80s/90s On-track plant... mostly

[ChrisH-UK]

I got interested in the strange yellow machines back in the 90s, back then if you wanted a model of anything like that you scratchbuilt it and I was young, enthusiastic, idealistic, and I had a camera, a scanner and a computer. I took pictures and planned to build a breakdown crane, tamper, twin-jib crane, dynamic track stabiliser and more.  I made drawings and started building things.

 

Twenty five years on what had changed? Well you could buy kits of some of this stuff, there were RTR models being planned, and my workbench still had the same list of unfinished projects but on a more positive note, technology had come a long way with 3d printing, photo-etching, laser-cutting, so it's time to revisit things and try and actually finish something.

 

A cheesy title for this could have been "something old, something new, something borrowed, something yellow" so lets start with a pic of something I made back in the 90s - a Cowans Sheldon diesel-hydraulic breakdown crane.

 

There are parts of this model I'm really proud of, like the hand-carved cab, the outriggers, the jib, the chassis side detailing and the hook and block and there are parts that haven't quite stood the test of time.  I might make an entirely new crane at some point but for now I have other things to work on.

 

Currently on the workbench is the Plasser & Theurer DTS-62N dynamic track stabiliser, another model I started in the 90s based entirely on photos. I compared the built chassis to scaled dimensions and the length wasn't that far off, the width was though, so I fixed that, realised I'd overdone it, fixed it again. (It wasn't a failure of measure-twice-cut-once, there were other issues)

Here's a pic of the prototype taken at Watford Jn some time in the mid 90s

 

 

and here's the frame so far, opposite way round to the photo above, didn't think about that when I took it, and the cabs behind it, the original parts that I made modified to be more accurate, boxes on the frame are all new construction, enhanced with etched parts I designed myself and plastic parts that proved to be easier than 3d printing some tiny parts.

 

 

Next step is the rest of the boxes and the framework to support the roof.

 

[ChrisH-UK]

So I mentioned photo etch, this will come into its own when I get round to working on the underside but it definitely has a place on the top side too, in window frames, grilles, and other detailing elements. I've been working with vector graphics for 25 years so producing the basic artwork was no big deal, especially as I already had done a plan of the machine in Inkscape. Having read various opinions on RMWeb and doing a bit of research I worked with PPD and tuned things to their requirements, it took me much longer than it should have to actually get the final design submitted and checked (due to time and funds and being easily distracted).

 

If anyone plans to use Inkscape and convert with Illustrator to a format PPD can accept be aware, Illustrator will cock it up and you will have to fix it. Illustrator specifies a different DPI to Inkscape, unless spotted you will end up with a work that is larger than your design, and therefore completely wrong!

 

Here's a sample of the artwork, just a small portion of the design for the DTS with the edges of other projects just visible above and below. 

 

So you submit the artwork and wait for an envelope to arrive, thinking will this bit work, will that bit turn out alright, what if it's all wrong, have I made a horrible mistake?

 

In this case what arrived was mostly very good, a little bit rubbish and a few pieces that weren't how it was supposed to be but still worked. In the picture below the grilles on the left look fuzzy, in reality they are clean and crisp, as is the fan, but notice the square next to it, and the printed square to its' right? They should look the same, but a tiny miscalculation in line width resulted in nothing getting etched. I also lost most of the bolt detail which met the minimum requirements for the material, but that was probably designed for lines rather than dots so next time I'll go larger with them. As for the ladders, they were originally designed to fold along all the red lines visible in the artwork above. I realised during the design process there was a low chance of them working as designed but decided to go with it and see what happened, they may not be what I intended but they fold up into very nice looking things that I'm delighted to use.

 

Now onto the weekend's progress. 

Originally the roof supports were going to be wire hoops in line with 4 of the 6 pillars that support the roof on the prototype, connected to brass angle, but keeping everything in line proved impossible so I fitted plastic spacers to the brass angle and found this rests stable on top of the cab ends, the wire hoops will still be used, but may not provide as much support as originally planned.

 

 

And finally, the last two boxes that sit upon the deck are shown roughly in position below. The small holes in the deck are for hoses and pipework that will connect to the boxes (except the pair on the left which will be vent pipes to the roof). The big hole in the deck is a wide gauge grid/grille on the prototype and I need to figure out the best way to represent this, I'm not even sure how visible this is going to be.

 

 

 

Next up - pillars and roof

 

 

Edited June 23, 2019 by ChrisH-UK
putting "next up" at the end

[Lyddrail]

Chris,

You have made great progress with the DTS, and the crane looks the part too.

Cheers.

