Appologies for the lack of detail info. The period is 1952 'ish' and the viaduct is brick built with bricked up arches below the track bed, three of which I am making occupational arches for various businesses. I will be using white metal stanchions from Lynx models with 2 handrails of piano wire. I am thinking these would be of the cast iron variety of handrail back then and after a couple of tries with spacing, I am thinking either 5'6" or 6'0" would be about right. Thanks for the photo, the railings look like the sort I envisage but not the stanchions. Howsgill viaduct is not the same type of viaduct that I will have, but thank you all the same.
Incidentally, I have tried long and hard without success to find photo's of occupational arch viaducts, they dont seem to have been a popular subject!