These are N gauge MDF kits for a short and long single track girder bridge . The are by In The Greenwood Laser . They are 45mm wide , 47mm high , and 97mm and 145mm long respectively.
The price was reasonable , the service from the the company was quick, and they are a nice simple kit to put together.
I made some supports and ramps from some 2mm MDF bases I had in stock. The end supports and bridges have small magnets in them to enable the main bridge to be removed to pack them away easier - and allow me to add other bridge types in the future too.
I gave both bridges a spray in an olive drab colour and gave them a bit of highlighting work. I added on roadway detail by making it in Powerpoint and print it off on heavier paper and glueing on with PVA.