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Subject: 
Re: Dimensions of a SD40 and GP35
Newsgroups: 
lugnet.trains
Date: 
Thu, 2 Dec 1999 08:02:23 GMT
Reply-To: 
cmasi@cmasi.chem.tulane.IHATESPAMedu
Viewed: 
786 times
  
My thinking was this:

I did not want to give up on the SD 40-2 because of the six wheel per truck
issue, but I knew I would need a four wheel per truck to provide power for my
train if I made the SD 40-2 a dummy engine which I did to make the six wheel
issue easier to solve. If the only difference between the GP 40 and the SD 40
was the wheels per truck (thats all my book [1] says about it) I thought it
would look strange to have identical engines on different trucks. Someone might
think that one is correct and the other is a mistake, and why would a rail road
company do put a GP and an SD model together? If they needed the six wheel SD
why would they be buying a four wheel GP. Anyway, I decided to model a second
engine. The second engine had to be a four wheel per truck engine, and smaller
than the SD 40. The other pictures in the book I have (there are many other
pictures, but I was looking for the classic America freight diesel) are the GP
38-2 and a GP 9. So, I figured that the GP 38 was the way to go. So, I asked
for the dimensions of the wrong engine, but Larry uncovered the informtation
that I was really looking for; that is, as long as the GP and SD series of a
particular model share the same platform.

What I got from your detailed discussion is that the SD (and GP?) 38, 39, 40,
and 45's (excluding the T2) were all built on the same platform and would have
the same length from coupler to coupler. The size of the hoods would be
different so the size of the porches would also be different. My book shows
that the back porch of the SD 40-2 is much larger than the back porch of the GP
38-2, but this doesn't seem to agree with what you are saying. At the moment my
back porch needs to be a stud or two longer. I guess I need to get a better
book that has more pictures so I can see what the GP 35 and GP 30 look like.

As for the six wheel per truck. Well, no power on this engine. I just could not
get a motor and a wheelset under there and make it look right. So, I have three
wheelsets in a row with 1 stud between each wheelset. Since three wheelsets
spead evenly in a 11 stud long truck cannot negotiate a curve the central
wheelset floats. It can move from side to side just enough so the three
wheelsets can conform to the curve. When I put pictures up, which should be
reasonably soon, I'll detail the trucks.

I am pretty proud of this one, which is why I am still waiting to show it.  I
want it to be finished first. (I even swapped out all the old LEGO bricks for
news ones fresh out of the box.) I am waiting for some more blue grill tiles,
some blue 2x2 round bricks, I am debating about decals (I made the stripes with
LEGO, but I cannot do the logo's in LEGO), and I need blue windows (4 1x2x2
blue, looks like I'll have to buy those).

Thanks,
Chris

P.S. What does the P stand for in the SD"P" 40. Is the steam for passenger
trains (ahh that could be why the P is there)?


Larry Pieniazek wrote:

The GP35 is rather a boring engine in appearance. If you could pull off
a GP30, that would be spectacular! Due to some "hacks" at design time,
they have rather elaborate and ungainly fairing on the top of the hood
which is a result of the "electrical cabinet, turbo charger, central air
intake and filter all competing for space" (quoting my source).

Note that the GP35 56'2" length is coupler tip to coupler tip. GP35s had
9 ft wheelbase trucks. (2 axle Blombergs unless they were riding on
trade in Alco Type Bs) From truck kingpin to truck kingpin is only
32'0".

An SD45 is 65'8" coupler tip to coupler tip or 40'0" kingpin to kingpin.
It has 3 axle trucks with evenly spaced axles, which are 6' 9 1/2" axle
spacing or 13' 7" wheelbase.

Note that the SD 38 and 39, having smaller prime mover engines, but
built on the same frame as the SD45, as John notes, will have shorter
hoods, and therefore larger platforms at front and rear (nicknamed
"porches" by boomers). The SDP40 used the extra hood space for a steam
generator, so didn't have the porches.

The SD45-T2 has an even longer frame at 45'5" kingpin to kingpin or
70'2" coupler tip to coupler tip. This is to allow for the extra space
alloted to air intakes. These -Ts were built for tunnel service and have
main air intakes mounted low on the hood to provide cooler, cleaner air
to the prime mover and traction blowers.

How are you going to model the SD trucks? My ersatz Alco used
articulated trucks, which looks sort of OK but the wheelbase is way too
long.

(all dimensions from the MR Cyclopedia, Vol 2, Diesel Locomotives. (C)
1980 Kalmbach Publishing Co., ISBN 0-89024-547-9)

John Neal wrote:

Well, Chris-

A GP35 was 56' 2"; an SD45 was 65' 8" (EMD used the longer underframe of
SD45 as a standard, which was then used for the SD38, SD39, and SD40).

The main difference, however, is that the GPs were a B-B (4-4) wheel
configuration, while the SD's were a C-C (6-6) wheel config.  *That* would
be noticeable at LEGO resolution;-)

-John

Christopher Masi wrote:

My train book list the length of one of these engines but not the other
(cannot remember which one at the moment). I have pictures of both, but
the big question remains; are they the same lenght or is one longer than
the other? If one is longer than the other is it something that would be
noticeable at LEGO resolution? For example, 60 vs 40 ft would be
noticeable, but 45 vs 40 ft wouldn't be that big a deal.

Thanks,
Chris

--
Larry Pieniazek larryp@novera.com  http://my.voyager.net/lar
- - - Web Application Integration! http://www.novera.com
fund Lugnet(tm): http://www.ebates.com/ ref: lar, 1/2 $$ to lugnet.

NOTE: Soon to be lpieniazek@tsisoft.com :-)



Message has 1 Reply:
  Re: Dimensions of a SD40 and GP35
 
(...) <snipped some good analysis> (...) The people who order power are usually thinking strategically, that is, what is the mix of loads, the track weight capability, the grades, etc, and how is it going to change over the 20+ year service life of (...) (25 years ago, 2-Dec-99, to lugnet.trains)

Message is in Reply To:
  Re: Dimensions of a SD40 and GP35
 
The GP35 is rather a boring engine in appearance. If you could pull off a GP30, that would be spectacular! Due to some "hacks" at design time, they have rather elaborate and ungainly fairing on the top of the hood which is a result of the (...) (25 years ago, 1-Dec-99, to lugnet.trains)

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