Add your custom HTML here
The Angled Deck
The original deck plan for aircraft carriers comprised a single 'runway' with the planes stored at one end. Thus planes were 'catapulted' into the air and away from the ship. On landing planes were brought to a stop with 'arrester wires' and/or the use of barricades. This meant that timing of the landing was crucial and accidents were not uncommon. The configuration of such aircraft carriers is exemplified in the two pictures below.
HMS Implacable
HMS Illustrious
DRFC's invention of the Angled Deck overcame this problem as illustrated below. Planes would take off on the straight runway as before but could land on the angled deck. This meant that in the event of a failure of the arresting gear, the plane could take off and come around and try again.
The first aircraft to be fitted, through modification, with an angled deck was the US Antietam, shown below, before and after modification December 1952.
The first vessel in the Royal Navy to be designed with an angled deck was HMS Ark Royal.
Below is DRFC's own account of how this important innovation in naval aviation came into being.
The Story of the Angle Deck (DRFC's own account)
Let us now take a look at the particular problem of deck-landing, as deck launching never posed quite as much difficulty; provided the power/weight/lift ratios were adequate it required no skill to get airborne.
Sometime around 1911, the first ever deck-landing was made on a platform fitted on the after deck of the cruiser USS Birmingham. A few years later, the RN's first experimental landing took place on the fore deck of the (then) battle cruiser Furious. From then on each navy followed different routes in putting this ability into regular operation. As soon as flush-deck carriers came upon the scene, the USN used transverse arrester wires and hooks to bring the aircraft to rest. Whereas the RN, after some faintly ridiculous attempts to use fore-and-aft wires and sideways hooks, decided that since a strong relative headwind could normally be counted upon, by ship's speed alone if necessary, the slow approach speed of aircraft at that time would enable them to come to rest without the need for any arresting device – and in the 1920s they did not even have brakes. And it is true that there were hardly any over-run accidents.
Aircraft of the second generation came along in the 1930s with higher landing speeds, but also with brakes, which gave a good safety margin – and shortly afterwards the RN adopted the USN arrester wire system. Up till then, this long-in-use mechanism had been "classified". I remember that in the film "Hell Divers", whenever Clark Gable landed on the deck, a sort of black strip came up on the screen at the bottom to conceal the hook catching the wires. Incidentally, it was through this that we first learnt of "dive bombing".
The next innovation – and here again the USN led the way – was the safety barrier. A collapsible net made out of heavy gauge wires was mechanically erected for each landing to stop any plane that failed to catch any of the arrester wires. This arrangement enabled the fore part of the flight deck to be used as a park for all places as soon as they landed, the barrier being lowered for each to taxi forward. This gave a far faster speed of operation that had been the case when each plane had had to be put below on the lift before the next one could be taken aboard. Thus refueling, rearming, and routine maintenance could be speeded up by being done in the parking instead of in the hangar below. This was the system used in both Navies through the war. Barrier crashes were frequent and could cause serious delays.
So these were the first two period of the art of deck landing – firstly, the early "clear deck" policy, when pilots strove to reduce the landing interval to a minimum by timing their arrival seconds after the lift had resurfaced. I remember being told off by my flight commander because I hadn't done better than fifteen seconds. Then came the " barrier" period, which lasted in the RN from 1939 to 1955; this too called for a high degree of timing and also team work by the deck handling groups.
Because of the need to make naval aircraft more robust than their RAF counterparts, they were always heavier and therefore of a lower performance. Ways to offset this disadvantage were constantly being sought, but without much success in Britain. The American Navy, however, did produce fighters like the Hellcat and the Corsair, which stood a fair comparison with shore-based types. But with the advent of the heavier faster jets, it soon became obvious that the dimensions of the carrier's deck would impose a limit to the standard of aircraft that could be operated. The inevitable increase in weight and landing speed of the jets would make it impracticable to retain the existing combination of arrester wires/barriers/and deck park without a drastic reallocation of the deck space required to absorb the much longer pull-out of the wires. A solution to this problem was in fact waiting in the wings to be discovered. However, its emergence was fortuitous, one might even call it "serendipitous".
Earlier I referred to the quest for ways to reduce the performance gap which naval aircraft were inclined to carry. Just before the end of World War II, one of the Farnborough scientists proposed a scheme which would enable carrier aircraft to dispense with the need for an undercarriage. By thus reducing the all-up weight, greater performance could be achieved.
Such was the idea, and it was taken seriously. A rubber mat placed over inflated rubber bags was to be fitted on the flight deck. The aircraft would be arrested as before by arrester wires, and then some sort of trolleying device would clear the mat for the next landing. Trials were first done of this device at Farnborough by using a Vampire jet with its wheels retracted. All went well, so the next stage was to fit up the trials carrier with the same gear. Which was soon done, and then sea trials took place, and proved successful, at least to the extent that the actual landing presented no particular problem. However, the procedure for manhandling the aircraft after it was arrested remained to be solved.
