Following these in numerical order came a set of twelve passenger engines which might almost be regarded as Mr. Sturrock’s masterpiece in designing. These were single driving engines of generous dimensions and fine proportions, which must strike the observer as being well in the front rank of locomotives so far as grace of appearance is concerned, while their performances abundantly proved that in no way were workmanlike qualities of speed and power sacrificed to obtain a satisfactory outline.
These twelve engines bore the Nos. 229 to 240, Nos. 229 to 232 being delivered by Messrs. Kitson & Co. in 1860, Nos. 233 to 236 by Messrs. Sharp, Stewart & Co. (makers’ Nos. 11 59 to 1161 and 12 15) in 1860 and 1861, and Nos. 237 to 240 by Messrs. R. Stephenson & Co. in 1860, the whole being charged in the company’s books at a total of £35,ooo.
The accompanying illustration. Fig. 25, of No. 229 shows several interesting features, one being the great length of the firebox, which was provided with a longitudinal mid-feather, while the position of the leading wheels right forward under the centre line of the smoke-box and chimney is also noteworthy, as it is a practice that has since been adopted without any exception in all G.N.R. six- wheeled passenger engines. A further detail, not apparent in the drawing, was the employment of hoops on the jaws of the cranks, which at the time was a somewhat unusual precaution.
The leading dimensions of these splendid engines were : diameter of driving wheels 7-ft., and of leading and trailing wheels 4-ft. 3-in. ; wheel-base: leading to driving wheel centres 9-ft. 6-in., driving to trailing wheel centres 8-ft. 6-in., total 18-ft. ; cylinders 17-in. by 22-in. ; length of boiler barrel 10-ft., diameter 4-ft., containing 164 tubes of 2-in. diameter ; length of firebox casing 7-ft. 4-in. ; heating surface: firebox 177 sq. ft., tubes 883.6 sq. ft., total 1,060.6 sq. ft.; capacity of tender tank 2,400 gallons ; weight of engine only, 34 tons 12 cwt., of which 13 tons 6 cwt. 3 qrs. rested on the driving wheels.