Vickers Type 134 Vellore и Type 212 Vellox
Type 134 Vellore Мк I представлял собой равнокрылый биплан, предназначавшийся для перевозки грузов. На нем был установлен звездообразный двигатель Bristol Jupiter IX мощностью 525 л.с. (391 кВт), а открытая кабина располагалась перед крыльями и вмещала двух
человек, размещавшихся рядом. Позади и ниже кабины имелся вместительный грузовой отсек. Vellore I имел размах крыльев 23,16 м, массу 4309 кг и скорость 183 км/ч. Впоследствии самолет оснастили двигателями Armstrong Siddeley Jaguar VI, с которыми он отправился в 1929 году в полет по маршруту Великобритания - Австралия, но после аварийной посадки был поврежден и списан. Обозначение Vellore Mk II не использовалось, но были построены два двухмоторных самолета - Type 172 Vellore Mk III и Type 173 Vellore Mk IV, которые оснащались звездообразными двигателями Bristol Jupiter XIF мощностью 525 л. с. Последним представителем семейства стал Type 212 Vellox, построенный в единственном экземпляре для гражданских воздушных перевозок и вмещавший бортпроводника и 10 пассажиров. Самолет оснащался двумя звездообразными двигателями Bristol Pegasus IM3 мощностью по 600 л. с. и был облетан 23 января 1934 года, после чего его приобрела авиакомпания «Imperial Airways», где он использовался как грузовой.
Flight, September 1928
THE VICKERS "VELLORE"
A Freight Carrier which carries a Load greater than its own Weight
IN many ways one of the most interesting aircraft produced in recent times, the "Vellore," designed and built by Vickers, Ltd., of Weybridge, Surrey, for Imperial Airways, Ltd., is a single-engined biplane of all-metal construction intended to carry freight and goods, a form of air traffic which has been becoming steadily more popular, and which promises to assume large proportions. Hitherto there has been no machine available designed specifically for this particular kind of work, with the result that freight and goods have had to be carried in machines not really suitable for the work. In the "Vellore," however, Mr. R. K. Pierson has produced a machine in which high pay load per horse-power was the main object aimed at, coupled always with a reasonably good performance.
It is now a well-established fact that in order to keep down induced drag at low speeds it is necessary to have a high value of the ratio Span^2/Weight and in the "Vellore" the span has been kept very large, 76 ft. to be exact, so that the induced drag at take-off speed and at the low speed at which the machine climbs is very small.
As the "Vellore" weighs 9,500 lbs. fully loaded, the value Span^2/Weight = 0-608, which is very high for a commercial aeroplane. If it is assumed that the machine climbs at an air speed of 60 m.p.h., and as the ratio of gap to span is 0-132, the ratio of lift to induced drag corrected for the particular biplane arrangement employed is as high as 22-13 at the speed of 60 m.p.h. In other words, at that speed the induced drag is 430 lbs. only, corresponding to a thrust horse-power of 68-8, a figure which gives a good idea of the efficiency of the biplane wing arrangement of the "Vellore."
An examination of the accompanying illustrations will show that in this large biplane cellule, the fuselage itself, although of considerable actual dimensions, forms a fairly small percentage of frontal area, and the form is good also, with but few excrescences, so that one may assume that the total drag of the machine is low. This is borne out by the "Everling Quantities" given at the end of this article, from which it will be seen that the "High-speed figure" is as high as 24-65, a value which indicates a very small minimum drag. One may, therefore, accept it that the aerodynamic efficiency of the "Vellore" design is very good. That the structural efficiency is also above normal is shown by the fact that the load carried is 51-6 per cent, of the total loaded weight. In other words, the machine carries a load greater than its own tare weight. The actual figures are: Tare weight, 4,550 lb.; load carried 4,950 lb.; total loaded weight 9,500 lb. These figures indicate that the methods of metal construction employed by Vickers are very economical, and as Duralumin is the material employed throughout, with a few unimportant exceptions, advocates of this material for aircraft structures will find in the "Vellore" a very good proof of their contentions.
The fuselage of the "Vellore" is of Duralumin construction. It is built in two distinct portions, of which the front section is built up in the form, of a metal semi-monocoque. Doubtless this has been done in order to leave the luggage "hold" as free of internal bracing as possible. The rear portion of the fuselage is a girder, in which longerons and struts are circular-section Duralumin tubes, braced by tie rods. One of our sketches shows the attachment of a longeron to the monocoque front portion, and incidentally a good deal of the detail construction of both fuselage portions.
