Garden Railway Forum

I have a flat garden and fancy building a road arch as a scenic add on that will be permanantly set in the garden.

What is the besy way of constructing one?

What heigth and width should the loadlng gauge be set to as I don't want to stop visiting locos and stock running?

I'd go with concrete - I think you can buy road bridge sides snd I'd use bricks and a small paving slab to build the bridge which you could use as a path.

With regard to loading gauge, make it bigger than you think, just in case!

Buy road bridge sides! thats cheating I'll knock up a wooden mould

assuming a straight bit of track how high would the top need to be. as /i run Mamods its easy to do mamod hight + 5cm but is that enough for other 32mm locos?

I have seen somewhere bridges made from styro foam, details added with soldering iron then painted, looked really effective. I suppose if you want it structural eg for footpath you could just use the styrofoam to clad.

Sorry it was tunnel portals, but the technique would transpose to bridges easily.
http://users.stratuswave.net/~wd8jik/tu ... nnel.htm#c

They really do look good. My bridge will only need to support 16mm vehicles and the occaisional huge rabbit.

There was also a nice blog post by Rik Bennett about how he made his overbridges:

http://riksrailway.blogspot.co.uk/2010/ ... idges.html

(Lots of useful stuff on his site!)

For loading gauge I usually make things to clear vehicles 7'6" wide - so I usually go with 12' between bridge abutments, which is 192mm. Height is more complicated for me as I will eventually need to clear standard gauge vehicles on transporter wagons, so I need to go 13'6" or 14' - 216-224mm tall. However, height wise 180mm should be enough to clear most NG stock.

Peter in AZ

IrishPeter:78445 wrote:For loading gauge I usually make things to clear vehicles 7'6" wide - so I usually go with 12' between bridge abutments, which is 192mm.  Height is more complicated for me as I will eventually need to clear standard gauge vehicles on transporter wagons, so I need to go 13'6" or 14' - 216-224mm tall.  However, height wise 180mm should be enough to clear most NG stock.

Peter in AZ

I'm in a process of planning my first garden railway and have a lot of questions to experienced garden raillwayers. I need your help! How deep must be bridge abutments in the ground? Sometimes we have very severe winters and the frost line is about 1.5 m, do I have to deepen abutments and piers lower than the frost line?

Welcome OMA For a Garden railway Just sitting on the surface should be ok but I no experience of that much cold.

We can get -20C here but not for sustained periods and there is not much rain and snow here, so I have not had problems with frost heave.  However, we do have an almost daily freeze-thaw cycle in the winter months which can cause problems.  However, my line is ground level and laid on and in ballast, so it is as flexible as a real railway.  The regular maintenance is a little more demanding than a raised line, but I do not have the problems associated with concrete blocks or wooden posts shifting in the weather.

The few structures that live outdoors permanently have only a shallow foundation - just a few centrimetres so that they do not move side to side under load.  I have not found that to be a problem, but then my site is well drained, and we do not have any great degree of frost penetration - a few inches to about 30 cm at worst.

Peter in AZ

Thank you !