Hello Leo –
It looks like you have gotten good explanations of what may have happened.
Failures on a steam locomotive tended to be dramatic and highly visible.
Diesels tend to “internalize” their problems – they could have a crankcase explosion
and show little evidence on the exterior.
In the spring of 1956 my first railroad job was in a roundhouse full of steam locomotives
on the N&W. One fine day a ‘Y’ (2-8-8-2) was shoved in the house. It had a bent main rod.
The bracket holding the dry pipe against the top of the boiler had broken, letting the dry pipe
fall down onto the boiler tubes. A slug of water got into the steam passages and led to an
‘hydraulic lock’ on one cylinder. That engine would have stopped almost immediately, but
the train would have shoved the locomotive on down the track. Must have been one hell of
a ride for the crew. {On the N&W steamers were always ‘locomotives’, because most of them
had two ‘engines’. We had to be very specific: ‘front’ engine or ‘rear’ engine}.
In a perfect world the cylinder head should have blown off. That would have been a lot
easier to handle and repair.
In this episode on the Q water evidently got into the steam passages and locked up both sides.
The cylinder heads ‘should have’ blown, the main crank pins ‘could have’ failed, but who
‘would have’ thought the main rods would bend. The side rods generally stayed out of trouble.
PAW
The story comes direct from the fireman on the engine, who is a spry very senior citizen. I just checked the written version and he refers to side rods once and main rods twice.