Ballasting the track

[Rossi]

I know that there have been mentions throughout different posts on this subject, and I think most seem to regard roofing felt as the best option. My own little venture was to lay a covering of varnish on the track and sprinkle budgie grit on it. The concept behind this was actually to stop the chairs on the track separating from the rails due to the heat factor over here. Over time, it has not actually enhanced the appearance of the railway, although it did quell the separation for a longer time than usual. The varnish also turned a grubby colour and has now started to loosen in certain areas, so, whilst doing one job, it lacked being the definitive answer.

A few weeks back some friends kindly brought over a handful of various modelling mags they'd manage to find at a car boot sale. One, (Model Rail...November 2001) had an intriguing readers letter and response on track ballasting. Here is the editors reply in full. (He was asked to comment on trackbed that had been mentioned a few months earlier on a garden railway). The "product" used was "Rubbercrete"

"Rubbercrete" was "invented"-at least as a model railway foundation-by Model Rail contributor Trevor Jones and described in the Autumn 1998 issue. Essentially it is a fine concrete mixture which uses cork and rubber granules in place of sand and ballast. A boding agent called SBR (from builders merchants) is mixed with the water and this is the most expensive ingredient. The cork granules are large bags of fine grade model rail track ballast, while the rubber granules are ground-up car tyres. I found these the most difficult ingredient to obtain, those I got from Rushden Granulating being OK for "O" gauge but on the large size for "OO". You need to find a local company which is licensed to recycle car tyres and these granules are used in surfacing materials for childrens playgrounds.

Trevor lays the rubbercrete as a screed about 3/4 inch thick on top of the re-inforced concrete beam which he lays as a continuous foundation for his railway. My "O" gauge line is built on artificial stone walling blocks with a screed of rubbercrete on top. It provides a very good surface which takes track pins easily and which can be planed to remove any high spots.

The mixture is:

2 parts (by volume) rubber chips.

2 parts each of fine, medium and course cork granules.

4 parts cement

3 parts water mixed with half a part SBR.

The SBR turns the mixture a bluish colour but this disappears as it dries. The water content is critical and it must not be too wet or shrinkage cracks will occur as it dries.

End of reply.

There is mention of a video of Trevor Jones garden railway. (Model rail video No 1.) Not sure if this still exists as it is an old magazine, but I was just wondering if anyone had ever come across this form of ballasting. I've no idea what SBR is, and maybe this was just some fad that had been tried and then forgotten about...a bit like my budgie grit!

Might try and dig out something on Trevor Jones.

[cleanerg6e]

The rubbercrete that Trevor Jones invented. Well he didn't invent it as it was used as a trial on piggery floors as an insulation but it didn't have any abrasion resistance. You don't get abrasion on a model railway as the track takes all the abrasion. He also tried using a mixture of ballast with quick drying cement as a replacement to using PVA and ballast which he found turned pure white when it rained. The rubbercrete is not used to ballast the track but is used to provide a concrete base that you can hammer track pins into.

The SBR is an upmarket type of PVA. If you want to find out more try emailing Ben Jones the editor of Model Rail Magazine and ask him for Trevor Jones email address.

If you want to see his railway on DVD it is available from Telerail in the UK on Model Rail DVD volume 1 and also on the Garden Railway Expert. If you've used thermalite blocks which are basically just a very light concrete block you could use the ballast quick drying cement method. I think you would have to mix the two dry and then wet it once it's in place with water in a trigger bottle or one of those large pump bottles for spraying weedkiller. You'd have to set the nozzle to a fine mist so as not to disturb the ballast/cement mix.

If you buy the Garden Railway Expert DVD DON'T use the Paul Barnard method of putting loose lengths of roofing felt under the track as a cushion. When the owner cleans the track work you can see the track work bouncing up and down. Paul only put ballast in the '6foot' and he laid the Streamline Flexible Track to Peco Set Track spacing using the red Peco track spacing gauge, which is much wider apart than it should be.

Paul Barnard no longer has the garden railway business as he's now retired. A bloke near Manchester bought it but due to the state of the british economy he's been unable to do many as having a garden railway built for you is as you can imagine a very expensive job as it's so labour intensive.

Roy.

Roy.

[Rossi]

Roy,

Thanks for the info. I was under the impression that it was a direct ballasting project, but can now see that I probably misread the readers letter reply.

In the next few weeks I'm going to have a serious go at ballasting a part of the track. The only problem being the almost permanent bonding of it to the track. My track replacement stash is getting mighty low.

I will be laying onto decking (as against breeze blocks) and will have the track already secured.

As I've mentioned numerous times on here, the chairs tend to lift from the track after so many months of direct sun. Yesterday you couldn't place your hands on the track because of the heat from the rails. That is why I used several coats of varnish on the connections (chair and rail) to try and get some sort of heavier grip, plus in theory, the plastic wasn't actually getting direct sun. It has definitely worked, putting off the inevitable "warps" for a good six months more.

In true hindsight I should just have set the railway on the opposite wall of the terrace (north facing), but such is the folly of "no real plan". But then, I wouldn't have had the option of extending into the spare room next to the kitchen. Although this "hole in the wall from outside" suggestion is not getting any green flag from the authorities! One day maybe...

I'm still toying with the idea of this budgie grit notion. I even bought a bag of the stuff yesterday with no intention of giving it to the birds!

Probably one last go at this and see how it looks again.

Plus, I may have to accept the inevitable and realise that this track replacement is an ongoing thing.

[fungus]

I use a >5mm layer of a version of rubbercrete as a top layer for the track foundation, as it takes track pins and is reasonably easy to smooth. When dry, I remove any bumps, paint with roofing felt primer, then add a strip of 3mm closed-cell foam about 1mm outside the width of the sleepers. The track is laid on top of this and pinned in place, and more of the primer is run along the edges of and under the foam. When this is dry, I use real stone ballast, applied sparingly and neatly with a spoon and covering the edges of the foam, and it is then saturated with dilute weatherproof pva glue. It is important that this then has several days of warm, dry weather for it to cure properly and remain waterproof. The section of track made this way last Autumn seems to have survived the English winter ok. I have tried other ballast materials and none has lasted very long.

Budgie grit might be a suitable alternative to stone ballast, I've never tried. If the grains are smooth and rounded it might not hold together so well, but there's no harm in trying.