WARN Winch Performance Specifications: Pulling Capacity by Layer
By Steve Schoenfelder
WARN Industries
WARN lists winch performance specifications on each winch page (you can find the specs for the ZEON 8 here), this includes winch line speed and amp draw. This is good information so you can compare the performance of different winch models. We also show a column that says Pull by Layer. This column lists the pulling capacity of the winch with one layer of rope on the drum, two layers of rope, three layers, etc.
WARN winches are rated to pull their maximum load when spooling the first layer of rope onto the winch drum. So an 8,000 lb. capacity winch will only pull 8,000 lbs. when you are spooling the rope onto the first layer.
Now, you're asking yourself — I thought my 8,000 lb. winch would always pull 8,000 lbs.? Let me explain the pull by layer concept. As rope is stacked up onto the drum, you are effectively changing the gear ratio of the winch by increasing the diameter of the winch drum. To help explain this, think about that old 15-speed bike you had back in the day. It had 3 driving sprockets in the front at the pedals. When the chain was on the smallest sprocket, you had the most power and could climb steep hills — this is the same as spooling cable onto the 1st layer of your winch drum. When you moved the chain to the middle sprocket, you had less power but more speed. On the largest sprocket, you had the least power but the most speed.
When you look at the ZEON-8 Pull by Layer column (on the ZEON 8 page, in the 12V DC Performance Specs chart) it shows:
| Layer 1 | 8,000 lbs. |
| Layer 2 | 6,777 lbs. |
| Layer 3 | 5,878 lbs. |
| Layer 4 | 5,189 lbs. |
| That's a loss of about 15% capacity per layer. | |
You can view the ZEON 8 Performance Chart for full details.
So what does this mean the next time you need to pull yourself up a hill or out of the mud? Pull as much cable off the drum as possible so your winch is pulling as close to its maximum capacity as possible. (Remember to always leave a minimum of 5 wraps on the drum with wire rope, and 10 wraps with synthetic rope.)
If your only anchor tree is 20 ft. away and you have 125 ft. of rope on your drum, I would automatically use a snatch block. This does two things: it gets more rope off the drum, and it doubles the winch's capacity, putting less load on the winch motor. Less load on the motor means less amp draw, less heat buildup, longer run time, and less load on the battery and alternator. That's a win-win all the way around!
Take a look at our Basic Guide to Winching Techniques. The Winching Techniques Guide can be downloaded for later reference, and it's a great how-to on the operation of an electric winch and all the accessories needed to use your winch safely and effectively.