Off the top of my head, there are 13 tillers, leaving 130 ladder companies.

I don't have a copy of the Department's Unit Location Chart, so I don't know how many of the remaining are rear mounts and tower ladders. I'd estimate about 60% rear mounts and 40% tower ladders.

Does anyone have the exact number?

I figure the spare fleet would roughly reflect the same proportion of rear mounts to towers.