Louis Brennan with his Gyro-Monorail in New York. The Brennan Gyro-Monorail was balanced by two vertical gyroscopes mounted side-by-side, which spun in opposite directions. Louis Brennan (1852- 1932) was an Irish inventor who worked on early monorails, as well as developing the torpedo. Brennan was forced to sell his marital home when Government support for his monorail was withdrawn, and he went on to carry out research involving the development of the helicopter. In December 1932, Breannan was knocked down by a car and died of his injuries a month later.