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Promalp Bug
(Букашка Промальп)

Version A

Version B

Version A Version B
Version A Version B

Overview


Version A
(#470)

Front View Rear View Side View
Front View Rear View Side View

Technical Details

John Weinel brought this industrial descender back from the Russia in 1990.

Version A is 150 mm. tall, 116 mm. wide, 51 mm. thick, and weighs 517 g.

This descender appears to be made of three steel pieces welded together: the main plate, the riser, and the bollards. The back plate is 6 mm. thick. The upper slots are 70 mm. tall and have a maximum 19 mm. width. The lower slots are 35 mm. long and 12 mm. wide. The central hole is 12.7 mm. in diameter. The riser is made from 4.8 mm. plate. The bollard assembly is 28 mm. long and 25.9 mm. in diameter with an 18 mm. central hole.

There are no markings on this descender.

Comments

This descender is designed for double rope, but also works on single rope. Judging by the diameter of the bollards and the size of the slots, it was designed for 8 or 9 mm. rope, or possibly cable. The similar Krok Spider is intended for 8 to 12 mm. rope, so perhaps the limits are wider than they appear.

The device is rigged by bringing a bight through the back plate and over the bollard. There is nothing to keep the rope on the bollards; however, a carabiner can be clipped through the bollards to keep the user from entering disconnected free-fall if the rope should slide off. The large horns provide convenient tie-off points. The lower slots can be used with additional carabiners to increase the device’s friction. This will probably be necessary if one is rappelling on rope.


Version B
(#974)

Front View Rear View Side View
Front View Rear View Side View

Technical Details

I acquired this Version From Ural Sport in 2004, when Serguei Khramtsov made a personal shopping trip in Russia for me.

Version B is 153 mm. tall, 118 mm. wide, 53 mm. thick, and weighs 664 g. It appears to be made of three steel pieces welded together: the main plate, the riser, and the bollards. The back plate is 8.5 mm. thick. The upper slots are 72 mm. tall and have a maximum 19 mm. width. The lower slots are 28 mm. long and 12.5 mm. wide. The central hole is 14.3 mm. in diameter. The riser is made from 4.5 mm. plate. The bollard assembly is 28 mm. long and 30 mm. in diameter with a 19 mm. central hole.

There are no markings on this descender.

Comments

Version B has the following significant differences:

  1. The back plate is heavier, 8.5 mm. instead of 6 mm. steel.
  2. The riser is thinner, 4.5 mm. instead of 4.8 mm.
  3. The bollards are cut away at about a 45° angle at the back.
  4. The lower side slots are straight, not curved.
  5. Version B is painted with a speckled gray paint.

I don't like the idea of painting descenders, since I find that paint simply comes off and makes a mess of one’s rope.


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