Thanks everyone for the replies!
@vaporvac Here is a close up of the leaves and thorns, it is winter at the moment, I'm in Nottingham, England.
I don't prune it, I don't do anything to it, except move the long shoots from upwards (over the summer each shoot will grow about 6-8 meters upwards) and I attach them to the fence.
It blooms once a year, around June time.
I would be keen to try the cuttings idea, any tips? can I pot some cuttings up this time of year?
My main reason for wanting time know about the plant is because I may move house in the future and want to be able to have such an amazing plant at the new property, but don't want to risk killing the plant trying to move it. So I'll try some potted cuttings. It would be great to know what it is though, I've never seen a rose bush grow like this before!