[Until the 116 class,] the goods engines built for the Great Northern had consisted of four-coupled types, but in 1850 a notable movement was made in the putting to work of a six-coupled engine, which was followed during that and the following year by a number of similar locomotives. These had inside cylinders, outside frames and axle bearings, and equalizing levers between the leading and driving springs.
Other leading details in their construction may be seen from the accompanying illustration, Fig. 9, of No. 116. In all there were 31 engines built of this class, 15 being built by Messrs. R. & W. Hawthorn and 16 by Messrs. E. B. Wilson & Co. Of these the former firm built Nos. 116 to 120 in the year 1850, and Nos. 134 to 143 (makers’ Nos. 739 to 748) in 1850 and 1851, while Messrs. Wilson’s engines, of the same dimensions, but differing in details of fittings, as was customary at the time, bore the Nos. 144 to 158 and 167, and were built and delivered in 1850 and 1851.
Nos. 116 to 120 had cylinders 16-in. by 22-in. and driving wheels 5-ft. in diameter, equally distributed over a total wheel-base of 14-ft. The other engines of the class had cylinders also 16-in. in diameter, but with a stroke of 24-in. The boiler barrel was lo-ft. in length, with a diameter of 3-ft. lo-in., and contained 158 tubes of 2-in. diameter. The internal firebox measured 3-ft. 10 1/2-in. in length by 3-ft, 3 1/2-in., and the heating surface was—firebox 78, tubes 815, total 893 sq. ft.