“Folks, we’ve lost an engine,” announced the pilot. “Nothing to worry about. We have four and the plane can fly OK on 3.
“It’ll slow us down a bit; we’ll arrive about an hour late.”
A few minutes later, he came back on in his best pilot voice with, “We’ve lost another engine, but don’t worry, we can fly safely without it. Unfortunately it will add ANOTHER hour to our flight time.”
At this point one passenger muttered to his seatmate, “Gee, I hope we don’t lose any more or we’ll be up here forever.”
Modern coaches have a great deal of “backup” built into critical systems. Brake systems are designed so that if a part fails, the rest picks up most of the slack. Many buses have more than one alternator and several HVAC condenser fan motors. Gee, unlike cars, buses carry spare tires.
Ain’t redundancy grand?
As with so many things, it can be a mixed blessing. We need to think of it the same way we think of lifeboats. They are great to have, but not where we really want to end up spending the trip.
When an alternator poops out mid trip and the bus limps back safely, that’s good. Dispatching a bus on a summer day with a couple of lazy condenser fan motors, hoping it won’t parboil passengers, is a bad thing.
Heck you get it. Hope is not a maintenance plan.
A couple of years ago a coach passed me and I noticed one of its passenger windows looked strange. Seems that the outer pane on a thermopane sash had cracked and the operator knocked the shards out with a hammer, leaving the inner glass intact. It worked pretty well, but looked sketchy.
The point I am wandering towards is that we might want to think of redundancy like a hammer — it can be used to build things or break them. Knowing how and when to use it is critical.
It’s great at saving our bacon when the unexpected happens, but it’s a risky alternative to doing actual maintenance.
One customer pulled into our facility on a summer day with a loaded bus and virtually non-existent A/C. This model coach had multiple evaporator motors and almost half of them were working. Our trusty mechanic slapped some new ones in and voila — nothing.
A bit of extra detective work revealed that the HVAC’s thermostatic control was thoroughly confused because it was blanketed in dust. It had no idea what the temperature was and had suffered death by fuzzball.
The customer was irate that none of this was covered by warranty, and his passengers were not enchanted by their five hours at our bus garage.
When coaches first came out with redundant systems, they didn’t always alert us to failures. You could lose a component and not be sure. If things seemed a bit iffy, you could convince yourself that you were imagining it.
Surely when fuzzbus left the barn it had at least a hint of A/C.
Modern buses generally have that pesky orange light, and when it illuminates, it isn’t to brighten our day. The fact that everything seems fine is not an excuse to ignore it.
It could be something as innocuous as a failed reading light, but you really do want to be sure. The orange light is a close personal friend with the red one. If you are rude and ignore orange, frequently red gets even.
Preventative maintenance is the practice of fixing things before they fail in a nasty spot. Perverted maintenance is its ugly cousin that fixes things just after they cost you a ton of money.
The mixed blessing of redundancy sometimes helps seduce us from “preventative” to the dark side.
Around 1971 I was deadheading a Scenicruiser from Colorado Springs to Tucson. For the youths among you, a Scenic mounted 10 tube-type tires and carried a spare.
In ye olden days we thumped tires with billies more often than we used gauges. Coulda been that they ALL were low?
Rocketing through the desert, that puppy blew one tire inner tube after another. Not bright enough to make the connection between tire pressure, excessive speed, hot roads and exploding tires, I first mounted the spare, then began running the duals with single tires.
Never one to waste anything, I had heaved the flats into the luggage bays and forged onward. Pulling into a Phoenix truck stop, I limped to the shop on the remaining six tires, dragged the five flats out and begged the tire guy to fix them in time to pick up my charter group.
This, folks, is a classic example of redundancy. In this case, that second tire on each rear dual seemed to be a spare. Who needs 10 tires when six will do?
Either that, or it’s a glaring case of Perverted maintenance.
Dave Millhouser is a bus-industry marketing consultant and freelance writer. Contact him by email at Davemillhouser@gmail.com.