Bridge to embankment transition advice

[AndyB]

Hi all. 

 

I built a bridge for my latest n gauge model railway.

 

The kit went together nicely and the photos show how it will sit on my layout.  The sort if effect I'm looking for is the Victoria bridge on the SVR.

 

 

I'm making the assumption that the weight of the bridge is transferred downwards, rather than pushing outwards?

 

To either side of the bridge the ground will rise with the track running along an embankment. 

 

 

Where I need some advice is what to do at either end of the bridge. 

 

I was wondering about a retaining wall - I've put a piece of foam board in to show where this would go and could obviously make sides to this. 

 

Would a retaining wall be right?

 

If so can anyone recommend a type of stone or brick finish I could use? For preference a downloadable product. 

 

Many thanks in advance for tips and suggestions. 

 

[simonmcp]

Hi AndyB,

 

Bridge "Abutments" come in many forms. Your assumption about the direction of the forces generated by the weight of the bridge and any load it carries is slightly out. In simple terms (a civil engineer may be along later to explain the full complexity or elaborate, I just go by IK Brunel's advice to his apprentices - work out the thrusts and double the strength) the thrust will be at roughly 45 degrees downwards at the base of the place where the bridge joins what you call the retaining wall. For the purposes of your model a solid base just where your blocks of wood are, I would tidy them up and paint them a concrete colour, and a stone vertical wall where your foam block is (Scalescenes downloadable kits and textures, in the scratch building section do an Ashlar Stone sheet that would be great) would suffice. You also need what are called retaining walls or bridge wing walls to 'end' your embankments. The embankments would normally be at about 30 degrees but most people model them nearer 45 degrees. For photographic reference type in "bridge Abutments" into a search engine and opt to show images and you will get a mind boggling array of examples.

 

Simon

[AndyB]

Thanks Simon. 

That's answered my question very helpfully; much appreciated. 

I made some more progress last night and will put a photo up in the next day or two.

Andy

[Kylestrome]

10 hours ago, simonmcp said:

For photographic reference type in "bridge Abutments" into a search engine and opt to show images and you will get a mind boggling array of examples.

 

Better still, type "Victoria bridge SVR" and you'll get images of exactly how that bridge's abutments are built. 

 

HTH,

David

Edited April 23, 2020 by Kylestrome

[Siberian Snooper]

On 21/04/2020 at 19:29, AndyB said:

Hi all. 

 

I built a bridge for my latest n gauge model railway.

 

The kit went together nicely and the photos show how it will sit on my layout.  The sort if effect I'm looking for is the Victoria bridge on the SVR.

 

 

I'm making the assumption that the weight of the bridge is transferred downwards, rather than pushing outwards?

 

To either side of the bridge the ground will rise with the track running along an embankment. 

 

 

Where I need some advice is what to do at either end of the bridge. 

 

I was wondering about a retaining wall - I've put a piece of foam board in to show where this would go and could obviously make sides to this. 

 

Would a retaining wall be right?

 

If so can anyone recommend a type of stone or brick finish I could use? For preference a downloadable product. 

 

Many thanks in advance for tips and suggestions. 

 

You need some robust adjustments to take the sideways thrust. If you look at any girder type railway bridge, you will see more or less what is required. 

 

[AndyB]

As promised a couple of photos by way of an update. I hope this is as others envisaged / advised?

 

For now I've not covered the card formers leading down to the river bank do I can hear from others if adjustments are needed? 

 

For info the riverbed is the plyeood layer bottom left of the first photo and 2 layers of corrugated cardboard give the foundation for the river bank. The formers will be strengthened, covered in July clothes dipped in PVA and allowed to dry till they're as taught as a drum.

 

Look forward to opinions and suggestions? 

 

[Siberian Snooper]

The abutments look suitable for the job, nice work.

 

[AndyB]

I've yet to start a layout thread, so in lieu of that I thought to show how this little scene on the layout is shaping up?

 

Normally I'd obviously get the track laid before starting on the scenic work. On this section it'd have been tricky to do so without damaging the bridge with splashes of glue etc. Likewise getting the river painted and varnished would have been needlessly tricky.

So for now the track is in place, wired and tested but not fixed in place or ballasted. The bridge is in place temporarily and will be taken off again to do the varnish layers on the river and to paint the backscene. 

 

 

LHS abutment is yet to be done.

[AndyB]

Just to round this off a photo showing both abutments. 

 

There's a bit of tidying up to do, but this'll do for now and let's me move on to the next section of the layout.

 

With the bridge now in place I can fix the track in place - at last!