Slope Sheets and Hopper Body Assembly

Continuing to make progress on my hopper scratchbuilds this week, assembling the body sides and end sheets.

The above photo shows the layout of the end sheets on the styrene sheet, these were laid out and cut out at the same time as the body side sheets. The angles in this project make things interesting, but essentially it’s a fairly straightforward exercise in geometry.

The tops of the ends are completely straightforward being a simple flat panel, and with the .060″ square top chord extended around. The square stock was filed to fit and the ends assembled to the bodies.

Next step is installing the end slope sheets into the body. The main trick here is to be very carefully to install everything square.


I have a few more of the cars to work through this week yet, and then the next step after that will be to cut out and install the intermediate slope sheets for the central bay.

AC 8600-8629 Series Hoppers Part 1 – Background and Body Sides

AC 6056 at Wawa in March 1981. Slide from my collection, photographer unknown.

In the 1980s, the Algoma Central rostered three types of 100-ton hopper cars in Wawa iron ore service: 100 of the distinctive and unique round-sided black hoppers in the 8000 series, built in 1971 by National Steel Car, 300 of the green rapid-discharge hoppers also built by NSC (using an Ortner Freight Car design under license) in 1974-75, and 30 “standard” triple hoppers acquired secondhand from the Ontario Northland Transportation Commission around 1978.

The Ontario Northland hoppers were part of a 72 car series ONT 6000-6071 built by NSC in 1971 and were used in iron ore service from Adams Mine at Dane, ON to a steel mill somewhere in Pennsylvania. For this service, triple hoppers were provided into a pool by Ontario Northland, Canadian National and New York Central (CASO and TH&B cars). Around 1977 or 1978 this particular service to Pennsylvania had either changed or ended completely, and the cars either went back into general usage by their owners (CASO cars were likely renumbered back to original NYC & PLE source series) or were sold off. 30 of the ONT cars were sold to Algoma Central in 1978; I’m not entirely sure where the other 42 ONT cars went initially, but today they can be found on the New Hampshire Northcoast Railroad in New England. When first acquired, the cars were just given AC reporting marks and kept their original numbers for a few years, but were later renumbered into the 8600-8629 series sometime around 1984.

AC 8620 at Scotch Block (Halton Hills), ON October 18, 2008. Photo by David Graham. All the years of weathering have obscured the original colour and much of the lettering, but these cars were painted in the Ontario Northland’s dark green “Progressive” scheme.

While basically a standard design for a hopper, there’s no model out there that exactly matches this car. These are relatively modern welded cars built in the 1970s, but as they were intending to haul iron ore and rock, their size is much smaller than many other modern cars. Most models that are out there that are of an appropriate size tend to represent 90-ton cars a few decades older than these cars, with a different number of side posts/panels and riveted construction. One could accept a riveted car as a stand-in, but the difference in side panels causes issues for the spacing and placement of the lettering.

So, to solve this problem, I turn to my styrene supply to build a few of them for the fleet…

First of all, I spent time carefully working up my own scale drawings as a guide for this project. With the angles involved with the hopper bays, it’s a little more complicated of a build than a small shed or something. Using equipment registers I can find out the major overall dimensions, and using some relatively side-on photos available online, I was able to scale out a few dimensions and work up a drawing.

Actual dimensions of ONT 6000-6071 series, from ORER:

Inside Length 40’6″
Width 9’8″
Height 6’0″
Outside Length* 44’2″
Width** 10’7″
Height*** 10’8″
Capacity lbs 200,000
Cuft 2700

* Over couplers
** At top of side
*** From rail head to top of side

Basic undetailed scratchbuild hopper side.

The basic sides/end are constructed from .020″ styrene plastic sheet, with HO scale 4×4 side posts and an .060″ square top chord. To represent the angled bracing at the bottom, I cemented a strip of .060″ angle, open-side down along the bottom edge of the car side. (The bottom of the side posts are all cut off at a 45 degree angle with my Chopper.) General side dimension notes – top of side: 40’6″; top chord overhangs by 6″ for length of 41’6″; height of side: 7’6″, length of bottom of side: 31’6″ (length of bay cut-out: 4’6″), height of top ends, 2’9″.

