Update - see down the page for pictures of the Kinver model of the engine now running

We're nearly there folks!

Catch Me Who Can

It was in 1908 that the acclaimed Cornish engineer Richard Trevethick, had his third locomotive, the 'Catch Me Who Can,' built by John Urpeth Rastrick at Hazeldine Foundry in Bridgnorth, Shropshire. Trevethick was a leading exponent of high pressure steam, or ‘strong steam' as he called it and this new locomotive was to embody many of the design principles in which he believed. Weighing just eight tons, the engine was taken in July 1808 to Bloomsbury in London where, running upon a circle of track its demonstration became popularly known as the 'steam circus'. Here, hidden from the public gaze by a tall circular wooden fence, Londoners could, for the charge of one shilling ride behind the locomotive in a converted carriage at heady speeds of anything up to twelve miles an hour. The fragile cast iron rails eventually broke under the weight of the train and the project was disbanded. It remains to this day however as the first recorded occasion upon which fare paying passengers had been hauled behind any sort of locomotive and the 'Catch Me Who Can' had secured its place in history.

Whilst only fragments of old buildings survive on the Hazeldine site in Low Town, Bridgnorth, the importance of these events is still recognised by the town and the 'Trevethick 200' group has been formed to commemorate this historic occasion. On the 19th and 20th July 2008, the group intend to celebrate this bicentenary by holding a gala weekend at Severn Park, a site adjacent to the spot where the locomotive was actually built. A full size working replica of Trevethick's engine is currently under construction in the Severn Valley Railway's workshops at Bridgnorth and it is hoped that this will be completed in time for the event. The Kinver and West Midlands Society of Model Engineers were approached about running trains on a portable track at the gala and agreed to do so. The society also decided to build its own working replica of the locomotive in 5' gauge and run it on a fifteen foot diameter raised circular track at the gala. What follows is an account of the progress to date on this project.

Discussion was held to outline how to build a model that, whilst accurately portraying the original would actually work in such a small gauge. The firing; valve gear; boiler pressure; type of track and method of operation would all have to be taken into account. As the plateway of the original pattern would be hard to reproduce, it was decided that the locomotive would run on conventional rails, as per the replica. The original boiler was a single return flue type and it was felt that this would not generate enough steam in this gauge. Kinver member and professional boiler builder John Ellis has designed a multi tube boiler that is to be coal fired from underneath, the firebox being between the axles. The boiler has been pressure tested to 160 psi which means that the model can safely run at 80 psi, although it will be a case of test running to see what is actually needed.

The next problem to be overcome was the design of the cylinder and valve gear. The original locomotive had a cylinder diameter of 6' with a plug type valve operated from a beam by a bash lever. We felt the need to increase the size of the cylinder from a scale 1/2" to 3/4" in order to increase the power required to carry this single cylinder engine over its dead centres. In consideration of the valve gear it was felt that in 5' gauge, this would not be very robust and would be difficult to replicate. We designed a slide valve arrangement driven from the front axle by a single eccentric. This will be hidden from view by the footplate. The setting of the valve will of course need to be correct for practical purposes and to help the engine to run as evenly as possible. The valve has been given 0.020" lap with minimum or no lead and the locomotive will need to be pushed in order to get it to go in the right direction. The valve cut off is estimated to be around 95% as, like the original it was not designed to work expansively. Once again trial and error will play a big part in developing this.

The wheels were cast from a pattern provided by another member of the club, professional locomotive man Dan Jeavons. Eight wheels were cast, four for the engine and four for the landau to be pulled behind it. The locomotive's water supply will come from a beam driven pump mounted on the side of the boiler. This pump will incorporate a bypass valve, the water coming from and returning to a tank mounted in the base of the landau. A hand pump will also be provided in the landau to give an additional method of supplying the boiler with water.

Due to the position of the firebox the wheel sets could not be mounted on the boiler, so a small frame has been made to support the boiler, ash pan and grate. The front pair of wheels is allowed to pivot on a pin fitted to the front of this frame.

Now it is time to say particular thanks to some who have contributed towards the project to date. To Terry Harper who has provided all of the drawings and done a lot of the design work using C.A.D. modelling. To Mike Stevens who has made a superb job of the cylinder. To Mike Harrison who has drawn the short straw in putting it all together and of course to John Ellis and Dan Jeavons for their contributions mentioned earlier, 'Thanks chaps!'

Finally 1 would like to announce that 'Catch Me Who Can' can also be seen on the following weekend of 26th and 27th July when the Kinver and West Midlands Society of Model Engineers will be holding an Open Weekend at their Marsh Playing Fields site in Kinver, near Stourbridge, West Midlands. The 3 1/2" and 5" gauge raised track will be open to all corners with boiler certificates and the 7 1/4" gauge ground level track likewise, although this will be limited to smaller engines. An exhibition of members' models will also be held in the Community Association building adjacent to the track and a warm welcome awaits our visitors on what promises to be an excellent event. You can contact Allen Bellamy on 0 1746 761008 for more details. We hope to see you there.

After her 1st half mile run...There's a good doggy now...