"Andy Breen" wrote

Reading this prompts another thought, regarding the development of
locomotives in the earlies. I've not seen it listed before, but surely
one of the major advantages of a separate firebox (as adopted by
Stephenson's works from Rocket onwards, though not by some other builders
until much later [1]) is that it would allow the fire to be dumped
reasonably easily (as above), whereas with a flue-type grate the whole
fire would have to be raked out through the back of the box across the
footplate. Not idea, if the feed-pump has packed in, you're miles
from help and the water level is dropping...

It also depends on the crew knowing what to look for, and what to do if
something goes wrong.
http://www.raib.gov.uk/publications/...3_Kirklees.cfm

Whist the fusible plug did its job, the delay by the crew in dumping the
fire may well have caused damage to the boiler.

Peter