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I found thisWithout detailed histories of each factory there can be quite a bit of cross over. It could between 1 and 2 years to get a factory from start of production to reaching full production.
And in some cases it took a fair amount of time to even get to a few hundred engines a month.
I looked up the S.S. City of Flint and she sank in a storm on Great Lakes on Nov 11th 1940. She was only 500ft from shore and was salvaged and put back in service. NO idea what happened to the machine tools that were aboard.
Now from wiki we have on GLasgow...........................
"Engines began to leave the production line in November 1940, and by June 1941 monthly output had reached 200, increasing to more than 400 per month by March 1942."
But apparently Glasgow was starting production with parts shipped in from other factories to provide training. A good idea, to get the workers up to speed.
There was a whole lot of stuff going on at the same time, and while Ford only started construction of the factory buildings in April of 1940 modern factory construction is not a matter of throwing up buildings and seeing where you can stuff the machinery. You figure out how you want the flow of parts from the different depts to go and join together on the assembly lines lines. Once you have the factory floor plan laid out they you build the building. Ford may have been working on the plans for the factory for weeks or months before they broke ground.
Packard built 4 engines in their first month of production, Sept 1941, they only built 26 in Dec 1941 but in April of 1942 they built 505. Packard had a few advantages, they weren't being bombed for one thing.
I am not trying to say the US was better, I am saying that there was a lot of overlap between some of the factories and the way they were building engines in 1943/45 might not have been they way there were building them in 1940/41. Off course that goes for quite a few engines.
I read somewhere on the story of the Ford Manchester plant that the first discussions between RR and Ford were with Ford France. The Trafford Park factory in Manchester started work to become a shadow factory in 1938. Mass production is a science and a skill, it would have been foolish of RR NOT to pick the brains of Ford engineers if they had the chance.The RR files I have say that the Merlin 1 engine was never properly tooled up, I.e. it wasn't mass produced in general principle. So we can see that sometime between then and about 1940/1941, RR was in some transition phase between knocking up a few merins at derby and managing a series of large factories mass producing them.
So the simple answer to the source of this silly myth is that the notion of how RR made engines came from anecdotes from this transitionary period.
Totally agree re: New Factory design for specific application. Under any circumstances, Ford would start with the Process Plans for each part, carefully consider the machine tools required to make them, to world class process plan(s) desired for each class of parts. The next consideration is to match as well as possible the flow of parts from one set of machine requirement to the Next and plan for common batteries if possible to minimize movement (and tracking) of parts - with an eye to complete as much of a complex part as possibe in one machining/process center as possible. Quality and throughput time drive costs.Without detailed histories of each factory there can be quite a bit of cross over. It could between 1 and 2 years to get a factory from start of production to reaching full production.
And in some cases it took a fair amount of time to even get to a few hundred engines a month.
I looked up the S.S. City of Flint and she sank in a storm on Great Lakes on Nov 11th 1940. She was only 500ft from shore and was salvaged and put back in service. NO idea what happened to the machine tools that were aboard.
Now from wiki we have on GLasgow...........................
"Engines began to leave the production line in November 1940, and by June 1941 monthly output had reached 200, increasing to more than 400 per month by March 1942."
But apparently Glasgow was starting production with parts shipped in from other factories to provide training. A good idea, to get the workers up to speed.
There was a whole lot of stuff going on at the same time, and while Ford only started construction of the factory buildings in April of 1940 modern factory construction is not a matter of throwing up buildings and seeing where you can stuff the machinery. You figure out how you want the flow of parts from the different depts to go and join together on the assembly lines lines. Once you have the factory floor plan laid out they you build the building. Ford may have been working on the plans for the factory for weeks or months before they broke ground.
Packard built 4 engines in their first month of production, Sept 1941, they only built 26 in Dec 1941 but in April of 1942 they built 505. Packard had a few advantages, they weren't being bombed for one thing.
I am not trying to say the US was better, I am saying that there was a lot of overlap between some of the factories and the way they were building engines in 1943/45 might not have been they way there were building them in 1940/41. Off course that goes for quite a few engines.
