Winch efficiency: line speed, amperage, and heat factor

[I Leak Oil]

I'm willing to bet that most situations require less than 10 feet of pull. This isn't enough to generate much concern with power usage or heat. Heat is often a factor that is brought up in electric winch discussions or synthetic line. In real world use I would bet it is rarely an authentic issue.

 

[Metcalf]

I'm willing to bet that most situations require less than 10 feet of pull. This isn't enough to generate much concern with power usage or heat. Heat is often a factor that is brought up in electric winch discussions or synthetic line. In real world use I would bet it is rarely an authentic issue.

I will note I have witnessed heat damage to synthetic line being an issue, it was from excessive 'power-out' use on the winch. Melted the 1st layer of the line to the drum.

 

[comptiger5000]

I wonder at what point it's worth just running a hydro winch and not having to worry about power consumption (or duty cycle, provided you have adequate fluid cooling)?

 

[Metcalf]

I wonder at what point it's worth just running a hydro winch and not having to worry about power consumption (or duty cycle, provided you have adequate fluid cooling)?

If you have to have a number on the door and wear a helmet.....

Even then, I would likely go with a PTO driven center mounted system vs a hydraulic unit.

 

[RoyJ]

I would be interested to see how force most recoveries require in general.

Years back, I remember seeing an article on some averages from a load cell ( Bill Burke?). I think the number was something like 3000lbs (average) for most vehicle recovery situations. While I am not suggesting that everyone buy a small winch, it does make me wonder how much pull force you really use in a typical recovery situation. Generally we are not lifting the vehicle up off the ground, we are only assisting the vehicle or redirecting it.

I'd be highly interested in this as well. I'll look into a clamp meter in my future setup.

The only info I found online is from Scott's winch test, and the amperage was surprisingly low:

http://expeditionportal.com/tug-of-war-the-ultimate-12v-winch-test/

For the uphill Unimog test, the 8274 drew an average of 204 amps, and the Endurance 12 only 125 amps! According to Warn's charts, these roughly equates to 2500 lbs for the 8274, and 2000 lbs for the Endurance. Let's split the diff and call it average 2250 lbs.

I think the most punishing test would be a long recovery of a vehicle axle or frame deep in mud. The stiction of mud can generate resistance greater than 100% of vehicle weight, and the recovery distances can be long. This is where a snatch block solution can help by drastically lowering your electrical drain, and increase motor duty cycle at the same time.

 

[RoyJ]

I wonder at what point it's worth just running a hydro winch and not having to worry about power consumption (or duty cycle, provided you have adequate fluid cooling)?

I looked at a few hydro setups on Pirate and Mud, and most agree if you want any form of performance, a separate pump is needed (over stock PS pump). This is especially true for my 100 series, as they're not known for strong pumps.

Looking at the Warn 9000 hydro unit:

http://www.warn.com/industrial/winches/9RT.shtml

To achieve full performance, you'll need a minimum of 10 gpm at 2000 psi, and 15 gpm for max performance. This is a serious pump, and need a hefty drive system (PTO or multi-ribbed serpentine / V belt) to maintain full power. It would also required a decent size reservoir and inlet pipe to avoid cavitation at full flow.

Doing so, you'll be rewarded with 20 - 30 ft/min of line speed at max line pull (9000 lbs). This is 3 times more powerful than even the 8274.

For myself, it's hard to justify all the expense, weight, complexity, unless I'm doing full time recovery service. If money was no subject I'd get one though, there's an industrial Warn XL20 for only $1k Cdn ($750 USD) locally in fairly good shape, that's 1/5th the price of new. The 400+ lbs weight for the winch and rope alone is a problem...

 

[Metcalf]

I think the most punishing test would be a long recovery of a vehicle axle or frame deep in mud. The stiction of mud can generate resistance greater than 100% of vehicle weight, and the recovery distances can be long. This is where a snatch block solution can help by drastically lowering your electrical drain, and increase motor duty cycle at the same time.

