Brettell Road, 1960s black country (ish)

AJC

Western Thunderer
Hi Adam

The 1 plank wagon is fitted, not sure why the prototype was grey but that's the pic I found, there's another pic of a fitted one in the LMS wagon book.

I have moved the timescale of the layout forwards a bit to the late 50s and it seems the black patches weren't as set in stone then. As usual for me I dunno much about things like that I just copy what I see.

Cheers

Jim

Un/published picture or online Jim? Just curious really, I wasn't aware that any of those one planks were built fitted - but it's been years since I built my model of one - though the only one in Paul Bartlett's galleries (in colour) shows what Paul states to be a conversion, apparently by S&T under BR.

http://paulbartlett.zenfolio.com/lmsopen/h255e7fae#h255e7fae

I know that black patches weren't universal but I don't recall seeing a BR-build of the 16 tonner sans black patch when new-ish. Later, post patching up and repaired, yes.

Adam
 

Jim S-W

Western Thunderer
Hi All

94xx-tank-paint.jpg

Progress on my 2 pannier tank projects has continued with the 94xx body reaching the paint stage. Bachmann has recently announced a new RTR model of this class but i've never been one for waiting for someone else to do things for me. Those who know me will know that my interest is in the making things side of the hobby.

15xx-tank-revisited.jpg

The 15xx tank has been a bit more back and forth. The cab roof has been swapped for the roof from the original 94xx body. It did need shortening a little as the 94xx cab is bigger. The roof detail on the 94xx is nothing like so that was all replaced with more archers rivets. I also spotted that the rear cab windows are much further in than the way I had them (and the 94xx) so these have been changed too. Incidentally the Ian Beattie drawing in the April 1985 Railway Modeller also had the windows in the wrong place too so it wasn't just me!)

For such a small class there's a lot of variety. the cab door handrails were shorter originally and one class member (1506) seems to have had both long and short at the same time. The lower smokebox handrail also seems to have been added later (perhaps when the steps were changed) and 1503 seems to have had straight horizontal handrails on the rear of the bunker rather than the L shaped ones the rest of the class had. These were also mounted lower down for some reason.

Cheers

Jim
 

Jim S-W

Western Thunderer
Hi all

31-bogie-2-Tysley-22-02-0.jpg
No I haven't put this in the wrong place and yes this is a bogie off a class 31 but it serves to show how the real thing goes about springing 3 axles. When I first wrote bout building the chassis for my Jinty I didn't go into too much detail on how it was sprung, mainly because I wanted to check that it worked properly before telling people how to do it (or leading them down the wrong path , possibly!). In truth I knew it would work as when my friend Simon built his fully spring class 31 (from a Bill Bedford kit) he sprung it using a similar principle. AS he's an engineer and I've seen his 31 perform faultlessly on may occasions there was little to worry about other than I possibly didn't get it or couldn't do it!

Anyway after a few days of shuffling wagons around on Brettell Road I feel confident to tell you how it was done. I admit off the bat that CSB's work and work well as I've seen many examples of them (Continuous Springy Beams). I also admit that all the maths, tables and discussion put me right off the idea from the start. It just seems so 'faffy' somehow. Sure they first appeared when there was an element of the finescale side of the hobby who likes to pretend they were actually Stephen Hawking and seemed to revel in making things look as difficult as possible but there was always the thought in the back of my mind that a lot of the clever theory, whilst fine on paper, didn't actually translate to any effect in the real world. That and why don't real 3 axle vehicles do it that way then? (Yes I know a Jinty isn't sprung like a class 31 either!)

The principle of equalised springy beams is very simple. If you have a beam with a pivot in the middle the effects on either end will be the same. If you move the pivot to a 3rd of the way along the effects are more on one end than the other, By using 2 beams on 3 axles, with 2 of them acting on the center axle and the pivots towards the outer axles, the effects on all 3 should be about the same. It's a mix of old-fashioned, very rigid compensation beams and springs to get a sprung result. I am sure that you can apply loads of complicated maths to this to refine the thinking further but it works for me, appeals to me KISS approach to things and all you need is 4 handrail knobs and 4 springs of 18 gauge guitar string. Nothing has to be pivoted and you can just change the gauge of the springs to adjust the effect.
equalised-springing-drawing1.jpg

HTH

Jim
 

ZiderHead

Western Thunderer
… why don't real 3 axle vehicles do it that way then?

The main reason for using a 5 pivot CSB on a 3 axle model is because the pivot locations can be off a bit and the effect on the springing of each axle is negligible.

