I have finally after nearly 20 years had my dream carport erected. I have 108 m undercover outside now and it easily holds the 4 cars and boat with my play - work area to spare down one side.
I have had two back to back beams fitted for hanging carcass's after hunting. I need a roller or rolling hanger that will fit into the channel iron or C-Beam, I have seen them before but have no idea what they are called. The old indoor wooden hanging doors used same principle and some curtain rails as well.
I have attached a rough (very) drawing. Where can I get this - what is it called.
https://flic.kr/p/2ixZk2P