Laying track over a girder bridge

[Dixie Dean]

Can anyone tell me how track is laid across a girder bridge?  I presume sleepers stop at the edge of the bridge and the rails are laid on wood?  Is this both cross members and lengthways members?  Any pictures would be appreciated.

 

I watched this video of a cab ride on the Alrberg and you can see the difference at each bridge, but the surroundings to the tracks is covered in what appears to be metal sheeting, so difficult to see what's underneath.

 

For example: 

 

[Dixie Dean]

The bridge I am installing is this one from Kibri: https://www.modellbahnshop-lippe.com/Landscape+%26+Decoration/Bridges+%26+Accessory/Kibri-39703/gb/modell_35372.html

 

This picture is in relation to a bridge across the Tyne in Newcastle, looks like it might be relevant: https://twitter.com/ajcanizo/status/813459142262292481/photo/1

Edited October 1, 2020 by Dixie Dean

[Dixie Dean]

Well, I'm a bit disappointed that no-one else on here seems to have encountered this issue.  

[nigb55009]

I`ve walked the Keswick railway path many times, there are seven or eight bow-string girder bridges. The path is narrower across some of the bridges and you could see were the rails had been laid on longitudinal beams with a wooden walkway either side. I say could see, the path is being rebuilt after damage caused by Storm Dennis in 2015. I assume that H & E rules will mean the path will now be full width of the bridges. There must photos somewhere on the web of similar bridges. There are plenty of the Keswick bridges but none show clearly the position of the rails. Most were taken after conversion to a path.

[rovex]

It depends on the type of bridge. Some have a metal trough which is full of ballast and ordinary track sits on that.

An alternative has been mentioned above timbers stretch between the two girders and on top of that two longitudinal timbers sit with the rails running along those.

This latter type is more difficult to model as you'll have to buy some chairs for the rails to sit in and of course make sure you keep the rails to gauge.

[Dixie Dean]

Thanks guys, I'm leaning towards laying some longitudinal wood, maybe using balsa, and perhaps cutting up some spare ties I have to make sufficient chairs for the track

[ikcdab]

2 hours ago, Dixie Dean said:

Well, I'm a bit disappointed that no-one else on here seems to have encountered this issue.  

Steady on, we're not all poised to answer as soon  as a question is posted!

The majority of girder bridges had the longitudinal timbers carrying the rail - very similar to the old GWR baulk road. Normally this would be decked with wooden planks. Google "railway girder bridges" and you will find examples. 

[Wheatley]

On your Twitter pics the concrete longitudinal beam under the rails is the waybeam, this is supported by the bridge structure. On older bridges it is a timber beam to take the rail chairs and fastenings, but that one is concrete with the baseplates cast in. 

 

The waybeams may rest on cross-girders which are in turn supported by deeper longitudinal girders parallel with the waybeams (which appears to be what is going on in the Newcastle pics) or they may sit on longitudinal 'I' beams or inside 'U' shaped girders. 

 

The gaps in between all this are covered with wrought iron or steel plates to stop staff falling though (!). At the transition between ballasted track and the waybeams there will be a crosswise plate, either iron/steel or timber up to the level of the top of the waybeam to stop ballast falling onto ghe bridge deck. 

 

There are numerous variations on this. 

 

On a ballasted deck the main bridge girders and cross girders  (with some form of decking between them) form a trough which is then filled with ballast and the track laid on top. 

 

Somewhere in here is a cross section showing a waybeamed bridge converted (badly as it turned out) to a ballasted deck.

https://assets.digital.cabinet-office.gov.uk/media/547c9005ed915d4c0d000185/R022010_100203_Stewarton.pdf

 

Your fishbellied bridge would almost certainly be waybeamed in British practice (not sure about US or European) but the kit has been designed to allow ordinary sectional track to be used. 

 

This is the Loch Ken viaduct in southwest Scotland, the waybeams are resting on transverse girders supported by the main lattice girders, the Keswick line bridges are similar but with the side girders the other way up on some.

http://smithiesshutter.wordpress.com/2013/07/15/loch-ken-viaduct/

Edited October 2, 2020 by Wheatley

[melmerby]

3 hours ago, nigb55009 said:

I`ve walked the Keswick railway path many times, there are seven or eight bow-string girder bridges. The path is narrower across some of the bridges and you could see were the rails had been laid on longitudinal beams with a wooden walkway either side. I say could see, the path is being rebuilt after damage caused by Storm Dennis in 2015. I assume that H & E rules will mean the path will now be full width of the bridges. There must photos somewhere on the web of similar bridges. There are plenty of the Keswick bridges but none show clearly the position of the rails. Most were taken after conversion to a path.

Original Bridges 66 (Low Pearson) & 71 (Brundholme) have been scrapped.

In Harold Bowtell's "Rails Through Lakeland" there  are a selection of engineering drawings of Bridges 71 & 75 and it shows cross girders with longtitudinal baulks with the track on, with horizontal wooden stays for aligning the baulks, there's also a photo along bridge 75 with a Cauliflower approaching and the bauk track can clearly be seen.

