The workshops of the Llangollen Railway in North Wales (www.llangollen-railway.co.uk) provide maintenance for its own rolling stock; they also support other heritage railways around the UK and can build brand-new steam locomotives to order.

They are currently playing a key role in the restoration of the iconic streamlined A4 Class locomotive Sir Nigel Gresley, which was built in 1937 and holds the post-war steam speed record of 112mph (set on 23 May 1959 while hauling a full train of passengers).

This loco has had many overhauls, and the latest is taking place in full public view at the National Railway Museum in York — except for its boiler, which has been stripped of its streamlining and transferred to Llangollen for refurbishment and re-certification.

As part of this project, the boiler stays must be replaced; these threaded shafts support and brace the metal walls of the firebox against the pressure (up to 250psi) and are an important safety feature.

As the boiler has 296 of these stays of various lengths, with Whitworth threads on both ends, an upgrade from manual turning was deemed wise.

Llangollen Railway took the decision to invest in an XYZ SLX 425 Proturn lathe with 1.25m distance between centres, and this decision has paid off.

Each boiler stay can now be machined complete in half the time previously taken on a manual lathe.

Machinist Michael O’Toole said: “The ProtoTrak control makes life very easy, as it guides you through everything, the TraKing feature is very handy, and the ‘Do-One’ canned cycle is extremely useful for machining features such
as radii and chamfers.”

The ‘Do-One’ feature allows the operator to combine manual and CNC operation to create radii, tapers and fillets — and to repair threads.

The operator simply inputs the angle or radii into the control and can then manually create the shape or form required, using the electronic hand-wheels.