Suggested reading…
Isambard Kingdom Brunel
https://en.wikipedia.org/wiki/Isambard_Kingdom_Brunel#Great_Western_Railway
Brunel gauge was indeed a thing back in the day….and Brunel came up with the idea because a ‘broader gauge was the optimum size for providing both higher speeds[44] and a stable and comfortable ride to passengers. In addition the wider gauge allowed for larger carriages and thus greater freight capacity.[45]
It’s funny though, it doesn’t really dawn on you how big the Brunel Gauge is until you get out a tape measure.
Heck, I didn’t even know who Brunel was until I saw him being portrayed in the ceremonies for the 2012 Olympics (Kenneth Branagh portrayed him)
She was built with the idea of being able to travel anywhere in the Empire in a single voyage. Most non-nuclear powered ships nowadays can’t do that.
And the intelligence questions just changed. The question isn’t just ‘why is this here?’ any more. It’s also ‘and what’s at the other end?’, because this branch line can’t interface with the rest of the rail network without going through break-of-gauge, which is a major undertaking (jack up train, insert new bogey, lower train), especially as 7′ stock may be too wide for clearance even if swapped onto 4′ 8.5″ bogeys (especially on bi-directional track – ouch!).
So either it’s going through break-of-gauge, and there’s a big facility for that at the other end of the branch line. Or there’s something specific at the other end that needed to travel here. Or everything predates standard gauge.
This will all be dealt with in comic. I’m lucky in the fact that I have a character that has some railroad experience in the family. Back in the early days of the comic, I had a raid on a train depot for the purpose of the River Crossings people obtaining foodstuffs while they were fighting for independence (Cassie’s Dad was one of them…back in April 2005)
I meant to go into a little more detail on some of this stuff back then…I’m just glad that I can finally get back into this now