Truck cranes are common clients of most workshops. Widely
spread, big and small, these machines rely on hydraulics to operate,
and careless operators and owners make them a steady piece of profit
for many hydraulics related businesses out there. This involves both
spare parts sales (pumps, valves, jacks...), and troubleshooting. Most
of the times these machines have extremely simple hydraulic circuits
and aren't that much of a troubleshooting challenge, but just today I
recalled a funny truck crane episode, that happened to myself some
years ago, and from what I keep hearing from other mechanics and crane
owners, is not so uncommon to happen.
Every technician knows - when troubleshooting a pice of hydraulic
equipment, you will have to operate it at some point (make movements)
to see what is wrong and whether the problem is solved. For that
particular crane truck the malfunction was one of the outriggers that
wouldn't come down. The problem was quickly identified and solved, and
I was cheerfully extending and retracting the outriggers to show the
satisfied client that the puzzle was solved and how great a hydraulic
technician I was to have solved the outmost complicated mystery on the
spot... You can't argue that watching a hydraulic machine readily
respond to your commands is a thrilling experience, and, I was
beginning to get carried away... when, regrettably and rather
unexpectedly, my enthusiastic performance was interrupted by a
squeaking sound of something being crushed, as I lowered one of the
outriggers from the other side of the truck (the one I couldn't see)...
"oups!" -said I, and rushed to see what it was, mumbling (with my
fingers crossed)
"please don't let it be the guy's dog...."
"please don't let it be the guy's dog...."
"please don't let it be the guy's dog...."
The "it" turned out to be my tool box. The poor
thing got utterly deformed, but, luckily, nobody got hurt. The
strangest thing, however, was something that happened a week later to a
guy from my workshop (the one who was laughing the most over the
anecdotic predicament), who lowered an outrigger of an alike crane
smack dab in the middle of a brand new Webster flow meter (the part that has LCD and all the electronics, not the robust turbine part), crushing it to dust...
These stories are a good reminder to all hydraulics
technicians of the primary purpose of oil hydraulics - power transmission! Transmission over distance!
Which means that an actuator can be quite a long way away from where
you are controlling it. That is why let us agree that it is mandatory to check if the "invisible" machine's movement, you are about to start, is safe to be made.
I guess with the outriggers, one might as well say: "Watch where you step!!!"
