Aerowagon

The Aerowagon or Aeromotowagon (Аэроваго́н, аэродрези́на) was an experimental high-speed railcar fitted with an aircraft engine and propeller traction invented by Valerian Abakovsky, a Soviet engineer from Latvia. It produced speeds of up to 140 km/h. The Aerowagon was originally intended for the express transportation of important documents and to carry Soviet officials on government business.

Crash incident
On 24 July 1921, a group of delegates to the First Congress of the Profintern, led by Fyodor Sergeyev, took the Aerowagon from Moscow to the Tula collieries to meet with local miners and to visit an arms factory. Abakovsky was also on board. Although they successfully arrived in Tula, on the return route to Moscow the Aerowagon derailed at high speed near Serpukhov, killing six of the 22 people on board. A seventh man (Paul Freeman) later died of his injuries.

An official investigation concluded that the cause of the derailment was the poor condition of the railway track. Artyom Sergeyev (the son of victim Fyodor Sergeyev) claimed sabotage arranged by Trotsky.

Deaths
The following people died as a result of the accident: All seven men lay in state at the House of the Unions, after which they were buried with honors in the Kremlin Wall Necropolis. Sergeyev is buried in Mass Grave No. 12, Konstantinov, Abakovsky and Freeman are buried in Mass Grave No. 13, while Strupat, Helbrich and Hewlett are buried in Mass Grave No. 14.
 * Ivan Konstantinov, Bulgarian delegate
 * Paul Freeman, Australian delegate
 * Oskar Hellbrück, German delegate
 * John William Hewlett, British delegate
 * Fyodor Sergeyev (known as "Comrade Artyom")
 * Otto Strupat, German delegate
 * Valerian Abakovsky, the Aerowagon's inventor

Legacy
The Aerowagon was a precursor to the German Schienenzeppelin railcar, the American M-497 Black Beetle railcar and the Soviet turbojet train, all three of them being experimental vehicles featuring the combination of railcar and aircraft engines.