The front portion of the fuselage has two deep longerons at the bottom, built up of angle sections and corrugated walls, while the top longerons are quite light angle sections. The members corresponding to struts in a girder type of construction are in the form of box-section members formed from angle sections, T-sections and corrugated strip, in the manner shown in our sketch, and also visible in one of the photographs. The covering is Duralumin sheet, longitudinally corrugated for stiffness so as to enable it to take part of the loads as a stress-bearing member. The luggage "hold" is of large dimensions and entirely without bracing members internally, so that should occasion arise, the whole of it could be used for bulky goods.
A hinged trap door in the floor of the rear portion of the fuselage gives access to the "hold," and hoisting tackle is provided inside the latter for lifting freight into the machine and drawing it along the floor, which is in the form of corrugated Duralumin sheet, very substantial and stiff.
The pilot's cockpit is in front of the freight hold, separated from it by a wall, the communicating door being on the starboard side. The pilot's seat is on the port side, behind and above the engine, and provision is made for raising and lowering the seat. In the raised position of the seat the view is remarkably good, as the pilot is then well above the engine. A short ladder of Duralumin tubing runs from the cockpit floor to the seat, and if an engineer, navigator or spare pilot is carried, this ladder folds down and forms a seat for him.
The "Vellore" is equipped with every conceivable aid to navigation, such as a turn indicator in addition to the usual instruments; wireless transmitting and receiving apparatus; night-flying equipment, and so on. In fact, for a freight carrier, the "Vellore" appears needlessly encumbered with "gadgets," but doubtless these were demanded by Imperial Airways in order that the machine might be tried out under all manner of conditions.
The engine fitted is a Bristol "Jupiter IX," which is, of course, a geared engine, the increased propeller efficiency due to the 2 to 1 gearing being particularly desirable in a machine like the "Vellore," which carries a large load per horsepower at a relatively low forward speed. The petrol tanks, with a total capacity of 162 gallons, are placed in the top plane, so that direct gravity feed is employed.
Like the fuselage the wings are of all-metal construction, with exception of the covering which is fabric. The special form of wing spar construction developed by Vickers has already been described in detail in FLIGHT, so that it will suffice if we recall that the feature of the spar is the "wandering web," which crosses over from front to back of spar every few inches, leaving every rivet readily accessible. This "wandering web" fits into channel section flanges at top and bottom. The ribs are also Duralumin channels, and in place of tubular drag struts stronger ribs are used, some of these being extended aft of the rear spar to form supports for the Bristol-Frise ailerons. The interplane struts are of heavy gauge Duralumin, each strut being made in two halves, the joints being along the front and rear edges of the strut, where the rows of rivets occur. In the photographs published herewith the wing tip skids are in the form of hoops. These have now been replaced by straight sprung skids of a form not unlike tail skids, and similarly sprung. This was deemed advisable in view of the low wing loading of the "Vellore," which renders the machine somewhat liable to be blown on to a wing tip when on the ground.
The tail of the "Vellore" is of the biplane type found on so many Vickers machines. It is also unusual in that no less than four rudders are used, but it will be observed that there are no fixed vertical tail surfaces. The rudders are balanced, and with the total area split up into four relatively small ones, the loads on the rudder control pedals are very light. The tail skid shoe has a castor action, which makes the machine easy to steer on the ground.
The undercarriage of the "Vellore" is of the oleo-pneumatic type, with a long travel, and the track is fairly wide in actual dimensions, although relatively small for the large wing span. Hence the special wing tip skids to which reference has been made.
The main dimensions, areas, &c, are shown on the general arrangement drawings, but some of them are repeated in the following specification for the sake of convenience.
Engine Bristol "Jupiter IX."
Maximum horse-power 525 b.h.p. at 2,200 r.p.m.
Propeller drive Geared 2:1.
Fuel capacity 162 gallons (730 litres).
Wing span (top and bottom) 76 ft. 0 in. (23-470 m ).
Wing chord (top and bottom) 9 ft. 6 in. (2-895 m.).
Total wing area (including ailerons) 1,416 sq. ft. (132 sq. m.).
Length o.a 51 ft. 6 in. (15-695 m.).
Height o.a 16 ft. 9 in. (5-106 m.).
Width folded 20 ft. 9 in. (6-325 m.).
Weights and Loading
Weight empty 4,550 lb. (2,064 kg.).
