Three examples were built by Wolverton Works in 1861 with driving wheels together with McConnell’s patented firebox, which were intended for the fastest expresses. They were heavier than had been planned, so a further two engines, ordered and under construction, were cancelled in February 1862. This led to McConnell’s immediate resignation. The three completed engines (Nos. 372/3/5) went into store, so hardly ran in their original state. One of them (No. 373) was put on show at the International Exhibition in South Kensington from May to November 1862.