I acquired my heightec-PMI Powerlock from On Rope 1 in 2008.
My Powerlock is 162 mm. tall, 184 mm. wide, 30 mm. thick, and weighs 737 g.
The Powerlock consists of a number of parts mounted on a roughly decagonal 2.9 mm. thick stainless steel back plate. A swinging front plate of the same material covers the active parts. The front plate has two curved cutouts to clear pins to be described later, and some additional cutouts of less obvious purpose. A 17 x 17 mm. subtriangular hole is punched in the lower corner of each plate, and the lower portion of the plates are bent slightly inward. These holes align to form the main attachment point.
The active parts are an upper bollard assembly, a fixed pin, a lower bollard assembly on a pivoting handle, and a fixed brake block.
The upper bollard is a turned aluminum block that is 38 mm. in diameter and 17.5 mm. thick. The center 15 mm. of the rim has a shallow U-shaped groove that reduces the central diameter to 35 mm. The bollard sits between two washers on a mushroom head shoulder pin riveted to the back plate. The reduced section under the head fits into a curved slot cut in the front plate. The bollard mounting is eccentric (about 8.8 mm. off-center), and a spring forces the bollard to rotate counter-clockwise, toward the fixed pin. The fixed pin is 11.9 mm. in diameter and 18 mm. high, and is riveted to the back plate. In use, the rope runs between the upper bollard and the fixed pin. A small tab stamped in the back plate limits how far the upper bollard can open.
The brake block is a stainless steel rectangular block riveted to the back plate. A roll pin prevents block rotation.
The lower bollard is a stainless steel casting that is fixed to the handle plate. The casting is a skeletonized D-shape, with the flat surface on the right side. When the user releases the handle, the flat side of the D moves away from the brake block, wedging the rope against the underside of the block. The handle assembly is made from an irregular piece of 2.9 mm. thick stainless steel. The handle itself has a soft plastic grip. Near the grip is a guide tab folded upwards, while the opposite end has a 13 mm. high, 7.9 mm. diameter pin riveted to it. This pin squeezes the rope against the upper surface of the brake block when the user pulls the handle downward. The handle and front plate pivot independently on a common axle riveted to the back plate.
The front of the Powerlock is etched with "CE 0120," "prEN 12841 A/B/C," a bulls eye icon, "Ø11," a rigging diagram for something, a book icon with the letter "i," "heightec PMI," and "Powerlock." The rear is stamped "MAX200KG."
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Warning:
the rigging diagram etched on the front of the Powerlock does not show the active parts in their correct relative positions, nor does it show the rope running correctly through the device. Ignore the diagram on the device and follow the one in the instructions. |
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Even following the instructions, the Powerlock is awkward to rig. The cover plate is shaped so that there is no position where the rope easily slips into place; one has to fight to get the rope in place. Once rigged, the Powerlock is rather sensitive to rope diameter. I found that it would not slide on my 11 mm. ropes, even though this is the only recommended size. I needed to use thinner ropes to avoid having both locking mechanisms engaged simultaneously.
The instructions say that the Powerlock is also approved for "ascent of a rope," but that is so awkward that no rational person would choose it as their preferred ascender.
Although I find this device interesting from a collector's perspective, it is large, heavy, complex, and not very user-friendly. It has all the disadvantages of autostop descenders (see my 1995 internet post on rappel safeties for more information). I can not recommend it for caving or climbing use.