Rog is a Civil engineer and these were left over from some jobs he was doing. You can get them from builders yards, B&Q etc, but it's often worth strolling past a building site towards the end of a job to see if there are any hanging around (pipes, that is, not builders!!:lol as they are very expensive to buy.Its nice to see Tim so happy with his new wifebun.
I love your pipe tunnel, where can you get them from?