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Overview

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Version A
(#370)

Front View	Rear View	Side View

Technical Details

I acquired this rack from CMC in 2007.

The rack frame is made from 9.6 mm. stainless steel. The frame is 352 mm. high and has a 32 mm. internal width. The open leg is 210 mm. long above the lock nut. The welded eye has a teardrop shape and is 26.4 mm. wide internally. The lower portion of the rack looks like it was sandblasted after welding.

The rack has six black hard-anodized aluminum brake bars. All six bars have a 12.6 mm. central hole extending the length of the bar. The first 14 mm. of the holes on the fixed-frame side are enlarged to 18.5 mm. This allows moving the bars so that they pivot on the fixed side of the frame.

The top bar is a 25.4 mm. diameter, 89 mm. long hyperbar. The hyperbar is a solid 4.8 mm. stainless steel pin set 25 mm. from the rack frame. The pin is press fit into a blind hole drilled in the top of the bar. The pin extends 21.7 mm. above the top of the bar. The closure slot is angled to latch the bar.

The second bar is also 25.4 mm. in diameter. It has a straight slot. The top two bars have single precut rope grooves. The remaining bars are 22.3 mm. diameter bars with angled slots and no grooves. All six bars are offset so that the bar centerline is roughly tangent to the circumference of the frame.

The unloaded side of the top bar is marked with "CMC Rescue Rack," "MEETS NFPA 1983(06ED.)," "LOT No. 4104," the Underwriters Laboratories Classified seal, and "5F04." The unloaded side of the second bar is marked with "Ø9.5-11.5mm, L 13.5 kN MBS" and "Ø11.5-13mm, G 13.5 kN MBS."

Comments

This rack is very well made. The hard anodizing should limit brake bar wear when used on clean ropes. The central holes lighten the rack, but one should be sure to replace the brake bars before they wear through to the hole. The enlarged hole at the one end is a nice way to modify the bars so that they will pass over the top of the rack and pivot on the fixed side of the frame, where they belong. At the same time, this saves weight in the bars. The top two bars are larger than the others, showing that CMC recognizes that these bars heat more than the others.

This rack’s weight is about average for J-frame racks, meaning that it is light for a full-sized rack. The axial holes in the brake bars provide significant weight savings. Eliminating the hyperbar would save some weight without sacrificing any utility in caving environments. Some rescuers like the hyperbars more than saving weight, it’s a personal decision.

I would have made the free end of the frame 30 to 40 mm longer to allow more bar motion for reducing friction on longer drops.

The rope guides are a nice touch. The one on the second bar is in exactly the right place. The one on the top bar works fine where it is, but I would have moved it down about 30 to 45° to where the main wear will occur.

In the strength markings on the top bar, "L" means "Light Use" and "G" means "General Use." I suspect that the strengths listed involve rope failure since the rack probably isn't stupid enough to become weaker when used on thin ropes.

Overall, I think this is an excellent rack, so I give it a star.

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Version B
(#2520)

Front View	Rear View	Side View

Technical Details

I acquired this rack from Inner Mountain Outfitters at the 2019 NSS Cnvention.

This rack is 381 mm. tall, 89 mm. wide, 35 mm. thick, and weighs 782 g.

The frame is made from 9.5 mm. stainless steel bent into shape, with an internal width of 32 mm. and a 31 mm. diameter ### welded coiled ### eye. There are H+1+4 brake bars. The bars are 25 and 19 mm. in diameter and 89 and 60 and 60 mm. long. Allowing 45 mm. for the rope leaves 65 mm. for spreading the bars. 9.6 mm. SS frame, 1 hyperbar and 5 standard hard anodized semi-hollow Al bars, welded eye, lock nut

The rack frame is made from 9.5 mm. stainless steel. The frame is 381 mm. high and has a 32 mm. internal width. The open leg is 240 mm. long above the lock nut. The welded eye has a teardrop shape and is 31.5 mm. wide internally. The lower portion of the rack looks like it was sandblasted after welding.

The rack has six black hard-anodized aluminum brake bars. All six bars have a 12.6 mm. central hole extending 70 mm. into the long bar and 41 mm. into the short bars, in each case ending just before the notch. The frame holes in the short bars are elongated to 15.2 mm. This allows moving the bars so that they pivot on the fixed side of the frame.

The top bar is a 25.4 mm. diameter, 89 mm. long hyperbar. The hyperbar is a solid 4.8 mm. stainless steel pin set 26 mm. from the rack frame. The pin is press fit into a blind hole drilled in the top of the bar. The pin extends 20.4 mm. above the top of the bar. The closure slot is angled to latch the bar.

The second bar is also 25.4 mm. in diameter. It has a straight slot. The remaining bars are 22.3 mm. diameter bars with angled slots. All six bars are offset so that the bar centerline is roughly tangent to the circumference of the frame.

The loaded side of the top bar is marked ith a "USA MADE" icon, "<ROPE," another icon, and "CMC™." The unloaded side of the top bar is marked with the Underwriters Laboratories Classified seal, "MEETS NFPA 1983(2017 ED)," ’"T"Ø8.3 - 13 mm,’ ’"G"Ø13 mm ONLY,’ "PN 300890," "LoT #," "19038-60," and a book-with-an-"i" icon.

Comments

This rack is very well made. The hard anodizing should limit brake bar wear when used on clean ropes. The central holes lighten the rack, but one should be sure to replace the brake bars before they wear through to the hole. The slotted hole at the one end is a nice way to modify the bars so that they will pass over the top of the rack and pivot on the fixed side of the frame, where they belong. At the same time, this saves weight in the bars. The top two bars are larger than the others, showing that CMC recognizes that these bars heat more than the others.

This rack’s weight is about average for J-frame racks, meaning that it is light for a full-sized rack. The axial holes in the brake bars provide significant weight savings. Eliminating the hyperbar would save some weight without sacrificing any utility in caving environments. Some rescuers like the hyperbars more than saving weight, it’s a personal decision.

I would have shortened the rack by about 25 mm. while keeping the free end of the frame unchanged, thus keeping the same available bar motion for reducing friction on longer drops.

Most users will have no idea what "T" or "G" means. Those markings have value only to CMC’s lawyers.

This rack is getting to be too long for my taste, and so I'm not giving it a star.

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