heightec Powerlock D32	heightec Powerlock D321	heightec–PMI Powerlock

Overview

Heightec once marked some of their products with the "heightec-PMI" brand for sale by PMI in the U.S.A.

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heightec Powerlock D32
(#3112)

Front View	Rear View	Side View

Front View: Open for Rigging	Rear View: Open for Rigging

Technical Details

I acquired my heightec D32 Powerlock from Janine Campanile in 2021. Its markings suggest that it was made on June 21, 2011.

My heightec D32 Powerlock is 162 mm. tall, 184 mm. wide, 30 mm. thick, and weighs 732 g.

The D32 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," "¤Ø11," a rigging diagram for something, a book-with-an-"i" icon," "heightec," "Powerlock," "D32," "www.heightec.com," and "210611 439.

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.

Comments

The heightec Powerlock D32 is the same device as the heightec-PMI Powerlock.

Even following the instructions, the D32 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.

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 cannot recommend it for caving or climbing use.

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heightec Powerlock D321
(#3134)

Front View	Rear View	Side View

Front View: Open for Rigging	Rear View: Open for Rigging

Technical Details

I acquired my heightec Powerlock D321 from heightec in 2022.

My heightec Powerlock D321 is 206 mm. tall, 175 mm. wide, 32 mm. thick, and weighs 519 g.

The D321 consists of a number of parts mounted on a 4.0 mm. thick anodized aluminum alloy back plate. A 2.9 mm swinging front plate of the same material covers the active parts. The front plate has two curved cutouts to clear notched anvils to be described later, and some additional cutouts of less obvious purpose. A 17 x 25 mm. oval hole is punched in the lower end of the fixed plate and a similar-size hook is cut into the swinging plate. The lower portion of the plates are bent slightly inward. The holes align to form the main attachment point. The upper portion of the hook is covered by a plastic gate. The gate pivots on a steel rivet, and a spring set in a deep slot closes the gate. With the gate closed, the opening is 24 mm high.

The active parts are an upper bollard assembly, a lower bollard assembly on a pivoting handle, and two fixed anvils.

The upper bollard is a round, skeletonized stainless steel casting. It is 36.5 mm. in diameter with a slight 15.3 mm. wide U-groove that reduces the internal diameter to 4.1 mm. The bollard is eccentrically mounted on a rivet through the side plate, and can rotate counter-clockwise toward a cast steel anvil riveted to the lower left of the bollard. The head of this rivet extends outside the pivoting plate, and a circumferential groove in the head fits into the upper curved slot in the pivoting plate. A pin extension on the rear of the bollard fits into a curved slot in the fixed plate, limiting the bollards motion in both directions. A strong spring forces the bollard counter-clockwise, toward the anvil.

The lower bollard is part of an autostop assembly. It is a stainless steel casting fastened to a handle made from 2.9 mm. aluminum. The lower surface of this bollard has an 12.3 mm. wide, 3.5 mm. deep U-shaped rope groove. The right surface is flat. A 26.8 mm. tall cast stainless steel anvil is riveted to the rear plate opposite this flat surface. This anvil has a notch near the top that engages one of the slots in the pivoting plate. The handle and front plate pivot on a rivet attached to the fixed side plate side. The handle has a "rubbery" plastic cover for comfort. Friction from the main rope’s passage tends to turn the lower bollard and force the flat face towards the anvil, thus locking the rope and ideally arresting the descent. The rappeller uses the handle to keep the autostop feature disengaged. An extension to the handle has a cast steel friction block riveted to it. When the handle is squeezed too far, this block forces the rope against the second anvil.

The front of the D321 is printed with "D321," "Powerlock," "Rescue Descender," the heightec logo, "heightec," "Patented," "EN1891 (A)," "•Ø," "11 mm," "Max 200 kg," a book-with-an-"i" icon, a human icon, "↑," a rigging illustration,"UKCA," "0120," "CE0598," "EN12841:2006 type C," "151121," and a rectangle containing "EN341:1993 type B" and "Max descent height 100 m." It is stamped with "C9990." The side of the larger anvil has a cast illustration of light going through a prism. The friction block has a cast heightec logo.

Comments

This Powerlock shares several parts with the contemporaneous heightec Prism and heightec Quadras. The former explains the curious prism logo cast into the larger anvil. The Powerlock is the only one of the three that has a spring-loaded upper bollard.

As much as I dislike auto-stop descenders (for a variety of reasons), I dislike double-stop descenders even more. It is very difficult to design a simple double-stop descender that is not strongly affected by rope diameter. This may be why the Powerlock D321 is rated for 11 mm. ropes only. Since EN1981 requires specifying rope diameter to the nearest 0.1 mm, this is an exceptionally narrow range (at least on legal paper). My tests using PMI Pit rope, a very common (and my favorite) American caving rope were not favorable. To be fair, I'll mention that my test rope was not an EN1981 rope (that standard is not used or recognized in the USA), but any descender used for American caving should function well on that rope, among others.

My first observation was that the D321 was exceptionally difficult to rig, perhaps more so than any other descender that I have ever tried (and I've tried more than most cavers). The cover plate is shaped so that there is no position where the rope easily slips into place, and so one has to fight to get the rope in place. The spring on the upper bollard is far too strong, and pulling the bollard away from the small anvil to get the rope into place requires strong fingers. The spring is undesirable and unnecessary (neither the heightec Prism nor the heightec Quadra have a spring here).

When I brought the rope back and tried to get it under the friction block, there was no room to bend the rope 90° and slip it under the block. Time to start over. I was eventually able to fight the rope into place, starting from the trailing line end, but it was a struggle. I repeated the task with a limp 11 mm. caving rope. I had similar problems, and although easier, it was still a fight.

To quantify the problem, I put an 11 mm. steel rod between the lower bollard and large anvil, and then measured the clearance between the friction block and the large anvil: 5 mm. I also measured the clearance between the lip on the friction block that the rope had to pass under and the rod: 5 mm. No wonder it was difficult, bending an 11 mm. caving rope into a sharp 90° bend and sliding it into a 5 mm. space is not going to work very well.

I found that the D321 would not allow me to descend any of my realistic 11 mm. caving ropes. For the record, I am 1.9 m. tall and weigh 850 N - not light by any reasonable standard.

Although I find this device interesting from a collector’s perspective, it is large, heavy, complex, and not caver-friendly. It is extremely difficult to rig, and gives far too much friction for a normal caver, and has a double-stop feature that is effectively in the "permanent stop" position when used on common 11 mm. caving ropes. I cannot recommend it for caving or climbing use, where it earns a lemon award: .

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heightec-PMI Powerlock
(#1168)

Front View	Rear View	Side View

Front View: Open for Rigging	Rear View: Open for Rigging

Technical Details

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," "1Ø11," a rigging diagram for something, a book-with-an-"i" icon," "heightec PMI," and "Powerlock." The rear is stamped "MAX200KG."

Warning: the rigging diagram etched on the front of the Powerlock does not show all 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.

Comments

The heightec-PMI Powerlock is a rebranded heightec Powerlock D32.

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.

In early 2021, I discovered that the adhesive that held the red handle onto my Powerlock had deteriorated and released a clear, sticky, oily liquid that flowed over the rest of the device, creating a small mess. The device had never been exposed to unusual temperatures.

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 cannot recommend it for caving or climbing use.

[ Top | heightec D32 | heightec D321 | heightec –PMI ]