The Crimean War and Indian Mutiny in the 1850s both required that large numbers of troops be moved across the globe at short notice.

Designed to carry an entire battalion of infantry, the result was a magnificent barque-rigged steamer of considerable size; with a top speed of 15 knots, and able to take the direct route via the Suez Canal, they were able to reduce the length of the voyage significantly, but perhaps more importantly, the uncertainty in the time needed to make the journey round the Cape of Good Hope was also reduced.

[1] They were lightly armed with three 4-pounder guns, and were initially fitted with a single-expansion trunk engine (except Serapis) and single screw, producing 700 nhp.

[1][Note 1] The ships spent most of their active careers conveying British troops to and from the Indian subcontinent, although other voyages were made, most notably to Canada.

[1][4] All the ships of the class could be distinguished by a different coloured hull band, with Crocodile wearing yellow, Euphrates blue, Jumna red, Malabar black and Serapis green.