Old Signal Maintainer's Hut
Download the 3d virtual model below.
Click the grey “down”arrow beside the files at the bottom of the page
The BIMx files are 3D models which you can navigate
The free software for PC or Mac can be downloaded at Graphisoft
Use the esc key to show & hide the menu - it must be hidden for “fly” mode - then you can use the mouse. Press “controls” in the menu to see the commands.
Best for use on an iPad, search for the free BIMx software at the Apps Store, and you can navigate with your fingers. Let me know if you have any problems.