Jump to content

STONE-BUILT OO GAUGE GARDEN RAILWAY VIADUCT


mick
 Share

Recommended Posts

Seeing as your viaduct has stood the test of time, I think its likley the next raised section of my railway will likley use a similar brick block method. The big problem with the design is that I will need twin tracks over a single viaduct and with the blocks seeming to be 10cm wide I dont think Ill be able to get both tracks across with clearance. My question is, do you think it'd be easier to rotate the bocks sideways so the longer sides are abut together or would it be better to double up the blocks. I have found some aerated bocks that are 7.5cm wide so the latter would give a track bed that is 15cm wide which seems more reasonable than 10cm.

Link to comment
Share on other sites

Yes, the viaduct has done really well and made it through 6 winters now so I'd certainly recommend the blocks for any similar type of construction. The drawback as you point out is that by the time you add parapet walls there's only enough room on top for a single track.

1 hour ago, Archie said:

...I think its likley the next raised section of my railway will likley use a similar brick block method...

Do you mean just a simple raised section or are you thinking of something more elaborate like a viaduct? I'm not sure I'd fancy the task of creating the arches in a double thickness block although it isn't something I'd previously thought about. I'm sure it would be possible. If you just want the blocks as a base for a plain raised section then you should be able to lay them either way, even flat on their bellies.

Link to comment
Share on other sites

35 minutes ago, mick said:

Do you mean just a simple raised section or are you thinking of something more elaborate like a viaduct? 

 

It will most likley be a viaduct type structure from about where the bay tree is

image.thumb.png.71d8d981353487faa9ce81499daf8dfb.png

as you can see on the pieces of wood that are level with the current track it is much lower than your viaducts but is still too high to just sit on solid blocks or to float in the air. I think I could potentially align the two sides with bolts if it were constructed and then use the hole saw or rasp method to get the curves, or I could try to build another kind of bridge, maybe a girder bridge would be more suitable? 

Edited by Archie
Link to comment
Share on other sites

I had that thought, the only problem I see is keeping the block in the gap level whilst its drying. With that said it may save on costs, doing 2 lines of bricks over 15 metres would start to get costly.

Edited by Archie
Link to comment
Share on other sites

5 hours ago, Archie said:

...doing 2 lines of bricks over 15 metres would start to get costly.

15 metres! Wow, I didn't realise you were considering building that length.

I can't see an easy solution so if it's to be a viaduct them there's going to be some work involved. I take it the possibility of single track over a viaduct is a no go?

Another option worth considering, which is something I'd like to have incorporated on my own layout, would be an embankment, possibly with a road or river passing beneath to break it up a bit. That would make a great viewing point too and be a lot less work. I was thinking create the track bed with a row of blocks and then banking up the earth on either side to be turfed or planted.

Link to comment
Share on other sites

6 hours ago, Archie said:

I had that thought, the only problem I see is keeping the block in the gap level whilst its drying. With that said it may save on costs, doing 2 lines of bricks over 15 metres would start to get costly.

Use a 6" block Then add a wooden trackbed and walls. The walls will not then impinge on the width of the block.

Link to comment
Share on other sites

2 hours ago, mick said:

15 metres! Wow, I didn't realise you were considering building that length.

I can't see an easy solution so if it's to be a viaduct them there's going to be some work involved. I take it the possibility of single track over a viaduct is a no go?

Another option worth considering, which is something I'd like to have incorporated on my own layout, would be an embankment, possibly with a road or river passing beneath to break it up a bit. That would make a great viewing point too and be a lot less work. I was thinking create the track bed with a row of blocks and then banking up the earth on either side to be turfed or planted.

That was probably a bit misleading, the viaduct itself is going to be 5-10 metres but the whole length is around 15 metres. I included the embankment in the 15m which I was also considering to do on blocks although it may be easier to do it with wood like the rest of the layout, and then fill the void with rubble to build up an embankment. The only issue I have is the amount of space through the flowerbed being significantly thinner than the bed on which the rest of the layout is situated making a realistic embankment hard without filling the whole bed with dirt.

A single track viaduct would probably not work as I am using DC and would rather avoid the complicated wiring, it also means the track can't be split into block sections as easily for multiple train running. One option would be to squeeze the parapets as far out as possible and run a length of gauntlet (overlapping) track across the viaduct to keep the tracks separate. But again it would make multiple train running hard, but in that case not impossible.

One option, as Roddy said, is to put a wooden track bed over the top of the blocks, and as I only need an extra few centimetres or so it wouldnt look too bad either. Again though, just like the double blocks, it adds an extra layer of complexity to the build.

 

Link to comment
Share on other sites

It all depends on what you want, specifically how long you would like it to last.

Wood isn't the best option especially close to ground level. I've used wood before several times and it's not the most stable material to use. Even the slightest bowing makes running problematic at times. I've still got a decent length of plywood baseboard along the bottom of the garden which is well coated in bitumen, several coats, and covered in roofing felt to protect it. It's been fine but it is elevated so that probably helps. Close to ground level I've had lots of problems resulting in having to relay large sections. Even with several coats of bitumen, roofing felt sandwiched between the concrete footings and the track base, and the plywwod top covered in roofing felt, it still rotted away after 2-3 years.

The block bases are stable and weatherproof giving you some peace of mind but they are a much more permanent and prominent fixture in the garden and not everyone wants that.

  • Like 1
Link to comment
Share on other sites

  • 4 months later...

Quick opinion. On my curved viaduct, because the blocks are sawn at an angle the inner edge is 20cm and the outer 23cm. So with a 127mm core cutter (call it 13cm) the piers are going to be only 7cm thick at the front and 10cm thick at the back in a trapezium shape. So the question is should I go back to screwfix for a smaller core cutter?

The next sizes down are 117mm and 107mm. So that would give 8cm-11cm or 9cm-12cm piers. There won't be any serious weight on them, the back end isn't seen and from the front at 7cm the piers will be way overscale compared to what a real one would be. Going bigger on the piers will look worse so I'd only go bigger if someone sees a real structural reason for it.

I won't be drilling this week.

Link to comment
Share on other sites

Structurally at a width of 7cm-10cm I can't see that being a problem. I imagine the greatest force on them will be during the actual cutting and that would be my biggest concern so it's going to require a steady hand.

As for the piers looking overscale, I wouldn't worry too much about it especially with the viaduct being not very tall. It should look fine.

  • Thanks 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...