Two of the class were sold and used as Arctic exploration vessels, both eventually being lost in the ice.

The Philomel-class gunvessels were an enlargement of the earlier Algerine-class gunboat of 1856.

With this new classification, a further twelve of the class were ordered by the Admiralty on 14 June 1859, receiving their names on 24 September the same year.

They were constructed of wood in contract yards and then fitted out at naval dockyards.

The engine, which was produced by a range of contractors, including George Rennie & Sons and Robert Napier and Sons, was intended to produce a nominal horsepower of 80nhp, which equated to about 325 indicated horsepower (242 kW).