05/17/2007
| GP38, GP38-2, GP40 & GP40-2 |
Just a note about the brackets. The etching is done from both sides. The result is a small ridge around the inside of the hole. I
use a #78 (0.016") drill bit and ream them out. After that the solder slides perfectly through the holes. My methodology is to place
all the brackets and then thread the solder through them. I use needle nose tweezers. I do not glue the solder to the brackets.
Only to its start point and end point on the frame.
Before I start, I first need the usual disclaimer. You should always first consult prototype photos if you can find them. What I am
trying to give you is a generic understanding of how the TM's are routed. You can use what you find here to help you simulate what
is seen. If your photos do not agree with what I am showing and writing about, then by all means go by your photos. My goal is to
give you a reference to start with.
OK, enough with disclaimers and product promotions. Let me get on with it. I'll start with the GP's. The -2 and non -2 models are
routed the same. If you see them routed differently, then most likely it is because of a rebuild as shown below. They should come
out and route back in a 2x2 bundle as seen in the
smaller photo here. The locomotive below is UP
GP38 #2417. It has a retrofit PAF box and started
life as a non -2 unit. I do not know for sure, but I
pretty positive it has been rebuilt to -2 specs. When
I photographed it, the engine looked new. Fresh
paint and such.
use a #78 (0.016") drill bit and ream them out. After that the solder slides perfectly through the holes. My methodology is to place
all the brackets and then thread the solder through them. I use needle nose tweezers. I do not glue the solder to the brackets.
Only to its start point and end point on the frame.
Before I start, I first need the usual disclaimer. You should always first consult prototype photos if you can find them. What I am
trying to give you is a generic understanding of how the TM's are routed. You can use what you find here to help you simulate what
is seen. If your photos do not agree with what I am showing and writing about, then by all means go by your photos. My goal is to
give you a reference to start with.
OK, enough with disclaimers and product promotions. Let me get on with it. I'll start with the GP's. The -2 and non -2 models are
routed the same. If you see them routed differently, then most likely it is because of a rebuild as shown below. They should come
out and route back in a 2x2 bundle as seen in the
smaller photo here. The locomotive below is UP
GP38 #2417. It has a retrofit PAF box and started
life as a non -2 unit. I do not know for sure, but I
pretty positive it has been rebuilt to -2 specs. When
I photographed it, the engine looked new. Fresh
paint and such.
The TM cables then will exit the from behind the air reservoir and duck under the frame just above the inner caliper on the rear
truck and go to the #3 traction motor.
I guess this is a good time to number the TM's. Starting at the front of the engine I will just count them back. Lead axle is TM #1
and the rear most axle being TM #4. This is for a GP. On a SD the rear most axle is TM #6.
The photo below is of an SP now UP GP40 that had the standard 2x2 bundle. You can clearly see the TM's coming out in a 4x1 flat
ribbon and going under the frame to TM #3. You do not really need to concern yourself with how the cables transition from a 2x2
to a 4x1 because the transition happens behind the air reservoir and you would never see it. You will be concerned with it on a SD
model though.
truck and go to the #3 traction motor.
I guess this is a good time to number the TM's. Starting at the front of the engine I will just count them back. Lead axle is TM #1
and the rear most axle being TM #4. This is for a GP. On a SD the rear most axle is TM #6.
The photo below is of an SP now UP GP40 that had the standard 2x2 bundle. You can clearly see the TM's coming out in a 4x1 flat
ribbon and going under the frame to TM #3. You do not really need to concern yourself with how the cables transition from a 2x2
to a 4x1 because the transition happens behind the air reservoir and you would never see it. You will be concerned with it on a SD
model though.
Here is an example of why you need to try and find photos of the unit you are modeling. But again, remember it is going to be very
difficult to get the exact type of bundle for a given prototype unless you are able to get up close and personal with it. Also you have
to keep in mind that in todays world a lot of the non -2's are rebuilt into -2's and may have had their TM cable bundles redone as
is with what you see in the photo below of UP #2417. Note the cable bundle coming out from behind the air reservoir is in a 2x2
bundle and not in standard cable blocks compared to what the standard route should be in the photo above.
difficult to get the exact type of bundle for a given prototype unless you are able to get up close and personal with it. Also you have
to keep in mind that in todays world a lot of the non -2's are rebuilt into -2's and may have had their TM cable bundles redone as
is with what you see in the photo below of UP #2417. Note the cable bundle coming out from behind the air reservoir is in a 2x2
bundle and not in standard cable blocks compared to what the standard route should be in the photo above.
