The last of four second-class torpedo boats built by Yarrow and Co., Poplar, for the Admiralty achieved a trial speed of 17.27 knots during trials observed by Messrs Allington and Andrews of the Admiralty and Mr Malston of Portsmouth. Formerly six runs over the measured mile were considered to be sufficient to test the endurance of this type of vessel, but these vessels were required to steam at full power for two hours and complete the customary six runs over the measured mile. The boats were equipped with forward steam impulse gear for discharging Whitehead torpedoes as proposed by Captain Gordon of the Vernon.