A Shildon Newport Locomotive

[IanT]

Well, as promised (on another thread) earlier, I'm going to try to describe my efforts to design and build one of these locomotives in Gauge '3'. For anyone reading this, I have a few warnings.

First, it will not be the highest priority job for me, I tend to work on this engine when I get stuck or frustrated with my other "projects". Rather than screw something up, I've found it makes sense to put them to one side until I have more time or patience to spare. So I tend to move between things. This is not really the most productive way to work, but I enjoy it and I guess that is all that matters.

Secondly, I frequently make mistakes. Sometimes I spot them, and sometimes I don't. So if you are tempted to build along, you are doing so at your own risk!

Finally, my preferred way of doing things may not be your preferred way of doing the same thing. You may choose different materials and methods, it's up to you, your choice. The way I will do it may not be the best way, it's just the way I've decided to do it!

So I think that clears the ground rules and (apart from that) you are quite welcome to watch this thread and laugh along as I make a mess of things - but please don't be too unkind, as I am a sensitive soul.

OK. There may be someone wondering exactly what the Shildon Newport locos were. This link probably gives the best precis - and will save me repeating it all to you.

http://www.lner.info/locos/Electric/ef1eb1.shtml

As I'm having trouble with editing this now it's gone down the page, I'll post this and then do another quick addition tonight.

[IanT]

My interest in the Shildon was first aroused when I purchased the two volumes of "Wonderful Models" ("The Romance of the World in Miniature and A Complete Encyclopedia of Modelcraft") edited by Percival Marshall in 1928. Therein was an article entitled "Electric Locomotive Construction" by Mr R W Dunn. This proved to be a pretty complete description of how to build a model of the Shildon for 2½" gauge. For its time I believe this would have been considered an accurate scale model. However, some dimensional checks proved that it was not exactly so and I decided to re-draw it to actual scale in 13.5mm! Easy Peasy (or so I thought!)

I had some line drawings with basic dimensions, but these were essentially 4mm scale and anyone who has tried to scale drawings "up" will tell you it's not that easy. So I gathered what photos I could and started to try and figure out the actual dimensions from the few facts I had (the wheel diameter was 4'). This took a while as most of the photos that showed the best detail were not full on, but angled. However, I did my best with 'perspective' measurements and started in with the CAD.

To cut this long story shorter, when Adrian sent me a copy of the GA (from Engineering, May 1916) I found most of my calculated dimensions were a bit out. They were too short in the vertical and too long in the horizontal. My conclusion was that anyone trying to use a digital image (to work out dimensions) these days, has to assume that the aspect ratio may have been altered, possibly by someone stretching a digital image to fit the 'frame'. Even photocopies are not immune from this – the wheels on the GA are not completely circular when measured up versus across. So on the first CAD drawings there were enough errors that it didn't make too much sense to proceed and I put the whole project to one side until I felt like re-doing it all over again.

That time eventually came recently and I've started over. The main bogie drawings are just about done and I'm working on the main body currently. I will also start in on actual bogie construction in the next week or so. I'll post a couple of Jpeg images of the CAD to give you some idea of what the bogies look like. If anyone wants to make a set, they are already pretty simple but could be even simpler if desired. You will need four lengths of mild steel (or whatever you intend to use) which are 40mm x 233mm.

I should note here, that I am by no means a professional draftsman and my drawings are simply for me to work from, so they wouldn't meet the standards of the average Model Engineer I suspect, but they work for me. I also convert from prototype units to show scale dimensions to two decimal places (mm). Obviously, I can't build to this precision so I usually just round up to the nearest mm but it does let me see what the accurate measurement should be.

But I think that's enough for tonight.  Regards, Ian T

[cabbage]

This is the model as per 1927, plus a few improvements -like coil spring suspension and PWAM control...









I do remember seeing another one in the Newsletter with the underside gearing exposed(?)

regards

ralph