Wednesday, July 8, 2015

Overland Sn3 Passenger Car Modifications - Part 1 | 2 Comments - Click Here :

    Jim Courtney and Keith Hayes - The Colorado & Southern inherited most passenger cars from predecessor railroads. Passenger cars were numbered by type (baggage, combination and coach in ascending order) and age. You can find the complete roster, photographs and other resources at Hayes Hendricks’ website, Passenger Cars of the South Park: Four passenger cars (and some fragments) have survived, notably RPO 13, coaches 70 and 76 and business car 911.
    Overland Models imported Sn3 brass models of the 13, 70 and 76 a while back. Note that while 70 is representative of cars 70-73, and 76 likewise is considered typical of 74-76, there are subtle differences among the cars. For example the letter board on 70 continues level under the roof extension at the platform whereas it dips down on the other cars. These are generally fine brass models, but can use some improvements before operation. This is the first of a three part series on modifying these models for more reliable operation.


    The issue with closer coupling of the Overland C&S coaches is not so much the length of the coupler shank, as it is the draft gear box used and how it is mounted.

    Overland has drilled and tapped 3 holes on the coupler pad below each platform.  You used the two paired holes to mount the standard Kadee draft gear box, the one with two little "ears" with holes.  Unfortunately Anjin located these pretty far out, next to the end beam.  The result is that the end of the draft gear box protrudes well out beyond the end beam.  No matter what shank length is used, close coupling isn't likely.

    In a fit of inspiration, I decided to try the "Darwin" universal coupler pocket, marketed by The Coach Yard at $4.95 per package of six boxes (enough for 3 cars).  The Darwin is an adjustable gear box, designed for HO passenger cars with such Kadee mounting screws.  Instead of 2 fixed "ears" there are two open slots, to allow the mounted coupler to be adjusted closer or further away from the end beam.

    Didn't work, foiled again by Anjin!  The two tapped mounting holes are to allow for small diameter screws (? 0/80).  The holes in the Kadee "ears" are much larger in diameter.  Thus, Anjin spaced the holes a bit further apart, to allow the heads of the screw to trap the outside edge of the Kadee "ears" to secure the box to the car.  The "Darwin" boxes have slots that are closer together, thus the holes on the Overland cars won't accept the "Darwin" adjustable feature.

But wait, there's more!  

    By chance, the third hole in the Overland mounting pad is perfectly located so if you mount the "Darwin" box using its center hole, the box mounts way back under the platform.  A standard shank length Kadee "whisker" coupler (either standard or "scale" head) seems to mount perfectly with the back edge of the coupler head as close to the coach end beam as possible.  In the photos, these are HO "scale head" couplers--I still think they look a bit small:

    Note that the two Overland mounting holes are hidden under the top edge of the slot flange, as it rejoins the draft gear box.  The Darwin box is also thinner than the Kadee draft gear, so the coupler is mounted at the correct height relative to the rail, not too low.  As a result, this is the closest coupling I can come up with for the Overland cars, 19 to 23 scale inches between the outside faces of the end beams, depending on the car.  

    I have tested the coupled cars on 28" radius curves, both pushed and pulled, and they do not derail coupled this closely.  The use of the PBL plastic trucks also prevents the possibility of shorts between the brass cars with this tight of coupling, as the car bodies are insulated from the rails.  I don't know whether the couplers will center adequately on this tight of a curve to allow switching of the cars on a curve.  In my operational plans, the cars will stay coupled in their respective passenger trains (the Leadville passenger and the Fish Train) anyway, so it is not an issue. I will leave the Kadee pins on to allow magnetic uncoupling in my staging yard's tracks.

    Also, note that I have removed the brass Overland air and signal hoses, as I'm pretty sure that they will foul on curves with the cars coupled this close together.  After painting and finishing the cars, I plan to install Jimmy Booth's Sn3 rubber air hoses for flexibility.  I have also removed the stock Overland safety hooks and chain and will replace them with chain of longer links and use Precision "small hooks", a brass casting.

Anyways, that's how I did it.
2 Comments - Click Here :
  1. Thanks for compiling this useful information Keith. I hope to upgrade the reliability of my fleet soon.

  2. Thanks to Jim for his tips!

    Keith Hayes
    Leadville in Sn3