 

Found a picture of Bridge 75 in footpath days:

 

I wonder whether the footpath boards are laid on the baulks?

 

Underside view of Bowstring:

 

 

 

Here's a video of one of the replacement bridges (Ain't no trains ever going over that!)

 

Edited October 2, 2020 by melmerby

[nigb55009]

I forgot about Bowtells book. It`s a long time since I read it, must dig it out.

[Dagworth]

2 hours ago, Dixie Dean said:

Thanks guys, I'm leaning towards laying some longitudinal wood, maybe using balsa, and perhaps cutting up some spare ties I have to make sufficient chairs for the track

Waybeams (use plasticard rather than wood, easier to glue to) and Peco individulay would be my suggestion https://peco-uk.com/collections/individulay/products/pandrol-rail-fixings

 

Andi

Edited October 2, 2020 by Dagworth

[Dixie Dean]

Thanks Andi, looks like the way to go.  Will put photos on when sorted.  Need to source the bits and pieces now.

[Dixie Dean]

12 hours ago, Wheatley said:

Somewhere in here is a cross section showing a waybeamed bridge converted (badly as it turned out) to a ballasted deck.

https://assets.digital.cabinet-office.gov.uk/media/547c9005ed915d4c0d000185/R022010_100203_Stewarton.pdf

 

Oh dear, that was a sorry tale!  I made the mistake of opening the report only to find that it was compulsive reading.  Shows what a shoddy organisation Network Rail has been at times. 

[Wheatley]

Fascinating isn't it ? In fairness Network Rail walked into a trap that the LMS, BR and Railtrack had set for them. 

 

I used to work quite closely with BR bridge examiners. A significant part of the work was done at night using handlamps, and being shot at was not an unknown hazard in the Tyneside parts of their patch !

[melmerby]

1 hour ago, Wheatley said:

 A significant part of the work was done at night using handlamps, and being shot at was not an unknown hazard in the Tyneside parts of their patch !

Probably thought they were rival "lampers"

[Wheatley]

They flatly refused to do one bridge outside Newcastle having been shot at on a previous occassion. When it was suggested that a hard hat and their waterproofs should be proof against an airgun pellet at what was likely to be extreme range, they pointed out that last time the 'airgun pellet' had left a dent in 1/4" wrought iron plate !

Edited October 3, 2020 by Wheatley

[DGO]

2 hours ago, Wheatley said:

They flatly refused to do one bridge outside Newcastle having been shot at on a previous occassion. When it was suggested that a hard hat and their waterproofs should be proof against an airgun pellet at what was likely to be extreme range, they pointed out that last time the 'airgun pellet' had left a dent in 1/4" wrought iron plate !

 

Of course if the wrought Iron plate were in the same state as the bridge in the report an airgun pellet might have made a decent dent in it, more likely a .22 rifle.

[Dixie Dean]

And here is the finished bridge - my thanks to Andi for suggesting the Pandrol clips and using plastic for the way beams, they worked a treat.

 

[melmerby]

Nice looking bridge.

How many hours went into it?

[Dixie Dean]

Thanks Keith.  Well, broken down I guess it took about an hour and a half to put the actual plastic kit bits together and bash them appropriately.  I had to add the rebates where the girder bridge fits on each side.  The painting of the stone bits probably took another hour.  Cutting the track and laying it using the PECO Pandrol clips on the plastistruck, and then painting it a woody and rusty brown, another couple of hours.  Not too bad really.  Next to to put it in place together with a Swiss style stone viaduct which will sit lower and in front of this one.  The track climbs around the layout, crossing the Swi ss style viaduct first and then the fish belly girder bridge second.  Something like this mock up:

 

Edited October 11, 2020 by Dixie Dean

[Dagworth]

16 hours ago, Dixie Dean said:

And here is the finished bridge - my thanks to Andi for suggesting the Pandrol clips and using plastic for the way beams, they worked a treat.

 

Looks great!

 

Andi

[CazRail]

Apologies, late to the party... thought I'd share anyway.

 

I made an attempt to model a lattice girder bridge on my layout, to which I used three wooden coffee stirers glued together to create the longitudinal/way beams/balk timbers(we call them balk timbers). I then used left over bits of said stirers to represent the transum timber between the balk timbers. I also used wire to represent the tie bars which sit next to the transums.

 

The track is just peco bullhead with the sleeper ends and four-foots cut out. 

 

This was my first ever attempt, and any more I might make will use finer wire and generally be finer.

[Theakerr]

What Glue did you use to fasten the chairs down?  I am using code 100 and the chairs are made of that slippery plastic that doesn't accept any of the glues i am aware of.

[CazRail]

On 28/12/2020 at 20:16, Theakerr said:

What Glue did you use to fasten the chairs down?  I am using code 100 and the chairs are made of that slippery plastic that doesn't accept any of the glues i am aware of.

Im not sure but I think I used super glue

[Theakerr]

I've got a couple of Super-glues so will give them both a try although in the past the Super Glues i had did not work