Engineering, Injuneering and Knitting

[Le Corbusier]

It is obvious the the Crossrail engineers haven't read any of Iain Rice or Mike Sharman's excellent advice since 80% of the track in the new Elizabeth Line tunnels is mounted on solid cast concrete bases.

http://www.crossrail.co.uk/construction/railway-systems/

I thought the argument was that in the real thing the flexure of the rail provided the 'suspension' but in a model because this didn't fully scale that it needed to be spread beyond the rivet/chair supports and hence the flexible under layer. It was my crass hypothesising which suggested that the real thing might get flexure from the ground. It was also a double solution as he also was trying to address acoustics which I suspect are not relevant to crossrail. Presumably CSBs now put our models more into the realms of crossrail?

[Tony Wilkins]

Hi Tim.
I once tried fixing down some lengths of track to a wood base (for a test track) using double sided foam tape (about 2mm thick). It worked well except that you only get one shot at it as the grab is very fierce. I got one piece of track out of line and had to remove it, which destroyed the tape in the process, so had to be replaced. There is still a slight kink at one rail joint, but I decided to live with it.
Would I use it for a layout? No.
Regards
Tony.

[Philip Hall]

From some of the films I have seen recently about Crossrail I believe that there are sections of track (beneath the Barbican Concert Hall, for instance) which have been specially designed so as not to transmit noise and vibration. I also think that the rails are mounted on resilient pads, so I guess there is some ‘suspension’ there.

Julian’s first picture in his recent post showed a picture of Ken Northwood’s North Devonshire Railway, much of which was laid on quite spongy track. It was done with the paper membrane as Julian says, but then just laid on top of foam (it might have been foam plastic) so it really was quite bendy. I saw this in action many times when a heavy engine (one to two pounds!) would depress the track as it went along. It was very quiet (as were the engines) and gave a smooth ride for the stock. I tried this many years ago on an early 00 layout and it worked well, and then used a variation on my old Taw Vale layout where a section was laid with the then new C&L Flexitrack mounted on a bed of thin draught excluder. The sponge was self adhesive on one side which stuck to a sub road bed of insulation board, and the track was glued to the foam with Copydex and ballasted with cork. Whilst it did flex a little it wasn’t much, but it was quiet because there was no PVA and granite around.

I now think, though, that track that flexes in a vertical plane is perhaps not the best of ideas, because the small amount of movement we can gain coupled with the small flanges of P4 and variations in level over the years could lead to trouble. I am also a bit nervous of foam and the like deteriorating over time. This new railway is one that I do not want to be digging up again as I get into my later years. I know I am pushing the envelope a bit here by using commercial chassis from time to time, but absolutely round wheels and flat track (as far as possible) are for me a good start and it works. Obviously when I build an engine from a kit or scratch I am going to build in suspension, but with my wheel accuracy preferences I have been able to save time. This has been proved many times when running converted stock on the Epsom Club’s Wadhurst. A Hornby T9, M7, King Arthur and trains of Maunsells and rigid wagons have glided round silently with not a shimmer and a shake. The track on that is ply and rivet glued with PVA, or PCB in the storage yards. It’s been down twenty years or more which leads me to think that it’s proven and therefore not likely to give me trouble.

So many solutions, so many things to try!

Philip

[grovenor-2685]

From some of the films I have seen recently about Crossrail I believe that there are sections of track (beneath the Barbican Concert Hall, for instance) which have been specially designed so as not to transmit noise and vibration. I also think that the rails are mounted on resilient pads, so I guess there is some ‘suspension’ there.

We have some of this on DLR as well, the concrete slab forming the track bed is supported clear of the tunnel invert on large coil springs. This does give a little resilience/movement but the intent is to decouple the vibration in the rails from the tunnel lining and hence the ground in areas with sensitive buildings above the tunnel.
Regards

[Le Corbusier]

So many solutions, so many things to try!

Philip

I really do love this hobby.

Tim

[Julian Roberts]

It is obvious the the Crossrail engineers haven't read any of Iain Rice or Mike Sharman's excellent advice since 80% of the track in the new Elizabeth Line tunnels is mounted on solid cast concrete bases.

http://www.crossrail.co.uk/construction/railway-systems/

Oh dear. I have had the impression from the Forum and this Society for some time that it is fashionable to sneer at Rice and Sharman. I wouldn't be in this hobby were it not for their writings. Which doesn't mean that I think everything Iain says is true, nor that all railway truth is contained in his books. It was a great pleasure to read Philip Hall putting some balance back.

So I don't know whether you just haven't read Iain's books Bill or are wilfully misrepresenting him. Below is from his book An Approach to Modelling Finescale Track.

Just to state the obvious: new High Speed lines have been mostly laid on ballast. Except in more challenging areas, tunnels being the obvious example as in your link. I think I read of a hybrid system of concrete track on ballast on some new ICE track in Germany.

[LesGros]

Julian,
Is there any chance the you could post images with the correct orientation? [and a bit less glare]
Your latest is almost unreadable; do you really expect people to take the time to download and rectify the image?

