Mountain Safety Research Longhorn |
Mountain Safety Research Eighthorn |
Douglas Co. Mountain Rescue Longhorn |
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I acquired this descender from Pathfinder Sports in Tuscon, Arizona in 1979.
The M.S.R. Longhorn is made from two pieces of half-inch (13 mm.) aluminum rod. The first piece is approximately 430 mm. long and bent into the shape of an inverted Greek letter omega. The second piece is about 40 mm. long and welded somewhat off-center inside the loop of the omega. The ends of the first rod are well-rounded.
The M.S.R. Longhorn is anodized black. The center rod is stamped with "MSR" on one side and "PAT APP #782437" on the other
The
Longhorn was invented as a replacement for the figure
eight descender. It provides about the same amount of friction
as the typical eight, but can be
rigged and derigged in the standard configuration without unclipping
the device from one's seat harness. This may help reduce the risk
of dropping the device down a drop, but my experience shows that
some people will manage to drop things no matter how well tied
in they are.
The Longhorn has many of the same advantages and disadvantages as the eights. On the positive side, the Longhorn is light-weight and simple. On the other hand, it is too large for a constant friction device, it has a low heat capacity, it tends to spin the rappeller, and there is no way to continuously vary friction on rappel. Since the Longhorn is a one-piece device, the entire device must be replaced when the rope grooves wear too deeply. Some people have managed to accidentally lock off a figure eight; it is nearly impossible to do the same thing with a Longhorn.
There are two basic methods used to rig a Longhorn The original method, shown in the top figure, is perhaps the most obvious. The bottom figure shows the improved method, which introduces less spin then the upper method. Both figures are shown from the rappeller's viewpoint, and assume the right hand is the braking hand.
The Longhorn is bulkier than most eights,
and offers no real advantage, so I seldom use mine.
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I acquired this descender from C. J. Rushkin at OTR-88.
This is a steel copy of the M.S.R. Longhorn described below. It is made from two pieces of half-inch steel rod. The first piece is approximately 420 mm. long and bent into the shape of an inverted Greek letter omega. The second piece is about 40 mm. long and welded inside the loop of the omega. The welds have been ground smooth, and the ends of the first rod are beveled.
The Douglass County Mountain Rescue longhorn is painted black. There are no markings on the device.
The Douglass County Mountain Rescue longhorn is almost identical in size and shape to the original M.S.R. Longhorn, but the steel construction makes it significantly heavier. It is far more wear resistant than the aluminum M.S.R., except the paint wears of easily. The weld does not bother me as much as the M.S.R. weld does, because properly performed welds in steel retain the full strength of the original material.
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I acquired this descender from Pathfinder Sports in 1978. I had tried to obtain the device directly from Mountain Safety Research, but apparently it was only in production for a very limited time.
The Eighthorn is made from a single 60 mm. piece of 11 mm. aluminum rod bent into the shape of a figure eight with two horns at the base. There is a substantial weld in the waist area that serves to keep the rope from jamming between the two rod segments in this area. This weld is built up to contribute significantly to the final shape of the device in the waist area. Another weld at the bottom keeps the attachment eye closed.
The Eighthorn can be used as either a longhorn or a figure eight. When used as a longhorn, it behaves almost identically to the M.S.R. Longhorn. When used as an eight, it behaves like any other eight except the horns get in the way. I view the Eighthorn as a novelty item for people who can't make decisions because it does not offer any advantage over either the Longhorn or the eight.
The manufacturing quality control on my Eighthorn was acceptable, but not outstanding. The ends of the horns are not rounded (they have an insignificant bevel instead). The welds on my Eighthorn are sloppy, but there are no pits or sharp edges. I repeat my objections to welds in aluminum; however, there is sufficient undisturbed base metal in the Eighthorn that I am not too concerned about strength loss from the welds.
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©2007, Gary D. Storrick