Any ideas?

[Upatdawn]

TheEnd said:

Yep, same fixing as on a water stopcock, which is what it is likely to be related to somehow.

a stopcock mounted on a remote bridge above a canal?

any water pipes would have been along the towpath surely?

[TheEnd]

Well, they are pipes and a valve.

Unlikely to be for gas, likely to be for liquids. Could have been some sort of a drain maybe.

[mrtwisty]

Get back in here and tell us what it is urban sports! Git!