The two ships displaced140 tonnes (138 long tons) and were 23.1 metres (75ft 9in) long, with a beam of 6.4 metres (21ft) and a draught of 2.6 metres (8ft 6in). The ships were powered by two 365 horsepower (272kW) azimuthing Z-drives and one hydraulic tunnel bow thruster. This gave the vessels a maximum speed of 11 knots (20km/h; 13mph). The ships had a crew of five firefighters.
The Fire class was equipped with three manually-controlled 3-inch (76mm)water cannons, two diesel-driven fire pumps capable of expending 2,500 gpm at 150 psi each.