When I was on a VFD the truck assigned to me was an old IH water tender with a CAT. Not sure what model anymore, but it was all air powered, the seat, wipers, brakes, throttle and so on. Anyhow it only had to sit for about a day and the air would completely leak out. So in a hurry to get to the fire, one had to first cycle the glow plugs for about 20 seconds, then let it idle (cuz you couldn't throttle it at all w/o any air) till it was aired up. All in all it took about 5-8 minutes to get out of the bay. Anyhow we put in a air-up-fast system using some regulators, valves and a SCBA tank. Then all one had to do was fire it up, push the fast gas button we put in the cab and walla, it would air up the system in a matter of seconds. I would think this would work well, especially if on were a FF and had access to an air station to refill his tank after a few *****. I would think a 3000 psi tank would last a long time blowin on a 125 psi horn. Unfortunately I can't submit pics, cuz after I left a member lost control of it when some lady came into his lane and he rolled the truck, all was lost, but he barely lived.