The Golden Valley Light railway

TDA Civil No 1 “Joan” (1997)

Alan Civil’s last project in BR’s drawing office before retirement was the chassis for the class 14X DMUs known as “Pacers”. Simultaneously, he was producing the drawings for this locomotive. Alan was apprenticed at Bagnalls at Stafford, and this locomotive draws heavily on their practice for their early locomotives of this size.

It is an Inverted Saddle Tank. The tank goes all the way under the boiler. Bagnalls later learned the error of their ways and later locos were normal saddle tanks.

This is a 6” size engine and this refers to the bore of the cylinders. Most were built as 0-4-0s, with a much shorter and taller cab. There are quite a few of that type about. The 0-4-2 type were produced to fulfil a demand for lower roof heights, and in order to achieve this, a step down in the footplate needed the footplate lengthening, hence the extra wheelset. We’ve never tried, but the design claims to be capable of negotiating a 40’ radius curve.

Bagnalls could be relied upon to build unconventional locos. They used different valve gears to avoid paying patent royalties to the likes of Walschaerts. This one has Bagnall Price valve gear, earlier locos used Baguley valve gear, but Baguley left the company and set up on his own.

Bagnall boilers with their circular fireboxes were much cheaper than normal loco boilers that have rectangular flat sided ‘boxes. The reason is simply that cylinders don’t fail when subject to pressure, whereas flat plates bulge and must be supported by a multitude of stays, all of which have threaded ends and engage with threaded holes that must then be made pressure tight by caulking. Those provisions all add much extra cost. The downside of Bagnalls’ circular firebox is that the boiler contains a much greater volume of water for its size, and so this loco takes 3½ hours to raise steam from cold compared with about 2 hours for a normal one of this size.

The loco has been out of service since 2017 (when its 10 year boiler certification expired), and now that O&K 7529 is complete and behaving, "Joan" is undergoing a full overhaul. To date, all boiler overhaul work has been completed, and it has been dry stored separately. The boiler now incorporates 3 welded in stay tubes to prevent flexing of the backhead, which takes the top of the inner firebox with it & consequently causes leaking tubes. All other tubes were renewed to standard spec, and beaded over at the firebox end.

Work already completed

• Chassis work proceeds apace.
• To date, the following work has been done to remedy wear or original defects:
• All axle (rolling) bearings have been examined to the maximum extent possible, short of pulling off the wheels.
• The rear pony truck suspension has been repaired and made to work the way it is supposed to. Lubricating oil feeds have been added to the driving & driven axle hornguides.
• Both the single piece eccentrics were loose on the driving axle, so were broken off and renewed as 2 piece split versions, with high strength clamping bolts and a small but definite gap at the split lines.
• Larger brake cylinders have been fitted to improve the brake force. The geometry has been improved and slotted links have been made & fitted to avoid the piston discs lifting off the diaphragms when the handbrake is applied.
• One new piston & ring has been made & fitted, as an original ring and land had broken some years ago.
• The Winson air compressor has had a new steam end valve designed, made & fitted, and tested successfully on compressed air.

Return to traffic in 2026 seems probable.

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