After seeing a drawing of a NYC 2-8-2 H-10b from a 1946 edition of “Dimensions and Classification of Locomotives of The New York Central System” and hearing some of the discussion of the slop involved with making our models, I’ve come to the conclusion that I don’t particularly like the errors we force upon ourselves to make models that run on really small radius curves. I’ve decided to modify my Mantua Light Mike to see if coming closer to 1:1 scale distances is possible.
Because of my so-so understanding of technical drawings, I used the distance between the centers of the loco trailing truck wheel and the first wheel of the tender front truck. They are (were?) 11’ 8" apart in the 1:1 H-10b (41.38 mm). The model started at 49.83mm center-to-center (or 14.23’ – just about 14’ 3").
If this fails miserably, I have 2 other Mantua locos with the same length drawbar, so I have a template to make a new one of the original length if this doesn’t go as well as I hope it will.
Here’s a before shot of the loco. I had already taken out the drawbar when I thought the project would make a nice little photo series, but other than that, I haven’t changed anything else. Ignore the so-so paint job on this loco… I’ve learned one way to NOT paint a loco – it’ll be getting stripped back to bare metal and repainted over this christmas break (but that’s a different story).
Now i’ve pushed the tender to the “proper” distance from the body of the locomotive. This is assuming that the distance from the center of the trailing truck wheel to the rear of the locomotive and the center of the lead wheel of the tender truck are the correct distances from the ends of the locomotive and tender. Otherwise, this is close enough and will at the very least look a lot better than having the loco and tender so fa
Some of the better-quality 1960s brass locos came with drawbars that were fixed at the cab end and had two, or even three, holes into which the tender drawpin could be inserted. The shortest setting was accurate to prototype, while the hole nearest the end of the drawbar would allow the loco to take the sharpest curve the rigid wheelbase would accept.
With DCC and tender pickup from both rails, the old ‘wireless’ drawbar has joined the mammoth, the dodo, the passenger pigeon and other recently-extinct species. Whether or not the latest steamers have similarly rigged drawbars, deponent knoweth not.
…so by shortening the drawbar you are getting closer to 1:1 standards??? I am afraid that there are many more things you need to do to get that little Mantua to Proto87 standards. With the modifications you will need to make you will be able to pay for it many times over.
I know there’s a lot of detail work necessary to make it at proto87 standards. I guess my initial post wasn’t clear in that regard.
I don’t like the distance between the rear of the cab and the front of the tender… So I’m going to start there and see if it’s possible to get a model to work in an acceptable manner by using (more or less) prototypical spacing between the engine and the tender.
If it works, I might try to do this with a few of my other locos (and maybe eventually start detailing things correctly per prototype). If not, I’m out about an hour or two for this initial conversion, and then the resulting re-fabrication of a “long” drawbar.
A couple things you have to be careful of and there are a couple other dimensions you might want to take into account.
What is the dimension from the rear driver axle to the trailing truck axle? (is the trailing truck longer of shorter)
What is the dimension from the rear driver to buffer/cab rear/drawbar screw?(is the locomotive longer or shorter)
What is the dimension from the lead axle of the tender truck to the kingpin on the tender truck? (is the truck longer or shorter)
What is the distance from the lead axle of the tender truck to the buffer/deckplate/drawbar screw on the tender? (is the tender trcuk closer to or farther from the end of the tender)
Any of these dimensions being significantly different from the prototype can change the distance between the axle of the trailing truck and lead axle of the tender. I’m not saying you haven’t improved things or that you are wrong, these are just a few more dimensions you need to consider when deciding where to make an adjustment. For example if the trailing truck was 18" too short (dimension #1 above) and the tender truck center was 18" too far back (combination of #3 and #4) then the dimension you measured (11’8" vs 14’3") could still be present, but NONE of it would be due to the drawbar. Food for thought.
those are some good points that I didn’t even think about.
At 35mm the distance between the driver axle and trailing truck axle matches the 10’ spacing of the drawing.
As far as I can tell from the drawing, the center of rear driver is 15’4" from the rear of the frame of the locomotive. The model is close, about 1 scale foot too long (not fixing that… yet).
the truck is shorter by anout 2mm than I think it should be. However it is about a scale foor or 18" too long toward the center of the tender.
The tender truck is too close to the end of the tender by about 2-3mm.
I think that I’ve come close, even when considering the differences in the dimensions of the model vs the drawing (save for about 4 scale inches give or take, assuming my calculations and measurements are correct). I guess the definitive answer will be the distance between the rear of the loco frame and beginning of the tender frame, which appears to be where the drawbar would have been connected - a total of 28.75". This is assuming of course that the measurements are to the center of the drawbar ffrom the ends of the frames, which is what the lines appear to be showing.
I have a scale 18" between the two frames, so if I was to fix the loco frame to be “right”, I think I would be dead on.
