The aft end of the thrust chamber.
A line led from
the fuel inlet to the fuel manifold (the larger opening at the exit
plane). The fuel then travelled between the two walls of the thrust chamber to
the injector at the forward end of the engine, providing regenerative cooling
and preventing the inner wall from melting.
Note the coil which was welded between the two
walls, forcing the fuel to circulate through the resulting spiral
passage. This increased velocity of the fuel, resulting in higher heat