2 pivot SBs are extremely sensitive to the pivot locations (CLAG calculate just 0.1mm off and you can load/unload an axle by 30%.)

The real thing is built to tolerances impossible in model scales so this isn't a problem.


edit: Whether you'd notice the difference in practice is another thing of course … :)
 
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Jim S-W

Western Thunderer
Hi Jon

Your last line says it all. It's easy to let the theory make someone loose sight of the practical. My friend tells me this happened with the 31 kit as while all the maths dictated the pivot points exactly, in practice it resulted in a bogie that was longer than the prototype.

Cheers

Jim
 

Steph Dale

Western Thunderer
Jon,
As soon as you break the spring beam, as Jim shows in his diagram, the stability in the system recovers. And, as such, mirrors the effect of a bogie with springs and beam equalisation.

Jim,
If the kit/parts come out with the wrong wheelbase that's just careless work by the developer; the calculations for beam pivots all work from the axle centre dimensions. Not the other way around!

Steph
 

demu1037

Western Thunderer
Hi all

31-bogie-2-Tysley-22-02-0.jpg
No I haven't put this in the wrong place and yes this is a bogie off a class 31 but it serves to show how the real thing goes about springing 3 axles. When I first wrote bout building the chassis for my Jinty I didn't go into too much detail on how it was sprung, mainly because I wanted to check that it worked properly before telling people how to do it (or leading them down the wrong path , possibly!). In truth I knew it would work as when my friend Simon built his fully spring class 31 (from a Bill Bedford kit) he sprung it using a similar principle. AS he's an engineer and I've seen his 31 perform faultlessly on may occasions there was little to worry about other than I possibly didn't get it or couldn't do it!

Jim

Jim,

Remember that on a 31, the centre axle is:
a - unpowered
b - smaller diameter

so may be not the ideal example to provide hard points for CSB!

eg: 47 bogies, where the spring cluster for the equalising beam is more centrally located 19 - Scan_20150128 (18).jpg

andy
 

Jim S-W

Western Thunderer
Hi andy

Are the sprung axle loadings on a 31 different? The unpowered nature and size of the wheel have no real relevance. Looking at class 47 (or class 37/50/55) bogies the pivots all fall on a third too.

HTH

Jim
 

ZiderHead

Western Thunderer
The 1/3 pivot on the 31 means the axles should be loaded equally, which makes sense considering how heavy the 31 is - unloading the centre axle would load up the outer axles. That would give better traction, but I assume that axle load limits for routes are based on individual axle loads rather than the average for a loco.

Jim I'm liking your idea the more I think about it, certainly for 3 equally spaced axles its much simpler than the CSB approach. :thumbs:
 

Jim S-W

Western Thunderer
Thanks Jon

But it's not my idea, my friend Simon did it first and I suppose the engineers of the real thing did it before him.

Cheers

Jim
 

Jim S-W

Western Thunderer
Hi All

A while ago I wrote about the benefits of using modern techniques and processes on my website, specifically laser cutters. However I have sort of come to change my view on this a little recently. You see, if you are doing more than 1 thing that is the same then laser cutting can offer a distinct time-saving. If however what you are doing is pretty much bespoke then the extra effort is, I have concluded, not really worth it. Take my retaining walls for Brettell Road. I did draw up the larger one but it took for ever. It turned out to be much quicker and easier to just get some sheets of embossed plasticard and get stuck in!

large-retaining-wall.jpg

small-retaining-wall.jpg

These walls use Slaters bricks and I have done the top row by cutting individual blocks from evergreen strip and gluing them in place. Even taking the time to do this (Which isn't exactly taxing but is long-winded) these walls didn't take all that long to do.

jinty-in-the-rain.jpg

Finally this is pretty much what I hope Brettell Road will be all about, dark and wet! It's always been my intention to depict a rainy night somewhere in the Black Country and this is the first time I've really been able to get an image that illustrates what I am looking for (although perhaps, not this dark!)

Cheers

Jim
 

Jim S-W

Western Thunderer
By strange co-incidence I was recently sent this link
http://www.sciencekiddo.com/2015/02/rainbow-paper-color-science-for-kids.html?m=1

I was going to try this with our Beaver Scouts but may well give the effect you are looking for.

Hi Adrian

Did you give this a go? I tried it and it looked great but then when it was fully dry it vanished.

Edit. Thinking about it, does the traditional oil slick look need daylight to work? Do they look different at night?

Cheers

Jim
 
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