length of only 17 ft (5.2m). It could accommodate four passengers on a pair of transverse bench seats. The gyros were located under the seats, and had vertical axes, while Brennan used a pair of horizontal axis gyros. The servomechanism was hydraulic, and propulsion electric. Strictly speaking, August Scherl merely provided the financial backing. The righting mechanism was invented by Paul Fröhlich, and the car designed by Emil Falcke. Although well received and performing perfectly during its public demonstrations, the car failed to attract significant financial support, and Scherl wrote off his investment in it. Shilovsky's work Following the failure of Brennan and Scherl to attract the necessary investment, the practical development of the gyro-monorail after 1910 continued with the work of Pyotr Shilovsky, a Russian aristocrat residing in London. His balancing system was based on slightly different principles to those of Brennan and Scherl, and permitted the use of a smaller, more slowly spinning gyroscope. After developing a model gyro monorail in 1911, he designed a gyrocar which was built by Wolseley Motors Limited and tested on the streets of London in 1913. Since it used a single gyro, rather than the counter-rotating pair favoured by Brennan and Scherl, it exhibited asymmetry in its behaviour, and became unstable during sharp left hand turns. It attracted interest but no serious funding. Post-World War I developments In 1922, the Soviet government began construction of a Shilovsky monorail between Leningrad and Tsarskoe Selo, but funds ran out shortly after the project was begun. In 1929, at the age of 74, Brennan also developed a gyrocar. This was turned down by a consortium of Austin/Morris/Rover, on the basis that they could sell all the conventional cars they built. 21st century: Monocab In October 2022 the Technische Hochschule OWL, the Bielefeld University of Applied Sciences, the Fraunhofer-Institut für Optronik, Systemtechnik und Bildauswertung and the Landeseisenbahn Lippe e. V. presented a gyro-stabilized monorail according to Brennan on a section of the Extertal railway in Germany. The system called Monocab is meant to permit bi-directional service on a single track since the vehicles use only one rail. The cabins that shall operate autonomously on-demand are designed accordingly narrow. In September 2020 Monocab was funded from the European Regional Development Fund and by the state of North Rhine-Westphalia with 3.6 million euros combined. Principles of operation Basic idea The vehicle runs on a single conventional rail, so