“The first passenger locomotive built for the G. N. R. Company to Mr. Sturrock’s instructions was No. 71, which began work in 1851, and was one of twenty constructed to the same leading dimensions. Of these Nos. 71 to 75 were built by Messrs. R. & W. Hawthorn, and Nos. 76 to go by Messrs. E. B. Wilson & Co., and the two accompanying illustrations.
Figs. 11 and 12, showing respectively Nos. 71 and 76, indicate that, while in details each firm still continued to follow its own practice, the general dimensions of the railway company’s locomotive engineer were closely adhered to.
These twenty engines were all built to the following chief particulars :—cylinders 16-in. by 22-in. ; leading wheels 3-ft. 6-in., four-coupled driving wheels 6-ft. in diameter; wheel-base 15-ft., of which 7-ft. 3-in. divided the centres of the coupled axles ; boiler barrel 10-ft. in length, with a diameter of 3-ft. 9 1/2-in., containing 157 tubes of 2-in. diameter; internal firebox, length 4-ft. 6-in., width, 3 ft. 3 1/2-in.; heating surface : firebox. 102 sq. ft., tubes 904 sq. ft., total 1006 sq. ft. ; boiler pressure 150 lbs.; weight 27 tons 18 cwt.”