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This was an email from a friend who used to work on these type of engines. I received this when he saw these pictures. Kinda gives some perspective. The last big diesel I worked on was a Sulzer 12RTA84...straight twelve cylinder two-stroke, 84 cm bore (33"), about a 100" stroke, 35 rpm slow speed, 95 rpm top speed, four turbochargers about as tall as I am, 57,500 hp. The descriptions in the link are pretty accurate. The cross head is the equivalent of a wrist pin. The piston rod is bolted solid to the piston and the round piston rod passes through a seal. Above the seal, the underside of the piston helps pump air into the cylinder scavenging ports. Below the seal is the crankcase. The crankcase holds about 30 tons of SAE 30 oil, and is generally good for the life of the engine. SAE 50 or 60 oil is pumped directly into ports in the cylinder wall to lubricate the piston and rings and is consumed. At full power the 12 cylinder engine consumed about a ton of this cylinder oil daily. This piston rod seal is the round assembly you see just above the square end of the piston rod in the picture of the piston and the rod. I've never heard of a "gondola" style bedplate, and I studied at the Sulzer factory in Winterthur, Switzerland. The large gear you see at one end of the crankshaft is for the turning gear...this allows the shut-down engine to be cranked over (for repairs and inspection) by the small electric motor you see on the left. The gear wheel you see in the middle of the crankshaft drives the camshaft for the exhaust valves and fuel injection pumps. The exhaust valves are opened by a hydraulic cylinder on the camshaft with a mating hydraulic cylinder on the valve. The exhaust valve has a compressed air cylinder to close it...no other spring. Intake takes place through scavenging ports in the bottom of the cylinder liner...two stroke, eh. The engine is started by admitting 450 psi compressed air into the tops of the cylinders in the correct sequence to roll the engine over. The engine is directly coupled to the propeller and is reversible. Earlier versions of Sulzer engines, not the "C" version, had water cooled pistons. The pistons are cast iron with replaceable forged steel crowns. In the lower picture the worker is standing alongside a fuel injection pump assembly...it holds injection pumps for two cylinders. The fuel is heavy black oil...centrifuged and heated to about 250°f to be fluid enough to atomize in the cylinder and burn cleanly. The engine starts on this black oil because it's kept continuously circulating through the injection system and kept hot. It only uses what we think of as diesel fuel if the steam system is shut down--the steam is needed to keep the heavy fuel hot. I know the links says that the engine was built in Japan, but the signs are Korean. All large engines are built in Asia these days for cost reasons, although there might be a few built in eastern Europe. There are three designers of large engines---NSD Sulzer, owned by Wartsila of Finland, MAN B&W owned by MAN of Germany, and Mitsubishi, with the majority being MAN B&Ws (Burmeister& Wain, used to be Danish, and Machinery Works of Neuremburg, now Augsburg). If these are large engines, what a medium sized engine...think a locomotive engine or larger. All engines are completely assembled on test beds, run at 100% and 110% of rated power into dynamometers (imagine the dyno that absorbes 100,000+ hp!) then disassembled and shipped to the ship builder for assembly in the ship. These large engines are also used for electric power plants when a steam plant would be too big (steam plants of this size are too inefficient).
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