This design is based 100% on the 2nd/3rd and 3rd/4th-radius double-track versions I have designed.

Getting reference photos for these isn't easy because this type of bridge isn't very common in the modern era, so I have had to guess a little. The side panels were fairly easy to do, but I had to work on the support frame and add some realistic-looking detail.

To help lay the track, I have added a couple of guide rails for it to follow, and you may want to glue the track in place (Track width approx. 30mm). I have also included versions without these guides.Spacing between track centres is approximately 67mm (Setrack Distance)

I have designed this item so it can be printed on most FDM 3D printers without supports, but I recommend printing with a 0.4mm nozzle.The deck section is approximately 149mm wide and 23mm high, but this comes in various lengths. 60mm, 80mm, 100mm, 120mm, 140mm, 160mm, 180mm, 200mm, 220mm and 240mm.There are a lot of files with this design but you will only need to download the lengths you require.

The curved versions can be found (Has the same bridge width and height):https://www.cgtrader.com/3d-print-models/games-toys/other/model-railway-2nd-and-3rd-radius-double-track-curved-bridge-deckhttps://www.cgtrader.com/3d-print-models/games-toys/other/model-railway-3rd-and-4th-radius-double-track-curved-bridge-desk

I will also look at adding some pillar supports for those who may need them.If you have any questions, please feel free to contact me.

The design has been tested on the Bambu Labs A1 printer with a 0.4mm nozzle. I used ELEGOO PLA+ Filament 1.75mm Grey https://amzn.to/4bU03sx (Affiliate Link)

This item has been designed at OO gauge, 1/76.2 scale.For HO Gauge print at 87%, 1/87 Scale,For O Gauge UK print at 175%, 1/43.5 scale,For O Gauge International print at 158%, 1/48 scale,For TT120 Gauge print at 63.5%, 1/120 scale,For N Gauge UK print at 51.5%, 1/148 Scale, (Caution: I have not test printed this in N gauge scale. will probably need a 0.2mm nozzle to print).

use this link to join CGTrader and download my designs.

https://www.cgtrader.com/designers/PJD1974?referral_id=3218445