Scratchbuild an operating coal tower

If your garden railroad is set in the steam or steam-to-diesel transition era, it’s going to need a coal tower. When I started to gather rolling stock and build my railroad in 2013, there were no commercial coal towers on the market.

The only existing product was from Pola, but I couldn’t find one on the used market. I started to collect information on full-size coal towers so I could build my own version of the Pola coal tower.

I estimated the overall dimensions of the tower measured 26” (67 cm) high, with a weight of 10 pounds (4.5kg).

I had to design three actuation devices: one for the chute, one for the chute gate, and one for the elevator used to lift the bucket of coal to the tower’s hopper.

For the chute, I used two 12V DC electrical actuators designed for car door locking systems. These are available at brick-and-mortar and online auto parts stores. These could be easily activated with an AC/DC transformer. I installed the actuators side by side on a board.

I used a mechanical crank for the chute gate. To operate the chute, which is a little more complicated, I used a kind of drawbridge. If left in the lowered position, the chute poses a safety concern as a passing train may hit it. To minimize this risk I added a position switch that illuminates a warning light. I also added a locking mechanism with a magnet to prevent the chute from accidentally dropping into the lowered position.

I feared the coal might run too quickly into the tender via the chute, so I inserted a small barrier near the chute’s output.

For the elevator I designed a hoist using a Playmobil power control unit to drive the winch. The unit is easy to use, with simple motion control forward and backward.

The bucket is guided by two side rails. When it reaches the top, it topples backward to empty the coal into the tower’s hopper. Then the bucket must lean forward, stabilize into the upright position, and move back down to be reloaded. I was able to achieve this by adding a counterweight to the rear side of the bucket.

As there are several electrical devices, I had to install wires going up to the top of the tower. To hide them I created a hollow vertical rod and put the wires inside the rod.

The tower includes a hopper that’s filled with coal (or at least something that looks like coal). At first, I used rice. It worked well, but unfortunately it’s white, so I searched for something black. I found a product that looked like coal, but the pieces had angular edges and didn’t slide down the chute, blocking the reservoir. I went back to using white rice for now. 

Instead of gluing the boards on the hopper one by one, I built a box with medium-sized boards. Then I glued this piece onto the box with the individual boards.

I have a video showing the construction details on my YouTube channel: https://www.youtube.com/watch?v=VarCTPEywqg

You can see the coal tower in action here: https://www.youtube.com/watch?v=rinlzC0lheo

Looking for drawings of a coaling tower? These plans are modeled after the D&RGW at Chama, N.M.