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Speleoshoppe Superack

Version A Version B
Version A Version B

Overview


Version A
(#401)

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

Technical Details

I acquired this rack from Jennifer Kerrigan around 1982, and a second from Jack Hissong delivered to me at the 2012 NSS Convention.

Version A is 323 mm. tall, 73 mm. wide, 25 mm. thick, and weighs 822 g. The frame is made from 9.5 mm. stainless steel bent into a U, with an internal width of 39 mm. There are four unfinished aluminum alloy brake bars. The bars are made from 25 mm. square bar stock and are 73 mm. long. Allowing 35 mm. for the rope and 19 mm. for the spacers gives a 149 mm. range for spreading the bars. Hex and acorn nuts secure the bars.

The top bar is stamped with a bat inside an oval and "SUPERACK." The left end of the four bars are stamped "1," "2," "3," and "4," respectively from top bar to bottom bar.

Comments

This is the original large-bar rack design based on Kyle Isenhart's article in The Nylon Highway #1. This rack was designed for long drops. The large bars provide a larger mass for absorbing heat, and tend to run cooler that standard rack bars. He later published the results of temperature tests (The Nylon Highway #4) that showed the Superack ran about 30 to 35°C (60°F) cooler than a standard rack for moderate rappelling speeds.

The Superack only has four bars (with spacers between the top two), and has less friction capability than a standard 6-bar rack. This generated some controversy in the caving press, with both sides having some valid points to make. When used by an experienced caver, the Superack does what it was designed to do, but it is not a beginner's rack.


Version B
(#1378)

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

Technical Details

I acquired this rack from Speleoshoppe as new old stock in 2012.

Version B is 322 mm. tall, 70 mm. wide, 26 mm. thick, and weighs 973 g. The frame is made from 9.5 mm. stainless steel bent into a U, with an internal width of 35 mm. There are six unfinished aluminum alloy brake bars. The top five bars are made from 25 mm. square bar stock and are 70 mm. long. The lowest bar is an unfinished Seaman-style bar.

The top bar is stamped with a bat inside an oval and "SUPERACK." Unlike Version A, the bars are not numbered.

Comments

Kyle Isenhart's original design (The Nylon Highway #1) had only has four bars, and controversy in the caving press prompted Ian Ellis to add two more bars to this rack. The fifth bar was a standard SupeRack bar, and the bottom bar is Ed Seaman's design (The Nylon Highway #9). My field testing and analyses (Design of Specialty Racks, The Nylon Highway #9) show that the fifth bar does not need to be as large as the upper bars, so I would have used a Seaman-style bar for both lower bars.