MODELING: Running Boards (Roof Walks)

For much of the steam and diesel era, running boards have been a fixture on “house” cars such as boxcars, reefers and stock cars.   Modeling wood running boards is a fairly straight forward process.  Consider the fact that the first thing your eye sees in looking at a model is the roof and running boards on freight cars.   It is workwhile to invest a little time in making the running boards look good.

Prototype photos give a clue as to the weathering effect on running boards both wood and steel.

Making your own running boards are simple using styrene.  Why styrene?  Well, it is more stable and less prone to shrinkage or expansion as a result of humidity or heat.  Most of our models are either styrene or resin these days.  Wood does’t scale very well.  The grain structure is nearly impossible to discern from any distance.  Wood tends to take stains or coloring inconsistently.   Observing what the prototype looks like is the best way to model.

The picutre above illustrates what styrene looks like on a resin model.  Weathering with acrylics can provide a realistic look.

Generally, wood running boards are approximately 18″ to 24″ in width.  Board width and spacing can vary as well.  Thickness is approximately 1.25″ which doesn’t correspond to a standard styrene thickness.  I tend to use .030″ thickness as my choice.  I have laminated strip styrene to create the 1.25″ thickness.  It tends to be a little flimsy when applied.

 

I liike to use a wood plank to assemble the running boards.  This one is basswood but anything but balsa will work.  I glued a strip to the edge to allow me to hold the boards while bonding the thin .015″x .040″ straps.   I used .015″  or .020″ spacers to set the gap between the boards.

 

I mark the location of the running board support on the roof.  The mark provides the location to avoid when applying the straps and it shows where the attachment screw detail would be added if you so choose.

 

Running boards are normally assembled from three boards to form the length required for the car.  the two outer boards are joined at the same location while the center board is joined one rib apart.  That is a typical approach.  Variations a widespread but they had to meet the ARA or AAR standards for interchange freight cars.

Lateral running boards also showed a lot of variation.  The NP boxcar model shows the road’s standard for wood boxcars.   Other roads like the GN also used this style.

The laterals shown above are for a steel car and have a steel sideframe that the boards are attached to.  The grab iron is also anchored to the steel frame.

This drawing illustrates the style typical for AAR 1937 boxcars.

Brett Whelan took this photo while visiting the US.  The roof belongs to a PFE R-30-16 rebuilt wood reefer.  It illustrates how the individual boards are attached to the roof and what the joint looks like.  The screws are designed to engage the steel bracket much like a self-tapping screw.  The car was in a state of decay at the Rio Vista museum when the picture was taken.

Dennis Storzek took this shot a Soo single sheathed boxcar showing the running board and lateral.  The attachement screws are evident.  You can also see the end support in this photo.

Here is a shot of my kit that I did for Chooch of the same car.   The car was weathered with acrylics and an alcohol wash.  Gray primer was the base color with highlights of black and some residual paint remaining under the grab iron.

Wood running boards attached to wood sheathed roofs used wood supports to provide a mounting surface.

Here is an AAR document which describes the running board and saddle or mounting bracket.

 

 

Hopefully this posting will encourage to make your own running boards when the need arises.

Gene

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