[Le Corbusier]

Julian,
Is there any chance the you could post images with the correct orientation? [and a bit less glare]
Your latest is almost unreadable; do you really expect people to take the time to download and rectify the image?

Is this better ... if you click on it it should enlarge. I think it was just the Ballast section Julian was highlighting.

20171221_073333.jpg

[LesGros]

Thanks Tim,

[billbedford]

[Oh dear. I have had the impression from the Forum and this Society for some time that it is fashionable to sneer at Rice and Sharman. I wouldn't be in this hobby were it not for their writings. Which doesn't mean that I think everything Iain says is true, nor that all railway truth is contained in his books. It was a great pleasure to read Philip Hall putting some balance back.

So I don't know whether you just haven't read Iain's books Bill or are wilfully misrepresenting him. Below is from his book An Approach to Modelling Finescale Track.

Both Rice and Sharman were writing 30-40years ago. The world, even that bit that concerns itself with model railways, has moved on.

[billbedford]

Just to state the obvious: new High Speed lines have been mostly laid on ballast. Except in more challenging areas, tunnels being the obvious example as in your link. I think I read of a hybrid system of concrete track on ballast on some new ICE track in Germany.

No model track it 'laid in ballast'. It is always fixed mirror less rigidly to a base. The idea of using a cork or foam underlay has as little to do with adding suspension and much to do with stopping a solid baseboard top acting like a sounding board.

[Le Corbusier]

Just to state the obvious: new High Speed lines have been mostly laid on ballast. Except in more challenging areas, tunnels being the obvious example as in your link. I think I read of a hybrid system of concrete track on ballast on some new ICE track in Germany.

No model track it 'laid in ballast'. It is always fixed mirror less rigidly to a base. The idea of using a cork or foam underlay has as little to do with adding suspension and much to do with stopping a solid baseboard top acting like a sounding board.

Interestingly in building acoustics we tend to use an isolator to prevent impact sound being transferred through a structure. To prevent a 'sounding board' effect wadding is usually the solution ... much as the acoustic matts fixed to the outer skin of car panels. I wonder if this might be effective with baseboards .... has anyone experimented at all with such an approach?

[Jol Wilkinson]

[Oh dear. I have had the impression from the Forum and this Society for some time that it is fashionable to sneer at Rice and Sharman. I wouldn't be in this hobby were it not for their writings. Which doesn't mean that I think everything Iain says is true, nor that all railway truth is contained in his books. It was a great pleasure to read Philip Hall putting some balance back.

So I don't know whether you just haven't read Iain's books Bill or are wilfully misrepresenting him. Below is from his book An Approach to Modelling Finescale Track.

Both Rice and Sharman were writing 30-40years ago. The world, even that bit that concerns itself with model railways, has moved on.

However, much of what they wrote, especially Iain, provided guidance and inspiration in those dark days. It is easy for some, as Julian puts it, to sneer at them or their work.

Yes, things have moved on, some new developments have been laudable, others a waste of time and some have sunk without trace despite their originators claiming to offer us a bright new world.

[Terry Bendall]

However, much of what they wrote, especially Iain, provided guidance and inspiration in those dark days.

This is one of the most sensible comments made on this topic so far. Back in those dark days the pioneers of working to P4 standards were struggling to get hold of supplies and to find ways of making things work. Both Iain Rice and Mike Sharman devised ways of doing things which worked and which still work. In the intervening period other methods have been devised which also work. Some may be easier to deal with and some may work more effectively than others, some may be judged to be "better" than others, but they all work.

There is a fundamental problem which some have alluded to in that you can't scale nature. The forces of a prototype loco and train acting on prototype track and its foundations cannot be replicated in any scale. Those who build live steam models are well aware of the problem with things like steam passages in cylinders which if made to scale would not pass sufficient steam to move the pistons.

We can if we wish criticise the early pioneers and suggest that just because their methods have been published in print form - the only way of doing things in those days, it does not make them "right". Equally putting forward ideas on discussion forums does not make them any more "right", just a different view which as a way of doing things may be equally valid.

As modellers we need to explore those methods that are available and decide which works for each of us as individuals. It might be that we do this through reading books, readings comments on forums or by talking to those who have build successful working models and then deciding which way we want to go. Iain and Mike took things out of the realms of the engineering workshop and brought them onto the kitchen table where "ordinary" people could achieve success and we own them a debt for that, just as we should be indebted to Mike and Alan Gibson who set up businesses to produce the wheels needed and if they had not put their money into the businesses P4 as we know it today would probably not exists apart from those who have the skills to make their own wheels.

Terry Bendall

[Paul Townsend]

Interestingly in building acoustics we tend to use an isolator to prevent impact sound being transferred through a structure. To prevent a 'sounding board' effect wadding is usually the solution ... much as the acoustic matts fixed to the outer skin of car panels. I wonder if this might be effective with baseboards .... has anyone experimented at all with such an approach?

Its very effective in the new built parts of our home but I don't fancy it under baseboards, tangling with wires, servomotors, TOUs, electronics etc.

[Le Corbusier]

Interestingly in building acoustics we tend to use an isolator to prevent impact sound being transferred through a structure. To prevent a 'sounding board' effect wadding is usually the solution ... much as the acoustic matts fixed to the outer skin of car panels. I wonder if this might be effective with baseboards .... has anyone experimented at all with such an approach?