ThomaP - while I don't discount the possibility that Packard needed to 'tighten' its own tolerances, I don't think it can be based on facts unless access to RR drawings and comparable Packard drawing can be compared.I have alway assumed that the comment/story re Packard tightening up tolerances was referencing the need for Packard to tighten its own tolerances. The tolerances for the Packard automobile engines of the time were not as tight as the tolerances on the Merlin engine.
Tolerances dont always scale up, you have to work to different tolerances or have different ways of doing things.I do not think it is a case of Packard needing instructions on tolerances so much as it is that the required tolerances for the relatively small in3 and low HP/in3 automobile engines of the time would have been significantly different than for relatively large and high HP/in3 engine like the Merlin/V-1710/DB601/etc.
Using the crankshaft as an example:
As pointed out by Snowygrouch in his post "An interesting read about the Packard built Merlin engine." the Merlin crankshaft tolerance was ~twice as tight as modern crankshaft tolerances for automobile engines. This was an amazingly tight tolerance for 1940, and was presumably a necessary tolerance.
It was not until the early-1990s that holding diameter tolerances of +/-0.00025" became relatively common on machined parts. This was due to a combination of increased capability of modern computer controlled turning and machining centers and the associated reduced cost of achieving the tolerance. Prior to the early-1990s a tolerance of +/-0.0005 was the best commonly achieved. During WWII +/-0.001 was the tightest commonly achievable tolerance.
(A general rule of thumb in machining is that for every time you reduce the tolerance by half you double the time it takes to make that particular feature.)
The cost of a Merlin engine (I think) was somewhere around $6000 in 1941. The cost of the most expensive Packard sedan was ~$5800.
There is no reason to believe that the Packard or Ford automobile engine of 1940 was held to tolerances as tight as modern high performance automobile engines. It would not have been economical or necessary within the industry needs of the time.
I know that if I were approached to manufacture a scaled up engine (such as from a 356 in3 V8 to a 1650 in3 V12) one of the first things to go through my head would be that - due to the size alone - tolerances would have to be tighter in order to achieve the required cumulative runout/ straightness/ flatness (to manage vibration and sealing problems) and to maintain fit/interchangeability of parts.
True - but debate between Packard and R-R is simply cut off by R-R in the context "we are the customer, giving you a contract to meet our specifications depend on a.) Willingness to do so, and b.) capability to do so, and c.) adhere to the QA/QC demands contained theerin".I do not think it is a case of Packard needing instructions on tolerances so much as it is that the required tolerances for the relatively small in3 and low HP/in3 automobile engines of the time would have been significantly different than for relatively large and high HP/in3 engine like the Merlin/V-1710/DB601/etc.
Using the crankshaft as an example:
As pointed out by Snowygrouch in his post "An interesting read about the Packard built Merlin engine." the Merlin crankshaft tolerance was ~twice as tight as modern crankshaft tolerances for automobile engines. This was an amazingly tight tolerance for 1940, and was presumably a necessary tolerance.
Not to belabor the point, but didn't Packard deliver the required tolerances required by R-R? As a tangent, the tolerances achieved dimensionally and spherically exceeded that in the 1945-1950 timeframe at Lawrence Livermore, Hanford, Oak Ridge and Savannah River nuclear weapons designs and fabrication. The tolerance issues were achieved by combination of computer controls and polishing techniques. Pause - I know this anecdotally, not by hands on observation. The increased tolerance achivements were requiredto improve efficiency of nuclear chain reactionsIt was not until the early-1990s that holding diameter tolerances of +/-0.00025" became relatively common on machined parts. This was due to a combination of increased capability of modern computer controlled turning and machining centers and the associated reduced cost of achieving the tolerance. Prior to the early-1990s a tolerance of +/-0.0005 was the best commonly achieved. During WWII +/-0.001 was the tightest commonly achievable tolerance.
The point is well taken and illustrates the imbedded direct costs and overheads associated with producing the Merlin and the Packard. There is no question that either engine required significantly more investment in machine tools and processes than associated with a Pacakrd (or Ford) vehicle of the 1940s. But recognize that tooling is depreciated from the Balance Sheet while overhead is baked into Indirect Costs - who knows what the unit cost (not price) was unless the books are available in detail. I assume (bad word) that the Packard contract was let as Cost Plus with exquisite details contained in R-R/Packard Agreement(A general rule of thumb in machining is that for every time you reduce the tolerance by half you double the time it takes to make that particular feature.)
