It is not to be supposed that the Great Northern express traffic is worked entirely by the outside-cylinder engines, which have already been illustrated in our pages, albeit Mr, Stirling’s engines with 8ft. drivers have earned a worldwide reputation. For many years inside-cylinder engines have played an important part on the line, and Mr. Stirling has found it worthwhile to perpetuate this type. Our supplement this week illustrates, through the courtesy of Mr. Stirling, one of these engines. This particular locomotive illustrated was built in 1885, but precisely similar engines are being built and put to work now as the traffic demands them. We give above a smaller view, which shows the engine and tender together. The wheel base of these engines is long, but they work a road which is free from sharp curves, and the traverse of the loading axle, and the play of the flanges, are found to give all the required freedom.
We give a section of one of the leading boxes, which explains itself.
The principal dimensions of these fine engines are as follows:—
Diameter of cylinders | 18½ in. |
Stroke | 26 in. |
Diameter of driving wheel | 7ft. 7½ in. |
Diameter of boiler (telescopic) | 4ft. 2in. and 4ft. outside. |
Boiler pressure | 160 lb per sq. in. |
Length of barrel | 11ft. 5in. |
Length of fire-box casing | 6ft. 2in. |
Number of tubes | 186 |
Diameter of tubes | 1¾ in. |
Heating surface in tubes | 1001 sq ft. |
Heating surface in firebox | 108.7 sq. ft. |
Grate area | 18.4 sq. ft. |
Weight on leading wheels | 12 tons 4 cwt. |
Weight on driving wheels | 17 tons 8 cwt. |
Weight on trailing wheels | 11 tons 1 cwt. |
Total weight | 40 tons 13 cwt. |
Total weight of tender | 38 tons 10 cwt. |
Total weight of engine and tender | 70 tons 3 cwt. |
During a recent trial, to ascertain the exact consumption of fuel, when hauling some of the quickest trains it was found that it consumed 30.6 lb. of best South Yorkshire coal per mile run, and four pints of oil per 100 miles run. The average weight of the trains hauled was 177.6 tons. The booked speed of these trains is considerably over fifty miles an hour ; so this performance is remarkably excellent.