Comments sought on laying track

[gordon]

Well now I've done the introduction page I'd like to ask for views on what I've uncovered on laying a 5" gauge railway track.
I have done a fair bit of research, visiting several ground level tracks and have driven on a couple.
Also I have asked members at the GL5 stand on various exhibitions for their thoughts and have read Turnout on track laying.

Here's what I conclude to be a reasonable set of design metrics.

1. Dig a trench 450mm wide and about 85mm deep.
2. If possible put edging around it - tanalised board is fine but pavers are so much better though the latter would need a wider trench (and I'd need about 5,000 of them!!).
3. Line the trench with Terram - though which of the Terram variants to use isn't clear. I have asked the manufacturer but no reply as yet. The garden in which it is being laid has been known to flood when the bordering river overflows during winter storms which may give a clue as to best variant.
4. Use 10mm washed limestone as the ballast. There have been many different suggestion including 6mm limestone to 20mm granite. The 10mm limestone as what I've seen on three tracks so I know that this is not a bad solution.

I'll post a separate topic on searching for track parts etc.

Cheers
Gordon

[Dave Noble]

Hi Gordon,

Welcome, and congratulations on making a start.

I admit I have never laid any 5" gauge track, but would still like to make a couple of comments. If you are using PNP garden track, then the sleepers, which are 22mm wide, would be laid at 100mm centres. Between each pair of sleepers (looking at them from the side) is an inverted triangular section of ballast which carries no load. This section is 78mm wide (100 - 22). Assuming an angle of repose of 45 degrees, then this section is 39mm deep, leaving only 46mm depth of ballast doing any work at this point. This doesn't sound a lot, unless you can be very sure that the ballast will not move once laid. I think it was Richard Williams who wrote about how much effort he put into ramming the ballast up into the underside of the sleepers, this seems very important to reduce potential movement.

In an idle moment when I was dreaming about building a railway, I contemplated some possible ways of consolidating the formation and ballast. It seemed to me that a vibrating plate compactor would be a very useful tool, and discovered that little ones about a foot wide, could be bought secondhand on Ebay for £100 or so. May be worth considering, especially when you think that you could resell it when finished.

Please keep us up to date.

[gordon]

Dave,
Useful comments; thanks.

On sleeper spacing I have a lot of pre-assembled track, some with PNP sleepers and some with wood.
The PNP ones are either spaced at 70mm or 110mm . The 110mm ones came from a working railway. However they were used by a diesel shunter and a couple of lightweight kids; mine will get used by a heavyweight Merchant Navy (amongst others) and so your suggestion of 100mm between is probably right.

It appears that the "best" way to lay the track is to put a three (or four depending on section length) piles of chippings per length and level on those then go and back fill and tamp the chippings up under the sleepers. Takes time but regular tamping is actually quite necessary say people who have these GL tracks.

I had never thought of buying a tamper, just hiring one, but your idea makes much more sense. Fleabay found me a fairly good one not too far from here - and as it needs to be collected then distance is a key factor.

Will keep you posted. Should be hiring the turf cutter by the end of the week to formally, and perhaps irreversibly, mark the track bed route.

Cheers
Gordon

[Alan Wood]

hi as i work on the full size railway the track laying is simalar to as u describe they line the trench with sand then terran then more sand and large stone witch they wacker plate to make a solid base to work from, they then place the sleepers on this ,after straitening up the rails are fitted and joints welded and finaly the top stone is dropped most of witch is placed at the ends of the sleepers to stop side movement but to allow longdetudenal movement , finaly the tamper comes to make any adjustments to the levels and super elevation. I know this is full size practice but i hope it may be of some assistance.

[Ballan Baker]

Hi Gordon, I have been involved in laying three tracks and the best results were obtained by laying the track on concrete. Most tracks need a much deeper base than you are proposing to use. The reason being that most gardens have some clay under the first few inches of soil. This will make the track heave up in the winter and drop in the summer whether it is as you propose or even laid on concrete. The answer is to dig deep down past the clay and lay smallish stones and broken tiles. like a French drain,then concrete a bed to put the rail on.Either side of the concrete have a porous membrane with gravel, about 4 inches deep and six inches wide. this will give the track a fighting chance to stay stable whatever the weather. I have witnessed a few tracks where very little under rail preperation has been made with consequential problems after. Ideally each sleeper needs to be screwed to the concrete, otherwise dust and soil will find its way under.
.Gilling and the track that Lindsey society run on have been done like this and the results are very satisfactory . Best wishes what ever way you decide.. Ballan Baker

[gordon]

Thanks Ballan.
Input appreciated.
The logistics and economics of using concrete make it a non starter - the track will be over 250 yards in length so using pre-mixed has the challenges of getting a truck in, or hand mixing which would take a hell of a long time, preclude this. Also the track is alongside a river for nearly half of its length and to to have a concrete "path" would require permission from the Environment Agency, and then probably the local planners, neither likely to succeed. Fortunately it is not a clay sub soil here (it's Pleistocene Gravel for the geologists amongst you).
My "home" ground level club track is at Wimborne that has similar base to my proposed base and has been down for years (decades) without much in the way of heaving. Just hope I have same "luck".
Cheers
Gordon

[hudrail]

Humm all suggestions seem good . Terram is a must its function is to stop ingress of soil into the hardcore and to enable any water to pass through into the soil . when you get the terram there is a top side and this can be found either printed on the matting or pour a cup of water on the material and the top side is the one where the water dissappears . If you wish to keep the hard core from the ballast then place a layer of terram above the hardcore as its as cheap as chips ! Any increase in depth of the trough is to be advised and will be well rewarded in the future . P N P plastic sleepers are the best as they have voids under the sleepers which help maintain the curves and levels due to temperature fluctuations as the ballast keys under the sleepers . well worth the money . You will also need a shufty scope to assist laying but as I don't know how to draw or download pictures then you will have to visit Brent House to see what I mean