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Version A
Version B
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| Version A | Version B |
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| Front View | Rear View | Side View |
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| Front View: Open for Rigging | Rear View: Open for Rigging |
I acquired Version A used from Ron Erickson in 2007.
Version A is identical to Version B except Version A does not have the spring-loaded pin with the knurled knob, and the bollards are not anodized.
The inner block has the serial number 007, corresponding to my secret agent status.
Although I acquired Version B long before Version A, it seemed reasonable to assign Version A to the simpler one of the two. The safety pin on Version B is not needed; I prefer the simplicity of Version A.
[ Top | Version A | Return to PolyBollards ]
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| Front View | Rear View | Side View |
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| Front View: Open for Rigging | Rear View: Open for Rigging |
I acquired my Alp from Troll USA in September 1999.
George Rex ran Troll USA and licensed the Troll Allp design. The following description follows the one given for the Troll Allp. I use the same description, with the common text in gray and the changes in normal text.
The Alp consists of three bollards, mounted between two side plates that pivot on a fourth attachment post. An adjustment screw assembly helps vary the friction in the device.
Each side plate is a roughly pentagonal piece of red anodized 1/8-in (3.3 mm.) 7075-T6 aluminum. The plates are 132 mm. high with a curved top. The top half of each plate is 60 mm. wide at the top, increases to 62 mm about 58 mm. down, then tapers to join a 22 mm. diameter circular arc at the bottom. The side plates are attached to a 16 mm. diameter 12L14 steel attachment post at the center of the bottom circular arc. The front plate is tightly bolted to the post, while the rear plate is loosely bolted. A spring acts to close the rear plate. The top and bottom rope bollards are bolted to the front plate, while the center bollard is bolted to the rear plate. The bollards do not rotate, but there are no visible pins preventing the rotation. All bolts are hex socket round-head bolts.
The bollards are also made of 7075-T6 aluminum, anodized black. Each rope bollard has a groove that fits into a corresponding notch in the opposite plate. The bollards are 16 mm. wide, measured from between the insides of the side plates. The top bollard diameter is 26.5 mm. in the center, and widens to 28.2 mm. about 1 mm. from the side plate, then remains constant. The center bollard has similar dimensions, while the corresponding diameters for the lower bollard are 22 mm. and 24 mm., respectively. The three bollards are mounted 106.5 mm., 63.5 mm. and 43 mm. from the center of the pivot point. When the rope is inserted, this asymmetrical arrangement ensures that the rope is pinched between the center and bottom bollards only.
The front plate has a spring-loaded pin that engages a small slot in the rear plate. To open the Alp, the pin must be withdrawn by pulling on a knurled stainless steel knob on the front of the Alp.
The rear plate has a small aluminum block bolted to the upper left inside of the plate. A 10 mm. threaded rod (with about 7 left-hand threads per centimeter) passes through this plate and presses against the upper bollard. A cross piece is pinned to the other end of the rod, making it much like a wing nut. The sides of the cross piece are painted red and green.
The front plate has a rigging illustration and a stylizes word "ALLP" stamped into it. The inner aluminum block is stamped "587," which is probably a serial number (the instructions have "US0587-99" written on them in pen, indicating country, serial number and year).
The instructions state that the Alp was designed for 7/16-in
(11 mm.) to 1/2-in (13 mm.) low stretch nylon rope. I
haven't had the chance to thoroughly test the Alp, so I can't
say how it performs with different ropes and under various conditions
of mud and water. What I have tested is its performance on clean,
dry 11 mm. PMI pit rope, a rather stiff caving rope, on short
drops. In these limited tests it has performed very well. When
the rod is unscrewed, there is enough friction to hold me in place.
As the rod is tightened, the friction is gradually reduced. The
transition is slow enough that it is easy to maintain control
with the braking hand. The rod turns easily, without any sensation
of having to force it. This surprised me, I didn't expect it to
work so well.
Getting used to the left-hand thread took less effort than I expected. The Alp is designed for the traditional right-handed user who brakes with their right hand at the right hip. Although I'm right-handed, I prefer to brake left-handed, so I’d rather have a mirror-image version, although this hardly is significant enough to be worth worrying about.
One should understand that part of the friction is obtained by squeezing the rope between the center and bottom bollard. As one turns the rod counter-clockwise, it forces the rear plate in the direction that separates the center and lower bollard, reducing the rope squeezing action. The friction decreases accordingly. This process only continues until there is no more squeezing. After that, there is very little change in friction. This is rather obvious, because there is no large change in the snubbing angle once the bollards are separated. The practical effect is that if one starts a rappel with the rod screwed in and finds out that the friction is insufficient, it will take many turns before the friction is significantly increased. One should always start with the rod unscrewed as far as practicable for the conditions.
Except for the rod, the Alp has an almost ideal shape for packing. Its a shame that the rod can't fold away for packing. I'm nit-picking here, but its an idea someone might consider implementing.
The instruction sheet states that the Alp can be used as a "mechanical safety belay," but gives no details of what this means (i.e., does this mean it can be used as a rope grab or a climbing belay device?). It also states that it can be used as a secondary (emergency?) ascender. I wouldn't want to try this, not because it wouldn't work, but because it would be too much work compared to simpler options.
Please see the Troll Allp page for some history of the Allp variations.
…and HEY! TROLL USA! It should be the Allp with two "l"s
in the middle, like in Dave’s name.
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