10Base5
The first (and I think last) time I came across 10Base5 cable (the 0.5 inch coax) was in the mid-90's at a university that had committed to 10Base2 (the thin coax). In one physics lab a networked computer needed to be installed at the other side of the room from the 10B2 port and the total length of that 10B2 line was at the limit of the specification. The solution was a 10B2 to 10B5 converter then about 5m of the over-size coax to the AUI port on the computer.
Shortly after I arrived we rearranged the lab so the the computer was next to the 10B2 junction, but we had to carefully coil the thick coax as there was a multi-month lead time on cable changes. Not too much later 10BT came in and all was well with the world.
Biting the hand that feeds IT
