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PUBLIC RECORD OFFICE

།།།།:「 །

Reference :-

885/26

PUBLIC RECORD OFFICE, LONDON |

ALLY WITHOUT PERMISSION OF THE BE REPRODUCED PHOTOGRAPHIC- COPYRIGHT PHOTOGRAPH-NOT TO

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Financial considerations may also affect the question. A Colony with a small annual revenue, or one that has difficulty in securing sufficient revenue to balance its expenditure, may be financially incapable of undertaking an expensive railway even if the prospects of its paying its way should be excellent, not only because in these circumstances the terms on which it could borrow the capital required are likely to be onerous, but also because it might be unable to meet unforeseen deficiencies in the earnings of the railway due to a series of bad seasons or a period of low prices for the products to be carried.

The expectation would frequently he that a railway would be operated at a loss for several years but would ultimately pay well. In such cases, if the losses cannot be met from other revenue, it may be necessary to add their amount to the capital cost, and the addition should be made in any event for the purpose of reckoning the cost to the community. On the other hand, it may be possible to avoid such initial losses by charging temporarily high rates on certain classes of products which can bear them, especially if they have previously been carried at still higher rates as headloads or in other ways.

The questions of standard gauge railways versus narrow gauge railways and of narrow gauge railways versus motor roads on the Gold Coast have recently received much attention on the part of the Governor, General Guggisberg, and the other local authorities. The Governor atated in his discussion with us that he had originally been disposed to favour the construction of narrow gauge feeder lines, but he had been advised against this by all the engineers whom he had consulted, and had abandoned the idea that they would be suitable on the Gold Coast. He explained the manner in which feeder traffic for the main line usually developed itself in the Colony, A road was cut, probably by a local chief, to a point on the railway line from a centre about 50 miles away, and branch roads to this main road were then cut from the villages in its neighbourhood. These were fair-weather roads only. In the dry season they were used by light motor lorries. The traffic passing on any single brauch road was not normally sufficient to require an expensive surface, but on the last 15 miles or so of the main road adjacent to the railway the traffic before long became heavier than the ordinary gravelled roads would bear, and the question was whether on this portion it would be more economical to make a first-class road with a concrete surface or to build a railway. The Governor had come to the conclusion that the best plan was to lay down a pioneer line of the standard (3 ft. 6 in.) gauge, with light rails and just enough ballast to make it safe to run a light locomotive and trucks over it. At this stage there would be no elaborate equipment, but only what was absolutely necessary. In course of time the railway would be pushed further out, and as opportunities presented themselves with the development of traffic, it would gradually be brought up to the standard of a main line. If, for instance, heavier rails were being put on the main line, perhaps at the coast terminus, the rails taken up could be laid on the feeder line to replace the still lighter rails which could then be used in extending the feeder line up country or for another feeder. Bridges and culverts would be built at once to main line standard, and curves and gradients should be limited to an extent which would enable them to be corrected to main line standard without excessive expense.

The view of General Grey, endorsed by the West African Section of the London Chamber of Commerce, is also in favour of standard gauge railway extensions and feeder motor roads limited to areas within 50 miles of a railway station and against narrow gauge lines. The opinion is expressed that there are so many districts in British West Africa where the prospects are that a standard gauge line will pay from the moment it is opened that the question of laying down narrower gauge lines hardly needs to be discussed. Taking into account the present position of labour supplies and prospects of obtaining money, General Grey considers that the programme for railway construction work in Nigeria and the Gold Coast will keep employed all the labour and will need all the money it is possible to obtain for the next 15 or 20 years building standard gauge lines.

The opinion thus appears to be unanimous, at any rate as regards the Gold Coast, both among the local engineering authorities and the commercial community as represented by the London Chamber of Commerce, that 2 ft. or 2 ft. 6 in. gauge railways are not required ir West Africa for the present. It should be noted, however, that this opinion appears to relate only to the ordinary narrow gauge type of railway. Colonel McDonnell, of Messrs. Stewart

and McDonnell, one of General Guggisberg's advisers in the matter, gives the following com- parative statement of the standards which from his experience he considers desirable for the construction of (a) light railways of 2 ft. gauge, and (b) standard gauge 3 ft. 6 in. branch lines capable of being improved up to main line standard:

Gauge

Ruling gradient

Maximum curvature

Minimum weight of rail ...

Minimum number of sleepers

Ballast per mile

Width of clearing...

Width formation cuts

Width formation fills

(a)

2 feet

2 per cent.

35 degrees

30 lb. per yard

2,200 per mile

1,200 cubic yards

100 feet

15 feet 6 inches

12 feet 6 inches

(4)

3 feet 6 inches.

2

per cent.

12 degrees.

45 lb. per yard.

2,000 per mile. 2,000 cubic yards. 100 feet.

17 feet.

15 feet.

50 tons

(15 ton looo. 6 cars)

Engine axle load ...