Note the different spacing between the ribs at the middle of the car compared the outer bays – this was deliberate and I took a lot of time to try to make sure the panel widths were scaled out properly based on the prototype photos. I worked it out to about 25″ between the 4″ ribs (or 29″ rib centrelines) for the four middle panels and 30″ (34″ rib centrelines) panel width for the outer panels.

Since if I’m going to build one, I can build more than one; and if I build more than one, it’s efficient to build them all at the same time, assembly line style, so once I finish basic construction on all of the sides for the cars, I can move on to assembling the sides with the ends…

Note: for anyone working in N-scale, I found this model on Shapeways.

Hopper Interior Paint and Weathering

While I had the airbrush and paint booth fired up this evening to do some priming and initial paint work on a different project I’ve been working on this weekend (more on that sometime later when I’ve made some more progress) I also ran about a dozen of these hoppers through the paint shop to paint the interiors.


I picked up at least part of the technique (with regards to some of the colours and order of use) from an old RMC magazine article, although probably any time anyone ever does something, they always put their own slight twist on it.

My first step is to paint the interior with a light primer colour. For some cars in raw grey this was not always necessary, but as I have several cars molded in several different colours including red, yellow, green and gray (most were stripped from various roadnames) and a primed interior is required to let the actual colours cover properly. Once primed, I gave the interior a base coat of Model Master “Steel” to give it the metallic silvery of bare polished steel. Then – working very lightly, and progressively up the sides of the interior – blend in Gunmetal, Rail Brown and Rust. Go real easy on the gunmetal and rail brown – the gunmetal is a dark almost black colour, and the rail brown just helps blend with the rust and shouldn’t be too prominent – and the whole interior can get a really light final mist of rust to blend all together.

The one really tricky bit about these interiors is the angled pipe bracing. You really have to be careful to mist the colours in from both sides around the braces to avoid “paint shadow” where the brace blocks the spray. (I did end up with a couple cars with a slightly noticeable vertical line at some of the braces.


I may go over some of these interiors later again, after the cars are fully painted and lettered, with some powders and pan pastels to add a bit of additional colour for specific loads that these cars carried around Michipicoten and Wawa – limestone, coke, sinter and raw ores, but otherwise this is the basic colouring for the car interiors. The top of the car will later be masked off completely to paint the exterior body of the car.

AC 8201-8500 Series Hoppers Underbody Detail

This post is mainly just included for completeness for the hopper series, as the details are basically just assembled according to the kit instructions, although as Walthers doesn’t really sell cars with modeler-applied parts anymore, I should perhaps note a couple of things.


Here’s four of the around two dozen cars currently in progress, with many more still in boxes waiting their turn. You can see the door connecting/locking bars and spring details all installed. You’ll note if assembling a kit car, or re-assembling a stripped down car (in which case you’re not likely to have a diagram/instruction sheet) that there are two distinct versions of the bar details that definitely have to go on in a certain direction, as one has an extra bit of the locking mechanism detail and needs to align with the cast lock detail on the hopper bottom. (However the arrangement of the mounting pins makes this impossible to screw up.)

If you’re adventurous you could also replace the flat thick kit pieces with styrene channel to better represent the prototype parts in finer detail, replace the tail end bits of the door bracing with additional bits of styrene strip, fabricate the extra loop for the door lock on the appropriate bars. I did not do this.

One major note that apparently needs to be mentioned is the door springs, which attach to the door bars on one end, and the centre sill of the underframe on the other to cushion the impact of the doors dropping open when the car is unloaded, as the rapid-discharge hopper design basically opens up the entire bottom of the car. You can see them installed in the model photo above, and half-visible in shadow to the right side of this detail photo (courtesy of Blair Smith) below:


If you get some of the latest Platinum Line releases from Walthers, any of their cars without additional detail parts for air-actuated doors (i.e. a big air tank mounted on the car end) have omitted the spring details. And unfortunately, since the detail parts are not add-on pieces on an included parts sprue, the springs are just not included in the box.

Apparently Walthers thinks that only the cars with air-actuated equipment has these door springs, which is entirely false. Sadly there’s not likely too much that can be said there, and since they don’t stock additional parts (I tried and failed to get replacements from them, and they seemed not to consider the missing parts a mistake) I will likely be saving a couple of parts sprues to make a mold and copy-cast in resin the needed parts for about 2 dozen such cars missing the springs.