HO Scale Model Railroad Freight Car Construction Tips:

My constantly sputtering efforts at model railroading


Intermountain Railway Company 4750 Cubic Foot 18 Rib 3-Bay Covered Hopper

IMHO, a very nice car, but the directions are somewhat lacking. Here's what I have been doing for about a dozen of them and it seems to work very well.  This tip sheet is intended to be used along with the Intermountain instruction sheet.


Drill #66 in the roof hinge eyelet holes, unless the car has been painted (rather than molded in the final color). In that case use a #65.

Drill #71 in the roofwalk grabiron holes.

Drill #72, just a little bit (no pun!) the long grabirons holes on the cage ends. If you drill into your finger, you've gone too far.

Drill #73, again just a little bit, the depression on the underside of the separate air valve.  Also, do the holes for the brake pipe mounts.  These are located on the top of the coupler pockets, closest to where the pockets sit next to the body.

Take an Exacto blade (#11 is good) and run it lightly once or twice around the two outermost holes at the ends of each of the coupler boxes (these holes are for the brake steps).

Look closely at the four horizontal ladder braces Parts (h). They have a notch at the end that holds the end-cage. The notch on one of them needs to be slightly enlarged: on the parts tree, it is the one on the outside edge, next to the bottom hatch.

On the bottom of the center bay is the gate where the mold was filled.  Some of them can be quite large.  Cut and sand this off so that the bay door will sit flat.

CONSTRUCTION: [STEP ] refers to the same steps listed in the Intermountain instructions.  However, some I have taken out of order.


A Install the body weights first.

B Install the dividers.

C Install the roof.

D Install the roofwalks. Do not install the roofwalk grabirons--wait until the end so they don't get crushed.


E Assemble and install the coupler boxes. Include a shot of graphite in the box, after you have installed the Kadee spring.  If you are constructing an undecorated model, consider not attaching the bottom coupler covers (g) and the couplers until you have painted them. Either that, or cover the couplers to prevent them from being painted the same color as the car body.

STEPS 3 & 4.

F Attach the 4 horizontal ladder braces (h).

G Attach the end ladder sections (i) [or cage ends].

H Mount the Triple Valve (m) then the separate valve and airline (n) to the correct diagonal brace (l).

I Install the other 3 diagonal braces, then the one with the valves. Its easier than trying to do it with the side ladders in the way.

J Install the air tank (k). You'll probably have to trim about 1/16" off the airlines, but check it.

K Now install the side ladders.

L Attach airline/brake pipe assemblies (o). I cut off about 1/8" to 3/16" from the end that goes inside the carbody.

M Assemble brake wheel and mechanism and install.


N Mount bottom ladder rungs.

O Install long grabirons.

P Mount brake steps.

STEPS 6 & 8.

Q Attach shakers.

R Attach bay doors.

S Assemble trucks and install. Put a shot of graphite in each axle pocket.


T Install hinge eyelets.

U Attach hatch covers of your choice.

V Install roofwalk grabirons.