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>From David P. Hummel, Jr. > > In the on going debate over what winch to use, people have brought up the > fact that the engine on the vehicle must be running in order to use a > hydraulic winch. On the other hand some people have pointed out that you > need the engine to run for long pulls on an electric. > > Well, what's it take to stop a Hummer engine? I know they can turn on > extraordinary angle, submerge in water (is aspirated externally through a > snorkle), nose down in the mud, etc., etc..... > > BTW, with the electronic governor, I assume the battery terminals cannot > short under water. Can they? > > Dave Hummel > W.H.O. and counting...... > An interesting topic. Here are some of my thoughts, for what they are worth. To stop a Hummer engine (not counting mechanical failure), takes one of three things. Loss of fuel (not likely), loss of air (i.e., deep water), or loss of oil pressure (the fuel pump will not operate if the engine does not have oil pressure - this is a safety feature for a variety of reasons). The oil pan in the Hummer is baffled to help prevent oil starvation on severe angles. This helps, but you can still get enough of an angle to starve it. (If all the oil runs to one end or side of the oil pan, the oil pump pick-up tube cannot get oil to pump). Also, the baffling will only work for a short period of time. If you leave the engine at an angle long enough (probably less than a minute), it will starve the oil pump, and turn off the fuel pump. I don't know what the governor type has to do with batteries shorting out. Water is a poor conductor of electricty at low voltage. It would take quite a long time to drain a 12V battery by submerging it in water. A lot has been said about how long an electric winch can pull without the engine running. This is actually a little more complicated than just how long 'till the battery runs out. The amount of battery drain created by an electric winch depends upon how hard the winch is pulling. Even at full capacity of the winch, it will still take several minutes for the batteries to fail. The concern here is that at full capacity, most electric winches only pull about a foot or two per minute. In most situations, a full capacity pull is not required, regardless of whether the engine is runnung or not. Also, the Hummer alternator puts out a little over 100 amps maximum. This is not enough to run an electric winch at full capacity. (About 600 amps at full load.) Because of this, it is not possible to run the electric winch continuously at full capacity. You can completely drain the batteries even with the engine on. You will have to let the system "rest" from time to time. This allows the winch motor and wiring to cool, and the alternator to re-charge the batteries. It is possible to make electric motors that will pull that hard without overheating, but they are very large and quite expensive. And, since the vehicle electric system cannot operate it for too long anyway, what would be the point. Other information about electric vs. hydraulic winches: Pull effort has much more effect on line speed for electric winches than it does for hydraulic. At lower pull efforts (such as re-spooling the cable after use), the electric winch runs much faster. (Two speeds helps, but they make two-speed electric winches too.) Electric winches can be readily moved from the front of the truck to the rear. ("Readily" means that it is easy to hook up. The electric is much heavier than the hydraulic.) The extra lines and fittings for the hydraulic are tougher to install (to the rear) than the electric cables, and a little messy to use. There are reasons that you may not want a movable-mount type winch (of either type). For instance, how much side-pull will the winch mount withstand? Charles Piper posted recently that he was able to pull his Hummer a long distance (80 feet, if I remember correctly) with his electric winch. The motor was not running because of oil starvation of the engine. He could not have pulled it 80 feet straight up, or through deep mud, but that was not where he was stuck. (The Hummer was on it's side, not the wheels, BTW.) My overall analysis goes something like this:
If you get stuck, and your engine is running, either winch will probably get you out. The more stuck you are, the faster the hydraulic works compared to the electric. If you have to pull a long way, or very hard, the hydraulic will probably get you out sooner.
If you get stuck, and your engine is not running, the electric will work much
faster than the hydraulic.
If you have a failure in the hydraulic system, you could lose your power
steering and brakes. (Carry extra fluid.)
If you have a failure in the electric system, you could drain your batteries,
and possibly start a fire (brush, not vehicle fire).
If I used the winch a lot, I would get the hydraulic. It will last longer
under heavy usage. (Mostly because it does not heat up very much.) It can
also be used without having to "rest" the system. This is refered to as
"continuous duty" (vs. "intermitant duty"). (All 12V electric winches that I
have seen are intermitant duty only. Read the book and see.)
A combination of prudence, and having multiple (preferably winch equiped)
vehicles is the best combination of all.
Here is a little more information about my off-road experiences. I have
averaged about 20 trips per year for the last 15 years. (Three in the Hummer,
the rest in my Jeeps.) In all that time, I have probably averaged 2 or
3 "winchings" per year. Most of those (about 3/4) were winching someone or
something else rather than pulling myself. (Your mileage may vary...)
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Technical note: Pulleys and line speed.
There is a lot of information about using a pulley to double the pull, while
halving the effort. The common explanation is not entirely accurate, however.
The speed of an electric motor is (mostly) governed by two factors: the power
available, and the work being done.
What this means is this: Lets assume you are making a fairly heavy pull (say
about 5 feet per minute) with a single line. If you double the line (using a
pulley), the winch will still pull the truck at about 5 feet per minute. The
difference is that the winch motor will be running at about twice the speed.
This is a GOOD thing, however. When the motor is running at a higher speed,
it is heating up less, and therefore can be run longer before resting.
Another side effect of using a pulley is that you will pull more cable off of
the winch drum. The winch pulls much harder with fewer layers of cable on the
drum. (Electric or hydraulic).
Hydraulic motor speeds are also effected by effort, but not as much as are the
electrics. (Please note: I am not stating that this phenomenon makes either
type better than the other!)
Just my (long winded) $.02 worth...
Dave Breggin
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