In the USSR, great importance was attached to the use of jet aircraft engines in transport. In 1970, the Kalinin Carriage Works completed the production of a jet locomotive, called SVL (high-speed laboratory car).
The body of the high-speed car was built on the basis of the ER22 motor head car, which had head and tail fairings, and the undercar equipment and chassis were covered on both sides with removable bulwarks.
Moreover, the cabin, front and rear walls of the ER22 are preserved, the fairings are only “attachments”. It's funny that as a result, the driver looks at the path through two glasses: the cab and the fairing.
The shape of the fairings was developed by Moscow State University and has a drag coefficient of 0.252. The car model was blown in the TsAGI wind tunnel.
As a matter of fact, KVZ planned to build the Russian Troika super-fast jet train with precisely these fairings. To reduce air resistance when driving at high speeds, the SA-3 automatic coupler is also covered with a removable fairing.
The head car ER22-67 was specially built by the Riga Carriage Works for SVL - that is, the drawings were ordinary, but special attention was paid to the quality of workmanship. Initially, the SVL was painted in ER22 colors: creamy yellow top and red bottom. The length of the car with fairings is 28 m.
The car has biaxial bogies, unusual for the head car, designed by the Kalinin Carriage Works and VNIIV with air springs of the central suspension. Such bogies were previously rolled under trailer cars of ER22 electric trains.
The car is equipped with disc brakes with pneumatic and electro-pneumatic control. There are sandboxes to increase the adhesion of the wheels to the rails during braking. On the roof of the car in its head part, two aircraft turbojet engines of the Yak-40 aircraft are installed on a special pylon, which create the necessary traction force for the movement of the car. The weight of two engines is less than 1t. Their maximum traction force is 3000 kgf.
The driver's cabin is equipped with an aircraft engine control panel, as well as conventional brake and sandbox control devices. A diesel generator was installed in the back of the carriage. The generator supplies power to the compressor motor, lighting fixtures, control circuits and electric furnaces. The equipped car weighed 59.4 tons, including a fuel supply (kerosene) of 7.2 tons.
In 1971, the experimental car was tested on the Golutvin - Ozyory line of the Moscow road, where a speed of 187 km/h was achieved. Then, at the beginning of 1972, the car made trips on the Novomoskovsk - Dneprodzerzhinsk section of the Dnieper Railway, where the maximum speed gradually increased (160, 180, 200 km/h). The result of the tests was a speed of 249 km/h.
It should be noted that the purpose of the tests was not to set a speed record. The tests were carried out to study the interactions in the wheel-rail system for future high-speed trains. The best option for testing was a car that “travels on its own,” without pushing off the rails with its wheels. It was not possible to attach the carriage to the locomotive, because in 1970 there were no locomotives in the USSR capable of maintaining a speed of more than 230 km/h for a long time. The railway track also did not allow speeds of more than 250 km/h.
After completion of the tests, the SVL was abandoned in the outskirts of the Kalinin Carriage Plant near the station. Doroshikha. There he remains to this day... 
