think these catapults may have been rocket powered.

It would not have suprised me that they had then taken this a step further and used cats on aircraft carriers.

[astir 8]

I've seen the catapult on the wreck of the M2 submarine off Portland.

It seems to involve a lot of nasty pulleys & cables and a large (presumably compressed air) operated ram.

It's very easy to believe that the power of this type of catapult would be very limited.

I understand that catapult trials ("frictionless takeoff") were carried out on heavy bombers at Harwell before WWII.

Anyone know anything about those trials?

[Kermit 180]

CAM Ships and catapults

Merchant ships carrying Hurricanes on catapults on the UK-Murmansk convoys were called CAM (Catapult Armed Merchant) ships. These catapults were indeed rocket powered, although I haven't seen a CAM ship with a small deck for recovery of the fighter after action. These ships were developed as a result of there not being enough escort carriers to go around at the time for the convoys. The first ones must've given the German torpedo bombers and long range maritime aircraft a shock, although the Germans later developed strategies for tricking the CAM fighters into launching and chasing a decoy. After the Hurricane had run out of fuel or ammunition and the pilot had ditche dor baled out, the main attack waves were brought into play.

If any of you are interested, heres a link to some photos of HMS Triumph and RN Fireflys, Seafires and others I have, I have used these on PPRuNe before, so apologies if youve seen them before.


Also, you might be interested in Fleet Air Arm
HMS Triumph

Kermie

[Windy Militant]

astir 8

The Harwell Catapult has recently been dug up as part of the ongoing site reclamation project .
Harwell Catapult

The Catapult was Pneumatic and used a large number of Kestrel engines as both motive power and compressors. The Oxford group of the PFA had a lecture from the Harwell PR officer about the Harwell site up to the time that The AERE was established and during this a number of drawings and pictures of the catapult were shown although the exact details of how it was operated have been lost it was an impressive bit of engineering. If you contact Harwell PR office they may still have copies of the edition of the house magazine "The Echo" which featured the history of the catapult.

[tony draper]

I thought the aircraft carried by the M class sub was a seaplane?
It was pulled from the deck hangar medivac the sub submerged and the aircraft took off from the sea and was recovered in a similar way. You could be correct of course,I had a picture of the M2 years ago I could be mistaken but I'm sure it had floats.
There was a documentry about the search and location of other M class sub recently, it carried a 12 inch gun on deck.

[Iron City]

Catapults in the modern (steam) sense are a British invention. Best reference book I've found for general naval aviation is title "Wings over the Sea" British author (can'tremember name,(book packed away) , global coverage Brit and US emphasis but lots of other good stuff.

No catapults in regular use on US carriers until very late/after WW II.

The armed merchantmen CAM aircraft were almost completly Hurricanes and all missions were one way unless a carrier or airfield was within range (in which case why launch the CAM Hurricane). The catapult was rocket powered and produced by the MoD department that employed Nevil Schute and other "inovative" folks.

[MightyGem]

Thanks to Speechless 2 and the rest of you for your input.

[astir 8]

You're quite right, the M2 aircraft was a floatplane and was recovered after landing by crane

But it was launched off the foredeck by catapult

It was a tiny aircraft - the Parnall Peto and maybe couldn't get off the water with pilot and observer on board.

There was an excellent article on it in "Aeroplane Monthly" a few years back.

Pity they forgot to close the hangar door when the submarine dived though.

[chippy63]

Just curious, did the Seafire have a strengthened undercarriage when on regular carrier operations?

[twenty eight]

Picture of M2 launching it's Parnell Peto aircraft

[Milt]

Would you call the contraption a catapult that launched Walrus biplane seaplanes from midships of the pre WW2 cruisers.

The aircraft would subsequently surface beside the ship and be lifted by crane back on to the launching contraption for reuse.

Perhaps they had to wind up the rubber bands again!!

[JDK]

I've recently seen a documentary (Ch 4, I think) which stated that RN Aircraft Carriers were equipped with catapults by the end of WW2. Having always had an interest in carriers and read a few books, it's the first I've heard of catapults on WW2 carriers.

Er, and at the start of W.W.II as well?