So the decision then had to be made on whether to fit this scheme into the next generation of carriers, which were then in the preliminary planning stage; and it soon became obvious that there was a world of difference between one-off trials and practical front-line operation. Two major points needed to be resolved – how were aircraft with no wheels to be dealt with ashore? If you provided them with special shore-going wheel kits you lost most of the weight-saving advantage in the basic design and anyway what about carrier aircraft who (sic)
were diverted ashore at short notice?
The one other big problem was how to ensure that speed of operation wasn't to be sacrificed by imposing some elaborate mechanical substitute for the previous easy routine of just taxying forward into the deck parks; and the vulnerability of the whole scheme was surely obvious.
My private opinion was that these two difficulties were insurmountable, but there was a strong desire on the part of the Naval staff and those who had been working on the scheme at RAE Farnborough to overcome them - stemming from a rather natural wish to justify the effort they had put into it.
On August 7 1951, a meeting was convened in my office in the Ministry of Supply. As Deputy Chief Naval Representative, it was my job to chair this meeting, and I spend some time over a sandwich lunch in preparing some possible ways of devising an operational layout that would help the task of movement after landing. I had a three-foot model of the Illustrious on my desk, and I kept trying to picture how this crazy deck could be installed to allow a reasonable speed of successive landings. I sketched a few ideas – putting the whole devise up on stilts with a deck park below, and other fanciful solutions, none of which looked really practicable.
And then right out of the blue it came to me – why not angle the deck about 10 degrees to port? You could still have the deck park forward in the usual place; no barrier would be needed except in, say, a lost-hook emergency, and you could even launch aircraft off the catapults while landing others. You would, of course, still have the problem of how to drag aircraft off the mat, but this would be a short haul sideways to clear the way.
At the meeting that afternoon, I decided to save up my angled idea until it had become clear to all that the paramount need in accepting the rubber mat idea was to retain the deck park. When it was coming to be seen that no simple solution was in the offing, I presented a large sketch I had prepared showing the mat and the four arresting wires offset 10 degrees to port. I admit I did this with something of a flourish, and was accordingly somewhat miffed at not getting the expected gasps of gratifying amazement. In fact, the meeting's reaction was a mixture of apathy and mild derision.
However, one of those present was Lewis Boddington, the civilian technical officer in charge of the Naval Air Division at the RAE, who had been conducting the whole flexible deck programme. After the meeting had closed, he asked to take another look at my sketch; and I remember he jotted in a few pencil lines to show that the port forward corner of the angled decks could be faired into the main edge of the deck. A small point, but it lodged in my memory.
The real breakthrough came about three weeks later. Lewis Boddington had also been considering the layout of the new Ark Royal's flight deck, and the way to be found to cope with the heavier and faster jets soon to enter service. Ark's sister ship and predecessor, the Eagle, was equipped with sixteen arrester wires and three different types of barrier (together with all their several hydraulic machines), and all this gear could only just cope with the first generation of (straight wing) jets. No way would such a layout be good enough for the newer types.
On 28 August 1951, Lewis wrote to the Deputy Director of Naval Construction, Mr Bartlett, copy to me enclosing a detailed drawing of the angled deck applied to the Ark Royal.
I have often thought it a curious reversal of roles – that I the experienced carrier pilot should think up a radical new theory and Lewis the scientist should be the one to propose its more immediate application.
Be that as it may, the immediate effect of our joint ideas was that it would pave the way for aircraft of much higher performance and weight to be used from a carrier's deck. And the clearing of all obstructions, barriers, deck park and so on, would mean that over-shooters could safely go round again.
The rubber deck scheme gradually faded into the background; and I helped to give it the coup de grace by writing a tongue-in-cheek piece of question and answer dialogue that pointed up its impracticability and (by now) irrelevance. I gave this paper a very selective circulation.
So far so good. Now it only remained to "sell" the idea to the Board of Admiralty. It so happened that the biennial Farnborough show took place in early September of that year, and as usual there were many American visitors, including a party of USN officers headed by a Vice Admiral Thomas Coombs.
As a matter of courtesy a small informal meeting was held in the Admiralty to exchange ideas with the USN on future developments, and during the meeting I thought to mention the Angled deck proposal. The visitors' reaction was not at all like that at the original meeting – they said very little but I clearly recall that they exchanged significant looks. A few weeks later we hear from Richard Smeeton in Washington the USN were already planning to angle the flight deck of the new giant carrier Midway, for a preliminary trial.
