Is there an example of a 4 track tunnel mouth on the market

Hello all,

At the moment I am having a dilemma with the tunnel mouths on my layout. As seen on the photo below I need a tunnel mouth (or 2) that will cover 4 tracks. I have looked on various websites to see if there are 4 track tunnel mouths available however the maximum I have seen is 2 tracks. It is possible to do it with 2 tunnel mouths however they can't be next to each other due to limited space. I am aware that I may have to kit bash two double track tunnel mouths.

Help would be appreciated. Further photos will be added in the next posts to help explain the problem.
Regards Connor

The extent of the problem can be realised.

Think you need a bridge rather than a tunnel Connor.

Like this



The only other option is to have two tunnel entrances further back where the lines are further apart.



Ed

Hi Connor
How about something like the entrance to the Shakespeare Tunnel in Devon. No need to twin bore but that style may solve the space issue at the entrance. You could even call it the "complete works".
Andrew

How about this?
» The Plank P4NewStreet

If it's an arched tunnel mouth you have in mind I would have said a twin bore would make more sense as a single bore over 4 tracks would look uncommonly massive.

Just my two coppers worth so I wouldn't take too much notice… 

Allan

Hi Connor,

That right-hand track is fearfully close to the edge - any chance you could move it in, ease that curve, and have enough space so that a derailed engine doesn't hit the floor at a scale 60 mph? Or add a triangular piece of road bed?

Four track tunnels are rare birds (cut and fill inner city excepted), most are long road bridges. I think you will be scratch building the portals in OO and you will need a compound curvature. You could try an O gauge double portal and cut it down the height to suit.

They were/are expensive to build in comparison with single or double bores (a lot more engineering and spoil to shift*). Have a look at Linsdale tunnels in Beds on the WCML - single, double and single bores, and which would be great fun to model. [Every railway deserves a castle or 2, and if you don't have a GWR one a brick one will do.] The Copenhagen tunnel north of Kings Cross is 3 double track bores.

Nigel

*Assuming a circular bore and piR²H:

12 foot diameter bore 1000 feet long - 52,560 cubic feet.
48 foot diameter bore 1000 feet long - 1,812,096 cubic feet
4 x 12 foot diameter bore 1000 feet long - 210,240 cubic feet.
2 x 24 foot diameter bores 1000 feet long - 906,048 cubic feet.

Exactly what I meant to say Nigel !!!!!

Tunnels or Castles?

Nigel

Scratchbuilding wouldn't be too bad if you used brick papers and cardboard, or brick plasticard (Which would also help in bashing the double-track portals, I would think). You could also adapt a card kit - Wordsworth Model Railway offers a nicely-detailed tunnel portal kit as well as brick papers for download.

You could stagger the portals with the left hand set back from the right, also if you Google image Woodhead tunnel portals there is a selection of cracking photos of double portals, though to do a similar set up would mean scratch building, but in my opinion it would be worth it, they are beautiful!


Cheers, Pete.    

Hi Connor.    By now you may have done the job? But if you haven’t, could you purchase two identical tunnel mouths and then “ cut and shut “ them together. Best wishes Kev 

I know of no 4-track tunnel portals on the commercial market.  I know of only a handful of 4-track tunnels in reality one of which comes to mind being at Chester.  The portals are massive.  The entire infrastructure is massive.  Because the arch has to be so much larger than for a 2-track tunnel and is therefore much higher in the middle than it might otherwise be.  Such a thing could be scratch-built using Scalescenes downloads for the brick / stone work and stout card or foam-board for the structure.  Good luck.

Thanks for the support everyone, however, the layout in question requiring said tunnel mouths has now been dismantled for at least 1 year now so is no longer relevant. I appreciate all the responses and I may use the advice in the future