Utilisation of Tank Locomotives.

Locomotive equipment on the New Zealand Railways follows on general lines page 21 the style of machines favoured at Home. A feature of present-day locomotive practice in Britain is the extensive use made of the tank locomotive for short-haul passenger and freight haulage. These tank locomotives carry their coal supply in a small bunker taking the place of the conventional tender, tanks fitted to the boiler sides accommodating water supplies. For branch line operation this type of engine

Express Travel in the Homeland.
A non-stop London-Birmingham Express on the Great Western Railway, England.

is found most convenient, as it is economical in fuel consumption and may be run in either direction without turning on the table. One of the largest users of the tank locatnotive is the London and North Eastern line, and this progressive system has just put into traffic in Scotland a batch of new 2-6-2 three-cylinder side tank engines of interesting design.

The new locomotives have cylinders working on the simple expansion system, with diameters of 16 inches and a stroke of 26 inches. Cylinders, valve chests and steam and exhaust passages, are formed as a monobloc casting, and all three cylinders drive on to the second pair of coupled wheels. The outside cylinders are fitted with Walschaerts valve gear and the inside cylinder with Gresley valve gear operated by extensions to the front of the outside valve spindles. Principal dimensions are as follows:—Grate area 22 square ft.; boiler working pressure 180 lb.; total heating surface 1609 sq. ft.; tractive effort 22,464 lb.; total weight in working order 84 tons; total length 42 ft.; coal capacity 4 tons; water capacity 2000 gallons. The locomotives have been built in the Doncaster shops—the home of the far-famed “Flying Scotsman” machines—to the design of Mr. H. N. Gresley, the L. and N.E.R. Chief Mechanical Engineer.