PRODUCTION ENGINEERING FOR PROFESSIONALS

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Built in 1903, the Welshpool and Llanfair Light Railway served the communities along the winding valley that joined the mainline at Welshpool. This narrow-gauge railway allowed livestock, coal and timber to be transported easily, as well as providing a passenger service until the early 1930’s.

 

The line operated until 1956 when British Rail deemed it uneconomic. A regular steam hauled public service once again returned to the line in 1963 when a group of enthusiasts took on the challenge of making it into a successful tourist attraction. Key to that success was the retention of two of the original locomotives and the acquisition of rolling stock from railways both in the UK and Europe. Now almost 120 years old, this historic collection requires regular maintenance and care, which is where the railways engineering workshop comes in to its own.
A little bit of catching up was required as the first maintenance workshop wasn’t built until 1968 and the locomotives lived outside in the elements until 2000. An extension to the workshop in the 1980s saw the development of the machine shop, with machine tools being ‘begged, borrowed or stolen’ from supporters of the railway. Things did improve in the 1990’s when a Heritage Lottery grant allowed some additional machines to be purchased, but when Mechanical Engineering Manager, Richard Featherstone joined the railway in 2016 he recognised an adequate, but not ideal situation. “We had a lot of manual machines and work on them was time consuming and given that we rely on some skilled volunteer labour, time is at a premium. What we needed was bigger and faster milling and turning capacity that also had to be user-friendly to cater for the skills and work that we have.”

An appeal for funds went out and as a result we were able to order two XYZ machine tools, an SMX 4000 bed and an SLX 425 ProTURN lathe. These machines made an immediate impact on the way that Richard Featherstone was able to support the maintenance of the engines. One example was spark arrester plates for the smokeboxes, which are made up of a sandwich of stainless steel plates and mesh held in place by 28 M6 screws. “These M6 drilled and tapped holes would traditionally have been marked out, centre popped and manually drilled, then adjusted by the fitters for assembly,” says Richard. “We now machine them on the SMX 4000 and every hole is in the right place and the comments from the volunteer fitters are typically ‘it fits!’ the time savings are significant.” Similarly, the SLX 425 ProTURN lathe is generating major benefits for Richard and his team of volunteers. Each of the couplings between engines and rolling stock has an adjusting nut which has a 11/4 4TPI round thread form. A batch of 15 off has been manufactured by a semi-skilled volunteer in an afternoon on the SLX 425. Prior to this using manual machines this was a week’s work! For traceability these parts are then put on the SMX 4000 and etched with the relevant details, again, this would have been done by hand with letter and number punches previously.

“Maintenance and refurbishment is a continuous process here as the engines and components are subject to an aggressive environment; we are either boiling things or burning things,” says Richard. “For example, after every 28 days of being under steam we have to replace/rework the two fusible plugs in each boiler. These are bronze plugs with a 99.9 per cent purity lead core. Their job is as a failsafe if water levels drop in the boiler, the lead melts and the flame is doused. Making these plugs was a black art as they feature a taper thread, which must be accurate, and a specific length as four complete threads should be showing on the inside of the firebox, a situation complicated by the fact that the female thread is re-tapped and opened-up occasionally. Now it is a straightforward procedure as I can call up the program on the ProtoTRAK control on the SLX 425 and adjust offsets and be confident we will produce accurate parts first time. Again, with the focus on availability of labour and time, with me currently being the only full-time member of staff in the workshop, these fusible plugs used to take a skilled-man four hours to produce a pair manually. It is now possible to turn a pair of plugs in under 15 minutes.”

Programming is done at the machine by Richard at present; he is then happy to hand over the operating of the machines to semi-skilled volunteers, although this situation should improve when he recruits an additional full-time machinist. One feature that Richard is particularly enthusiastic about on the SLX Lathe is the TRAKing facility, which allows him to use the handles to move through the program, while remaining in full control “I love the TRAKing feature as you know you can back off if you have any uncertainty about the tool path. That said, the ProtoTRAK control is so easy to use, with step-by-step instructions it is so easy to get things right first time.”

Visit:
www.xyzmachinetools.com

Looking For Skilled Volunteer Enginners
The Welshpool and Llanfair Light Railway is always looking to recruit skilled engineers on a voluntary basis. Expression of interest can be made by calling the railway on 01938 810441.

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