Archibald Sturrock had a total of twelve 2-2-2 express locomotives built by three manufacturers in 1860 and 1861, which had a driving wheel diameter of seven feet. They were at the same time generously sized and very handsomely proportioned, so that they are sometimes described as Sturrock's masterpiece. The long firebox, which was raised compared to the boiler barrel, is clearly visible. The leading axle was now directly under the smokebox. This arrangement was adopted for all further GNR three-axle passenger and express locomotives. 