In the late '70s, the CRR GP7s went through rebuilding projects.  According to my sources, engines 910, 908, 900, 901, 904 & 907 became GP16s 4600-4605, respectively.  Those GP16s came from Paducah, and had the "saddle bag" air filters, angular cabs (like second generation diesels) with chopped short hood, and other minor changes like most Paducah GP8/GP10s.  Two SCL GP7s and CRR engines 913 - 915, 909, 911 & 912 were rebuilt as GP16s in SCL's Tampa shops, and renumbered 4606-4613, respectively.  The Tampa rebuilds basically had a chopped nose and a few other minor changes, but retained the curved cab roof.

 

I like the looks of the basic chop-nose GP7/9 and SD7/9 engines over the somewhat awkward looks of the Paducah GP8s, etc., so I will try to get a Tampa GP16 as close to the prototype as practical.

 

I will use an Atlas GP7, and a LifeLike GP20 sill for this project.  The primary change will be the nose chop, but for me to gauge the nose height, I need to get the cab setup.  After some consideration, I decided that in order to get the numberboards and windshield as close as possible, and do it in such a way that I can work the seams well, I needed to cut the front off of an Atlas GP38 cab, and put it on the front of the GP7 cab.  To the right, I have prepared the GP7 cab, and the GP38 cab face.  Notice that I left some curve to the front of the GP7 cab, and the GP38 cabface was cut down to the top of the numberboards.

 

After some filing to make sure everything fit well, I glued the two pieces, and added copious amounts of green putty, as seen below. 

 

 

 

 

 

 

The putty in the picture to the left also illustartes how I was able to locate the seams in such a way so that I can work them with knives and sanding sticks without damaging the existing cast on details like door frames and handles.  If I had kept the GP7 face, and tried to insert a windshield/numberboard piece, the seams would be in the tight area between the windows, and I surely would have damaged some of those details.

 

Then I went through a few cycles of letting the putty cure, sanding/carving to a finish, and painting with Undercoat Gray to check how smooth things were.

 

 

 

Once the cab was glued together, I could gauge the nose height.  So, each time I set aside the cab to allow the putty or paint to cure, I worked on chopping the nose.  But before I put any work into the nose, I shaved off all of the details like grab irons and lift rings that would be replaced, and drilled holes for them, and I shaved off details that wouldn't be replaced, like marker lights, the rear hand brake, and the edges of the numberboard in front. 

 

For this engine, I kept the sand hatch, riveted panel, and the headlight..  And I wanted to keep as much of the bottom of the nose attached, as it would result in a stronger shell.  To accomplish this, I ended up with a seam that was "stairstepped" down in the front, to avoid having a seam too close to the headlight.  The picture to the right was taken after I went through lots of filing and checking for fit.  At that moment, I was dry-fitting everything together to check for alignment one more time before gluing things in place. 

 

Note how the cab has progressed, but still needs some work.

 

 

 

 

 

 

 

 

After the glue cured on the nose, I cut out the brake area on the fireman's side of the nose, and cut a nose handbrake out of a spare shell.  As you can see in the picture to the left, I was more concerned about getting the handbrake kocated correctly (square and level with the nose), than I was about getting the seams perfect.  I also tried to fill the numberboard holes with styrene, but on the fireman's side, the piece sgifted, and the glue set before I could correct it.  At least that could be fixed with more putty.

Now that I had the nose height, I could modify the frame to match.  So while putty or paint was curing on the nose, I disassembled the frame and motor, and using a Dremel, I cut the frame.

 

The cab sit's so far back that I wasn't able to cut the frame all the way back for a "see-through" effect.  Instead, I only had to cut a little back at the red arrow to clear the cab, and cut down the frame to the level of the yellow arrow (the same level as the blue arrow).  Since most of the fuel tank skirt is being removed, I need to make the area above the tank look a little more realistic.  To do so, I made a few notches at the green arrows.  After the cutting, I washed the frame in soapy water, and reassembled everything.

 

 

 

 

 

 

 

I chose to use the GP20 sill, because it's battery box arrangement is much closer to the GP7/9, so it requires less work.  But it still requires some work, which is the removal of the box behind the cab, on the fireman's side.  The shot to the right illustrates how I cut the box out, and tried to save as much of that step as I could.  I then patched the holes with styrene, placed the steps in their location, and let the glue cure.  I then puttied it up, and carved and sanded it to suit.

 

After several cycles of puttying, sanding, and painting on the cab, nose, and step, I finally got things where I wanted, as seen in the shot below.  At this point, I can add the details, such as grab irons, lift rings, cab sunshades, firecracker antenna, wipers, and horns. 

I cut out the few remaining skirt pieces from skirt pieces from a GMM GP18 super detail set.  I glued them to the sill, and strengthened that bond with some short pieces of styrene, to give more surface area for connecting those pieces to the sill.  On the fireman's side, I used the bell left over from the Southern Gp38 #2815 project, as only a part of it "peeks" from around the skirt piece.  On the engineers side, I carved some shape into some styrene dowel to represent the air brake system filter, and added some wires in that area to represent the piping that has been exposed by the removal of the skirt.

 

After test fitting this, the added wiring interfered with the frame and contact strips, so I had to remove the piping, and rebend them so that they did not stick in as far, and cleared the frame.

 

To modify the trucks, I cut off the outboard brake hangers, added sanding lines on one end, and shaved the cast on brake lines and replaced them with wire.  Above, you can see the stock truck on the left, and the modified truck on the right.

 

For the tank, I shaved off the cast on piping details, rounded off the tops of the air reservoirs, added wire for the piping, and cut down the top of the fiuel tank to the proper height.  With the lack of fuel skirt, this will expose some of the frame, including the portion where the pickup clips slide into the frame.  In addition to notching the frame back in a few small places, I added a strip of .005" styrene cut to fit to represent the frame edge.  And these few modifications gave the tank area the "depth" that this prototype has.

 

Next, I installed GMM early EMD stanchions (some GP16s had later "channelled" versions, and some had the early version, like #4611), and then bent some .008" wire for the handrails.  Once I was happy with the shape, I glued the handrails to where they connect to the sill, and after that cured, I carefully soldered the wire to the stanchions.  I sliced thin pieces of solder (so small that it's hard to get a handle on them), and I would set the solder slices on the joint, then touch the joint with a soldering iron for one or two seconds (no longer).  This takes some time over simply ACCing the joints, but it ends up with a much stronger and durable joint.

 

The nose handrails were made from .006" wire, and was glued into place.  Louvers from the GMM GP18 detail set have been added below the cab on each side.  The footboards and cast on MU hoses have been shaved off of the pilot, holes for the details drilled, and the coupler pocket has been modified to fit Z/Nn3 couplers.

As of this writing (6/16/06), this is where the project stands.  I need to correct some of the handrails and undersill details, then it is time for paint and decals.  This project will have to be put on hold for awhile until after an upcoming move.  But hopefully, the layout will be uncrated and ready to receive the engine when it is complete.