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 High-speed engine
6.65 m long, 2.04 m wide, and 3.38 m high. Its dry weight is 45.3 tons, significantly more than the weight of a fully loaded truck/trailer combination. The three engines in the 8000 series all have 20 cylinders, arranged in a V-
shape at just 48°, a total displacement of 347 liters, a 265 mm bore, and a 315 mm stroke. This means that each cylinder has significantly more displacement than the combined capacity of the largest truck engines. The
three 8000 series models differ in their power output, ranging from 7,200 kW (9,792 hp) to 9,100 kW (12,376 hp).
The consistently constant rated speed of 1,150 rpm is impressive for such large engines. The most powerful of this series is said to consume approximately 2 tons of fuel per hour, albeit at full power. The 190 g/h of CO
2 emissions seem downright moderate in comparison. The engine is not started electrically, but by a starter powered by approximately 40 bar of compressed air. A brief check of the engine is required after
each start.
The coolant is preheated, and there are heat exchangers for the oil/coolant. Unlike the large slow-running engines that use tons of oil, this one features a wet sump lubrication system with 1,600 liters in the oil pan, which
is pumped around twice per minute at rated speed. The engine operates according to the common rail principle with correspondingly high pressures, even features cylinder deactivation, and is vented via a hand pump, for
example, after assembly work. The fuel gets so hot that it requires additional cooling in the return line.
A marine engine, of course, doesn't need an air-flow cooler, but instead draws coolingfrom the surrounding sea using a raw water pump. However, this water doesn't reach the engine directly, but only as far as a heat
exchanger. Not only is the engine itself cooled by its own cooling circuit, but also the intercooler and the four turbochargers. Unlike slow-running engines, this engine has a clutch and is available with gearboxes. Several of
these engines can be combined, and jet engines can also replace propellers.
There is no cylinder block on this engine, as you might be familiar with from a car engine. Even in a truck, the only coherent part except than the crankshaft may be its housing. The cylinders and cylinder heads are then
mounted on this. The crankcase of the 8000 series requires three melting furnaces in specialty foundries, all of which must keep the alloyed steel at the correct temperature for the casting process. Of course, the resulting
blank, at 16 tons, is significantly heavier than the final engine component.
Many days of waiting for cooling and work until the blank is cleanly separated from its sand mold. The tolerances, ranging from a few hundredths of a millimeter to such a huge part, are incredible. It takes time for the
crankcase to be machined in most places. This is where it loses another 10 percent of its weight. Constant inspections accompany assembly, for example, of the crankshaft and the pre-prepared, nested piston-cylinder
units. Weeks pass before assembly is completed.
Many days of waiting for cooling-down and work until the blank is cleanly separated from its sand mold. The tolerances, ranging from a few hundredths of a millimeter for such a huge part, are incredible. It takes time for the
crankcase to be machined in most places. This is where it loses another 10 percent of its weight. Constant inspections accompany assembly, for example, of the crankshaft and the pre-prepared, nested piston-cylinder
units. Weeks pass before assembly is completed.
The engine features a central camshaft that operates four valves on each cylinder. The crankshaft, in contrast, is a single-piece unit, but has bolted-on counterweights. During its decades of downtime, the only major parts
to be replaced on the entire hull engine are the pistons and their wet liners. This can be done in port within a single working day. Other components include the turbochargers, so large and heavy that they can only be
transported by crane. As a group, they form the typical tower at the rear of the engine.
The engine features a central camshaft that operates four valves on each cylinder. The crankshaft, in contrast, is a single-piece unit, but has bolted-on counterweights. During its service life of several decades, the only
major parts to be replaced on the entire hull engine are the pistons and their wet liners. This can be done in port within a single working day. Other components include the turbochargers, so large and heavy that they can
only be transported by crane. As a group, they form the typical tower at the rear of the engine.
| Boost pressure: Twice as high as in smaller diesel engines. |
This large engine also ultimately has to be put on the dynamometer. Presumably, there is no electric brake for this power and torque class. This is where the good old water vortex brake comes in. Installing it in a ship is
more complicated than, say, installing a diesel engine in a truck. With these huge, slow-running engines, the engine can't be removed until scrapping of the ship.
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