Floating Aerodromes

This chapter discusses the evolution of the aircraft carrier, which, although it has been a unit of the Royal Navy for more than twenty years, is still an experiment

THE NAVY GOES TO WORK - 5

READY TO TAKE OFF from the flight deck of H.M.S. Courageous. Machines detailed for flying are brought up from their hangars by lifts and placed one behind the other. The ship’s head is then put into the wind and her speed considerably increased. The nets seen at the side of the deck are for the use of the personnel when the ‘planes take off or alight. H.M.S. Courageous was built in 1915 as a cruiser under the Emergency War Programme. Her conversion to an aircraft carrier was carried out between 1928-1930 at a cost of £2,025,800. She is 786 feet long, has a displacement tonnage of 22,500, a speed of 30½ knots, and can accommodate forty-eight aircraft.

THE term “aircraft carrier” is a convenient if somewhat inadequate label for a ship that is a mobile floating aerodrome, self-contained in every way and almost as well equipped for the operation and maintenance of aircraft as a first-class aerodrome on land. The modern carriers of the British and other navies are marvels of ingenuity and easily the most fascinating men-of-war afloat. The smartness and efficiency with which flying operations are conducted on board a carrier of the Royal Navy must be seen to be believed. Considering that barely nineteen years have passed since a British aviator first landed on the deck of a ship at sea, the progress made can only be described as wonderful.

Great Britain has always been the pioneer in the development of the aircraft-carrier - a type which has enlisted air power in the service of long-range naval defence and which has introduced the third dimension into naval tactics and strategy. It may not be generally known that the Navy Estimates for 1914, introduced six months before the war of 1914-18, provided £81,000 for a new ship “for carrying seaplanes”. This was the Ark Royal (now Pegasus), a merchantman bought and converted to her new role. She had accommodation for ten seaplanes, a flying-off deck 103 feet in length, and cranes for hoisting machines inboard when they alighted, alongside.

On the outbreak of war the old cruiser Hermes and six cross-Channel steamers were hurriedly equipped with seaplane hangars and cranes, and from one of these improvised carriers, the Engadine, a seaplane took off to reconnoitre for the Battle Cruiser Force at Jutland on May 31, 1916. As the war progressed and the value of air scouting became more evident, it was decided to adopt larger carriers. The Cunard liner Campania was taken over, rebuilt and provided with a 230-ft forward flying-off deck. From this deck seaplanes were launched with wheeled trucks under their floats, the trucks being detachable by the pilot once he was in the air. Later they were arranged to be automatically released by gear on the deck.

PERSONNEL OF THE ROYAL AIR FORCE, in HMS Furious. A Wing Commander is responsible, under the captain of the ship, for all flying work in an aircraft carrier. Each plane is constantly in touch by wireless telegraphy with the ship and with the leading machine of its squadron. When a flight is finished the carrier is steamed at very high speed, and from a point high up in the bows a jet of white vapour is poured out. The ship’s helm is moved until the vapour streams down the deck in line with the white painted band running fore and aft. A pilot then knows that the ship is running dead into the wind, and, at a signal from the Wing Commander, lands his plane on the stern of the carrier.

By this time the superiority of aeroplanes over seaplanes had been demonstrated, but there remained the problem of providing “landing-on” facilities for the aeroplane. In March, 1917, therefore, the big “hush hush” cruiser Furious, which had been built to carry a pair of 18-in guns, was re-designed to become the first genuine floating aerodrome. One successful landing was made on her deck, but the second attempt ended in disaster, and not until further drastic changes had been made in the lay-out did landings become feasible without undue risk. Since that date the Furious has been further altered. The funnel has been suppressed, boiler smoke and gases now being discharged overside through horizontal ducts; and the great flight deck, measuring 700 feet by 80 feet, is left clear of all obstructions. With a speed of 31 knots and a capacity for thirty-five aircraft, the Furious, although more than twenty years old, is still a very efficient unit of the Fleet.

Similar in general design are the Courageous and the Glorious, which were converted from cruisers to aircraft-carriers in 1928-30. In these ships, however, an “island” superstructure, carrying a vertical funnel and the navigating bridge, is placed well forward on the extreme starboard side of the flight deck. Each vessel has a speed of 30½ knots and can carry forty-eight aircraft.

The other carriers are the Eagle, originally laid down as a Chilean battleship; the Argus, a converted merchantman, and the Hermes, until recently the only British carrier to be originally designed as such. A new ship, the Ark Royal, of 22,000 tons, was begun in the autumn of 1935. Leading particulars of the Navy’s aircraft-carriers are given in the table below.

The Royal Australian Navy has a seaplane carrier, the Albatross, a ship of 4,800 tons and 21 knots. She has an outfit of nine seaplanes which are launched by catapault, but as there is no flying-on deck she scarcely comes within the class of vessels under discussion.

