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Aviation History
1955
1955 - 0379.PDF
25 March 1955 379 ANY FIELD AN AIRFIELD —or, How to Become Independent of 8,000 ft of Concrete: The Bleriot Lecture ON Thursday of last week, the eighth Louis BleriotLecture [by M. Georges Hereil, general manager of theFrench S.N.C.A.S.E. national aircraft group] was read before the Royal Aeronautical Society by Prof. A. R. Collar. Choosing as his title "Making Aeroplanes Independent of Runways," M. Hereil presented a valuable compendium of most of the principal experiments which have been adopted with this aim in mind. A considerable proportion of these experiments were of French origin and—though the paper did not make this particular point—France certainly seems to be devoting a greater proportion of her national income to this type of development than any other country. The paper began by summarizing the various factors leadingto the employment of, and the disadvantages of, large runways. Of the latter, the three most important were the very greatexpenditure required, the lack of flexibility imposed upon air forces and the vulnerability of large fixed bases. There were twodistinct points to be considered in discussing the take-off and landing of aircraft: the ground area and the type of surface neces-sary. In the first case, the determining factors were the wing- loading, the lift and the accelerating and braking power available.In considering the second point, the determining factor was runway-loading. M. Hereil deliberately confined his attentionto means for launching and retrieving conventional fixed-wing aircraft and, in particular, concentrated upon devices which couldbe rapidly applied to orthodox machines. He did not consider any type of V.T.O. aircraft, aerodynamic solutions or those usingengine power, water-based aircraft or helicopters. It was of interest to note that, throughout the history of aero-dynamics, inventors had conceived devices which, although not exactly solving the problems currendy being met, embodied theessentials of the modern solutions. The great interest raised by the problem was shown by the number of patents granted in theU.S.A. between 1904 and March 1952; 158 such patents were solely concerned with devices for launching aeroplanes bycatapult. The first major part of M. Hereil's paper dealt with the limita-tions of runways as they exist at present. Financial ouday was the first real limitation and, of this, the major portion was dueto the amount of labour involved and the need to use mechanical means for construction. It was necessary to employ a level tractof land several miles in length and, once the construction was completed, the region was irretrievably lost to cultivation. As an example, figures were given for a typical NATO air-field in France. The airfield comprised: a 2,600 yd runway, 50 yd wide, with a 65 yd border on each side and a 300 yd over-runat each end; a parallel taxying strip of the same length as the main runway; four connecting strips; several dispersal areas; andvarious access roads. The average total cost of such a base exceeded £2im. It was stressed that the above figures referred to a tactical basefor fighter/bombers; for medium bombers of the B-47 type the average cost of an airfield was £10im. The building of airfieldswas thus seen to place a heavy burden on military budgets and, in the 1952 French budget, appropriations amounted to £63.6mfor airfields as against only £54.4m for aircraft production. Civil airports were still more cosdy. Figures for large airportsincluded: Idlewild £35m, Grand Orly expansion scheme £30m, London Airport £20im and Newark £18m. It was true that inthis case the cost of the runways was only about 20 per cent of the total and, furthermore, that a civil airfield was more or less per-manent. Considerable sums had already been spent on the estab- lishment of world air routes; by January 1st, 1950, the total costin the U.S.A. alone had already reached £35Orn of which £230m was for trunk-route airfields. Each year new airfields were com- pleted and new airports open to traffic. This meant that, in sofar as civil aircraft were concerned, the need to find a means of eliminating runways lost some of its importance. On the otherhand, it was feasible that, while still using ground runways, some of the methods designed to make military aircraft independentof them could be applied with advantage to civil airliners. The lecturer then turned to the limitations and vulnerabilityof runways in military operations. It was pointed out that there were many actions during the second World War and in Koreawhen air operations were paralysed by a shortage of usable air- fields. With the piston-engined World War II aircraft, it hadbeen possible to improve deployment by using sections of auto- bahn, but jet aircraft were not amenable to such operations. InKorea, for example, the U.S.A.F. averaged approximately 260 daily sorties when operating the same number of aircraft asachieved 5,000 sorties on the Ardennes front in 1944. The possibility of a requirement for large numbers of tacticalbases close up behind moving armies led naturally to a discussion of the time factor involved in the construction of present-day run-ways. Recent military history provided two good examples of this factor. The first related to a Berlin Airfield; the Tegel base,built during the most critical period by 17,000 German labourers working in three shifts, took three months to build. The secondexample was from Korea; K6 airstrip was started on September 16, 1952, and was not completed until February 13th, 1953 [Verymuch better times than this have been established by American airfield construction battalions—Ed.]. The accompanying sketchshows some of the many different operations responsible f©r the long time taken to complete modern runways. The importantwork of excavation and removal of about 14,000,000 cu ft of soil obviously needed powerful tractors, scrapers, bulldozers andgraders and so forth; and, for surfacing, a concrete mixing plant with an output of over 3,500 cu ft per hour had to be establishedon the site. The next illustrations in M. Hereil's paper were of World WarII airfields immediately after heavy bombing attacks. It was, said M. Hereil, impossible to camouflage a large and important baseand the whole installation was very vulnerable to attack even with ordinary bombs. If nuclear weapons were used, not onlywould the destruction be widespread but also, owing to radio- active contaminations, the effect could last for several days, duringwhich time the airfield would be out of action. Thus it could be seen that large airfields caused grave concern to techniciansand military commanders whose efforts were directed towards the same object—never to construct an objective important enoughto justify an atomic attack. The paper then went on to discuss the conditions and require-ments which had gradually led to the necessity for long concrete runways. These factors included increases in all-up weight andin tyre pressure, increases in wing-loading and the adoption of more stringent international requirements and operating pro-cedures to provide airfields properly matched to civil transports with the maximum safety. The lecturer next turned to the main subject for considerationin the second part of his paper, which began with a list of the various means for making aircraft independent of runways.Stricdy speaking, catapults were launching systems. Since the original example of the catapult used by the Wright Bros., thesedevices had been employed mainly on aircraft carriers. It was worth noting that, whereas for a long time the aircraft to belaunched were carried on rail-mounted trolleys, present-day naval catapults consisted of an accelerating claw flush with the deckattached to the aircraft by means of a strop, the wheels of the aircraft actually running along the flight-deck itself. It was forthis reason that aircraft design for carrier work frequently required tyre pressures greater than those for corresponding land-based WORK PROGRESSING SEQUENCE OF OPERATIONS TrR 'A¥///'///\^/'// //¥///'// / / /%/ M N O P Some of the principal operations involved in constructing a concrete runway: A, tractor and scraper; B, motorized grader; C, grading surface; D, sand fill; B, roller for compacting the sand fill; F, roll of Kraft paper; G, concrete batch-mixer; H, concrete spreader; J, "pervibrateur" finisher, K, "poutre yibrolisseuse" finisher; L, sweeper; M, expansion joint; N, joint finishing; O, tarpaulins; P, layer of hay.
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