The cost of a Merlin engine (I think) was somewhere around $6000 in 1941. The cost of the most expensive Packard sedan was ~$5800.
Agreed again - but the question being asked is 'Could They', and what extra ordinary steps, if any, would have been required to a.) acquire the tooling, b.) firm up the process plans to machne, inspect and approve the 'extreme' (greater than auto, but within reach technically) tolerances required for criical parts, c.) acquire and install the upgraded tools (i.e including making in-house, d.) train for the upgraded processes and equipment. All this would have led to pricing and contractural framework to be Paid.There is no reason to believe that the Packard or Ford automobile engine of 1940 was held to tolerances as tight as modern high performance automobile engines. It would not have been economical or necessary within the industry needs of the time.
Absolutely agreed. I will bow to your hands on experience in the related field, noting that even at Bell Helicopter and Vought and Lockheed were uch considerations and design attributes requiring 'flatness' and 'sphericity' beyond standard manufacturing strike zone.I know that if I were approached to manufacture a scaled up engine (such as from a 356 in3 V8 to a 1650 in3 V12) one of the first things to go through my head would be that - due to the size alone - tolerances would have to be tighter in order to achieve the required cumulative runout/ straightness/ flatness (to manage vibration and sealing problems) and to maintain fit/interchangeability of parts.
I think you are getting the wrong end of the discussion. The whole "thing" stems from a discussion between Cyril Lovesey of RR and someone from Ford in the early days of Ford being involved in RR production. To paraphrase the guy from Ford said "we cannot manufacture to these tolerances" to which Lovesey replied, are they too demanding" the Ford guy said "no, to make car engines we use much tighter tolerances because every piston has to fit in every cylinder". However at the time Lovesey had no experience of production engineering, his main work was on the racing engines, where you probably do machine the bores and then machine pistons to fit.I am not saying in anyway that Packard or Ford were not able to meet the specifications. I am only addressing the possible origin of the statement(s) (I have read accounts of the statement as coming from the Ford rep or the Packard rep) that 'they would have to tighten the tolerances for mass production'. Such a statement would make sense if it was addressing a need for Packard or Ford to adopt tighter tolerances than they usually used for their mass produced automobile engines. It would not make any sense otherwise.
I admit I got a little down into the weeds but the point I was trying to make was that GM was investing very large sums of money in all sorts of things (appliances, air conditioning, leaded gasoline) in the 20s and 30s and they continued to do so even in the depression. For example, they bought Opel for 33.36 million in 1931 and built a new factory for it as well. Other examples include buying Vauxhall and Holden and launching a new truck brand in the UK (Bedford).$500,000 in 1938 dollars is well over 10 million in today's dollars and even though GM was a large corporation back then, this was a depression era and no big corporation was going to make an investment like this unless they are going to get a return. The individual(s) responsible for the business sector behind something like this would probably lose his/ their job(s) and wreck his/their career if this investment wasn't profitable. Just ask Alexander P. de Seversky.
In the bigger picture, once again you miss the fact that large aircraft companies normally do not risk development of a technology unless they know they have a contract in hand or they are pretty certain they can sell their product at a later date. You can't compare the manufacture of diesel engines, automatic transmissions or any other automotive products to the aviation industry of the late 1930s, especially when technology was continually expanding and the future was so uncertain.
And despite the size of GM (per your numbers which I wont dispute) $500,000 in the late 30s is about 12 million in today's dollars. I don't know if you actually worked in the aviation manufacturing industry, but I seen managers canned for not making profit margins, let alone losing a fraction of that amount.I admit I got a little down into the weeds but the point I was trying to make was that GM was investing very large sums of money in all sorts of things (appliances, air conditioning, leaded gasoline) in the 20s and 30s and they continued to do so even in the depression. For example, they bought Opel for 33.36 million in 1931 and built a new factory for it as well. Other examples include buying Vauxhall and Holden and launching a new truck brand in the UK (Bedford).
