The German team at Khimki was completing build of a subscale, 7 tonne thrust version of a radical new flat-plate injector, cylindrical combustion chamber. This is identified in Glushko's memoirs as the ED-140 (without noting its German origin). The ED-140 configuration would form the basis of Glushko's rocket engines for the next fifteen years. For Korolev's R-3, Glushko proposed to copy the V-2 approach by using 19 of these 7 tonne chambers as 'preburners' to feed a main mixing chamber, producing a high-performance engine of over 120 tonnes thrust. The preburners had a chamber diameter of 200 mm as opposed to the 240 mm of the ED-140, but the same 60 atmosphere chamber pressure. The spherical chamber had special interior structures to ensure even mixture of the combustion gases and a stable chamber pressure. However during development problems in fabrication of the large spherical mixing chamber, and synchronisation of propellant feed to the 19 preburners could not be solved. The engine was never put into production, but valuable experience was gained in the scientific basis for increasing thrust and specific impulse in other future engines. Glushko instead would scale up the ED-140 concept (flat-plate injector, cylindrical combustion chamber with a 60 atmosphere chamber pressure) to 25 tonnes thrust and cluster these chamber to make his engines for the first generations of large Soviet ballistic missiles. The original design specification was for a specific impulse of 288 sec in vacuum. Only one mock-up engine was completed, a cold flow-test article using kerosene and water. It can be seen at the NPO Energomash museum.