I think the load/speed info is good to have and to keep in the back of your head, but I think your over thinking it.
The chances of needing to....and being able to rig....multiple back to back double line pulls is pretty slim.
Do we really need to recover that fast?

What is faster? Rigging multiple double line pulls to separate anchor points or just taking a break in the middle of a single line pull to let the vehicle system charge?
I guess we could come up with a rough idea how long it would take to re-rig vs how long it would take to let the vehicle system charge back up...
We could also factor in some statistic on how likely you are to sustain a personal mechanical injury while rigging a winch point.
I know when I have to use the winch, rigging a winch point is usually HARD work trudging through hip deep snow or mud.

Mud like that falls into the recovery preparation category in my opinion. You're likely better off to get out the shovel and help the winch by clearing some of the resistance. The other option is that you might just be better off going back the way you came in. Depending on how your winch is setup this may lead to headaches. Being able to winch backwards is always an interesting question. If you have enough room to spin the vehicle you can sometimes use the winch, if enough anchor points are available, to spin the vehicle around to return to firm ground.

Always lots to think about....

 

[toymaster]

.... You're likely better off to get out the shovel and help the winch by clearing some of the resistance. .....Being able to winch backwards is always an interesting question.....

I'm in agreement, having the right gear and knowing how to use it goes a long way to self-recovery. I've spent many hours trying to think of exactly what to carry in the jeep. I have a 2 door jeep so every square inch of space is a premium.

As the OP suggests having a large winch and snatch block is a step in the right direction. What stays on and in the jeep are two winches with synthetic rope (125' up front and 100' out back), 30' recovery strap, 1 tree saver, 1 snatch block, 4 clevises that will tie it all together, and a folding shovel for material removal or burying an anchor (or used for when nature calls). Taking time to choose the right gear is essential, which is what this thread is about....

 

[RoyJ]

I think the load/speed info is good to have and to keep in the back of your head, but I think your over thinking it.
The chances of needing to....and being able to rig....multiple back to back double line pulls is pretty slim.
Do we really need to recover that fast?

What is faster? Rigging multiple double line pulls to separate anchor points or just taking a break in the middle of a single line pull to let the vehicle system charge?

Good points... but again, my method is not intended as a winching bible. I realize there are instances where it won't be practical. What I am proposing, is a solution to save power and wear and tear when conditions DO allow.

If rigging up a snatch block is too time consuming, then chances are it's a competition, and that's not the intended audience. If you have a $100k rock buggy, the last thing you care about is an extra battery or two. There's a guy in New Zealand doing just that - two 7.8hp motors on his 8274, two 8D batteries, and triple alternators. Most of us aren't in that category.

So, where I think my setup would benefit - casual overlanding, being the only winch truck, and helping 4 other trucks up a muddy slope. Long steady pulls, where running 400 amps would kill the batteries. Or long / multi retrievals in mud, where at least in my experience, digging takes 5 times longer than rigging a double line.

For conditions that absolutely won't allow double line, and one must do multiple or sustained pulls on a stock electrical system, then I recommend getting the lowest geared winch possible, essentially an "internal snatch block". My study shows a Zeon 12 or 16.5ti at 6k or 8k lbs is much more efficient than a XD9000 at 8k.

 

[RoyJ]

For those of us that are more visual, I find this graph basically summarizes what I'm illustrating at a high level:



The x-axis is torque, which is linear to a winch's line pull. It starts at freewheel, and ends at stall. For safety, most manufacturers rate their max pull well before actual motor stall.

The two curves I'm focusing on is power (orange), and efficiency (green).

Unless you're hypermiling a winch, we probably don't want be at peak efficiency, as it'll be too slow. Throughout my study, I'm trying to pinpoint the max power of each Warn winch model, so we can do the most amount of work, and still be decent on power usage.

What I'm trying to avoid is the right half of the scale, where the line pull numbers look impressive, but current (power consumption) goes through the roof and you're not doing any useful work. This is the ComeUp Blazer at 8000 lbs, where it's more like a space heater than winch.

