The other ends of the wires were connected to steam-powered winding engines, which were arranged so that speeds could be varied within fine limits, giving sensitive steering control for the torpedo.

The torpedo was fitted with elevators controlled by a depth-keeping mechanism, and the fore and aft rudders operated by the differential between the drums.

Beanse [5]: p2  expands Brennan’s observation of the driving belt powering the planing machine was taut and the non-driving side was slack.

Brennan began making rough sketches of such a torpedo, and as the concept developed he sought the mathematical assistance of William Charles Kernot, a lecturer at Melbourne University.

The British Admiralty had meanwhile instructed Rear Admiral J. Wilson, the Commodore of the Royal Navy's Australian Squadron, to investigate the weapon and report back.

Alexander Kennedy Smith was also working to obtain the Victoria government's backing for the project and raised the subject in the state's legislature on 2 October 1877.

The newly appointed Inspector-General of Fortifications in England, Sir Andrew Clarke, appreciated the value of the torpedo and in spring 1883 an experimental station was established at Garrison Point Fort, Sheerness on the River Medway and a workshop for Brennan was set up at the Chatham Barracks, the home of the Royal Engineers.

Brennan decided to accept £40,000 as a quick answer to his financial worries but his business partner J.R. Temperley assumed control of the negotiations and demanded £100,000.

A scandal eventually blew up over this sum, which was wildly extravagant in comparison to the £15,000 paid for manufacturing rights to the Whitehead torpedo only 15 years previously.

In 1905 the Committee on Armaments of Home Ports issued a report in which they recommended the removal of all Brennan torpedoes from fixed defences due to their comparatively short range and the difficulty of launching them at night.

Further sites proposed as funds become available at Plymouth (Bovisand), Milford Haven, Clyde, Forth, Falmouth, Hong Kong, Singapore and St Lucia.

The launching rails at Cliffe Fort in Kent are crossed by the public footpath and though heavily rusted are very easy to get close to.

There is also a display at Lei Yue Mun Fort in Hong Kong which shows a replica Brennan Torpedo with the side cut away so the workings are visible.