Fixing external track

[Airbuspilot]

Gentlemen

A friend is building a very large G scale garden railway using LGB rolling stock. We have completed laying around half the track, approx 100 meters to date. We have made a concrete foundation with the track currently sitting on top. At this stage there in no intention to ballast the track, that may change with time.

Our plan was to drill the concrete, insert plugs and screw through the track to the plugs. We are in a very hot climate and already expansion is causing visible track movement. My concern is that screwing through t he plastic sleepers may cause cracking and may not stop expansion causing problems.

Can anyone suggest a novel fixing method for hot environments?

Thanks again

Robin

 

[Madman]

Been there, done that. Yes, the track will expand and cause issues with the sleepers or rails. If you want to use the method you've described, don't screw through the sleepers. A piece of metal, like a flat mending plate with a screw inserted into the concrete. Instead use this method. Don't tighten the screws hard. Leave them ever so slightly loose. This way the track can move with temperature changes.

 

[Sean.]

Over here in New England I do not secure the track at all...it floats on the ballast like the real rail roads.. the track moves and adjusts by it's self most times..

 

[Airbuspilot]

Over here in New England I do not secure the track at all...it floats on the ballast like the real rail roads.. the track moves and adjusts by it's self most times..

Thanks Dan and Sean

i saw an earlier post which said not to fix the track but to use ballast to float the track, may be problematic for us as the concrete base may be too narrow and to ballast around 200 meters of track could take a while. I will try Dan’s idea as a starter which will get us up and running then possibly try the ballast idea later.

Thanks for your advice

Robin

 

[Greg Elmassian]

You cannot stop expansion any more than you can stop electrons orbiting the nucleus of an atom.

The track will move, and curves will be an issue, so you probably will need to use something like what Dan showed, and try to keep the rails on your curved concrete. If you constrain it this way, then the curve will grow "longer", so perhaps you can put some kind of expansion tracks at the end of the curves, where they joint to straight track. (these by Split Jaw)

 

[Paul M]

Do you need to fix it down? On my first, admittedly very small, layout I just laid the track down on the base and left it. As long as the fish plates are reasonably tight it should be fine

 

[Gizzy]

My track is not fixed, but floats in the ballast.

If you are using LGB or PIKO track, you could use the plastic 'dog bone' joiners to help hold the track in place, especially on curves.

I have done this, although I now use rail clamps....

 

[Greg Elmassian]

I was holding my tongue about trying to screw down track.... it's a bad idea is all I will say, you cannot fight physics and win.

There is a typical progression in the learning experience:
1. screw the track down solid ever foot or so.
2. it is observed that track gaps grow, track kinks, rails ripped out of the ties (sleepers)
3. At this point people either go to free floating the track in ballast (success)
OR
4. People try to let the rails slide in the ties, which fails...
5. let the track slide a bit with loosely fixing it at greater intervals
WHICH LEADS TO
6. letting the track completely float in ballast.

Have seen this over and over. Rail in sunlight will expand and contract and at a different rate than the plastic ties, which is also at a different rate than your concrete base.

Greg

 

[dunnyrail]

Track clams will help, though things may move around a little you are looking at the complete track layout as a single entity.

 

[Greg Elmassian]

Clamps will hold the ends of the rails together a bit better, but this is about the track itself moving as it grows longer and shorter... different issue, and clamps won't change the amount the rails move.

Greg

 

[GAP]

My sleepers are screwed down to the wooden frame of my track bed and have been for 2 years, I have no issue with the track pulling out of the sleepers or their moving. Some of the holes through them are larger than the screw diameter (I use button head screws) but others have had the screw just drilled through them and are quite tight.
My rail has about a 1-2 mm gap at each joiner and these gaps widen in the cooler weather and close up in the hotter weather (temp range 4C to 35+C)
On my previous layout the sleepers were held in place with metal pegs pushed into the ground through hole drilled in them, they sat on concrete pavers dug into the ground till level with the surface. Same gap and joiner configuration it was down for about 10 years.

 

[3 minutes of fame]

Been there, done that. Yes, the track will expand and cause issues with the sleepers or rails. If you want to use the method you've described, don't screw through the sleepers. A piece of metal, like a flat mending plate with a screw inserted into the concrete. Instead use this method. Don't tighten the screws hard. Leave them ever so slightly loose. This way the track can move with temperature changes.

View attachment 290475

This. It allows the track to move enough not to distort or lift, but stays aligned.

Some space in fish plates and a short wire to provide continuity will also help.

 

[maxi-model]

A couple of things come to mind - Are you principally using flexi track, where the sleeper webs are free to slide independent of the actual rails (i.e. the webs are only really there to maintain track gauge and support the rail) ? Or, are you predominantly using "set track" where the sleeper web is firmly anchored to individual rail sections, to maintain a preset curvature or length, with the rail fixed to the web at the joiner ends or physically by screws to the the foot of the rails ? Using the former "flexi" type track system predominantly will help minimise your distortion issues through unavoidable heat expansion/contraction - the different materials for the rail and sleeper webs will be able to expand/contact without unduly affecting/constraining each other. You can't escape it for points and crossings but everywhere else you could use "flexi".

