|4x4Wire.com Reviews Master Pull's Synthetic-fiber UHMWPE Winch Rope||Short Cuts|
By: Randy Burleson - 9/2000
Testing on the Winch Hill
|Master Pull's UHMWPE Winch Rope - vivid colors courtesy of the UV-protective coating.|
We used this purple rope at CA4WDC's 34th Annual Sierra Trek, where 4x4Wire staffed Winch Hill Four. For those that have never run Trek's Fordyce Trail, Winch Hill Four is a bouldery ascent up a narrow slot through vegetation and rocks. The trail climbs three sets of ledges, the last with polished tree roots. With a bit of spotting, most rigs made it through this section with little difficulty. Still, with nearly 150 rigs on the trail on Saturday, we ended up spooling out cable for five to ten rigs.
Earlier when I was still running wire rope, I used my winch to yank my front axle back into alignment when I replaced a broken spring centering pin. The winch worked well to center the axle, but bent the frame of my roller fairlead and broke a bolt on the passenger side roller. I didn't winch much further, but that few inches of wire rope scraped up the side of the fairlead pretty well... and I subsequently forgot about it ....
|Wrapped cross-spool the wrong way...|
|...this rope is seriously deformed...|
|...yet when the tension is released and then reapplied....|
|...the UHMWPE rope returns to its normal weave.|
The next time I used my winch was to pull vehicles up Winch Hill Four. The most well-anchored position required an angled pull. As luck would have it, that pull took the rope across the scraped and bent fairlead. I didn't notice this until I'd finished two lengthy pulls. I snapped a picture of the fairlead after the rope dragged across it. The purple rope showed slight fuzziness, but most surprising was the metal, which was actually polished smooth, and had a slight indentation. The tensioned rope actually eroded the metal! We used that rope repeatedly for the rest of the day, dragging it across the stepped ledges and tree roots. The rope did get noticeably dirtier, but showed no wear. Abrasion is nasty on any rope -- even wire rope. I beat on this purple rope and drug it hard across sharp rock and metal edges -- it holds up well.
|Here's my bent roller fairlead. Look close to see where the wire rope tore up the metal, and a polished section in the middle of that roughness where the Master Pull Plasma rope polished it back flat.|
I have always been pretty careful to keep a pretty straight wrap on my steel cable, because it piles up very easily on one end of the spool. Especially when I loaded extra rope on the spool, a bad wind could easily result in smashed cable. This is one of the real features of the Master Pull rope: you can cross-wind this rope over itself, and smash it completely out of shape with no damage. On Winch Hill Four, with the long, off-to-the-side pull we used, the rope rapidly piled up at one end of the spool. When this happened, we'd just stop, have the winched vehicle set his brakes, then release a few feet and wind a few wraps of rope toward the center of the spool. This would wind the cable tightly across itself, sometimes at nearly 90 degrees. The result was a mangled-looking rope, but when you released the load, the rope returned to its normal braid, with no damage. Especially on this long off-center pull, this was great!
With more flexible spooling, I was able to pack an extra 20 feet of rope onto my winch, and could probably have fit another 30 beyond that. Master Pull's 30-foot extension rope added even more reach, allowing us to reach all the way to the base of Winch Hill Four. Regardless of what kind of cable you use, winching on an additional layer of cable provides less leverage, and less pulling power. Longer cables are better, though, because is easier to double-up the rope for shorter pulls than to work with a short cable.
The brightly-colored purple rope and screaming yellow safety hook attracted attention wherever we went at Sierra Trek. I tossed the bagged extension to countless curious folks, and few could believe that this lightweight rope was strong enough for vehicle recovery. The snazzy black bag hides 30 feet of rope, with a spliced eye at either end. The whole package (bag, rope, and thimbles!) weighs less than two pounds!
