The Wartsila-Sulzer RTA96-C turbocharged two-stroke diesel engine is the
most powerful and most efficient prime-mover in the world today. |
Aioi Works of Japan's Diesel United, Ltd built the first engines and is
where some of these pictures were taken.
It is available in 6 through
14 cylinder versions, all are inline engines. These engines were
designed primarily for very large container ships.
Ship owners like
a single engine/single propeller design and the new generation of larger
container ships needed a bigger engine to propel them.
The cylinder bore is just
under 38" and the stroke is just over 98". Each cylinder displaces
111,143 cubic inches (1820 liters) and produces 7780 horsepower.
Total displacement comes out to 1,556,002 cubic inches (25,480 liters) for
the fourteen cylinder version.
| Some facts on the 14 cylinder version:
|Total engine weight:
||2300 tons (The crankshaft
alone weighs 300 tons.)
||108,920 Horsepower at 102
||5,608,312 lb/ft at
| Fuel Consumption
Fuel consumption at maximum
power is 0.278 lbs per hp per hour (Brake Specific Fuel
Fuel consumption at maximum economy is 0.260
At maximum economy the engine exceeds 50% thermal
That is, more than 50% of the energy in the fuel in
converted to motion.
For comparison, most
automotive and small aircraft engines have
BSFC figures in the 0.40-0.60
lbs/hp/hr range and 25-30% thermal efficiency
Even at it's most efficient
power setting, the big 14 consumes 1,660 gallons of heavy fuel oil per
section of the RTA96C:
The internals of this
engine are a bit different than most automotive
The top of the connecting rod is not
attached directly to the piston. The top of the connecting rod
attaches to a "crosshead" which rides in guide channels. A long
piston rod then connects the crosshead to the
I assume this is done so the the sideways
forces produced by the connecting rod are absorbed by the crosshead and
not by the piston. Those sideways forces are what makes the
cylinders in an auto engine get oval-shaped over time.
the "thin-shell" bearings. Crank & rod journals are 38" in
diameter and 16" wide:
sitting in the block (also known as a "gondola-style" bedplate).
This is a 10 cylinder version.|
Note the steps by each crank throw that
lead down into the crankcase:
& piston rod assembly. The piston is at the top. The large
square plate at the bottom is where the whole assembly attaches to the
And some piston
The "spikes" on
the piston rods are hollow tubes that go into the holes you can see
on the bottom of the pistons (left picture) and inject oil into the
inside of the piston which keeps the top of the piston from
overheating. Some high-performance auto engines have a similar
feature where an oil squirter nozzle squirts oil onto the bottom of
cylinder deck (10 cylinder version). Cylinder liners are die-cast
ductile cast iron. Look at the size of those head studs!:
completed 12 cylinder engine:
|This ship is powered by a RTA96-C engine:
This is a modified copy of the page produced by Todd