Although the Crampton locomotive enjoyed long popularity in France in general and with the Est in particular, it reached its limits in the late 1870s. Thus, Regray initially had seven locomotives made with 2-4-0 wheel arrangement. Since the Belpaire firebox had its rear end above the second driving axle and the 2.31 meter diameter wheels were still very large, the locomotives were referred to as “coupled Cramptons” or “super Cramptons”. On numbers 508 to 510, the firebox was pulled further forward so that it lay between the driving axles. The locomotives had double outside frames which held the cylinders between them.