Plasma rope is made from Ultra High Molecular Weight Polyethylene Fiber (UHMWPE). This synthetic fiber has been used for years by ocean-going tugs to replace thicker-than-your-wrist mile-long cables and chains. UHMWPE's lightweight characteristics make a huge difference in these massive dimensions, but its best quality is its minimal elongation. With only 0.44 to 0.79 percent stretch per length and well less than a tenth the weight of steel cable, if UHMWPE breaks, there's no whiplash; it drops harmlessly to the ground. Wire rope can whiplash and tear through just about anything in its path.
|Fiber Core Wire Rope||Independent Wire Rope Core (IWRC)||Master Pull UHMWPE|
|N.S., or Nominal Strength, listed above, is shown in number of tons. One ton equals 2000 pounds.|
|The wire rope statistics are drawn from the Wire Rope Corporation of America (WRCA) website at: www.wrca.com.
UHMWPE strength figures are from Master Pull.
Master Pull reports that Plasma rope is significantly stronger than similarly-thick wire cable (see table). The winch ropes and extensions are also available in 3 colors in charcoal gray, deep purple, and blue colors, in 5/16, 3/8, and 7/16-inch thicknesses.
UHMWPE rope can be folded in half on itself with no damage. Wire rope has a minimum radius in which it can be bent but not be damaged.
|The latching safety hook is made from quenched and tempered grade 80 alloy steel.|
The Safety Hook
The safety hook itself is worthy of note, and not just because of the screaming-zonker-yellow paint. Open hooks have been outlawed in some industries, but this hook's spring-loaded safety latch locks the hook shut under load. With the rope attached to the opposed pivot, tensioning the rope holds the hook closed. Straps and chains simply can't slip out when the rope is loaded, and the latch prevents slippage even when the rope is unloaded. The release trigger also keeps the hook open for easy loading.
With a safe working load limit (WLL) ratios of 4:1, these hooks are serious overkill. Luckily four-wheelers groove on that. Three hooks are offered, with strengths of 17,000lbs, 28,400lbs, and 48,000lbs.
|You can wrap Plasma rope sloppily; it won't pinch or deform like wire rope...|
|...and Plasma rope is much easier to coil and handle.|
|Conventional wire rope handles like an angry steel snake, wanting to spring back into a slinky form, reminiscent of its spool shape.|
Spooling the Rope
When I got home after Sierra Trek, I respooled the rope. I ran it through my bare hand, established tension, and quickly completed a perfect wrap. Had I tried that with anything other than a brand new steel cable, I would have come away bleeding from the inevitable meathooks. I haven't encountered many cables that didn't have broken strands.
|Conventional wire rope in need of replacement. Keep your hand clear!|
I had concerns about the Master Pull rope's resistance to heat. The manufacturer states that the rope will withstand temperatures up to 150 degrees, but actually fails at 280-300 degrees. On extended hard pulls, a winch can generate significant heat. In one long 100' pull up Winch Hill Four, most of it hard, the winch generated a serious amount of heat, but the rope was fine. An even better trial was powering out the full 120' during testing. Powering out my winch is slow, and it generates a substantial amount of heat, because the motor has to reverse against the automatically engaged drum brake inside the winch spool. The winch got too hot to touch with a bare hand, but the rope was still OK. Both Warn and Ramsey recommend against using their winches for lowering loads for long distances.
This winch cable is great for my uses, but for some folks, it might not be the best. If you 'wheel exclusively in junkyards amidst sharp, jagged chunks of steel, a wire rope might last a bit longer... During continuous, repeated immersion in mud, UHMWPE rope will soak up abrasive particles that may hasten the eventual breakdown of the fibers. That said, I've tested this rope in granite dust, dragging it across ledges, boulders, and roots -- and even a sharp metal edge -- and though my Plasma rope is dirty, it shows only the slightest signs of wear. Any fiber breakdown looks to be quite a long time off.
|UHMWPE Rope at Sierra Trek.|
This rope is a great addition to my recovery gear. Only a fraction of the weight of steel cable, this UHMWPE rope is easy to store, carry, and deploy and it is safer to use than steel cable. UHMWPE may sacrifice something in ultimate durability and longevity, but the gains over traditional steel rope are remarkable. My wife is even willing to pull cable now, something that NEVER happened with wire rope.
There's no way around it, though, this easy-to-handle American-made fiber is more expensive than wire rope. You just have to make your own call whether the benefits outweigh the cost. For me, the safety is a nice value-add, but I'll be running it primarily because I can use it without tearing up my hands on steel wire's kinks, curls, and wire splinters.