Meanwhile, Lewis Boddington and I had agreed to pool our participation in the project 50/50, and to press ahead with arranging suitable trials. We were both well qualified to do this as we were ex officio jointly responsible for the trials period program of the carrier used for such work in between training duties. So we decided to ask for the Triumph's flight deck to be marked with a landing path centre line set at a 10 degrees to port and since it was not practicable to reposition the arrester wires, the trial was to be limited to touch-and-go landings, arrester hooks not being lowered. These trials were completely successful, and the pilots concerned were most enthusiastic.
However, neither the news about the USN's intention to modify the Midway nor the results of the satisfactory trials in the Triumph persuaded the Admiralty to take any action other than to agree that the new scheme would be considered for fitting into the design of a new generation of Fleet Carriers (which, in fact, were never built).
Then in May 1953 the USS Antietam came upon the scene. The USN, whose Midway trials had been similar to ours in the Triumph, had done a quick-fix modification to this carrier, one of the Essex class. Limited structural alterations had been prefabricated ashore and were installed in record time.
As a quid pro quo for the fact that the idea was of British origin, and apparently because they knew the Admiralty were dragging their feet, the USN offered to send over the Antietam to give a demonstration of the new technique. Which offer was gratefully accepted, and the ship spent a week operating in the Channel, with the RN pilots participating. Lewis and I were specially invited on board, and were presented to all concerned as the two inventors. The success of this visit persuaded the Admiralty that retrofit action should be started forthwith.
The Centaur, already in service, was the first to be equipped with the angle and, best of all, the Ark Royal, then nearing completion, was modified too. Though only given a 5-degree angle instead of the hoped-for 10 degrees, the Ark was able to use the new technique to the full extent. Some years later, during a major refit, a full 10-degree angle was provided, and from then on all fleet carriers in all navies were so fitted.
During all these early developments, Nick Goodhart, who worked alongside me in the same Ministry of Supply office, was designing a scheme to provide pilots with visual indication of the optimum approach and landing path. His premise was that with the faster landing speed of jets and the touch-down stability of their new tricycle undercarriage it should be quite practicable to guide them right down on to the deck; and that this could be done by giving them a steady light source.
Red, green, and amber "sector lights" had been tried before, both at sea and ashore with the RAF. But Goodhart's (sic)
was to be rather more complex and accurate than that. He proposed a large mirror facing aft and reflecting a powerful light placed some fifty yards away. The correct 3-degree angle of descent would be shown by lining up the reflected light with a row of green lights providing a datum on the mirror itself. The guidance would be self-evident – above the green line meant "too high" and vice versa.
One minor snag was soon solved. To allow the pilot to see the light while he was still turning in towards the final approach, I suggested the mirror should be curved laterally. And of course it was obvious at the outset that gyro stabilisation would be essential.
Nick and I did the very first trial of the reflected light idea on the desk in our office. We borrowed a small vanity mirror from Miss Montgomery, our secretary, and propped it up at a simulated 3 degrees approach angle. Not having a small light, torch, or whatever, we then borrowed Monty's lipstick and stood it on end a few feet away. Looking at the lipstick in the mirror, we found it easy to keep it in view while we moved forwards and downwards. The oft repeated version of this is that we got Monty to do the test. Maybe we did, but only after we'd checked it out ourselves.
Although Nick's mirror landing device had been conceived by him before the birth of the Angle solution, it was blindingly obvious that the two revolutionary inventions would be complementary. Which of course is what happened. The actual detailed design and construction of the mirror was undertaken by RAE Farnborough, and its introduction into the Fleet was simultaneous with the new deck Angling. From then on the Batsman with his ping-pong bats was out of a job.
The result of these two fundamental innovations was that all Fleet carriers in the RN and the USN were rapidly converted – and some of the consequential benefits were instantly apparent.
1. The saving in arrester gear units and barriers – Ark needed only four wires and one (emergency only) barrier. The reduction in weight and the extra space that this conferred enabled more mess-decks to be fitted in, thus reducing congestion in living spaces.
2. Since landing accidents would obviously be far less frequent, fewer aircraft and spare parts would be needed so costs would be greatly reduced.
3. Similarly, death and injuries to aircrew and deck handlers could be kept to a minimum – with a big boost to confidence and morale, not to mention the saving in training costs.
4. As experience was gained of the new scheme, less obvious advantages came to light. New areas of parking, (abaft the island for instance); an added flexibility in the relative wind speed and direction, easier and faster deck handling, less wear and tear on the command, etc.
In short, the strains, dangers, and complications of trying to use a carrier's forward deck for several different purposes simultaneously were all largely removed by diverting the landing path direction away from the main parking and working area forward. A glance at the latest giant USN carriers shows how this concept has been fully exploited; though sadly it is past history for the RN."