Now I do not have any good photos for routing cable down the right side of the frame for a non -2. That is OK though because as
I explained earlier, the non -2 and the -2 have the same cable routing. You will see it in the -2 photos later with one exception
which I will point out. The routes on the right side are the same, but there is one bracket on a -2 frame that is not there on a non
-2 frame which causes a slight route change on the -2.
On the right side, the TM cables come out of the frame in the same location as on the left side in a 2x2 bundle. Then they flatten
into a 4x1 bundle. They do not lay flat against the frame, instead they run perpendicular to the frame. I will show this with the -2
cable photos.
If you are wondering about my terminology for the cables, when I mention a 4x1 bundle it means 4 cables in 1 row. If I mention a
4x2, it means there are 8 cables with 2 rows of 4 each or a 2x2 bundle I mean 4 cables in 2 rows with 2 cables each. I hope that
clarifies things a bit.
The below photo is UP GP40-2 #5247. On the left side you can see the cables come out in the same location as on the non -2
unit. They stay in a 2x2 bundle all the way back. This configuration is true for a GP38-2 as well. All that I have looked at are the
same.
I explained earlier, the non -2 and the -2 have the same cable routing. You will see it in the -2 photos later with one exception
which I will point out. The routes on the right side are the same, but there is one bracket on a -2 frame that is not there on a non
-2 frame which causes a slight route change on the -2.
On the right side, the TM cables come out of the frame in the same location as on the left side in a 2x2 bundle. Then they flatten
into a 4x1 bundle. They do not lay flat against the frame, instead they run perpendicular to the frame. I will show this with the -2
cable photos.
If you are wondering about my terminology for the cables, when I mention a 4x1 bundle it means 4 cables in 1 row. If I mention a
4x2, it means there are 8 cables with 2 rows of 4 each or a 2x2 bundle I mean 4 cables in 2 rows with 2 cables each. I hope that
clarifies things a bit.
The below photo is UP GP40-2 #5247. On the left side you can see the cables come out in the same location as on the non -2
unit. They stay in a 2x2 bundle all the way back. This configuration is true for a GP38-2 as well. All that I have looked at are the
same.
I want to apologize for some information I cannot give you. I wish I had it, but I do not know exactly how many brackets are needed
per side or what the spacing between the brackets is. My methodology is to guestimate and place them to what looks reasonable
from the photos I have.
In the photo below you can see another view of the 2x2 bundle running back along the frame to disappear behind the air reservoir.
per side or what the spacing between the brackets is. My methodology is to guestimate and place them to what looks reasonable
from the photos I have.
In the photo below you can see another view of the 2x2 bundle running back along the frame to disappear behind the air reservoir.
At the rear of the fuel tank and air reservoir, the TM cables on the left side of the -2 unit exit and go under the frame in a 4x1
bundle. Here the order of the cables come out as such. I will number the cables as follows in the 2x2 bundle. Top outside cable
is #1, bottom outside cable is #2, top inside cable is #3 and bottom inside cable is #4. When this 2x2 bundle flattens to a 4x1
bundle, The #2 cable becomes the outside and then the #1 next followed by the #4 and then the #3. Although as I mentioned, for
modeling purposes you will not see this transition because it happens behind the air reservoir.
bundle. Here the order of the cables come out as such. I will number the cables as follows in the 2x2 bundle. Top outside cable
is #1, bottom outside cable is #2, top inside cable is #3 and bottom inside cable is #4. When this 2x2 bundle flattens to a 4x1
bundle, The #2 cable becomes the outside and then the #1 next followed by the #4 and then the #3. Although as I mentioned, for
modeling purposes you will not see this transition because it happens behind the air reservoir.
On the right side of a -2 frame for both the GP38-2 and GP40-2, the bundle comes out as a 2x2 just like on the left side and in the
same location on the frame as the left side. This is also true for the non -2 units. Then the bundle transitions to a 4x1 flat ribbon
and the bundle runs perpendicular to the frame all the way back. This transition you do see and the order is a follows. Looking at
the frame as if you are looking at a dice with four dots on it. The upper left dot is TM cable #1, upper right is #2, lower left is #3 and
lower right is #4. Cable #2 becomes the outer most cable on the 4x1 bundle. Cable #1 is next followed by cable #3 and then
cable #4 is the inner most cable.