The armament of the Royal Navy’s carriers is varied. It ranges from six 4-in anti-aircraft guns in the Argus, to sixteen 4·7-in anti-aircraft guns in the Glorious and the Courageous. Future carriers will probably be armed exclusively with dual purpose guns, capable of being used with equal facility against air or surface targets.

The carrier, of course, is not meant to fight other ships, and her armament is purely defensive. Because of her high sides and broad expanse of flight deck she offers a tempting and extremely vulnerable target. A few shells or bombs blowing craters in the flight deck might render all flying impossible; other elements of great danger are the petrol tanks, the bomb- and torpedo-magazines and the large hangars occupying most of the interior of the ship.

When crowded with aircraft these hangars contain much inflammable material, and even in normal times elaborate precautions against fire have to be taken. Thus the aircraft-carrier, though an indispensable unit of the Fleet, must be a source of anxiety in time of war and would require special protection. The Navy would welcome any development in aviation likely to obviate the necessity for giant carriers. It is possible that some adaptation of the helicopter or autogiro system may eventually solve the problem.

THE FLIGHT DECK OF H.M.S. EAGLE, showing the bridge and funnel on the extreme starboard side. H.M.S. Eagle was designed and her construction begun by Armstrong-Whitworth in February, 1913, as a dreadnought battleship for the Chilean Navy. At the outbreak of the Great War, in August, 1914, work on the ship stopped. She lay on her slips until 1917, when she was bought from the Chilean Government for £1,334,358. Her design was then modified, and in March 1920 she was commissioned for ship and flying trials. She was not, however, completed until 1924. Various modifications to H.M.S. Eagle have raised her total cost to £4,617,636 (including her purchase price from the Chilean Government). H.M.S. Eagle was refitted in 1932.

Before describing a typical carrier of the Royal Navy we must consider two of the American Navy’s vessels of this type, the Saratoga and the Lexington. Begun in 1920-21 as battle cruisers and converted in 1927, they are the largest and fastest carriers afloat. The displacement is 33,000 tons, the length 888 feet by 106 feet beam, and turbo-electric drive gives them a speed of about 34 knots. Some years ago the Lexington steamed from California to Honolulu (a distance of approximately 2,100 miles) at an average speed of 30¾ knots - a wonderful performance.

Either ship can accommodate from eighty to ninety aircraft, and the total complement, including aviation personnel, is 1,899, a record number for a man-of-war. The armament is exceptionally powerful, consisting of eight 8-in and twelve 5-in anti-aircraft guns. A characteristic feature is the single huge, flat-sided funnel placed on the extreme starboard side. It is not surprising that these wonder ships should each have cost £9,000,000.

The following description of a British carrier and how she goes to work is based on personal observations during a cruise in H.M.S. Furious. Because of her singular appearance this ship is generally referred to by naval wits as “Noah’s Ark” or “the Covered Wagon”. Above the hull proper the high sides are flared out to give additional width to the flight deck, 75 feet above the water. For half its length the deck is fenced with palisades, to prevent aircraft skidding overboard. Deep nets are fitted on either side to safeguard the personnel. A broad band of white paint runs fore and aft, exactly in the centreline. At the extreme forward end of the deck is a telescopic bridge and control station, lowered, when necessary, until its top is flush with the deck. In this structure the captain and the senior flying officer take up their posts when flying operations are in progress.

Going below, one is impressed by the enormous size of the hangars, which are about 18 feet high, 60 feet wide, and from 400 to 500 feet long. As petrol gas is always present they are treated as dangerous spaces. Fixed bulkheads being impracticable, the hangars are partitioned off by steel roller fire curtains worked by electro-motors, and are further subdivided by heavy curtains of fireproof material. Fire pumps, sprinklers and chemical foam showers are fitted throughout, and can be brought into play at once from almost any part of the hangars, which are also specially ventilated on the exhaust system. Only the most essential electric leads are permitted near the hangars. Air-locks are fitted to all access doors between decks.

To operate a large number of aircraft it is obviously necessary to carry a considerable quantity of aviation spirit. This is stored in cylinders in the hold at either end of the ship, with pipes leading to fuelling points in the hangars and on the flight deck. The cylinders are so arranged that they can be dumped overboard and sunk at the first sign of any real danger. On the forward end of the flight deck large transverse wind screens are fitted to provide a shelter in the lee of which aircraft can be finally tuned up before taking off. When not in use the screen’s fold into recesses in the deck and offer no obstruction. The lifts used for carrying aircraft from the hangars to the flight deck, or vice versa, are about 50 feet wide and 45 feet long, and are large enough to take machines with their wings spread. In the latest carriers these lifts move at comparatively high speeds.

