North East model railway – Matters Arising 1

There’s been several comments made about the use of foam rubber underlay on the layout, mostly because it is not liked. An explanation of why I used it is probably useful.

I wanted to make sure I would be able to acoustically completely disconnect the sound of the trains from the baseboard. Previous layouts I have built have sounded deafening when several trains are run at once. This layout was built with the intention of filming and therefore the sound of the trains running is of equal importance as the visual impact.

The baseboards are fibre insulation boards (notice board material) mounted on open frame 12” squares (300mm). My original intention was to mount the track directly to the insulation board, but after laying some track and testing it, the sound deadening was not acceptable. Even adding another layer of insulation board didn’t improve matters.

Another consideration in the track laying equation is the track itself. The track rails are nickel silver. The main straight is around fifty feet long (15 metres) and over that distance quite a lot of expansion and contraction takes place.

The traditionalists run with the idea of mounting the track on maybe cork and then gluing the ballast to the track with PVA glue. This bonds track and baseboard together so tightly it defeats the very effect it seeks to avoid. This method does not allow for sufficient expansion and contraction of the rails on all but the smallest layout. A side issue with this method is the lack of any way of replacing damaged pieces of track in the future without the use of a hammer and chisel or a road drill.

The foam rubber method is an ideal solution to the sound deadening, expansion and contraction and maintenance issues.

The sound deadening qualities are excellent.

All the track work is laid on Peco underlay using their thin pins, lightly pushed into the insulation board. As the track expands and contracts the insulation board has enough ‘give’ to allow the movement required.

To take away the harsh edges of the underlay the gaps between the tracks and at the edges are infilled with loose granite chippings. The word ‘loose’ is key here, allowing movement, and, when maintenance is required the loose infill can easily be swept up and replaced afterwards. Sometimes, there is the odd derailment from the loose infill getting onto the tracks but is a minor irritation.

I’m sure there will be those of you who say you should leave gaps between the rails so you don’t get the expansion. Those who say that are theorists. I can’t imagine anybody who has a temperature controlled environment where the entire layout could be constructed in one go and thus avoid this problem.

I tried to lay the track during the summer months leaving gaps on all the pieces, the wide ranges of temperatures (especially in front of windows) can still thwart the most carefully laid track.

If you play the video below, pay attention to the sound the wheels make, this is the effect I wished for. 

To view the channel, follow the link below

www.youtube.com/user/dougattrenholmebar