Every winch behaves differently. The Blazer, due to tall gearing, appears to put out max power at 2000 lbs line pull. The 8274, running the 4.6hp Bosch, puts out max power at 4000 lbs line pull. The 9.5XP, with a monster 6hp Bosch, puts out max power at 8000 lbs.

If you want the most speedy recovery, then aim for those spots by using combinations of snatch blocks. If you need to conserve power, then aim a little lower, as we know max efficiency occurs. AGAIN, WHEN CONDITIONS ALLOW. Don't do this if it's unsafe, reach is too long, you're too tired, you're in a hurry, you got an 8000amp alternator, etc...

 

[Metcalf]

My study shows a Zeon 12 or 16.5ti at 6k or 8k lbs is much more efficient than a XD9000 at 8k.

I would be concerned about fitting a larger winch, especially the 16.5ti on the front of smaller vehicles. On a full size truck it should be ok.
If I remember right, the heavier winches are suppose to be mounted foot forward which may complicate things.

The Zeon 12 seems reasonable at 98lbs with steel cable. ( I remember being impressed with them at UA this year )
The 16.5ti is 140lbs!

I did note that the specs between the Zeon 12 and 12S are different?
The steel cable 12 is listed at 216:1
The synthetic cable 12S is listed at 162:1. I am guessing typo?

I like your idea of a multi speed winch a few posts back.

 

[verdesardog]

I drove tow trucks for several years, the one I liked best had two PTO winches. It was a beast! then there were the hydraulic winches using PTO pumps, they were ok but not nearly as fast or powerful as the pto's. I have a 10500# mile marker hydraulic on my CTD. It is slow but oh so powerful, it can winch all day long with synth line. It does have two speeds so rewinding the line after a recovery is fast. It does use the power steering pump and works fine, I even still have steering and hydro boos brakes while winching. I will never have another electric winch on any vehicle I own.

 

[I Leak Oil]

It would be an interesting comparison to make these same graphs for some of the big 3 winch maker's products, older models and new along with some of the off brand stuff, comeup, engo, smittybilt, etc. Like a field of 9000 pound competitors. I wonder if some of the published specs might be massaged by moving some sort of safety factor. I've always heard that the 8274 is under rated but have never seen proof of it aside from it's obvious longevity.

 

[comptiger5000]

IIRC, the Mile Marker hydros (not as fast as that Warn except in the high speed / low pull line recovery mode) only need ~4 gpm and 1500 psi (and will work at reduced speed with less flow), which you can get by just replacing the stock PS pump with a beefed up unit and still only having to run 1 hydraulic system.

EDIT: Just did a little research. They have their 9k, 10.5k and 12k winches spec-ed as 3.5 gpm / 1500 psi. That's not too tough to meet, although those winches are a bit slow (5.5 - 6 fpm on the first wrap of the drum in low gear, doesn't look like speed is load dependent). So their standard hydro setups are a little slower than something like an 8274, but they'll pull that speed all day if you need them to. They also have a 9k "high speed" winch they suggest for tow trucks. Looks more like that Warn unit, as it needs ~15 gpm (at unspecified PSI), but will pull 9k at 26 fpm :Wow1:

Weight doesn't look too bad either, they say 100 - 110 lbs depending on which of those sizes you get, and that's with 100 feet of 3/8" cable on the drum. A little more research also indicates that if you run the bigger of the 2 solenoid setups with the Milemarkers (used on all except the 9k and 10.5k integrated solenoid versions) you can feed up to 6gpm and you'll get more speed.

 

[Metcalf]

If you want the most speedy recovery, then aim for those spots by using combinations of snatch blocks.

I wonder what would be the best way to know how much weight the recovery is going to take? It is hard to aim if you just don't know. I remember a vehicle recovery manual from the military that might have given some rough figures on how to calculate something. If the vehicle can help at all, I think the pull weights might be FAR lower than we are listing figures for. 1-3K in help might be the magic spot?