Sommaire pour Issue 4696 de Model Engineer

MARTIN EVANS Editor DIANE CARNEY Assistant Editor YVETTE GREEN Designer Bradford Cud As regular readers will know, the recently instituted Bradford Cup was awarded to Mike Tilby, voted the author of the best article or series in Model Engineer during last year, for his series on steam turbines. Your editor travelled up to the National Railway Museum in York, to meet Mike, Graham Astbury, representing the Bradford Model Engineering Society, presenters of the cup, and Roger Backhouse, ‘official’ photographer. We are all editors of various club and national magazines so we agreed that we must surely be, collectively, a ‘misprint’ of editors. Anyway, back to business. The photograph shows the cup being handed over by Graham to Mike, witnessed of course by Roger and me. Many thanks to the Bradford…

Continued from p.111 M.E. 4694, 1 July 2022 The gear change control mechanism The operation of the reversing gear needs a lever that is easy to access and has a simple securing arrangement to keep the gears engaged in either direction of running and for there to be a neutral point to enable the engine to be pre-heated before use and to deliver water to the boiler as required. The mounting plate for the gears which works against the frame plate ‘A’ has to have a pivot stub or tab, bolted onto the top right-hand side corner that then has a link strip that is attached to the control lever. In addition, the plate also needs a retaining keep or strap around the back of plate ‘A’ to steady the…

Rolls Royce Dear Martin, I read with interest the letter by John Bauer from Ontario in Canada in issue 4692 of Model Engineer (June 3) where he mentions the Rolls Royce Merlin engines being built by both Packard in America and also by Ford in the UK. The Packard built Merlins revolutionised the Mustang fighter and turned it into something special, especially at altitude. The UK Ford built Merlins, according to the book titled ‘Ford at Dagenham’ by David Burgess-Wise, were in fact built in a shadow factory in the Manchester suburbs not far from where Ford set up its original factory in Britain. Apparently, so the story goes, Ford found that the manufacturing tolerances set down by Rolls Royce were too loose. The problem that Rolls Royce faced was…

Continued from p179 M.E. 4695, 15 July 2022 Challenges in researching the prototype Many hours have been spent reviewing the host of original drawings for the prototype with the copies I have being faint in some areas, which has proven to be frustrating. Some time ago I was contacted by the Guinness Brewery Museum in Dublin after the curator was put in contact with me. It was during an exchange of emails between us that the mystery as to why some of the drawings I had obtained were faint became apparent. It appears that the building where much of the Guinness Brewery archive material was originally stored was once flooded. Luckily, most of the 60 or so original drawings were recovered. However, some were damaged by the flood water, hence…

As the introduction states ‘the main criterion of selection is simply that the bridges chosen... appealed to the author’. So this book offers an eclectic choice of bridges from around the world. Though most come from Europe and North America it is interesting to see that many eye-catching modern designs are from China, Malaysia and Taiwan. Many historic and unusual bridges feature including ancient arch bridges in various Muslim countries. There are even pontoon bridges and demountable bridges based on the principles of the Bailey bridge, notably one in Sudan. Not all bridges mentioned are illustrated but there are lists of bridges by country, unusual bridge features (like chapels), bridges by length and even natural fibre bridges. The highest in the world is India’s Chenab bridge. Few British bridges feature…

29 July - 10 September 2022 July 29-31 Welland Steam Rally Woodside Farm, Welland. See wellandsteamrally.com 30 Cardiff Model Engineering Society Steam-up and Family Day, Heath Park, Cardiff. See www.cardiffmes.co.uk 30/31 Fareham and District SME Steam Railway Weekend, Club Track 10:30 – 17:00. Contact: info@fdsme.org.uk 31 Bristol SMEE Public running, Ashton Court Railway BS8 3PX noon – 17:00. Contact: secretary@bristolmodelengineers.co.uk 31 North Wilts MES Public Running, Coate Water Country Park, Swindon 11:00 – 17:00. Contact: Ken Parker, 07710 515507 31 York Model Engineers Open Day. Contact: Bob Polley, 01653 618324 August 3 Bradford MES Evening Running and Social Evening, Northcliff Railway 19:30. Contact: Russ Coppin, 07815 048999 3 Bristol SMEE Auction, Begbrook Social Club BS16 1HY. Contact: secretary@bristolmodelengineers.co.uk 4 Guildford MES Open Day, Stoke Park, Guildford 10:00 – 13:00. See…

