Tallahassee Amateur Radio Society for many years actually had an aluminum crank-up tower on the club communications van. Retracted, it lay on top of the van in a kind of cradle. Extended, it was 50+ feet tall. When the van was scrapped, I had hopes of purchasing that tower to mount on top of my MH, but at length decided it would place too much strain on my roof. Oh, well, it took two or three guys to deploy and stow, so wouldn't have been practical for me anyway..