So having created a security kiosk I was happy with yesterday and with only a limited bit of building time this evening I decided to set up a little production line to produce the two others I required. 

(sort of cabin I was looking to create found on a Google search with some useful dimensions that just needed dividing by 148)

By close of play I had managed to complete all three:

(three completed cabins) 

And located on the layout

(two controlling the entrance onto the upper and lower linkspans) 

(and one controlling the access ramps) 

Following this trial run with scratchbuilding I feel emboldened to perhaps try a portakabin or two which are required around the place. A bit more research required on dimensions and door / window sizes. That and the Linkspan wheelhouse will keep me busy for this week! 

Many thanks for reading and happy modelling! 

Paul