Indholdsfortegnelse for February 2023 i Engineering in Miniature

I I’m old enough to remember when no one began a sentence with “So…” and you could pull one tissue out of a box without the whole pack following suit. I can also remember the last year that Maunsell locomotives were a common sight on the Southern Region, which was 1962. Passing the 11-Plus exam in 1961 meant a place at Brockenhurst Grammar School and a classroom with a pretty good view of what is now known as the BML, the Bournemouth Main Line. As train spotters we enjoyed going to school more than most! At that time electrification was on the distant horizon. We travelled to school on push-pull trains pulled (or pushed) on the Lymington branch by Victorian tank locos that would have been familiar to our grandparents.…

A new publication from the useful series of model engineering guides produced by Crowood Press deals with a subject we don’t see enough of in our pages, steam-powered model boats. This compact but comprehensive guide runs to 176 pages and includes more than 275 colour photos and diagrams. The highly experienced author takes readers through every aspect of building a model boat, from the initial design of its steam propulsion system, to the building of the boat itself - marine subjects that may not be so familiar to many EIM readers such as creating the hull shape and the propeller design. The book is not just about theory, however. Included are plans and descriptions to enable the reader to build three types of boat, starting with a screw-driven ‘pond runner’…

GENERAL NEWS The return of the Harrogate Model Engineering Show has been confirmed - as reported in last month’s EIM the event is scheduled to take place in the exhibition halls of the Yorkshire Event Centre at the Great Yorkshire Showground on 10th-11th March. The dates are unusually a Friday and Saturday (the second unfortunately clashing with the Midlands Garden Rail Show detailed above) and the show will be a combined event alongside the long-established Harrogate Model Rail model railway exhibition. Unfortunately we still cannot give you much detail on the model engineering content of the show - the event’s website, www.theeventsoffice.com states that it will cover all the major spheres of interest including rail, marine, traction engines and more than 100 club and trade stands, while the model railway…

There is an enormous amount of published work on miniature injectors. Having made several of them for my locomotives using published designs, often a key question I have had was “How important are the different dimensions?” and “How does any variation from the published dimensions influence performance?” To try to address these questions, I decided to undertake a new project that would involve: My project has been published in detail as a digital download, available at this link (https://bit.ly/3hZDjhz). The basic injector The basic components of the miniature injector are shown in Figure 1 and the four cones and body are shown in Figure 2. For those not familiar with the steam injector shown schematically in Figure 1, it consists of a coaxial arrangement of a Steam Cone, a Combining…

Last month in the first part of this short series I described the Rugby ME’s largely successful experiments with Ecoal 50, a manufactured sustainable fuel combining biomass with coal. But being the experimenters we are, settling on the first thing we tried that worked wasn’t our idea of a really thorough investigation, so we set out to try some more fuels. For our next trials, we opted to buy four different fuels - Columbian Doubles, Trevithick Welsh Steaming Ovoids (Hargreaves), Wildfire Ovoids (Coal Products Limited), and Scottish coal from the Ayr coal field. Using two online coal merchants, we had half a ton each of the Columbian and Scottish coals delivered, and a quarter-ton each of the processed fuels. We knew we needed a good supply to make our purchase…

The brake blocks for our 7¼-inch gauge ride-on tender were made from a laser-cut brake-block ring. We designed this ring in CAD and it formed a part of the (fairly substantial) laser-cutting job which was undertaken by a local company. The ring was cut from 15mm mild-steel plate - mild steel is acceptable in this case since the wheels are also manufactured from mild steel. With cast-iron wheels, there is a danger of the brake blocks wearing the wheels (rather than the other way around), if they are fabricated from steel. If, however, the braking system is only ever going to be used for parking, with the brakes fitted to the loco serving to stop the train (in addition to vacuum brakes on the carriages), then this may be less…

This is one of those excellent books that comes along all too occasionally, throwing a spotlight on a subject that has previously received very little in the way of coverage and something that many an EIM reader will likely know nothing about - certainly your reviewer had never previously heard of gas-powered trams… Perhaps this is not surprising because as the author describes, the gas-powered tram was a short-lived phenomenon, designed to replace horses and steam on the roads. Its proponents argued that gas provided a far simpler and much less costly alternative to electricity with all its extra infrastructure of overhead catenary, power generating stations and such. It seems that for a while the concept did make progress, designs were patented and gas tram systems went into operation in…

In the last part of the series I reached the point of having a rolling chassis, having completed kits 1-10, with the exception of painting the wheels which can wait. I finished just in time to collect the next batch of kits from Steam Traction World (STW) in Daventry - a five-hour round trip from my home in Mid Wales with the trailer. This batch of kits, 11-21, included some chunky and expensive bits including the boiler, cylinder block and crankshaft. Some of the ‘kits’ are therefore down-payments on the boiler and cylinder block so in terms of hardware there was a slightly smaller pile than the first batch. The boiler Photo 14 shows the boiler which is a substantial lump. Made by STW it is all welded steel, has…

So having decided on which loco to build, let’s make a start. The obvious place to begin a project is with the frames - after all everything else is fixed to them. If you don’t fancy the idea of making the frames, have a look at one of the companies that offer laser-cut frames - these can save a lot of time and effort. The frames are made as a pair, the two plates being fixed together and machined as one. Some careful drilling and machining is required to ensure everything will be square and work properly. Most but not all of the holes are drilled right through both plates - some will be in one frame only. Take note of the hole sizes marked on the plans - some…

Thank you for the last excellent edition of EIM including coverage of the recent exhibition. The results show, I believe, a flaw in the awards system. The front cover rubric admits they could all be winners! I suggest that a different system of awards could be introduced, where the cash prizes are abolished, and joint 1st (2nd or 3rd etc) are introduced. After all, we don’t make our models to make money… I can’t help comparing the way Model Engineer does its award system. If a number of models are found to be of similar excellent standard, then as many gold, silver or bronze medals are awarded irrespective of numbers. This seems a much fairer way of making awards. The outstnading modle can be awarded a further accolade in the…

Pen & Sword’s rapidly expanding reference library profiling major British steam locomotive classes now encompasses one of the most iconic of all with this superb new offering focusing on the Gresley A4 Pacifies, fastest and most-admired engines of their time. Well we say this is a book on the A4s - you don’t actually see an example of the so recognisable streamlined locomotives until after 140 of the book’s 240 pages. The evolution part of the title is very relevant, the authors spending much time and detail describing how designer Sir Nigel Gresley progressed through his earlier designs in his constant search for the fastest, most powerful locos. And the study goes outside the UK too, looking at streamlined locos on the continent that contributed to Gresley’s thinking. Design and…