Designed and built in the workshop here, we originally conceived our first locomotive, "Stafford", as a robustly-engineered, easy to drive locomotive - something equally at home on a garden railway or public running at the local club.
With more than 100 locomotives built, the design has proved a powerful, reliable performer on private, club and commercial railways throughout the UK and overseas - it has now expanded to a range of engines from 5 inch to 10 1/4 inch gauge, with a choice of styles and wheel arrangements.
Having worked on some hundreds of locomotives over the years, a lot of the design choices fell into place easily:
An all-welded steel boiler with replaceable tubes - easy to service and maintain, with the ability to run at 120psi (Clubman range) or 150psi (Estate range) making for easy steaming and a good reserve of power
Full-sized controls - the regulator, reverser, steam and water valves are built to fit a driver's hand, they aren't scale versions which are difficult to get hold of and, when you do, are discovered to be red hot!
Steel wheels. Cast iron wheels + steel rails = grooves in the treads - at the end of the first season on my Tinkerbell (admittedly running a commercial service), which needed tyres at less than a year old. In contrast, the wheels on our demonstrator engine still look pretty much the way they left the lathe.
Sealed ball-bearing axleboxes, which reduce maintenance, increase service life (by keeping grit out of the bearings) and ensure that as much power as possible gets to the drawbar, rather than ending up being used to overcome rolling resistance.
Walschaert's gear for it's accurate control of the valves over a wide range of cutoffs - this allowed us to set out the gear to give generous full-gear cutoff for reliable starting (and I've lost count of how many big engines I've driven that need a bit of driver's leg assistance to move away after stopping on a "dead spot" in the valve gear) whilst still allowing economic high speed running with the lever "notched up"
Cast iron cylinders with slide valves. Pistons are in iron, fitted with the incomparable Clupet rings
TIG-welded stainless steel water tanks. I can't remember how many grotty old rust-filled tanks we've cleaned out and repaired on other engines over the years (usually they either start leaking or shedding rust into the injectors, both if you're unlucky). We build all our water tanks - for both locomotives and tenders - in stainless steel, wouldn't consider anything else.
Ball valve regulator - as fitted to my Tinkerbell in 2002 and still going strong (not to mention just about every other successful commercially-built locomotive of the last ten years). Silky smooth in operation, light action even under high working pressures, absolutely steam tight and easy to replace should the need ever arise.
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