New Generation Programme L58-64

New generation programme L58-64.

The ‘new generation’ programme was headed in 1984 by the 580 mm bore/640 mm stroke L58/64 series whose designers sought a highoverall operating economy, reliability, ease of maintenance, componentdurability and unrestricted heavy fuel compatibility. The rugged (Figures22.1 and 22.3) result can be contrasted with MAN B&W Diesel’s previouslarge bore engine, the 520 mm bore 52/55B (Figure 22.4).Among the main features of the L58/64 and its 400 mm and480 mm bore derivatives is a stiff monobloc frame casting withcontinuous tie-rods from the underslung main bearings to the topedge of the engine frame, and tie-rods from the cylinder head to theframe diaphragm plate (Figures 22.5 and 22.6). This arrangementwas associated with: an optimum flow of forces from the cylinder head down to the crankshaft; minimal deformation of the cylinder liner;more reliable piston performance; all parts of the frame under pre-stress; cross-braced crankshaft bearings; an amply dimensioned outboardbearing for absorbing high radial forces at the power take-off end ofthe crankshaft; no cooling water passage in the casing (eliminatingthe potential for corrosion); sturdy landings to prevent plant deformation; and camshaft drive gear and vibration damper integratedin the engine casing.