Dating via the Details: Wheels, Running Boards and Ladders

In a previous post, we looked at data, stencils and lettering that can update or firmly root a car’s appearance to a 1970s or newer time frame. Here we’ll look at some of the concurrent physical changes to freight car hardware (and rules regarding the same) that will also help indicate the modeled time frame.

Running Boards, Ladders, and Handbrakes

Model of a modern (1974-built) boxcar built with low ladders and no running boards (roofwalk). The “ribbed” outside-post construction of this car is also a post-1960s signature.

The earliest railroad boxcars featured handbrakes that were operated via means of a wheel attached to a vertically-mounted brake staff that would be operated by a brakeman walking on wooden running boards down the centre of the car’s roof.

While automatic air brake technology was introduced and improved during the late 1800s, this arrangement stuck around, with the handbrake to tie down a parked car still located at the top of the car end, and running boards (later made of steel instead of wood) to allow brakemen to move down a cut of cars to set (or release) multiple hand brakes.

The first major change in rules regarding running boards came in 1945 when wood walkways outlawed on new cars. New cars were to feature expanded metal running boards, but the wood walkways were generally not replaced on older cars. (Obviously metal running boards would have existed before this but I don’t have any “first” dates of adoption.)

The most significant change came in 1966 when the rules were changed to no longer require running boards. New cars ordered after 4/66 or delivered after 10/66 were required to be built without running boards and low-mounted handbrakes. Running boards also began to be removed from cars, with the original target date for completion being 1974, but full compliance lagged behind a bit. By 1982 walkways were banned on boxcars and reefers in interchange service in the US.

Older 1940s built boxcar that has been upgraded and modernized to remove running boards (although the former supports are very much in evidence) and cut down ladders. On this car the brake gear has also been lowered, however on many cars the brake wheel was left in its original position, with full height ladders remaining on the “B” end corners to reach the handbrake.


Journal Bearings

50 ton truck with plain bearings (left) vs modern 100 ton truck with roller bearings (right)

Railroad car axle bearings came in two distinct “flavours”. The old style featured a solid axle end which turned on brass bearing inserts inside an oil-filled journal box cast as part of the truck. This is what is known in the trade as a “plain” bearing – sometimes also referred to as “friction” bearings, although only after roller bearings became common. Modern railway axles use a self-contained, sealed package of roller bearings

Some lists of dates show the first usage of roller bearings on motor cars and some steam engines and freight cars in 1923 and first roller bearing on passenger equipment around 1926.

As far as I can tell from trolling through several lists of important dates, the first significant regulations about roller bearing journals came in the 1970s, with roller bearings required for all cars with 6 1/2″ by 11″ journals in 1972 and  roller bearings required for all cars with axle loading greater than 55,000 lbs in 1974. (Basically, larger 90-100+ ton capacity cars being built then.)

By 1991 all cars in hazardous materials service must be equipped with roller bearings and may not be equipped with plain bearings and in 1995 plain bearings were banned from interchange entirely.


The earliest freight car trucks were wood beam trucks with a heavy wood beam upper member and cast iron or steel journal boxes, spring hangers, bracing and other hardware. By 1870 “archbar” truck frames fashioned from heavy steel bar bolted together started replacing wood beam trucks as standard. Later trucks used various types of cast sideframes. Archbar trucks were banned from interchange service after July 1, 1940.

By 1958 all trucks applied to new cars were required to have AAR approved side frames with U-shaped castings and integral journal boxes. Cast truck side frames with T, I, or L shaped cross sections were prohibited under cars in interchange service.


The last few changes are harder to note quickly from a distance as they’re underneath the car, but can still be seen in a side view.

Ribbed-back cast iron wheels (left) vs steel wheels (right)

Modelers may have noted that there are generally two styles of wheels available with some model trucks available (either as replacement trucks or included in some full kits or RTR models). Some wheels have a fancy-looking ribbed back appearance, while others have a profiled but plain back face such as the truck at top right in the photo. (Of course, some model wheelsets also have a completely smooth undetailed [inaccurate] flat-backed design….)

The ribbed back wheels represent older cast iron (not steel) wheels. The ribs cast into the back surface of the wheel helped dissipate heat from friction. Steel wheels did not require or have these ribs.

In 1958 cast iron wheels were banned from interchange service, therefore ribbed wheels would be out of place on any model set in the 1960s or later.

