Front	Rear	Side
Handle Extended	Front: Open for Rigging	Rear: Open for Rigging

Technical Details

I acquired my Spusk from Krok in 2021.

My Spusk is 108 mm. tall, 77 mm. wide, 41 mm. thick, and weighs 394 g.

The Spusk consists of a spring-loaded pivoting steel lever/handle assembly and a fixed anvil mounted between two steel plates. The rear plate is stationary, while the front plate pivots on the lever axle so that it may be opened to admit the rope. The anvil is attached to the rear plate with two rivets, one of which is extended with a mushroom head to engage a notch in the front face plate. The front plate has a l4 mm. attachment hole. The rear plate has a similar hole, except there is a non-rotating bollard riveted to the rear plate. The bollard width is 14.3 mm. and the diameter is 22 mm. The bollard has a 1.6 mm. deep U-shaped groove around the circumference. The central hole in the pulley shaft is 14 mm. in diameter.

The lever is a 55 mm. long, 13.4 mm. wide rocker-arm with a shallow U-shaped groove on the upper end and inner face. The handle mechanism sits behind the rear plate. The mechanism is attached to the rocker arm by two rivets. The handle assembly consists of a housing, a spring mechanism, the handle arm, and a cover held in place by six machine screws. The handle arm is 124 mm. long and is made from 2 mm. steel. The distal end has a 27 mm. wide, 14 mm. thick rubber hand grip with three shallow finger grooves. When the handle is rotated clockwise (as viewed from the front) past the top of the FED-21, the integral cam makes contact with the bearing behind the anvil. Continuing to move the handle downward (counter-clockwise), it rotates the rocker-arm in the same direction, reducing the pressure on the rope between the rocker arm and anvil, allowing the rope to slide.

The pivoting printed is printed with the Krok logo, ’"Лоцман-СПУСК,’ "Max 300 кг Ø 10," "Max 400 кг Ø 11," "Max 500 кг Ø 12," and "WLL10 kN MBS 15 kN." The rear plate is printed with "TP TC 019/2011," "EAC," a book-with-an-"i" icon, the Ukrainian Conformity Mark, "EN 12841-2014/B,C," and "20.06.30.17." The inside of the rear plate is etched with "Верх" (top) and a an illustration of cable with a loop at the top.

Comments

The name of this device may not mean what you think it does. The original Russian is "СПУСК." While "спуск" translates as "descent," in this case "СПУСК" is an acronym for "Спуско-Подьёмное Устройство Страховочное КRОКа," meaning "Lowering and Lifting Device Safety KROK," and so we should call it "Spusk" rather than "descent."

This descender is designed for 8 to 12 mm. rope. It is closely related to the Krok Drop-Roll, and can also be used as a rope grab or ascender. The Krok web site provides the following limitation for using this as a descender:

Due to the fact that the area of ​​contact of the rope with the surface of the rocker arm and the stop is not large enough to fully dissipate the heat released during friction, descents are allowed for short (up to 5-10 m.) distances and at low speed so that the steel surfaces of the clamps do not have time to warm up to the melting temperature of the rope and have time to cool down.

This limitation effectively removes the Spusk from consideration as a caver or climbers primary rappel device, but the lowering capability may have value in some industrial settings.

I tried using the Spusk as a descender on 9 mm. nylon static rope, and found that the control arm was far too sensitive for my taste. When released, the Spusk had enough friction enough to hold my body weight (90 kg.), but it took only a small movement of the control arm to drop me into free-fall.