Innholdsfortegnelse for March 2023 i Engineering in Miniature

The new year in the workshops of the Fairbourne Miniature Railway on the mid-Wales coast began much as the previous year had ended, with a bit of work being carried out on our 6-inch scale Welsh Highland Railway-style 2-6-4T ‘Russell’ alongside an awful lot of tidying up and cleaning! The activities on Russell involved the final measuring up to allow me to work from home while the workshop is out of action due to having a new roof put on it. This first involved pressing out the vesconite bushes from the loco's rods. Most of these came out extremely easily with a bit of gentle pressure from my fingers - only a couple needed a couple of light taps with a hammer to get them out and one of them…

Latest in the Pen & Sword-published and growing locomotive library produced by David Maidment focused on the final years of the Great Western Railway's renowned Castle class of 4-6-0 locomotives, and again takes an in-depth look at these engines. As in the several previous editions in the ‘locomotive portfolios’ series that we have reviewed in past issues, the book is very extensively researched, starting with a recap of the early history of the class before describing their work in the service of British Railways, their performance analysed through a number of charts of individual journeys with times and speeds included. A number of personal recollections are included from those who worked on the engines, and while there are no drawings to aid the modeller included in this particular book, there…

The roster of 12/4-inch gauge railways in the UK will increase by one later this year when the Mease Valley Light Railway opens at the Statfold Narrow Gauge Trust, near Tamworth in Staffordshire. Trust spokesman James Gorton has provided us with more details of the line, construction of which started in 2021 and which when complete will add a whole new element to the extensive narrow gauge collection, already considered a must-visit site by many enthusiasts. Construction of the locomotive shed and turntable was carried out first to provide a home for the acquired stock, with track being laid up to the field boundary. The railway, which is being laid in S10 rail with new hardwood sleepers, will form an initial lkm-long line with a passing loop approximately halfway and…

Part Five of 11 Last time in our ride-on tender build project we made most of the braking system, including the brake blocks and much of the handbrake operating hardware, and we complete these parts this month. Handbrake control rod The handbrake control rod is made from a piece of 6mm diameter silver-steel rod, to the dimensions shown in Figure 44. The only machining required is the small reduction in diameter just above the lower threaded section of the rod. This will ultimately accommodate an E-clip which prevents the rod from being removed or forced upwards in use (when releasing the brakes, for example). Both threading operations were undertaken with the rod mounted in the lathe chuck, although this is not essential. Using a parting-off tool on a long section…

Part Eight of an occasional series At the end of my last article I promised some detail on the superheater for my 7-inch scale Fowler steam lorry. The first thing to say is that a good superheater is vital on an undertype steam lorry and in my view that was why the Sentinel lorry was such a successful product. This model therefore takes inspiration from the later Sentinel superheater design in having twin coils, each consisting of a downward and upward concentric spiral, mounted in the smokebox. My calculations showed that each coil needed around three turns to give a target steam temperature of 350 degrees C. Superheaters The superheaters are ⅜-inch BSP pipe which has an outside diameter of about 17mm - I used heavy gauge so winding coils…

This month I offer one of those quick ‘obvious once you are shown it’ tips for a beginner machinist. When parting off parts with a hole down the middle on the lathe, especially small parts, it is handy to use a catch pole to stop said part disappearing forever into the chip tray with all the swarf. This can easily be accomplished by holding a piece of rod by hand. If the component you are parting off is particularly small, or you need two hands to part off, then a piece of of bar held in the tailstock chuck and poked down the centre hole works very well. Do YOU had a useful tip to offer your fellow model engineers? Send it to editor@engineeringinminiature.co.uk…

Part Two of three Last month I began my project to answer two key questions regarding the performance of miniature injectors, these being “How important are the different dimensions?” and “How does any variation from the published dimensions influence performance?” As detailed in the first part of this short series I have built a group of six 26 oz/min miniature injectors and an experimental test facility, the plan being to vary dimensions of the injector cones and measure performance, comparing the results. The full project has been published in detail as a digital download, available at this link (https://bit.ly/3hZDjhz). A theoretical model During the measurements undertaken for this project, it seemed that well-made injectors to the standard design of Brown (2011 - full references included in part one of this…

Over the past two issues I've described our continuing efforts and successes at the Rugby ME to establish alternative sources of more sustainable locomotive fuels, as the likelihood of future steam coal supplies (Photo 22) becomes ever more uncertain. So having had another enjoyable testing session, what next? The two lump coals were the next fuels to be tried, and again we opted for running one engine on one, and the other on the second - there seemed little point running both on the same fuel at the same time, they are essentially the same engine. Both of these lump coals are classed as house coal, and very definitely not for use in smokeless zones, as we shall see! If you are reading this in England, from 1st May 2023…

To start with the problem - our 5-inch gauge club track has some quite significantly sharp curves on its route. The sharpest is of 8½ metres radius and many of the published designs just cannot accommodate such tight radii. In many cases it seems they are designed best to travel in straight lines! Certainly many prototype locomotives have large leading bogie wheels that are very close to both the frames and cylinders. Making them all to scale is virtually a guarantee that they will have trouble on the bends. Not only are there the sharper curves we need to deal with but also out-of-scale wheel flanges. Then there is the blessing (or curse) of gauge widening to deal with. And finally we have track vertical curvature (or perhaps dips and…

Camden Miniature Steam Services is renowned for its model engineering books that are as fascinating as they are specialist and this certainly fits the brief. Probably the first book on such a subject, this describes in detail a loco that has been built in model form but never in full-size. Stirling cycle or hot-air engines have never been able to produce enough power to adequately propel a locomotive but when Peter Scott set out to produce such a locomotive in model form, fuelled by a small methylated spirit burner, the result proved rather more powerful than expected, able to haul half a brick on a flat wagon. Using this book anyone can build their own version of Peter's engine - the process is described in detail, with full-size and very…

The pace is quickening again as we start our latest round-up of the goings on around the various tracks and clubs of the UK - I may be penning these words at the end of January, one month of the year when most of us stay indoors, but already our diary listing is growing again as clubs prepare for their public-running dates throughout 2023 - and yes, I fully appreciate a growing number of hardy clubs keep running right through the depths of winter! One club that is no doubt looking forward particularly to the new season is the Melton Mowbray & District ME - the club's Norman Smedley tells us that since before the pandemic some members have been very busy extending the ground-level track at the club's Whissendine…