In the photo below you can see the 4x1 bundle. Also in the photo I will explain the route difference to a non -2 unit. Do you see the
deck support I put the letter "A" on. That is not there on a non -2 unit. This deck support is both in front of the air reservoir as seen
here and also behind the air reservoir. The TM cables do not reach to the rear deck support. You can see how the TM cable
routes outside this support. On the non -2 units, the cables simply keep running back along the frame without interruption.
same location on the frame as the left side. This is also true for the non -2 units. Then the bundle transitions to a 4x1 flat ribbon
and the bundle runs perpendicular to the frame all the way back. This transition you do see and the order is a follows. Looking at
the frame as if you are looking at a dice with four dots on it. The upper left dot is TM cable #1, upper right is #2, lower left is #3 and
lower right is #4. Cable #2 becomes the outer most cable on the 4x1 bundle. Cable #1 is next followed by cable #3 and then
cable #4 is the inner most cable.
In the photo below you can see the 4x1 bundle. Also in the photo I will explain the route difference to a non -2 unit. Do you see the
deck support I put the letter "A" on. That is not there on a non -2 unit. This deck support is both in front of the air reservoir as seen
here and also behind the air reservoir. The TM cables do not reach to the rear deck support. You can see how the TM cable
routes outside this support. On the non -2 units, the cables simply keep running back along the frame without interruption.
A
When the cable reaches the rear of the fuel tank and air reservoir it simply dips under the frame in the same order. Unlike the
SD's, on the GP's the TM cables do not dip under the frame near their respective traction motors. Instead on all the GP's, the TM
cables for the rear traction motors dip under the frame right behind the fuel tank on both sides. The SD's are much different as
you will see. Again I put a letter "A" on the rear deck support I mentioned earlier.
SD's, on the GP's the TM cables do not dip under the frame near their respective traction motors. Instead on all the GP's, the TM
cables for the rear traction motors dip under the frame right behind the fuel tank on both sides. The SD's are much different as
you will see. Again I put a letter "A" on the rear deck support I mentioned earlier.
The below photo is of SP now UP GP38-2 #609. I put it on here to illustrate how the TM cables come out of the frame in a 2x2
bundle and then quickly change to a 4x1 bundle. See that small vertical pipe coming down from under the deck. Straight back
from that is where the TM cables come out of the frame.
bundle and then quickly change to a 4x1 bundle. See that small vertical pipe coming down from under the deck. Straight back
from that is where the TM cables come out of the frame.
TM cables
A
TM cables
That about does it for the GP series of locomotives. I do not know about the GP50 or GP60. What I have shown above is for the
GP38/ 38-2/ 40 and 40-2. Next I will go over the SD series. These are a bit more intensive because there are a lot more cables to
see an they are more visible on an SD than they are on a GP. Also, there is a big difference in the routing and bundling between a
non -2 SD and a -2 SD.
GP38/ 38-2/ 40 and 40-2. Next I will go over the SD series. These are a bit more intensive because there are a lot more cables to
see an they are more visible on an SD than they are on a GP. Also, there is a big difference in the routing and bundling between a
non -2 SD and a -2 SD.
The cable routing here is non standard. Standard
routing for this side of the GP38/38-2/40 & 40-2 is a
2x2 bundle as shown further down on a GP40-2.
My best guess is this cable routing was done after
the rebuild.
routing for this side of the GP38/38-2/40 & 40-2 is a
2x2 bundle as shown further down on a GP40-2.
My best guess is this cable routing was done after
the rebuild.
The next couple photos are to illustrate how I have applied the traction motor cable to one of my model projects. These were
started a long time ago, well before Railflyer came out with the cable blocks. I used 0.020" styrene for blocks and annealed brass
wire. I did need to make the cable all the way behind the air reservoirs, but I did on this one. On my finished EJ&E unit, I only
made the cables till they disappeared behind the reservoirs.
started a long time ago, well before Railflyer came out with the cable blocks. I used 0.020" styrene for blocks and annealed brass
wire. I did need to make the cable all the way behind the air reservoirs, but I did on this one. On my finished EJ&E unit, I only
made the cables till they disappeared behind the reservoirs.
To start the cables, I drill a hole in the frame and glue all four cables into it. After the glue dries, I then bend the cables back and
glue them in place. With the new Railflyer cable blocks and solder for cables, this whole process got 100% easier.
glue them in place. With the new Railflyer cable blocks and solder for cables, this whole process got 100% easier.