ALTHOUGH SEVERAL SHIPS WERE CONVERTED TO AIRCRAFT CARRIERS, H.M.S. Furious was the first genuine floating aerodrome. Built under the Emergency War Programme, H.M.S. Furious was begun as a cruiser in June, 1915, and completed in July, 1917. She was rebuilt in November, 1917, as an aircraft carrier, and again in 1918. Since then further alterations have been made, her mast having been removed and her funnel suppressed, so that boiler-smoke and gases are now discharged overside through horizontal ducts. H.M.S. Furious is 786 feet long, has a displacement tonnage of 22,450, a speed of 31 knots, and can accommodate thirty-five aircraft. With her numerous alterations she is said to have cost £6,000,000.

In the early days special gear was fitted to the deck to check the momentum of machines when landing and bring them to a standstill. It consisted of transverse wires engaged by hooks on the under-carriage of the aircraft. The problem of exerting just the right amount of pull - and no more - progressively to check the speed of the aircraft was one of great difficulty. Serious mishaps frequently occurred when the arresting gear was in use.

For a time, therefore, it was abandoned in favour of the simpler method of man-handling the machines to a standstill by parties of seamen and R.A.F. ratings stationed in the nets at the sides of the deck. Immediately a machine alighted and began to taxi along the deck, these men dashed out, seized the wings and quickly brought it to rest. Recently, however, mechanical arresting gear has been re-introduced. This is of improved efficiency and should give satisfaction.

When a carrier’s aircraft are ordered to take the air the machines detailed for flight are brought up on deck by the lifts and “parked” one behind the other in two or more lines. The engines are then started up and left running for several minutes. Pilots and observers climb into their places, and mechanics make a last-minute inspection of every machine to make sure it is in perfect order. Meanwhile the ship’s head has been put into the wind and her speed much increased. At a signal from the Wing Commander, R.A.F., who is responsible, under the captain of the ship, for all flying work, the first machine takes off with a roar and, after a very short run along the deck, shoots into the air directly ahead of the ship.

Spectacular Landings

One by one the other ‘planes follow, and in a surprisingly short space of time a score or more of “fighters”, “spotter reconnaissance”, and “torpedo bomber” machines are aloft. They may be “spotting” for the big guns of the battleships at long-range practice, or locating and bombing an “enemy” cruiser which is reported within a radius of 100 miles from the carrier. Not a single flight is undertaken without some specific object in view, for every gallon of petrol consumed has to be accounted for. While in the air each machine is constantly in touch by wireless telephone, not only with the ship but also with the leading ‘plane of its own squadron. Between the ship and her ‘planes an alternative method of visual signalling by flags is also used.

When the flight comes to an end, the really spectacular part of the operation begins. The ship is steamed at very high speed and from a point well up in the bows a jet of white vapour is poured out. The ship’s helm is moved until the vapour streams down the deck exactly in line with the white-painted band running fore and aft, and as the vapour is clearly visible to the pilots in the air they know that the carrier is running dead into the wind.

The Wing Commander signals the leading ‘plane to land. Executing a perfect circle the pilot brings his machine down to the level of the ship’s stern and an instant later his wheels mount the overhanging ramp and run along the deck, where the arresting gear comes into action and deck parties take charge. The ‘plane is then run forward along the deck to the nearest lift, which immediately descends. In the brief time the ‘plane takes to reach the hangar the wings have been folded back and the machine is wheeled to its place in the hangar, while the lift goes up to receive the second machine, which has already landed.

Landing becomes a more complicated affair when the sea is rough and the carrier shows a tendency to roll or pitch, or to do both. Such occasions call for consummate judgment on the part of the pilot, who must choose the exact moment to land when deck and machine are level.

When flying is in progress a carrier must be escorted by two destroyers, which keep station on her starboard and port quarter respectively and follow all her movements. As the destroyers are under a full head of steam they can dash off to the rescue at once should an aeroplane fall into the sea.

The Fleet Air Arm has not only come to stay but also it is assured of far-reaching development. The design of aircraft-carriers is constantly under consideration, and future ships of this type may differ radically from those now in service. Even the latest carrier is, in a sense, experimental, for the type is in process of evolution and its final phase is beyond the power of prediction.

BECAUSE OF HER ODD APPEARANCE, H.M.S. FURIOUS is often referred to as “Noah's Ark” or “the Covered Wagon”. Above the hull proper her sides are flared out to give additional width to the flight deck, 75 feet above the water. For half its length the flight deck is fenced with palisades to prevent aircraft skidding overboard. At the extreme forward end can be seen the telescopic bridge and control station, which can be lowered until its top is flush with the deck. In this structure the captain and senior flying officer take up their posts when flying is in progress.

You can read more on “The Navy Goes to Work”, “Navy Week” and “The United States Navy” on this website.

You can read more on “The Fleet Air Arm” in Wonders of World Aviation