7j43k Wheel diameter appears to have been 38" when delivered, but was made larger when the top speed was lowered (by regearing). Note that E units had smaller wheels than F's. Ed
Wheel diameter appears to have been 38" when delivered, but was made larger when the top speed was lowered (by regearing). Note that E units had smaller wheels than F's.
Ed
According to RMC all were dolevered with 38" wheels. They were latter converted to 40", except unit No 176 which retained the 38" wheels.
Also I was in error saying the RMC plans show a truck wheelbase of 10' The correct dimension shown on the plan is
4'6" + 4'6" which of course equals 9'0"
I tried to sell my two cents worth, but no one would give me a plug nickel for it.
I don't have a leg to stand on.
DSchmitt You are probably correct thatb they are not actually 10'0' but to say "no way" is a bold stratement. EMD could have have made them exactly 10' (center of axel to ceter of axel) if theey wanted to. But since the modeler will be using exsiting model trucks the dimension on the model will be whatever they are, so the exact protoype dimension is not relevent.
You are probably correct thatb they are not actually 10'0' but to say "no way" is a bold stratement. EMD could have have made them exactly 10' (center of axel to ceter of axel) if theey wanted to.
But since the modeler will be using exsiting model trucks the dimension on the model will be whatever they are, so the exact protoype dimension is not relevent.
When I said that, it was because the trucks on the NW3 and NW5 look to me like standard EMD Blomberg trucks. And those are 9'. A long way from 10'. Incidentally, when Mantua/Tyco made their self contained diesel truck for their "F9" and etc., they used the incorrect dimension of 10' because they were trying to fit a motor between the two axles.
Anyway, my boldness is backed up by my copy of a Great Northern diagram book, which shows the NW3 as having trucks with a 9' wheelbase. Which makes me wonder about the 8'-10" shown in the previously cited source.
Another disagreement with that source is that the top speed is either 65 or 75 mph, depending on the unit.
Other dimensions from the diagram:
truck centers 31'-0"
length over coupler faces 54'-3"
length over end sills 50'-0"
width over side sills 10'-0"
width over eaves 10'-2"
height overall 14'-5 3/4"
height at eaves 12'-6 3/4"
height of walkway over rail 4'-8 1/4"
bruce22Correct Uncle Bob
Oh, OK.
I think it depends on which dimension you're talking about. For example, a possible reason that truck centers would be a half inch off of even feet would be that when the frames were fabricated, the layout was to the foot, but "circumstances" happened. With a cast frame (which the NW3 did not have), it could have been caused by shrinkage on cooling. For a welded frame, heat from the welding process could have accounted for the odd dimension. Or even a worker who set up the fabrication who thought a half inch off was good enough. But the person measuring the final dimension did not. For overall length, if it includes couplers, the couplers are kind of off the shelf items; so when they're stuck on the end of an item with a tight foot dimension, the result could be an odd dimension.
I don't think anyone at the builders would have chosen an "almost" dimension just out of the air.
You are probably correct thatb they are not actually 10'0' but to say "no way" is a bold stratement. EMD could have have made them exactly 10' (center of axel to ceter of axel) if they wanted to.
But since the modeler will be using exsiting model trucks the dimension on the model will be whatever they are, so the exact protoype dimension is not relevent. The cab, hood, etc will also be made from available components so their dimensions will be determined by them. While the RMC dimensions and the Diesel Shop are not the same, they are close. Close is good enough for a bashed model.
To be sure the dimensions are exactly correct one woud need to have the actural builders drawings and confirm the dimensions by measuring an actual locomotive. Then one would have to scratch build everything.
DSchmitt The plan in Railroad Model Craftsman...It shows the truck wheelbase as 10'0"...
The plan in Railroad Model Craftsman...It shows the truck wheelbase as 10'0"...
There is no way that the truck wheelbase could be 10'.
Just because it's drawn doesn't make it true.
I think the poster is asking why EMD, GE, etc. use odd dimensions instead of rounding up or down to the nearest foot or half-foot.
I don't know, either, but it probably has to do with clearances, and the size of locomotive components.
bruce22Not really relevant perhaps but can anyone tell me why dimensions of locos are generally not to the nearest ft. i.e. on this loco the length is 53' 10,5" , not 54' , hgt 11'11" not 12' , cab width 9' 11.5" not 10' ? etc.
Because it is more accurate.
I am not a scratch builder but does this not increase the difficulty in building ?
A fraction of a foot in HO is still very significant. In those cases where it is not, one can always round to the nearest foot. But that should be left to the final user, as some people may feel the need for non-roundedness.
There is an error in the Diesel Shop data as presented.
The "Distance between the Truck Centers" and the "Wheelbase (Locomotive)" dimensions are reversed.
The truck centers dimension should be 30'10". 22' is the truck center spacing on a standard length SW or NW locomotive, not the NW3 which is longer.
The plan in Railroad Model Craftsman has the truck center spacing as 31'6". It shows the truck wheelbase as 10'0" (correction 9'0") and the overall length (face of coupler to face of coupler) as 54'3". Cab width 10'0".
Since the model would be bashed from existing components, It is unlikely to match the dimensions from either source, so the discrepancies are of little consequence. I agree that one should refer to as many pictures as possible.
I would be wary of depending on plans drawn up in the '60's. I recommend reconciling them with the dimensions in the following:
http://www.thedieselshop.us/Data%20EMD%20NW3.HTML
and, of course, a lot of photo comparison. On the plus side, it's sorta almost a regular EMD switcher; so you've got a head start.
I'm trying to scratchbuild/kitbash an HO model of the EMD NW3 built exclusively for the Great Northern in the late 30's, early 40's. This was an early attempt at a roadswitcher, using the mechanicals of an NW2 switcher on a stretched frame with EMD road trucks.
I have had absolutely no luck in finding a set of drawings or plans of this unusual diesel locomotive.
Does anyone know of a source of, at least, some basic drawings or plans of this locomotive?
Larry B