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Forums - Research / Post-WW2 |
This Post WW2 forum is intended for asking and discussing reference or historical related issues pertaining to any time after WW2 (1945+) subjects. |
| Topics | 1422 |
| Messages | 5130 |
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| Subject: | Re: "Enigma" ? |  |
| Date: | Jan 4, 2003 |
| From: | Kurt Laughlin | |
"Artur Zinatullin" wrote
> > I really don't know where "+/- 10 cm or more " came from ,
> > being "close and personal" with T54/55 and T34 can tell you that
> > all dimensions I took from them are very close
> They say, that wartime production machines may differ
> in hull dimensions some 50 mm. Even 20-30 mm on left and
> right side of the same machine.
> Once again, it's about wartime production
I do not believe this at all. If this were true, parts made at different
factories - or plates cut in different rooms of the same factory - would not
fit together. Suspensions would not work because torsion bars would not be
able to reach their mounts. Driveshafts would not fit between transmissions
and final drives. Turrets would drop through their races.
Cutting and fitting is the most time-consuming way of making things there
is. It also requires the most skillful operators because a job done
improperly simply won't work. In a mass production environment, the
quickest, most efficient way to produce things is to have every piece and
every process absolutely identical. From a manufacturing perspective,
things could not be better or faster than when there is no need to account
for variations in parts.
This is not to say that there are not "large" dimensional variations on some
real parts, but that these variations are simply cosmetic and
inconsequential. A large welded hull joint may protrude 2mm above the
surrounding plates on some tanks, 5mm on others; 25mm simply does not make
any sense. How would it be justified in the environment of life or death
production to spend an additional hour putting in 10 more kilos of weld
metal? A cast turret may vary by 10mm across it's largest dimension, but a
difference of 50mm would be intolerable when one calculates how much extra
steel that represents. Yes, "buying it off" may maintain production at the
foundry, but when that turret interferes with items on the assembled hull -
after 1500 man-hours of effort have been invested in fitting it out - the
production at the assembly plant would grind to a halt. I know from my
research that such problems were viewed very critically in the American
system. Do you think that a plant manager under Stalin or Hitler would be
more willing to take the risk?
I have many production drawings from the Sherman tank. Machined dimensions
typically are allowed a total variation of .010 (0.25mm), the "looser"
dimensions perhaps 1/32 - 0.8mm - total. Sheet metal assemblies (like the
air cleaners) allow 1/4 (6mm) overall. Even the hull weldments are held to
similar values. The largest tolerance I have seen is the 12 feet +/- 1 inch
on a tarpaulin. The fact is, large tolerances are undesirable because they
slow down production.
KL |
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|
 | Iraqi T-55 up-armored - Dave Connolly - Dec 25, 2002 |
| . . . As for plane T-55, ... - Artur Zinatullin - Dec 25, 2002 |
| . . . Re: artistic license? - Christophe Jacquemont - Dec 26, 2002 |
| . . . . . . don't think so - Janusz Smolinski - Dec 27, 2002 |
| . . . . . . . . . Re: don't think so - Christophe Jacquemont - Jan 2, 2003 |
| . . . . . . . . . . . . "Enigma" ? - Janusz Smolinski - Jan 3, 2003 |
| . . . . . . . . . . . . . . . Re: "Enigma" ? - Artur Zinatullin - Jan 4, 2003 |
| . . . . . . . . . . . . . . . . . . Re: "Enigma" ? - Kurt Laughlin - Jan 4, 2003 |
| . . . . . . . . . . . . . . . . . . . . . Re: "Enigma" ? - Kim Voss - Jan 6, 2003 |
| . . . . . . . . . . . . . . . . . . . . . Re: "Enigma" ? - Artur Zinatullin - Jan 6, 2003 |
| . . . . . . . . . . . . . . . . . . . . . . . . Re: "Enigma" ? - Christophe Jacquemont - Jan 6, 2003 |
| . . . . . . . . . . . . . . . . . . . . . . . . Re: "Enigma" ? - Paul Roberts - Jan 7, 2003 |
| . . . . . . . . . . . . . . . . . . . . . . . . . . . Re: "Enigma" ? - Artur Zinatullin - Jan 7, 2003 |
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