Ken Swan’s delightful Wren design built by Andrew Marsden and featured at a Harrogate exhibition.

The Wren was designed using original works’ drawings and is to a scale of 3-1/4" to the foot.  The full size Wren was built by Kerr, Stuart & Co Ltd. A feature of their locomotives was that they were designed to be used where skilled labour and extensive maintenance facilities were scarce. Most contractors just bought a locomotive and expected it to run as long as water was in the boiler and fire in the grate. An occasional squirt from an oil can passed for maintenance. The Kerr Stuart locomotives were ideal for this type of environment as they were mechanically simple and robust, and part were easily accessible. Early designs had outside Stephenson’s valve gear, while later designs in the smaller gauges had a modified Hackworth gear