dsc46476.jpg

Various views of the regenerative cooling tubes making up the engine's thrust chamber.

Picture 6 of 7.

Note the point where the regenerative tubes bifurcate (split in to) (see dsc46467.jpg for a view of the bifurcation point on the exterior of the thrust chamber).

The only other common engine of which I can think whose regenerative cooling tubes bifurcate is the Saturn V's F-1 engine.