I've just finished boarding and panelling my loft, which gives me a lovely big clean space to build that layout I've always promised myself.
I was born in Welwyn Garden City and I remember my first primary school being within sight of Digswell Viaduct, and seeing the Flying Scotsman crossing the viaduct[1]. Years later my wife worked for Tony Marchington and our first son was born on the day Tony vested Oxford Molecular Group, making him enough money to buy 4472[2]. So I want to base the layout on the ECML, and model Digswell viaduct, station and tunnel.
Buuuuuut....
Digswell Viaduct is about half a kilometre long, which by my reckoning is slightly longer in OO scale than the longest straight I can manage along one wall of my loft!
Presumably people usually manage this problem by artistic licence, missing out the odd arch? Or should I just buy a bigger house? ;-)
[1] I am now old and crumbly so that memory could easily be faulty - please don't tell me if it is! [2] We made diddly squat from the IPO, of course, and ended up paying more tax than we made profit.