Its very effective in the new built parts of our home but I don't fancy it under baseboards, tangling with wires, servomotors, TOUs, electronics etc.

In cars you don't stuff the void .... rather you strategically bond areas to the 'drum skin' panel and it dampens the whole thing. Just fitted some to my campervan and it made a massive difference. Might work on baseboards.

DSCN0219.jpg

[Chris Mitton]

We have some of this on DLR as well, the concrete slab forming the track bed is supported clear of the tunnel invert on large coil springs. This does give a little resilience/movement but the intent is to decouple the vibration in the rails from the tunnel lining and hence the ground in areas with sensitive buildings above the tunnel.

I understand that Birmingham's Symphony Hall is supported entirely on twenty (IIRC) massive rubber blocks, in order to avoid the CBSO being supplemented by subterranean rumbles from Wolverhampton-bound trains leaving New Street, which pass directly underneath.
Regards
Chris

[Alan Turner]

We have some of this on DLR as well, the concrete slab forming the track bed is supported clear of the tunnel invert on large coil springs. This does give a little resilience/movement but the intent is to decouple the vibration in the rails from the tunnel lining and hence the ground in areas with sensitive buildings above the tunnel.

I understand that Birmingham's Symphony Hall is supported entirely on twenty (IIRC) massive rubber blocks, in order to avoid the CBSO being supplemented by subterranean rumbles from Wolverhampton-bound trains leaving New Street, which pass directly underneath.
Regards
Chris

Yes that is correct and the track beneath is also on special rubber pads as well.

regards

Alan

[Enigma]

However, much of what they wrote, especially Iain, provided guidance and inspiration in those dark days.

This is one of the most sensible comments made on this topic so far. Back in those dark days the pioneers of working to P4 standards were struggling to get hold of supplies and to find ways of making things work. Both Iain Rice and Mike Sharman devised ways of doing things which worked and which still work. In the intervening period other methods have been devised which also work. Some may be easier to deal with and some may work more effectively than others, some may be judged to be "better" than others, but they all work.

There is a fundamental problem which some have alluded to in that you can't scale nature. The forces of a prototype loco and train acting on prototype track and its foundations cannot be replicated in any scale. Those who build live steam models are well aware of the problem with things like steam passages in cylinders which if made to scale would not pass sufficient steam to move the pistons.

We can if we wish criticise the early pioneers and suggest that just because their methods have been published in print form - the only way of doing things in those days, it does not make them "right". Equally putting forward ideas on discussion forums does not make them any more "right", just a different view which as a way of doing things may be equally valid.

As modellers we need to explore those methods that are available and decide which works for each of us as individuals. It might be that we do this through reading books, readings comments on forums or by talking to those who have build successful working models and then deciding which way we want to go. Iain and Mike took things out of the realms of the engineering workshop and brought them onto the kitchen table where "ordinary" people could achieve success and we own them a debt for that, just as we should be indebted to Mike and Alan Gibson who set up businesses to produce the wheels needed and if they had not put their money into the businesses P4 as we know it today would probably not exists apart from those who have the skills to make their own wheels.

Terry Bendall

Nice one Terry. The last sentence in particular being absolutely true IMHO.

[martin goodall]

Railway Modeller, December 2017, page 1074 (at the bottom of the page).

[Terry Bendall]

Railway Modeller, December 2017, page 1074 (at the bottom of the page).

Yes very appropriate Martin.

Terry Bendall

[dal-t]

Could someone drop a clue as to what that's all about for those of us not in a position to purchase UK magazines (whether we might wish to or not)?

[Julian Roberts]

Julian,
Is there any chance the you could post images with the correct orientation? [and a bit less glare]
Your latest is almost unreadable; do you really expect people to take the time to download and rectify the image?

Les I do apologize. Also I apologize for not apologising there and then! Thing is I've several times before on other threads had the same problem where I have apologized! I have tried reloading upright photos umpteen times but they insist on taking a recumbent position. How Tim managed to stiffen their resolve and man up I really wonder! So thanks Tim for doing the magic that eluded me. Time does preclude perfection and that's why I'm so slow at model making!

[Terry Bendall]

Could someone drop a clue as to what that's all about for those of us not in a position to purchase UK magazines (whether we might wish to or not)?

Someone might put up a scan or picture later but I will describe the cartoon which hopfully you will e able to picture

Title - Railway Modelling six decades apart...

1957 Middle aged pipe smoking gentlemen in tweed jacket quietly and happily playing with his layout (complete) with in the background music coming from a 1950s style wooden cased "wireless"

2017 A part built layout with in the background the owner fuming over a computer which on the screen has the word "Forum\" at the top. Steam at a pressure of 285 psi emitting from the ears of said owner.

Terry Bendall

[dal-t]

Thanks, Terry. Get the picture - think in 1957 I was happily playing with a double oval of OO on the carpet, while now I'm worrying about making an 18* siding for a trio of tank wagons look realistic enough, so it seems the cartoonist has his fingers pretty accurately on my pulse, at least!