Ark Royal is most obviously equipped; note the two tracks and the dip on the flying off deck between them on the bow. I suspect the query comes from a change in the type (steam, not mechanical?) as it's not a big deal that they were there.

HMAS Manoora, and all the County Class Cruisers of the RAN and RN had catapults for Seagull V and Walrii in '39 (Gone, replaced by radar, and for more room for ack ack in '43.) among many others, including most British Battleships. There were catapults on Japanese and American ships and carriers throughout W.W.II and planned for the German carrier Graf Zepplin.

The Germans were firing Dornier Wals, and later Do18 and others as mailplanes from merchant ships in the thirties; to extend the range across the Atlantic.

Farnborough had a catapult (or 'accelarator') for tests in the thirties; see the British Pathe website for footage of the Seagull V prototype being fired off. Used to test RN aircraft and other items.

The Avro Manchester (and IIRC) the other British heavy designs were stressed for catapult (or 'accelarator' again - It's like 'chassis' not 'undercarriage' or 'gear') launch, as the theory pre-war was that was better than putting tarmac on grass airfields.

These were all cordite fired, except the Carrier examples. Part of the Walrus launch process was the pilot was shown, on a tray (drinks sir?) the charge bag before it was loaded in the chamber, to 'prove' the 'plumbers' (torpedo chaps who looked after these things - not, surprisingly, 'guns') weren't going to screw up. Din't always work though. They were'nt regarded as 'rockets' at the time. I think they landed after (in a 'turn slick') rather than surfacing like a duck! The Peto and M2, worked like that, as previously stated.

The big change was the hooks and strop arrangement we are familiar with today. In W.W.II the RN and I believe the rest used a bloody great trolley (like a shopping cart!) that the a/c had to be attached to to be fired off, and the trolley stopped with a 'bang' at the end of the track, to be wound back and reused. Most clumsy, and there's few pics of these in action on carriers - perhaps they were a secret weapon!

I've never come across a reference to a landing deck on a CAM ship; though unhooked Hurricanes did land on the carrier HMS Glorious when escaping Norway. Despite this, Glorious was sunk on the way home while learning how to fight a modern war, with 'Bing' Cross and his brave pilots. Flyboy, you may have confused them with Escort Carriers which had Swordfish and Wildcats - but not Hurricanes. I don't think it's likely without a hook, gear, room and a trained captain, but stranger things...

[Schiller]

1. There were two types of merchant ships carrying aircraft during WW2, CAM ships and MAC ships.

Catapult Armed Merchantmen carried a single Hurricane aircraft on a rocket-powered catapult which could be launched on a one-way trip to attack enemy spotters (usually Condors). As far as I know they were only ever employed on convoys to Russia. Brave pilots.

Merchant Aircraft Carriers were oilers or grain-carrying ships that had their upperworks removed and replaced with a 460-foot long flight deck. They had arrester gear and a barrier, but no catapult, and 3 or 4 Swordfish aircraft. They carried their normal cargo and were used on North Atlantic convoys on anti-submarine patrols: no convoy thus equipped lost a ship to submarines. There's an excellent book "Bring Back my Stringbag", by John Kilbracken who commanded a Swordfish MAC flight.

2. The primary use of the catapults on WW2 carriers was to effectively increase the number of aircraft that could be launched on a strike. Ranged aircraft could be launched by catapult (often known as "accelerators") until the deck length ahead of the range allowed for the much faster launching of the remaining aircraft by free take off.

3. Great things, steam cats. As an exchange USN officer in 800 Sqn explained to a visiting group of finishing school girls once, "It doesn't half drag your f*resk*n back". It was the only thing the girls found interesting during their entire tour of the ship.

[henry crun]

"As far as I know they were only ever employed on convoys to Russia."

Not so Schiller.

There was a gap in the Allies air cover in the mid Atlantic.
The Condor had the range to cover that area and report the position of convoys for their U-boats.

CAM ships were introduced to deny the Condors the free range they had previously enjoyed in that mid Atlantic gap.
That is where most of them were used.

[Perimeter_Fence]

I recently spoke to an ex-FAA pilot who flew Wildcats off HMS Searcher ....the first ten or so aircraft were fired by catapult and that made space for the others to take off "normally".