Friday, February 12, 2016

HOJ POJ Reno: The Water Tower

[Fitting the braces to the legs calls for a little agility.
E. L. Moore commenting - with considerable understatement - on the most difficult part of the HOJ POJ water tank project in his Railroad Model Craftsman article of April 1968.
Amen brother.
J. D. Lowe commenting on the comment.]

The HOJ POJ project included an onsite water tower near the main complex. That model wasn’t one I saw at the meet-up, and wasn’t part of the HOJ POJ remnants, so I decided to build one for the diorama as per the instructions in E. L. Moore’s article.

I must say that if you want to build a water tower for some other purpose, I wouldn’t build one according to this article. This isn’t meant as a slight against the original, just that there are kits and modern scratch building techniques that will produce a somewhat more realistic water tower with less work. I built it completely old school because I want it to fit in with the style of the complex.

I found it to be a finicky project. It took me a long time and I wanted to give up on a few occasions :-( I’d guess and say it uses some laborious construction techniques from the ‘50s and my 21st century mouse-sized attention span couldn’t handle them :-) I’m sure in the hands of a master like E. L. Moore, this project isn’t too bad, but for me, it was tricky. In the end, the structure is ok, but not great. Anyway, if after all my grumblings you still want to give it a go, let’s get started.
The whole project is built around a humble fishing bobber from the 1950's. Luckily I had a couple and used a very damaged one for this project
Mr. Moore says he removed the central shaft and replaced it with a long 1/8" diameter stick that models the water pipe and provides some structural stiffness to the assembled model. The shaft wouldn't come out of this bobber so I cut most of it off. I eventually learned that it also wasn't square to the body, so I had to cut off that remaining stub shown in the picture.
The tank body, whose diameter is the same as the widest diameter of the bobber, is rolled and glued up from a piece of construction paper. An inside stiffener is cut from 1/16" balsa.
The construction paper tube is slipped over the bobber and glued in place. It fits quite snugly. 
The balsa stiffener is then dabbed with glue along its perimeter and pushed into the end of the tank. It's quite a solid little structure once the glue is dry.
The roof is made from a circular disc of construction paper that is sliced to its centre so it can be shaped into a cone.
Two nested, smaller cones are glued inside the main roof cone. E. L. Moore recommends using three internal cones, but I found two made for a sufficiently stiff roof.
Here's the built-up, painted and lettered tank. The roof apex has a decoration inserted that was carved from a round toothpick. The whole thing was painted aluminum and the lettering was from some very old rub-on transfers from '70s. This version of the tank still has the straight-up final J that eventually got scraped off replaced with a skewed one.

I must admit that my assembly sequence was goofy. If I were to do it again I'd paint the construction paper first and then apply the letters before rolling it into a tube. 
On next to building the girder legs. The first thing I did was cut 8 strips, 3/32" wide from 1/32" thick sheet balsa stock.
The next thing to do is glue on some spacers, cut a scale 1' long from 1/16" balsa. Do this to 4 of the strips, then glue on the remaining strips to create 4 built-up legs.
Here are the half finished legs. The next step is to wrap each leg with diagonal bracing cut from paper. 
I took a sheet of paper from the computer's printer and sliced off 8 thin strips.They were coloured black with a Sharpie pen.
Gluing these strips in place made me a little nutty, but once I got the hang of it, it wasn't too bad. First, glue a strip on a girder end at 45 degrees to the balsa. Let it dry, then start wrapping it up the leg.
It's a little hard to tell from this photo, but the trick is to make the spiral loops equally spaced at about 1/2" between each loop. Once you've made a loop, dab some glue on the paper, press it to the leg and move onto wrapping the next loop. After awhile it becomes second nature. Each leg is wrapped with two strips, spiralling in opposite directions. After the glue was dried, there was a bit of touch-up with black paint to hide small glue smears and missed spots on the legs.
The spirals on the leftmost leg aren't too tight. It was the first one I tried, but I decided to use it anyway. I made it one of the back legs. It doesn't look too bad on the finished model - not noticeable. I think it's because everything is painted black. That hides a lot of imperfections.
Once the legs were done, next came the tank platform. Two donut shaped pieces were cut from 1/32" balsa and glued together with the grains perpendicular.
It too was painted black and then slipped onto the tank.
The railing was drawn out on a piece of overhead transparency film with a Sharpie pen. I made it a little longer than the perimeter of the tank platform so there'd be a gluing edge.
It's a little tricky to get it snug to the platform, but, alls-well-that-ends-well.
At this point I went crazy. I figured I could stand the tank unit up on the four legs, coax them into position, slather on some glue, and voila ! it would be standing up and all I'd have to do is glue the cross-braces to the legs. Oaths were sworn. Glue was glopped. Nerves were frazzled. But, gravity was not defied. Time for plan B. I drew up a template and glued cross-braces to pairs of legs. They were 1/32" strips sliced from a 1/32" thick balsa sheet.
The night dragged on. Braces were cut. The glue dried slowly. 
With shaky hands, and a lack of concern about focusing the camera, the tank was hoisted up on the braced leg pairs and magic occurred ! It stood up. And it was square and straight! The age of miracles is not over!
A couple days later I added the wood frame cover around where the water pipe should be and started gluing the remaining lower leg braces in place. That did a lot to stiffen the overall structure. E. L. Moore made the braces from balsa strips and metal wire. I'm not sure why the mix, but I speculate that's what he had on hand, so that's what he used. The bracing on the upper third is simply thread zig-zagged through the legs, so I did that too. That was the last step.
Ok, well, not quite. I glued a styrene ladder on the left front leg. I ran out of ladder stock and didn't have any left to build the tank ladder to the roof - I'll see what I can find at the local hobby store. But, other than that, it's ready to add to the diorama.


  1. Paper zig-zag bracing! AACK! Gives me nightmarish flashbacks of the infamous Alexander Little Hook build! That is an otherwise excellent kit, but I'll be darned if I could see how anyone would have built one satisfactorily using the paper supplied. I remember the instructions specified how to cut the paper with the grain in order to maximize the strength. Even then it was too flimsy and I fell back on styrene strip.

    Anyway, you sir are to be commended for your dedication to this art, but perhaps committed for your insistence on sticking with the 'prototype' materials and techniques. Reminds me of the replica prop builders scrounging for old kits to find the exact greeblies the original model makers used.

    Excellent work, as usual.


    1. Thanks Galen! Luckily the project didn't leave any lasting emotional scars, and as Debra sometimes says to me, I think of it as a learning experience :-) But, it does look right when placed beside the other buildings in the complex. I've got a couple more old school pieces to build for the diorama and it should then be finished.