4 tons

100 ton. (30 ton loco. 6 cars) & tona,

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These figures are clearly not applicable to the Dutton-Stronach loco-tractor or road-rail system, which, according to the claims of its designers, can be worked with much steeper gradients, sharper curves and lighter rails; and we recommend that the West African Govern- ments should be invited to consider carefully whether, in view of the recommendations from South Africa, it would be worth their while to lay down an experimental loco-tractor line, either (a) with a view to its permanent employment along a short feeder route where a long extension is not likely to be required in the future, and where the traffic is not likely to grow beyond the capacity of such a line, or (b) as a temporary measure pending a reduction in prices of materials and rates of interest.

18 February, 1921.

APPENDIX.

DESCRIPTION OF PRODUCER GAS PLANTS.

1.

Description of the "Bamber Plant marketed by Producer Gas Plants Limited, fitted to a 40 H.P. 3 ton Thornycroft petrol engined lorry as exhibited before representatives of the Im- perial Economie Transport Committee.

The generator surmounted by a fuel hopper com. prises one unit and is mounted on the near side of the vehicle by the side of the driver's seat. In plan it is about 2 feet square and stands about 4 feet high. The whole is enclosed in sheet steel. Its flat top is provided with a circular door for the purpose of charging the hopper from time to time with fuel. The fuel gravitates into the generator through a tube centrally situated in the base of the hopper and maintains the fire level with the outlet of this tube, which is about 8 inches above the grate. Hence the fire is automatically maintained at a constant depth. The petrol tank is utilised for carrying the water supply for the generator, the water being fed from the tank through a sight-feed lubricator adapted for the purpose, and thence conducted through a copper tube to a tray below the fire-bars. Here the water is converted into steam partly by radiation and partly by conduction of heat from prongs which project down from the fire-bars into the tray. Below the tray is the ash-pit. The generator is also equipped with a hand-operated fan for use when initially starting up from cold-a process which lasts about 20 minutes.

Air enters through an aperture in the ash-pit chamber and, after picking up the steam, passes up- ward through the fire. The issuing gas, which con- sists mainly of carbon-monoxide, hydrogen, and nitrogen, with a small percentage of carbon-dioxide, is led through a pipe from the upper part of the generator into the dust-box to allow of solid matter held in suspension to settle out, and from thence the pipe is continued round the chassis frame and back to the induction pipe of the engine. This circuitous path is adepted in order to allow the gas to cool be- fore entering the engine. Close to the induction pipe of the engine an air inlet valve is inserted which can be adjusted to suit the local atmospheric con- ditions in order that the mixture of gas and air drawn into the engine shall always be correct for giving maximum power.

II.

H. J. READ.

W. H. MERCER,

JNO. EAGLESOME.

Description of "Smith" Plant marketed by Afajor Tulloch fitted to a 32 H.P. 24 ton petrol engined Albion lorry as exhibited before representatives of the Imperial Transport Committee. The generator, which is circular in section, about 2 feet diameter, and stands about 2 feet 6 inches high, is mounted on the near side of the vehicle by the side of the driver's seat. The fuel hopper is situated in the canopy over the driver's seat and contains about 1 cwt. of fuel. A pipe about 4 inches diameter serves to conduct the fuel to the generator. The amount of fuel admitted is controlled by an oscillat- ing valve situated on the top of the generator and worked by an eccentric from a counter-shaft driven from the engine. Below the valve and inside the generator the fuel feed pipe is continued to a height of 6 inches above the grate. The oscillating valve is adjusted to allow sufficient fuel to pass to enable the fire to be maintained up to the level of the outlet of this fuel pipe. Hence the fire is always kept at a constant depth of 6 inches. As such a shallow fre is liable to develop holes quickly, which would be detrimental to the quality of the gas formed, oscil- lating fire-bars are employed operated from the engine- driven countershaft to keep the fire in a state of constant agitation and thus avoid the formation of holes. The patrol tank is made use of to hold the water supply and the water is fed by a mechanically driven pump, also operated from the counter-shaft, into a cast-iron hollow ring situated above the fire in the generator. Between the tank and the pump the water is made to pass through a sleeve surround- ing the gas outlet pipe from the generator which preheats it and at the same time helps to cool the issuing gas. At the bottom of the generator is an ash-pit with a suitable outlet. The generator is also equipped with a hand-operated fan for use when initially starting up from cold-s process which lasts about 20 minutes.

Air is drawn in at one side of the ring biler “and, after picking up the steam generated therein, passes out at the opposite side into a pipe communicating with the space below the fire-bars. The mixture of air and steam passes upwards through the fire, and the issuing gas is conducted by a pipe from the top of the generator into a dust box and from thence to three dry scrubbers packed with wood wool, which are arranged transversely acTORA the chassis frame. From the scrubbers the pipe continues to the induc- tion pipe of the engine, and close to the latter is inserted the air inlet or mixing valve which can be adjusted to suit local atmospheric conditions in order that the mixture of gas and air drawn into the engine shall always be correct for giving maximum power.

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