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Louis Brennan - Castlebarman who invented the dirigible torpedo

The invention of the dirigible torpedo established Louis Brennan as an ingenious inventor and placed him in a buoyant financial position, and it is interesting to record that 100 years ago a shore station for the launching of the Brennan torpedoes was established at Fort Camden, at the narrow mouth of Cork Harbour.

Brennan was born on January 28, 1852, at Castlebar, the son of Thomas Brennan, a hardware merchant, and Bridget Brennan, nee McDonnell.  The family emigrated to Melbourne in 1861 and Louis resided there until 1880.  He was working as a watchmaker when the germ of the idea for the dirigible torpedo came to him. Brennan torpedo servicing areas and launching ramps were also built at Gravesend, Plymouth, at Sheerness and at the Isle of Wight.  The British Government thought so highly of the invention that they paid Louis Brennan £100,000 and gave him other financial support.  The amount awarded by the British Government was the highest up to that time to an inventor for the engineering concepts and applications were much in advance of their time.

It was while in control of the planning machine worked by the leather driving belt that Brennan stumbled on the mechanical paradox that it is possible to make a machine travel forward by pulling it backwards. He demonstrated this by means of a cotton reel, with a pencil thrust through the hole in the centre.  By resting the ends of this pencil on two books and unwinding the cotton by pulling it from underneath, he caused the reel to move forward; the harder he pulled the faster the cotton unwound and the quicker the reel travelled in the reverse direction.

The Brennan torpedo substituted for the reel a steel cylinder and for the cotton a coil of piano wire. Brennan could think only of torpedo for the application of his paradoxical principle, as it did not need to make a return journey. Brennan received a development grant from the State of Victoria and the working model was successfully tested at Hobson’s Bay, Melbourne, in March, 1879.

A full size model, embodying an improved pattern of the torpedo, was constructed at the Government’s expense in England, between August, 1881, and May, 1882, and in the spring of 1883, Brennan was placed in charge of an experimental station at Garrison Point, Sheerness, not far from the School of Military Engineering at Brompton Barracks, Gillingham, Kent, the leading military scientific school in Europe. Investigators held searching tests on the accuracy of the torpedo against stationary and moving targets, and declared that Brennan’s mechanism was very ingenious.  The torpedo could be propelled and directed from the shore at a rate of 20-25 knots for 1,000 yards or more, and meanwhile its course could be varied by the operator on shore.

Louis Brennan was superintendent of the Government torpedo factory at Gillingham from 1887 until 1907, by which time the torpedo was inferior to the 9.2” guns being used at shore batteries

Taken from Castlebar Parish Magazine, 1986 


Louis Brennan now set his mind upon inventing a train which ran on one rail.  Today the Monorail system is becoming popular again in answer to modern traffic congestion.  The invention was to be a success but because it lacked financial backing it never became popular as a means of transport.  In 1907 he was ready to exhibit his first model.  He did so at his home in “Woodlands” in Kent.  The reporters present were impressed by its performance. 

 Image of Louis Brennan demonstrating a model of his monorail invention

By 1909 Louis Brennan had built his first full-sized monorail car.  It would be another first for Louis Brennan – but just by half a day.  It was discovered that a monorail demonstration would be carried out in Berlin on November 10, 1909, at midday.  He decided that he would try out his vehicle on the morning of the same day and pip the Berliners at the post.  That morning, through the gates of the factory and on one rail came the 22 ton Brennan monorail.  It ran on a single row of wheels. The spectators climbed on board and away they went.

When it went on display in White City in 1910, Winston Churchill drove the machine and the Prime Minister, the Home Secretary and the Chancellor, among others, were around the track.  It seemed that success and wealth were at hand.  But the monorail never became a commercial success and as a result Louis Brennan had to sell his beautiful house, “Woodlands”.  He moved to Hampshire after the sale.

Extract taken from "Remembering Castlebar's Louis Brennan" written by Mayo author Michael Mullen in the Connaught Telegraph

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