Ts it a Commercial Proposition?
Some' interesting estimates of! the cost of transport by airships were given in a paper read by Air-Commodore E, M. Maitland, c.t.c., D.8.0., before the Royal Society of Arts, recently says "Engineering." Commodore Maitland dealt with the route from England to India vid Cairo, and assumed that the journey would be completed in two stage of 50 hours. each. Four airships, similar to the R. 38 now. under construction ati Bedford, would be required to maintain a weekly service in each direction, each ship flying for 2,500 hours per annum and having period of three months in the shed for overhaul and repairs, airship of the size assumed would have a length of 695 ft. a gas capacity of 2,700,000 cub. ft., and a maximum speed of 70 m.p.h., while it would be capable of cornying a load of 15 tons for 50 hours at a continuous air speed of €0 m.p.h. For the purposes off calculation, however, the speed over} the ground was taken as 45 m.p.h, giving a yearly ground mileage of 312,500 for each ship.
Under commercial conditions the; cost of constructing four airships of the above-mentioned capacity, it was estimated, would be £800,000, and a sum of £45,000 was allowed for the construction of a mooring station at Karachi. This, with a working capital of £200,000 brought the total capital expendi-titre to £1,045,000, and interest on this, at 15 per cent., would come to about £157,000, or, say 7s. per mile flown over the ground. The} annual operating costs of each airship, allowing £40,000 for maintenance, £40,000 for depreciation, £9,000 for crew, £12,000 for gas and £30,937 for oil and petrol, worked out at 3s, 5d. per ground mile. Bases in England and in Cairo, it was assumed, would be built by the. Government. and leased, to the company at a yearly rental of 6 per cent. of the cost of construction, and, on this assumption, the total cost of running each of the bases would amount to £116,700. An additional sum of £12,000 would) be required for operating the mooring station at Karachi, and this would bring the total annual cost of the bases to £245,400 which would be equivalent to 11s. per ground mile.
Text read from the printed page and cleaned; old type leaves the occasional error.