[ChrisH-UK]

Sometimes even Pete the Greek can't help you (I'll get to that later)

 

So I thought I'd take a couple of minutes to talk about the full-sized version. Before these machines existed the main way to get freshly maintained or newly relaid track to bed down was with the passage of trains running maybe at half line speed, maybe slower for at best, a couple of days, at worst a couple of weeks. You might be able to get away with that on secondary routes but it would be a major headache for mainlines. Plasser & Theurer did have a tamper with a dynamic track stabilising wagon but went on to produce a standalone machine -- the DGS 62 N and in 1987  produced the DTS 62 N for BR and the differences between Euro and UK specs are more than just letter substitution, the roof profile is totally different because of our loading gauge, the equipment is mostly similar with what at face value are subtle differences.

 

 

Thirteen machines were built, 10 for Intercity  and allocated to Area Civil Engineers across the regions (4 for ER, 3 for LMR, 2 for WR, just one for Scotland) 3 were for NSE, each for a different division (Southern SE, Southern Central and Anglia). At privatisation they passed into the hands of all the well known Infrastructure companies and appeared in the colours of Jarvis, Centrac, Balfour Beatty, Carillion and Fastline, it seems they fell out of favour with some as most were either scrapped or exported to Eastern Europe, the middle east or Australia. Balfour Beatty still operate their pair and one has been fitted with a pantograph for overhead line work.

 

They work by applying massive forces to wheeled stabilising units mounted beneath the chassis and make extensive use of hydraulics, being completely open framed there's a lot of detail to model and a lot of compromises could be made, but it's not like I had much sanity to begin with so I plan to model as much of it as I can and probably require the services of mental health professional when I'm done.

 

 

Onto this week's progress, starting with the roof.

I'd already figured I could form the profile from a single piece of styrene but decided it was sensible to do each half separately and make adjustments in the middle.  Figuring out where to score the fold lines is where my friend Pete the Greek comes in. Of all the maths I learned in secondary school I only use trigonometry on a regular basis and my Maths teacher always referred to Pythagoras as Pete Pythagoras or Pete the Greek so with the help of my Mediterranean friend I produced this.

 

 

 

The corner that doesn't look right above was kind of funky, it got fixed once I formed the other end and mounted it on the metal roof beams, which was a challenge, as modellers we often wish for more hands. As you see below I made use of cable ties.

Fitting the main support pillars was a faff, before I used the cable ties keeping everything lined up with both holes in chassis and roof beams was impossible, after there were still issues. The hoops I had made were too short so I had to cut them to rework them which made them wobble around, fine brass tube joined them back together which stabilised everything and made it apparent that one set of pillars was in the wrong place, which is the reason why there are now holes in one of my plastic alignment pieces. Everything else seems square so I'm happy to have got 75% correct at first attempt and 100% at the second.

Cabs have now been secured to the frame, beams still need to be secured to the cab, roof won't be fitted until most of the deck mounted equipment is in place by which time I need to figure out whether to install directional lighting and how I'm going to access it if the roof is glued in place.

 

 

Next step - more deck detailing

 

 

 

 

[ChrisH-UK]

Some time has passed since the last post on here, real life gets in the way. I've not had much time for physical modelling but quite a bit of time for trying to figure things out, like the grille from the post on june 23 - I'm thinking laser-cutting but with a twist. But the biggest has been figuring out how to represent some of the detail parts around the deck, that's the biggest issue of modelling something like this - everything is on show.

 

Personal photo, taken with permission.

 

So that's pipework all over the place, pumps and filters, electrical boxes, cabling and who knows what else. It would be easy to say "screw it" and not bother, but there's so much stuff going on it just wouldn't work if you didn't represent some of it, the model would be missing part of its character.  

 

I'd already shown some of my etch earlier in the thread but knew that wouldn't be the only way of doing things. As well as using those etched parts I figured 3d-printing would be my friend, it still will be, but not as much as I originally thought, at the sizes required it's difficult to sprue the parts or use a grid box, and printing a lot of small parts individually just isn't economical, so that has led to a lot of crafting of tiny pieces of plasticard, styrene section and leftover sprue.

 

This is the result so far

 

 

Should have included a ruler for reference, but the largest of these is 16.5mm wide and the smallest (still threaded on the wire) is 2.5mm wide. Of course to most people these are still anonymous pieces of plastic with no context, the only pieces that may be identifiable are the middle two in the bottom row, the control desk (slightly to the right in the photo of the prototype) and the radiator/fan assembly (in the center of the other photo) - it's also the piece I am happiest with.

 

Next - more tiny parts and making better sense of these

 

 

 

Edited January 1, 2020 by ChrisH-UK
Grammar

[Lyddrail]

Chris,

I have only just refound your topic. Small bits look very good. With scratch building you have to pick what to add and leave off. But you are right these are very visible. 

Regards the roof, I made mine on a tamper removable in one piece to retain access. It fits into the cabs with plastic sections to make a push fit into the cabs.

Cheers.