The common rail for fuel injection is a manifold running the length
of the engine at just below the cylinder cover level; the rail and other
related pipework are arranged on the top engine platform with ready
accessibility from above (Figure 12.32). The common rail is fed with
heated fuel oil at a high pressure (nominally 1000 bar) ready for
injection into the engine cylinders. The fuel supply unit embraces a
number of high pressure pumps mechanically driven from the
crankshaft and running on multi-lobe cams, which increase their supply
capacity and hence reduce the number needed. A four-pump set is
sufficient for a six-cylinder RT-flex 58T-B engine. The pump design,
based on fuel injection pumps used in Sulzer four-stroke engines,
has suction control to regulate the fuel delivery volume according to
engine requirements (Figure 12.33