Load carried 4,950 lb. (2,245 kg.).
Total loaded weight 9,500 lb. (4,309 kg.).
Wing loading 6-7 Ib./sq. ft. (32-71 kg./m.2)
Power loading (on 525 h.p.) 18-1 lb./h.p. (8-21 kg./h.p.).
Speed at ground level 110 m.p.h. (177 km./h.).
Speed at 5,000 ft. (1,525 m.) 106 m.p.h. (171 km./h.).
Speed at 10,000 ft. (3,050 m.) 101 m.p.h. (163 km./h.).
Landing speed 50 m.p.h. (80 km./h.).
Climb to 5,000 ft. (1,525 m.) In 10-5 minutes.
Climb to 10,000 ft. (3,050 m.) In 29 minutes.
Service calling 12,000 ft. (3,660 m.).
Absolute ceiling 14,700 ft. (4,480 m.).
Range at full throttle 750 miles (1,210 km.).
High-speed figure 24-65
Distance figure 5-3
Altitude figure 5-8
Both the actual performance figures and the "Everling Quantities" indicate that the "Vellore" is an unusually efficient design, and it will be interesting to see how it behaves when put into practical use by Imperial Airways. That it is one of the closest approaches to a commercial aeroplane which will pay for itself that has been produced so far seems evident.
VICKERS "VELLORE": Freight Carrier, with Bristol "Jupiter" Engine. From the pilot's cockpit an excellent view is obtained.
THE VICKERS "VELLORE" FREIGHT CARRIER: Three-quarter rear view. Note the biplane tail and the four rudders. The man standing next to the machine gives a good idea of the size.
Самолет Vellore I в первоначальной конфигурации с двигателем Bristol Jupiter.
NOT A CONJUROR: The man in this photograph is not balancing the Vickers "Vellore" on a stick, but is starting the "Jaguar" by means of a long detachable cranking handle.
TOWARDS AUSTRALIA: The Vickers "Vellore," with Armstrong-Siddeley geared "Jaguar" engine, on which Moir and Owen are making a fast flight to Australia.
For the Australian Flight: Our picture shows Flt.-Lieut. Moir and Pilot-Officer Owen inspecting the Armstrong-Siddeley Geared "Jaguar" engine which will be fitted to the Vickers "Vellore" machine on which they hope shortly to fly to Australia.
In Course of Construction: This photograph shows the front portion of the fuselage and gives a good idea of the type of metal construction employed.
The Vickers "Vellore": Photograph of one of the all-metal wings.
Vellore III. AN all-metal biplane of large size and carrying capacity, fitted with two Bristol "Jupiter" engines. The most powerful machine in King's Cup Race. First public appearance.
Vickers Vellore high-speed freight carrier
THE SCRATCH MAN: The Vickers "Vellore III" gets away.
THE HEAVY STUFF: Although a freight carrier, the Vickers "Vellore" (2 "Jupiters") was looped and generally stunted by Mr. Summers at the Brooklands Meeting.
FOR FREIGHT WORK: Wrightson & Pearse, of Heston, are to use a Vickers "Vellox" (two Pegasus ) on special freight work. The "Vellox" carries a load of 5,300 lb. and has a maximum speed of 160 m.p.h.
The "Vellox" (two "Pegasus") heavy load carrier;
NIGHT BOMBER AND TRANSPORT TYPES: In the foreground the nose of the Handley Page "Heyford." Flying past is the Vickers "Vellox."
LOOKING DOWN: Visiting machines can be seen parked around the edge of the aerodrome, while in the foreground is the large Vickers "Vellox."
IN THE LINE: The first machine is the Westland G.P. monoplane. Beyond may be recognised the Fairey G.P. and "Seal" and the Vickers "Vellox."
The Vickers "Vellore": A view inside the freight "hold," looking towards the pilot's cockpit.
The Vickers "Vellore": Sketch showing the type of Duralumin rib used instead of drag struts. This rib also carries the Bristol-Frise aileron hinge.
The Vickers "Vellore" Freight Carrier: These sketches show clearly the form of metal construction. On the left is the junction of the front and rear portions of the fuselage, the front portion being built up of sheet Duralumin, while the rear is a Duralumin tube girder. Note the construction of the freight hold floor. Inset is a sketch, with details, of the hinged door in the floor through which the freight is loaded and unloaded.
Vickers "Vellore" Bristol "Jupiter IX" Engine