Merlin crankshaft assembly

[Greybeard]

Workers at a Rolls Royce factory lowering the crankshaft assembly into the crankcase of a Merlin aircraft engine, England, 1942

[limeyrob]

If you like this i suggest reading "Not Much of and Engineer" by Sir Stanley Hooker.  Its an excellent read and he he talks a lot about the development of the Merlin.  There's a great bit about being told by Ford engineers that the RR Merlin drawings and tolerances were not good enough for mass production.  They re-drew the lot.

[Catz]

I'm fairly sure that the Merlin engines were made in Crewe, near where i live, and Bentley sold the old factory where the engines were made to the local council which was then used as the Refuse Depot.
I worked for the council on the bins and that part of the factory was used by us as a store room and also where we clocked on in the morning before the days shift.
You could see the ventilation turrets with huge fans in the ceiling where the fumes were extracted when the engines were fired up on the test beds.
Bentley have done some major restructuring of the Crewe site and where we had our base was sold back to Bentley and Cheshire East Council had a purpose built depot in Middlewich but whether they have pulled the old factory building down i don't know. The main Bentley factory on Pyms Lane is still there.

[Greybeard]

If you like this i suggest reading "Not Much of and Engineer" by Sir Stanley Hooker.  Its an excellent read and he he talks a lot about the development of the Merlin.  There's a great bit about being told by Ford engineers that the RR Merlin drawings and tolerances were not good enough for mass production.  They re-drew the lot.

Were the RR tolerances too tight for mass production or the opposite?

[limeyrob]

Opposite, the RR drawing were very much for hand / selective assembly.  The Ford engineers were horrified and said if they were going to mass produce the engines they had to be much more precise.  Essentially Ford taught RR how to tolerance the parts and set up the production.  Hooker is very complimentary about them.  I've read elsewhere that at this stage in the war Ford would not manufacture for war but would help. I think they suggested Packard.

[Greybeard]

I understand now 👍

[Rex]

Opposite, the RR drawing were very much for hand / selective assembly.  The Ford engineers were horrified and said if they were going to mass produce the engines they had to be much more precise.

That makes sense when you consider RR's engineering philosophy. Selective assembly gives the best assembly, but on the Detroit production lines near enough is good enough especially when they're on a moving production line.
Doesn't mean that RR's production was somehow sub-standard, just that Ford's would be quicker, less skilled labour required and hence cheaper.

[limeyrob]

Well I owe a correction, it is Ford engineers from Ford UK at Trafford who redrew all the drawings for mass production.  It took a year and once done the Ford factory at Manchester went into production making 400 Merlins a week.  These same drawings would then go to Packard but the original work was done in the UK.