This allows the locomotive to be hauled by another locomotive at speeds above 20 mph.

Greenbat incorporated a folding cab, to allow the locomotive to fit down small mineshafts.

The 4-4-0 wheel arrangement, with its three-point suspension, was noted for its good tracking ability, while the flangeless middle wheels allowed the locomotive to round tight curves.

This allowed the locomotive to be turned on the shorter turntables found on this part of the network.

The loop is used to allow the locomotive to run round the train and reverse at the same time.

The M&KR would not allow the locomotive over their line, so horse traction took over from there to Leaend.

This device allowed the locomotive to heat up to three two-axled carriages.

This allowed the "locomotive" - often a cableway powered by a steam engine at the surface - to operate both safely and, more importantly, at higher speed.

This height restriction allowed the locomotive to travel easily through low-profile tunnels in the Northeast Corridor.

The frame of the locomotive was in two halves joined with a ball and socket joint, allowing the locomotive to negotiate sharper curves.