York Model Engineers have added two new buildings, a workshop and a store, at their Dringhouses track site just south of York (photo 1). Observant passengers on the adjacent East Coast main line can see the buildings and, if passing on Wednesday mornings, note members at work around the site. Origins A new workshop was suggested by a long-standing member and workshop user, John Brady and other members. John admits he had long complained about the state of the roof on the old workshop which couldn’t be repaired satisfactorily. That workshop was also rather small and inconveniently laid out (photo 2). Plans for a new workshop were first considered in 2019 by a committee of members who worked hard to develop various options and likely costings. The first idea was…

Continued from p.107 M.E. 4694, 1 July 2022 For the final part of the tender, I thought that I would give you the details of the water filler and the briquette feeder. For a start the briquette feeder just consists of a piece of ¾ inch tube ½ inch long with a cap bolted on top of it. It also has a small flange welded on top of it to which the top plate is bolted. I have included a drawing (fig 24) showing the position of the water dome and the original position of the coal plate and the water filler. The only photograph I have of the briquette feeder is not brilliant but I think it serves its purpose. It is positioned about half way between the tender…

This project was started in the middle of the Covid lockdown with a need for a driver’s truck to test a new locomotive design. Being impatient I wanted something that could be put together quickly and, if possible, without the need for welding. What I wanted was a Meccano set, ready to assemble with as little machine time as possible. It had to be a rugged, sprung frame with a wheelbase of around 29cm capable of traversing my garden track that has an inside radius of 9 feet at one end. I could have bought a commercial truck but that would take away the fun of the design and build and in our present times I needed a project to occupy me. After a little research and some inspiration taken…

Continued from p.161 M.E. 4695, 15 July 2022 Valve guides Now we come to the valve crosshead guides, that are part of the steam chest covers, or will be once I have machined them and silver soldered them to the covers already done. I suppose the best way to describe them is to say they are a little like ‘arrowheads’ with inner grooves for the valve crossheads to slide along. The first task was to machine the bronze blanks to size and then to machine the slot for the crosshead to slide in. Before I could machine the top slot, on the other side, I first needed to sort out a piece of metal to bridge the first slot so that it could be held securely in the machine vice…

Continued from p.166 M.E. 4695, 15 July 2022 There was another adventure awaiting me and that is the topic of this final part – how to design and build the drive coil. There did not appear to be a method of designing the coil from ‘first principles, ’ that is, from the force needed to replace the energy lost to mechanical and air friction. The coil, together with the magnet with which it interacts, would have to be designed by experiment. The friction losses in a pendulum are lower than for the large balance wheel, so the design of the coil and selection of the magnet was done on the balance wheel. I had on hand some coils that could drive a pendulum but not the balance wheel at the…

This rally is one of the model engineer’s railway operation events of the year and 2022 marked the return of a full rally after the pandemic restrictions. Those of you who have been to Gilling regularly over the years will know how unpredictable the weather in North Yorkshire can be at this time of year. Well, the gods were smiling this year with a dry and often warm weekend which saw plenty of track activity. For the benefit of any newcomers to this event, the basic rules are that apart from the drivers, no passengers are carried during the rally. All trains are made up in the shunting yards and then an appropriate locomotive is rostered to take the train round the railway for a specific time before being returned…

Continued from p.144 M.E. 4695, 15 July 2022 Now would be a good point to show the manufacture of the two flat belt drive sprockets. Two are required; one 40 tooth fitted to the crankshaft, the other 32 tooth fitted to the blower. A bit of R & D was required to find the best form that matched the tooth pattern on the flat drive belt but a 32 DP gear cutter produced an exact fit (photo 90). There is no shortage of suppliers of fiat drive belts online. In order to mount the blower assembly to the manifold an adaptor plate is required (photo 91). I mentioned in the introduction that for any aluminium plate components required I used aluminium tooling plate. For any readers unfamiliar with the advantages…

Continued from p.141 M.E. 4695, 15 July 2022 Pole changing methods In order to design a two-speed motor, I found from my text books that there were several ways of doing this but all of the methods described were for three-phase motors and I had a single-phase supply. The general concept of pole changing windings are described in a 1903 patent by Dahlander (ref 6). The simplest arrangement is for a two-speed motor where one speed is exactly half the other. The way that this pole changing motor works is that the coils have a shorter than usual span – with the coil span half that of the pole pitch. If the stator of the motor is drawn ‘unrolled’ as before, the coils can be seen as a flat set…

The RSME dungeon The club locomotives at the Rand SME are stored in, what I like to call, ‘the dungeon’. It’s an apt description because for most of their lives they stay dormant and unloved in this dark and dingy storage area, only to come to life when we have a live steam event. I’ve been a member of the RSME for longer than I care to mention and for a number of these years I knew of a loco-sized box in a back corner of the dungeon. There was a rumour of a very old locomotive lurking in that box that hadn’t run for years. Being of the generation where I was taught to mind my own business and keep my head down, I let well enough alone and…