That and ditch the concrete track bed. It's just one great big heat storage device. Sure going to a floating on ballast solution will still involve the base soaking up heat but the open nature of the sharp stone ballast should help minimise the effect.

Track clamps are very usefull at helping maintaining alignment of track formations where these expansion/contraction issues exist and also help minimise the risk of track joints being "hammered" apart by regularly passing stock. Fixing your issues is really a matter of increments by employing the methods suggested by others here. Max

Edit - I should add that I "float" my track, mostly "flexi" LGB code 332 type, on a sharp stone ballast laid over a shallow permeable membrane covered trough. My track is then "pinned" at roughly 4 ft intervals, through to the ballast, with single 5" nails placed through a sleeper centre. I use track joiners (Hillman & Massoth) throughout, direct to rail so they can be slid out. That allows individual track sections, like points, to be easily lifted out for maintainance without disturbing the rest of a particular neighbouring track formation.

 

[GAP]

I use flexi track for all except for points and crossings so what you say in the first line applies to my railway.

 

[korm kormsen]

where i live we got temperatures between 25°F(seldom) and 110°F(often enough). (-3 to 45°C)
so even after i went "indoors" i get temperature differences of 60°F. (35°C)

over the decades i noticed an important fact. brass rails expand and retract about 2mm (about a 12th of an inch) per foot between the mentioned temperature extremes.
for a piece of flextrack of 5 foot that is a difference of about 10mm (2/5") in length. - long enough to have straights expand into snake-lines and to retract completely out of the fishplate connectors.
but if laying 1 ft. sectional track sections in moderate temperatures i just need gaps as wide as the thickness of a creditcard between sections to allow for the possible expansions or retractions.
that allows me to fix each piece of track at one extreme to the roadbed. (one nail/screw every foot) result: no wandering of track, no slipping out of fishplates.
(plus a nice clickety-clack from the wheels.)

 

[phils2um]

If you concrete base is level you don't need ballast if you can't be bothered with it. But, if you try to fix the track to the concrete you'll regret it. Use rail clamps and let it float.

 

[Airbuspilot]

Gentlemen

I saw two replies just before I went to bed and when I wake up the entire community responded, does know one sleep?

Thanks everyone for your thoughts and advice. I am sure Greg is correct in terms of learning curve, I will suggest we hold laying track on phase two and look at all the options available. While ballasting is a slow process so is mixing and laying concrete, a floating solution would probably take the same amount of time.

Robin

 

[JimmyB]

I have a mixture, areas with floating track on ballast, track on concrete, I use to use standard fishplates to allow expansion/contraction and track pinned. I now use clamps to maintain track and do "screw" the occasional sleeper, but with a large hole to allow float, I find that especially on the concrete without the occasional fixing the track gets knocked out of alignment.
Mind I am a novice only having been at this for 3 years now.

 

[Greg Elmassian]

One thing about large scale is that the laws of physics still apply in a way very similar to the prototype.

scale weight: take the prototype weight and divide by the cube of your scale (32 or 29 or 22, etc) and you will find that this is a very workable weight, that a locomotive will pull prototype length trains.

Likewise track, you rarely see rail completely fixed in place, rather it is in ballast, and even then they can get sun kinks on long straight stretches, where expansion has nowhere to go.

We probably have it worse, since plastic seems to grow and shrink more than wooden or concrete ties. Believe me if railroads could lay track and never have to maintain/reballast they would! It is a huge expense.

Greg

 

[justme igor]

My sleepers are screwed down to the wooden frame of my track bed and have been for 2 years, I have no issue with the track pulling out of the sleepers or their moving. Some of the holes through them are larger than the screw diameter (I use button head screws) but others have had the screw just drilled through them and are quite tight.
My rail has about a 1-2 mm gap at each joiner and these gaps widen in the cooler weather and close up in the hotter weather (temp range 4C to 35+C)
On my previous layout the sleepers were held in place with metal pegs pushed into the ground through hole drilled in them, they sat on concrete pavers dug into the ground till level with the surface. Same gap and joiner configuration it was down for about 10 years.

Well here is your answer...


#1

Some of the holes through them are larger than the screw diameter

#2

My rail has about a 1-2 mm gap at each joiner and these gaps widen in the cooler weather and close up in the hotter weather (temp range 4C to 35+C)

its for driveble range temp, i guess, good temps btw...4C is a bit to cold for my liking

Why not setup a double track incl a corner?
one fixed as mentioned per GAP and one not fixed?
I would suggest to screw down your leading railway, if it fails..just un screw it?
Make marks on your unscrewed railway section, so you will know exactly in 8 moths from now how it is behaving...winter is coming, just do it, just a experiment, materials are not wasted!
I bet in those 8 months you will have 30C or higher...and below 0C
Every garden is different, every location is different...Sahara or north pole...ect
I understand you like to drive your trains.....i would like also....but first tracks..(i must build 1200 meters minimum)..take your time
There is no right or wrong way, test for your self...
Btw baking in the sun or chilling in the shade gives different expansion coefficient, at the same day.
Dont ask...experiment.

With best regards Igor