Perhaps a better way to state my case was that GM became a billion-dollar corporation in terms of market valuation in 1926. In 1929 they were neck and neck with Standard Oil (New Jersy) for the title of world largest corporation with a revenue of $1.5 billion. Obviously, those numbers dropped over the next few years, but GM was always profitable throughout the depression. Even if you cut that revenue in half the $500,000 still qualifies as petty cash to a company the size of GM. What I draw from all this is that GM had little faith in Allison. That is why I asked how much GM invested in North American. The move from the east coast to California and the establishment of a new factory was not driven by military contracts and must have been paid for by GM.
I do not think it is a case of Packard needing instructions on tolerances so much as it is that the required tolerances for the relatively small in3 and low HP/in3 automobile engines of the time would have been significantly different than for relatively large and high HP/in3 engine like the Merlin/V-1710/DB601/etc.
Using the crankshaft as an example:
As pointed out by Snowygrouch in his post "An interesting read about the Packard built Merlin engine." the Merlin crankshaft tolerance of +/-0.00025" was ~twice as tight as modern crankshaft tolerances for automobile engines. This was an amazingly tight tolerance for 1940, and was presumably a necessary tolerance.
It was not until the early-1990s that holding diameter tolerances of +/-0.00025" became relatively common on machined parts. This was due to a combination of increased capability of modern computer controlled turning and machining centers and the associated reduced cost of achieving the tolerance. Prior to the early-1990s a tolerance of +/-0.0005 was the best commonly achieved. During WWII +/-0.001 was the tightest commonly achievable tolerance.
(A general rule of thumb in machining is that for every time you reduce the tolerance by half you double the time it takes to make that particular feature.)
The cost of a Merlin engine (I think) was somewhere around $6000 in 1941. The cost of the most expensive Packard sedan was ~$5800.
There is no reason to believe that the Packard or Ford automobile engine of 1940 was held to tolerances as tight as modern high performance automobile engines. It would not have been economical or necessary within the industry needs of the time.
I know that if I were approached to manufacture a scaled up engine (such as from a 356 in3 V8 to a 1650 in3 V12) one of the first things to go through my head would be that - due to the size alone - tolerances would have to be tighter in order to achieve the required cumulative runout/ straightness/ flatness (to manage vibration and sealing problems) and to maintain fit/interchangeability of parts.
I dont think it is stated when the discussion took place because it makes a better story if it isnt, it also isnt stated that the discussion was with Ford not Packard. By 1940 RR were already mass producing Merlins in Crewe and the Manchester and Glasgow factories were either in production or tooling up. My guess is the discussion was much earlier, when Ford were first starting to work on the Trafford Park factory so 1938-39.Hey pbehn,
By the time that discussion took place (1940?), several thousand Merlins had been produced. By that point in time RR and associates would have sorted out the process such that at least 90% of the pistons and 90% of the cylinder bores would meet full interchangeability standards, and probably more like 95% and 95% - at least in terms of machined dimensions. The casting weights might have tossed a problem into the mix, such that the pistons might have been sorted by weight? I have seen Merlin pistons that were machined into weight specifications by removing material from the inside-bottom of the casting but I do not know if this was the normal method during the war, or if they were supplied in matched sets.
Actually the move from Dundalk MD to Inglewood Was driven by the BT-9 and then the BC-1 follow up funded the primary expansion at Mines Field, Inglewood. Just prior to that NAA got its foot into the AAC world with the XO-47 (Kindelberer/Schmued design).I admit I got a little down into the weeds but the point I was trying to make was that GM was investing very large sums of money in all sorts of things (appliances, air conditioning, leaded gasoline) in the 20s and 30s and they continued to do so even in the depression. For example, they bought Opel for 33.36 million in 1931 and built a new factory for it as well. Other examples include buying Vauxhall and Holden and launching a new truck brand in the UK (Bedford).
Perhaps a better way to state my case was that GM became a billion-dollar corporation in terms of market valuation in 1926. In 1929 they were neck and neck with Standard Oil (New Jersy) for the title of world largest corporation with a revenue of $1.5 billion. Obviously, those numbers dropped over the next few years, but GM was always profitable throughout the depression. Even if you cut that revenue in half the $500,000 still qualifies as petty cash to a company the size of GM. What I draw from all this is that GM had little faith in Allison. That is why I asked how much GM invested in North American. The move from the east coast to California and the establishment of a new factory was not driven by military contracts and must have been paid for by GM.