Scratchbuilding a CP GP20eco

[ironstef70]

Hi all, I am considering scratchbuilding and GP20eco (just as this Overland potential product advertising that never came alive):

CP GP20c eco

My question is:
Can a GP15 be a good starting point as far as dimensions and cab proportions (let alone the fans, dynamic brakes and details that will obviously need modifications) ?

Of course, it looks like I'll have to find another can, such as an SD70 or else, but four windows...

Stephane

[m a y o r 79]

I remember reading about these a few years ago. As I recall the initial rebuilds, and the CP units were built off of various old GP9 locos. I believe the concept though is that any old GP could be the donor unit. So GP7, 9,18 etc could all be viable candidates. That also means locos for different railroads could be slightly different depending on the donor unit.

For CP units I think a GP 9 frame would be a better starting point. The body and cab all look like they would have to be scratch built.

[spike]

The CPR GP20eco uses a new frame, not the old GP9 frame. I don't know off hand the truck centers. Maybe someone has the cab and nose. These look similar to the CSX SD40-3 cabs. Maybe check Shapeways.

The dynamic brakes look like GP60 style. Athearn, Smokey Valley, Big Dawg, and the old Rail Power Products all would work. Look at pictures for any mods.

I don't know what would work for the radiator grills. There must be some mesh that could be used. All of the rest of the hood could be made with styrene, and Cannon parts.

[m a y o r 79]

Your correct Spike, I was mistaken. The traded in units were used mostly for prime mover, tricks and internal components. They had new frames, hoods, cabs, etc.

Parts of the hood, dynamic and cab somewhat reselmble a GP 60, maybe that could be a suitable donor as well?

[ironstef70]

Yes I also believe you're right Spike. A GP60 shell would be a good starting point, then SD40 Cab, and the list goes on. Most of these parts are not available in brass. I was hoping the GP15 would have done the trick as older ALCO models locos can still be found.
It appears as a very costly undertaking. I've got better projects waiting....

Thank you all for the info. That Overland loco would have been an awesome model. Problem is after 2010, much of their models were selling for above one grand.

Stephane

[m a y o r 79]

Whats wrong with plastic?

[spike]

I misread the OP. I thought we were talking plastic too.

One more thing. The fans are sunken down between the radiators. They have a block heater. The stack is near where the sand fills are. The rear sand fill is in a notch, in the pointed end.

One day I had one in my consist. I don't run them regularly, since I stick to the road. We had a long wait for a meet. I spent the time nosing around.

I just was looking on Shapeways, and the CSX SD40-3 cab is available in HO.

[m a y o r 79]

I wasnt meaning to give a hard time about brass vs plastic, Stephane apparently likes brass better. Its just not a material Im at all familar with except for horn castings. My thought plastic might be more economical in this instance. It would be a very interesting build in any medium.

With these being built well after the 40 series wouldnt a more modern cab be a better starting point? Or was the cab so much more custom towards the older 40 series due to the frame size and other components they were working with to build them?

[ironstef70]

Jan 6, 2017 21:10:38 GMT -5 m a y o r 79 said:

I wasnt meaning to give a hard time about brass vs plastic, Stephane apparently likes brass better. Its just not a material Im at all familar with except for horn castings. My thought plastic might be more economical in this instance. It would be a very interesting build in any medium.

With these being built well after the 40 series wouldnt a more modern cab be a better starting point? Or was the cab so much more custom towards the older 40 series due to the frame size and other components they were working with to build them?

Oh, I did not felt like being hard time. I am much more familiar with brass than plastic, then I prefer brass for several reasons (weight, durability, strenght, ...). It is a concern for me.

Then, my parts inventory is according to what I do, and I don't want to duplicate.

Plastic certainly is more popular and cheap, but I hate to reglue back broken parts all the time (and I am doing a poor job at it). I simply prefer machining brass period, although I do resin at times for structures on my layout.

But any case, it seems like these shells would need to be cast in resin, or their customization would require lots of resin machining which I don't want to get into.
But I agree, it would have been an interesting project.

S.

[trainiax]

It's a little late to answer this - but I'm not sure that there are any existing models that would make a good starting point. The GP20C-ECO is essentially a new locomotive that uses a small number of parts from old GP9's (if I remember correctly, things like the trucks and air compressor). The trucks, air reservoirs, radiator fans and "laundry chute" blower duct are shared with other EMD units, perhaps a few other parts as well. But the rest of the locomotive (hood doors, dynamic brakes, cab, radiator intakes - even the overall dimensions) doesn't really have anything in common with older EMD models.

If it's of any use, I've made some GP20C-ECO drawings that I've posted on my Trainiax site. I had to use photos to obtain many dimensions since I didn't have many dimensions (or any diagrams) to work from, but with a bunch of good photos I think I was able to narrow down the hood dimensions to within a half-inch or so.