Rolling Stock.

The engineering magazines are full of articles about rolling stock-a 25 week serial on how to build a BR standard 4, scale Gresely coach in 10 parts, machining pistons over 6 weeks etc etc.. Not having a big interest in model engineering we decided it was best to leave that to those who can spend five years building a Britannia and then sell it only having run it once. Despite needing a 50ft radius to drive the thing the chances of the majority of us owning or having the will power to build one is remote.

As metioned in chapter 1, our first loco was a Polly 1 now produced by Polly Model engineering. This loco is ideal for running in the garden. It can turn on a 10ft radius and can easily haul 4 adults. Instructions for steaming are included with the loco but the most important part is the levels. What I mean by this is water, oil and coal. Driving a steam engine is a tricky balance of making sure you have enough steam to run, enough water to make steam, and enough fire to keep making steam. If any of these fall out of balance, then it is a quick stop for a top up.

The oil comes in two places. The first for oiling all moving parts and a bit for the rag for a quick wipe over. The second place is oil steam oil. This goes in a little box on the running plate. From here a crank from the wheels drives a pump which pumps the oil into the main steam pipe just before the cylinders. This lubricates the pistons and helps stop them going rusty. Without this you will soon find the piston rings start wearing away.

My dad has always gone on about his water softner and how good the water is. Well, not for steam trains. After a couple of steamings it soon became apparent that valves with slight leaks were getting stiffer. The problem was solved by installing a rain water butt. Running the loco on rain water left no traces of limescale.

Our second loco was a Compass House 0-4-0 Bulldog battery loco. Not being supplied with batteries I have welded up a tray to take two standard car batteries running in series to give 24 volts. While it is not recommended to use car batteries, as they are not designed for constant drain, they are cheap. The correct traction/leisure batteries are over twice the price. So far, two years on, our first set of batteries will still power an engine for an afternoon of running.

Traction is provided by two 12v 100w fan motors in parallel which means they are running on 24v. This might sound strange but is quite common as a way of increasing the power output. The only possible damage that could be caused from running on a higher voltage is damage from over speed. This is very unlikely to happen on a model engine.

Traction is provided by two 12v 100w fan motors in parallel which means they are running on 24v. This might sound strange but is quite common as a way of increasing the power output. The only possible damage that could be caused from running on a higher voltage is damage from over speed. This is very unlikely to happen on a model engine.

NOTE - The above statement was made in the very early days. It was possible to burn out the motors by simply overloading them. This we did but the up side was that it lead to the design and creation of the Trojan engine.

Coaches

Having purchased two bogies from Compass House early on, the challenge was to build a chassis. A year or so before, my parents decided that after many years of good service that they didn't have any need for a second set of bunk beds. At the time I thought that it looked a good sample of angle iron and I thought that it would come in use one day.
Using the width of the Polly as a rough guide and playing with bits of timber to decide what length looked right, we settled on 250mm × 1070mm. This agreed, I set to cutting up the angle iron to create the chassis. For the buffer beam a bit of 1" angle iron from my brother's old bath fitted the bill. The cross beams to mount the bogies on were bits of scrap iron left over from a lift engineer on site. I don't know what they were designed for but they certainly made good bogie mounting plates.
At this stage we used the chassis as a flat wagon with an old bit of timber for decking. We also took the desicion not to go to the expense of brakes. Sitting astride coaches leaves the driver in the ideal position to put there feet down in an emergency. It is almost an instinct to put you feet down and has much more braking power than using conventional braking systems. For general use the enginge braking provided by the locos is sufficient.
It was not until nearly a year later that we embarked on building the bodies for our chassis's. Having seen most ride on ground level coaches being a simple box contruction we decided that this was a bit dull to say the least. For people who spend years building a loco in the shed to then run it with nothing but a modified crate seems a bit strange to me.

For the coach windows we made a router template for the door and two seat windows and routered out the four sets on each side to represent a four compartment coach. Again, the 10mm marine ply sides were left over from work. To get the curve of the roof we used two layers of 3mm plywood which were pinned and glued together. After a few coats of paint and the addition of foot boards we think that what we have produced is not only a good riding vehicle but a good aesthetically pleasing coach when run without passsengers.

After our first year we started experiencing what appeared to be an increasing number of derailments. As the track settled in, the inability of the bogie coaches to handle twisted track soon became clear. The problem was that the cross bars on the bogies were tight with the chassis. This meant that if for example on the start of a corner the outer rail dipped slightly the chassis held the wheels up and you would find the outer wheel riding up and over the rail.

To help eleviate this we first tried two methods.
1. Sprung cross member. By springing the bogie mount we hoped that if the rail did dip down the springs would push the bogie down. This was relatively successful but actually made the coaches feel unstable.
2. Three leg stool. By placing washers between the bogie and the mount on one bogie it allowed one bogie to pivot. It was quite successful but you really needed to know which end of the coach to sit on. Sitting on the pivoting end was very unstable and led to more derailments.

The final and most successful method was to redesign the bogies. Going back to the drawing board, or computer in this case, I designed new bogie side frames and cross supports. The design puts two springs in each side frame which compress when the bogie is ridden on. When the track twists and the rail dips the springs push the wheels down. During our trails the only derailments were due to unstable passengers. Left one of our prototype bogies

While we were having problems with our bogie coaches our attention turned to short wheel base coaches. The first of these was again sized around the Polly and was constructed using standard angle iron. The horn blocks were made from nylon bar section which was machined using a crosscut saw and a router.

Originally we only wanted one as a kind of driving truck/tender for the steam loco but soon realised that a half sized coach body would fit on it. The joy of the four wheel chassis is that they hardly ever derail due to track problems. The main disadvantages are that they are not as smooth as bogie coaches and on the tight radius bends the flanges tend to cut into the rail.
The concept of having a timber upper body on a metal chassis means that we can have different bodies without going to the expense of a new chassis. On the four wheel chassis's we have a tender style body as a ride on truck which can be swapped with a short coach body.

Progress and development of our rolling stock continues but now with the view of marketable products.

Our Railway