Hornby brick arch bridge has leaning brickwork

[47137]

I bought one of the old-style Hornby brick arch bridges for my layout, and chopped it down to fit the space available below the track:

 

But I wonder - the two sides of the arch are leaning inwards, with the arch having a continuous curve. While on every real-world bridge I look at, the sides of the walls seem to rise vertically as far as the beginning of the arch. Do we have prototype bridges resembling the Hornby shape in Britain? Maybe I should make my own bridge.

 

- Richard.

[Campaman]

I think what you have there is actually a section of the Hornby viaduct rather than an actual bridge, hence the different shape.

[Pete the Elaner]

I was unhappy with the shape of any commercially available bridge or tunnel mouths, so I bought a laser cutter to do the job. I am lucky enough to have a friend who can draw up the artwork, which saved me lots of time learning how to do it.

There are some photos in my layout thread.

 

Changes made were:

 

The tunnel mouths I wanted were tall & skinny compared to anything available. Most railway tunnel mouths seemed to be taller than bridges, presumably to reduce the amount of smoke being reflected back at the train?

Brickwork around the arches do not have bricks in line with each other. Each row has a different radius so the inner ones need less bricks, which gives them a staggered look.

Hornby's brickwork in the OPs pic has stretcher bond. This was unusual when most railway bridges were built. English bond was a lot more common.

Edited January 15, 2019 by Pete the Elaner

[BernardTPM]

I think what you have there is actually a section of the Hornby viaduct rather than an actual bridge, hence the different shape.

Actually the same moulding was used as a bridge R189 and, in threes, as a viaduct R180. The odd shape below the arch is simply so the moulding will come out of the injection tool without sticking.

[47137]

Well, it is quite a sturdy model so I think I will clad it in a new finish and change the shape of the arch at the same time.

 

Thanks for all the notes. I never thought of the injection moulding machine.

 

- Richard.