In these enormous engines,
the cylinders are not bored as they are in your car.
Rather each cylinder is made up of a separate
very thick walled piece of pipe called a liner.
This piece of pipe is about 1 meter in diameter
and about four meters long.
Each liner weighs about 5 tons.
It is drilled with inlet ports,
and all sorts of cooling and lubricating passages.
On April the 19th, 2003,
the main engine on the Hellespont Alhambra suddenly shut itself down.
The crew discovered that one of the nine liners
had split into two pieces.
The top part was still in place
but the bottom two thirds was totally detached
and had fallen down about 10 mm.
The only thing that was keeping the bottom portion
from falling onto the crankshaft was
that it had hung up on some lubricating fittings.
If that had happened, the ship would have
been helpless until a tug arrived.
The main engine would have had to be totally rebuilt.
Despite our best efforts, we never learned why the liner failed.
The Classification Society, Lloyds Register, was useless.
Sulzer was less than cooperative.
But in investigating the failure we learned a lot
about how far the thermal stress levels in the liner had been pushed
in the quest for more and more power out of the same engine.
There simply were no margins.
Most likely, the liner had a small manufacturing defect
which combined with this imprudent design philosophy
resulted in the failure.