Flight, February 1923
ETABLISSEMENTS SCHNEIDER, Paris, Harfleur, etc.
IT might have been expected that a firm like Schneider et Cie., the famous French armament firm of Creusot and numerous other places, having turned their attention to aircraft construction,
would produce something out of the ordinary, and in a sense they have. But considering the almost unlimited resources of the firm, the machine exhibited at Paris can only be described as disappointing. Considering that enormous works are at the disposal of the firm, that metal of any kind and in any form and quantity must have been available, and that the question of cost probably did not enter into the matter, or, at any rate, to a very small extent only, one was justified in expecting something worth while when it was first announced that the Schneider establishment were going to exhibit at Paris. The realisation was, in this case, certainly far short of the anticipation. Not only was the machine shown of antiquated design, but the methods of metal construction employed were those with which most other constructors, French, German and English, were experimenting round about 1916 or 1917. Thus, the arrangement of engines in tandem on the wings was long ago found inefficient, and with the high-power engines now available, it has become entirely unnecessary. Constructionally, the Schneider designers have used, mainly, the Zeppelin type of construction, slightly modified, but in principle very similar to airship frameworks, with channel section spar flanges tied together by lattice bars. Although working well on airship hulls, this form of metal construction has long ago been discarded by aircraft constructors as being uneconomical.
Fundamentally, the Schneider "Henri-Paul," so named after a son of one of the Schneiders killed in the War, is a four-engined biplane night-bomber, with 370 h.p. Lorraine-Dietrich engines. As will be seen from the accompanying photograph, the machine looks like a cross between the Gotha bombers and the Handley Page V-1500. The wings, or rather the outer portion of them, are swept back considerably, probably so as to make up for the placing of the rear engines fairly far back over the trailing edge. The fuselage is of rectangular section, with flat top, and gunners' nests are provided both in front of and behind the wings.
As regards construction, the main principles have already been indicated. A wing skeleton was shown on the stand, and from this the details were ascertained. The spars of high-tensile steel, have flanges of channel section, to which are riveted the lattice bars. The latter are of a shape similar to that of the Zeppelin lattices, but the material is chrome-nickel steel. The formation of the lattice bars also differs from that used in the Zeppelins in that, whereas in the latter the lattices formed a series of "X's," they form, in the spars of the Schneider, a series of "N's," i.e., every other lattice is vertical. The drag bracing consists of compression struts in the form of aluminium alloy tubes, and of piano wire bracing with turnbuckles. The ribs are of aluminium alloy, and are mainly built-up of channel sections. Light longitudinal stringers run parallel with the spars, and steady the ribs between supports. The wing covering is fabric. The inter-plane struts are in the form of steel tubes, with aluminium fairings.
The fuselage is of tubular construction, with longerons of steel and struts of aluminium alloy. The bracing is piano wire, and the covering fabric, with the exception of the front portion, where aluminium alloy is used.
A biplane tail is fitted, each plane of which carries an elevator. There are three rudders, of which the central one is used for course setting when one of the engines stops. A triangular fin is placed ahead of the central rudder.
The undercarriage is of the four-wheeled type, and is only remarkable for the shock-absorbing arrangement, which is somewhat unusual. Each undercarriage incorporates at the lower ends of the struts a form of skid or longitudinal member. The wheel axle carries two longitudinal cantilever beams, free to swivel on the axle, and from these shock absorbers run to transverse bolts on the cantilever beams. Thus, each shock absorber can, if necessary, be removed separately, without interfering with the others.
As already mentioned, the engines are mounted tandem-fashion, between the wings. A streamline engine cowl encloses them entirely, and radiators are mounted above the engine nacelles. The front engines drive two-bladed screws, while the rear engines are fitted with three-bladers. It is of interest to note that the propellers fitted on the actual machine exhibited are Lumiere-Leitner-Watts all-metal adjustable pitch airscrews, which are particularly suitable for this machine, not only because they are made of steel, and therefore in keeping with the rest of the machine, but also because of their adjustable pitch, which enables the best pitch for the rear screws, working in the slipstream from the tractors, to be determined experimentally without requiring several sets of ordinary screws to be made. Also the fact that these airscrews are made both as two-bladers and three-bladers makes their fitting desirable. Not that metal airscrews are not always desirable, but in this case their use would appear to be the only logical one. Six large petrol tanks are mounted in the fuselage, each provided with a jettison valve for rapid emptying in case of emergency.
The main characteristics of the Schneider "Henri-Paul" are as follows :- Length, o.a., 20 m. (65 ft. 6 ins.); span, 30 m. (98 ft. 6 ins.); height, 6.1 m. (20 ft.); chord, 3 8 m. (12 ft. 5 ins.); wing area, 220 sq. m. (2,370 sq. ft.); structure weight, 4,000 kg. (8,800 lbs.); weight of engine units, 2,500kg. (5,500 lbs.); weight of fuel, 1,700 kg. (3,740 lbs.); useful load, 1,820 kg. (4,000 lbs.); total loaded weight, 10,020 kg. (22,040 lbs.); power loading (four engines of 370 h.p. each), 15 lbs./h.p.; wing loading, 9-3 lbs./sq. ft.; maximum speed near ground, 160 km. (100 m.p.h:); speed at 2,000 m., 150 km. (93 m.p.h.); landing speed, 80 km. (49-6 m.p.h.); climb to 2,000 m., 13 mins.; theoretical ceiling, 5,000 m. (16,400 ft.); radius of action, 750 km. (465 miles).