This engine basically started as a test of my ideas for modelling the upper and lower radiator screens on a GP15.  As things progressed, they turned out okay, so I completed the model.  I didn't have a particular prototype in mind when I started out this project.  I considered adding a second row of grab irons on the engineers side of the long hood end and painted this engine in MoPac blue, but that would have required painting the trucks and fuel tank in MoPac blue too, which would have kept me from using this chassis for other shells.  The details match the Conrail (now NS) prototype, and I might paint it in NS colors down the line.  But since this was a "test" project, I decided to test a paint scheme on it.  Since I had a couple of sets of Turtle Creek decals from the April 2003 issue of Model Railroader, I decided to letter it for Turtle Creek for grins, and now it can be used in practically every operating scheme as leased power, especially while other projects are being completed.

The first thing I did was carve all of the flashing off of the model.  Next, I carved off the two center exhaust stacks, and then trimmed off the lift ring, grab iron, and pilot details that I would be replacing.  Then I carved out the upper and lower radiator screens, as I would be replacing those too.

 

In the thumbnail to the right, you see a plain JnJ shell in silver and blue (I was trying a paint scheme), and the gray trimmed shell.

Before I put any more effort into other details, I wanted to try the upper radiator screens.  To start, I drilled holes around the radiator base.  I did these free-hand for this test, and even though it's a little ragged, it actually works fine with a black color scheme.  But I will have to make a jig for a straighter drilling job for something like a CNW paint scheme.

To the left, you can see that like the prototype screens, I started with the cross-wise wires (0.006" brass wire), so that they would eventually be on the bottom.  I was also able to fit the same number of cross-wise wires as on the prototype.

 

As you can see to the right, I finished off the screens with the lengthwise wires.  I fit as many as I reasonably could, but I did not get as many in as the prototype.  Regardless, the effect still worked out pretty well.

After I got the upper radiator screen finished, I decided that I would go ahead and finish the rest of the engine.  I added the lift rings, and then bent the grab irons out of 0.006" wire.  Then I filled in the coupler pockets for the Z-scale couplers.  The putty you see at the bottom of the end of the long hood is from when I drilled too far for the coupler screw hole.

I made the lower radiator screens out of Nu-Line Structures SD40T-2 screens (each kit has enough for two SD40T-2s).  The GP15 screens are small enough that I can make enough for four GP15s out of this kit.  The screens are now flush with the sides of the engine, just as with  the prototype.

 

The shot to the right compares the new screens with the original setup, and the see-through effect of the new lower radiator screens. 

Next, I added the horns, antenna, cab vent, sunshades, and did the handrails with a set of JnJ stanchions, and more 0.006" wire.  The windshield wipers will be added after painting.

 

I also added some BLMA modern style cut levers and JnJ M.U. hoses on the pilot.  Several of the GP15s with anti-climbers came without drop-steps, and some even came with the handrail going completely across the pilot (with no safety chain), and I chose to do that with this model.

I cut down the front of an Atlas GP7 chassis just enough to to clear the nose, removed the headlight boards (for now), and the shell simply slipped onto the chassis.  Then I shortened an Atlas GP40 tank, and fortunately, the slots in the GP7 chassis lined up well enough that I could simply slip the modified GP40 tank onto the chassis.

 

Next, I painted the engine with ATSF silver and engine black, and highlighted the ends of the handrails with reefer white.  Like I mentioned earlier, I used Turtle Creek Decals from the April 2003 Model Railroader for the road name and graphic on the side of the cab, and numbers from a number decal set for the number boards and side of the long hood.  After a coat of Testor's Dullcote, I used some clear styrene for the cab glazing, and then painted and installed the windshield wipers.

I will be continuing to upgrade this engine from time to time.  Since the lower radiator screens on the prototype have a see-through effect, I decided to try and modify the chassis for the full effect.  In cutting out the chassis to fit the hole, I had to remove the rear chassis screw and the rear bushing for the rear worm gear assembly.  In the picture to the right, you can compare the two worm gear assemblies.  For the modified worm gear, I simply slipped off the outside bushing, and cut the shaft down to the edge of the worm gear.  The rear worm now shifts back and forth a a little more when the engine changes direction, but it still stays in place, and I cannot discern a difference in performance since the modification.  Mind you, for this effect, I would have even settled for a little less performance. 

The picture to the left was taken after the chassis was modified, and you can see the rock face through the lower radiator screens now.  While it doesn't seem immediately urgent, I still plan on finding some nylon or plastic screws and using them to hold the chassis together more solidly, since I took out the original ones for the see-through effect.  For now, though, the shell actually holds the chassis pieces together. pretty snugly.

 

I do plan on modelling a GP15T (for turbo), which not only has a larger radiator section, but the lower radiator screens are moved forward slightly.  This puts the screen section for that model right where the gear tower for the rear truck is located, so I won't be able to do a see-through effect for that engine, unless I render the rear truck unpowered, which would really hurt performance.

The next upgrade that I plan on this engine will be to add working headlights.  The way that the GP15 shell fits over the GP7 chassis, I will have to come up with some way to install an LED up front without it showing through the cab windows.  And since this shell didn't come with headlight glazing, I'll have to try working with some fiber optics.