This is also a good place however to mention different sizes of wheels. Generally speaking, most older freight cars had used 33″ diameter wheels. However cars of 100 tons capacity or above rode on larger 36″ diameter wheels. Many modern trilevel autorack cars ride on low profile 28″ wheels. If you’re replacing wheels on your model freight cars and aren’t quite sure whether you should be using 33″ or 36″ wheels, take a look at the CAPY or LD LMT data lines below the car number. If those numbers are around 200,000 (lbs) or above, use 36″ wheels. Around 150,000 (lbs) is a 70-ton car likely with 33″ wheels.

Brake Systems

KC brake piping diagram

The first Westinghouse air brakes were patented in 1869.

In the early part of the 20th century, the common air brake systems in use on freight equipment (known as K or KC brakes) were a simplified affair where the brake cylinder, air reservoir and control valve were all combined as one unit. The more modern air brake system design (known as AB brake systems) that most people will be more familiar with are quite visibly different, with separate components for the brake piston, control valve, and a large air reservoir with separate halves for service [regular] and emergency brake applications.

In 1933 AB brakes were required on all new cars and the older K/KC brake systems were outlawed from interchange service in 1953.

AB brake piping diagram

Wawa Station Roof Profiling

I’ve been taking advantage of free time over the long weekend (“Family Day” civic holiday in Ontario today) to tackle the next major construction piece of the project – the “flat” roof.

In actuality, the roof is not quite flat in order to allow rainwater to properly run and drain and not build up on the roof and cause rot, leaks or other problems.

The architectural blueprints show how the roof slopes away from the edges to drains. On the upper roof over the second story a 2×6 board on edge establishes the height of the roof at the edge of the roof, sloping down to “zero” at the central drain. Construction details are: 7/8″ sheathing flat on the second story roof/ceiling joists, 2×6 support at perimeter (with successively cut down supports to allow roof to slope), 7/8″ top sheathing and finished with a tar and gravel surface.

This first photo (above) shows the styrene 2×6 strip added all the way around the perimeter of the roof. The second story roof was actually divided into two drainage areas, so an additional pair of support 2×6 strips run down the centre of the roof dividing it into half.

Roof sections made of .020″ thick styrene sheet being added.

Short pieces of .020, .040 and .060 styrene strip help support and reinforce the joints between roof sheets.

Roof sheets completed, and joints touched up with spot putty. The slope effect ends up actually being pretty subtle overall, but is obvious in the indented corner on the second story, as well as over the passenger waiting room wing where the drain is at the edge of the roof and everything slopes down to this point. On the large open area of the baggage room where the entire roof slopes to a central point, the effect is difficult to see without laying a straightedge on the wall caps, but the modeler knows it’s there!

The final finish work to the roof will involve a bit of trimming around the chimney and wall caps, and the final surface will be a representation of the bonded tar-and-gravel surface of the prototype. This however, will likely be one of the last steps after painting the rest of the structure.

Wawa Station Brickwork

Construction progress on the Wawa station continues to move forward. A major (but relatively simple) step in the progress is applying the brick texture to the lower levels of the structure, as well as constructing the brick chimney.

In these first two photos, we see the brick sheet in progress of being added to the lower story of the structure. I had some sheets of Plastruct HO brick that I’ve been using on this station; similar brick sheet products are available from JTT, N Scale Architect and other sources.

The brick sheet is cut to size, window and door openings roughly cut out and glued to the structure core using liquid plastic cement. Then the windows and door openings carefully cleaned up with needle files.

Fashioning the chimney is slightly more interesting, as the core is build up from various “4x” (4×12, 4×8 and 4×6) styrene strips and then laminated with the Plastruct brick texture sheet.

Wawa Station Trimwork

The Wawa station build keeps moving forward with the detailing of the structure.

The station featured these decorative eaves around the entire structure below the tops of the walls. To represent the proper shape of the eaves, I built them up out of styrene strip. The core is a 4×12 strip on edge forming the base of the protruding eave, with a 1×12 laminated on top to achieve a proper thickness and cover the joints between the larger strip.

To represent the decorative edging, fascia strips of 1×6 and 1×3 are added around the outside edge after the main core is built up.

Starting to look a bit more like the drawings and photos, but still much more to do…

More SDs coming from Bowser

New announcements from Bowser today with good news for ACR fans, including a second run of new road numbers on their popular SD40-2 from last year, and a new model of the GMD specific versions of the SD40, including Algoma Central in the list of paint schemes.

SD40-2 (second run – new road numbers)

Road numbers 185, 186, 188 (first run had 184, 187)

Product Listing

Pre-order deadline: April 13, 2018  Expected delivery: January 2019

SD40 (new model)

Road numbers 180, 181, 182

Product Listing

Pre-order deadline: April 27, 2018  Expected delivery: February 2019