|Left||Right||Open for Rigging|
I acquired my Rocker from Mountain Gear in March 2003.
The rocker consists of a movable lever and a fixed anvil sandwiched between two plates. The rear plate is a diamond-shaped stamping made from 4.3 mm. anodized aluminum. A round 15.0 mm. hole is cut in the right side of the plate, and a larger 23.8 by 24.2 mm. hole is cut in the left side. The front plate is pear-shaped and smaller, lacking the projection for the upper hole. The front plate pivots on the lever mounting pin, and a notch in the left side of the front plate provides clearance for the anvil mounting pin.
The anvil and lever appear to be 14 mm. slices cut from an aluminum extrusion and subsequently anodized. The anvil is attached to the rear plate by a round-head stainless-steel bolt that threads into a "nut" behind the rear plate. The "nut" is turned to form a rounded head; it has no flat surfaces for using a wrench. The bolt shaft is stepped, with an 8 mm. diameter for 4.6 mm. to engage the front plate notch, then 7 mm. where it passes through the anvil and rear plate to the "nut." A coiled pin through the rear shell keeps the anvil from turning. The anvil itself is shaped like a low, wide isoceles triangle, with a cutout opposite the lever end. The lever is mounted on a similar bolt, but is free to rotate. A small spring forces the lever to the engaged position. A cutout on the rear side of the lever provides clearance for the spring.
A 3 mm. thick lever lock pivots on a rivet near the upper hole. This tab allows one to restrict the motion of the lever to keep the Rocker from sliding on the rope.
The front plate has "CE0120," "EN353-2," "EN358," ANSI z359 1-1992," "Rocker," "YATES," "Rope @ Ø10.5-12.77 mm.," a book-with-an-"i" icon and the "Sieg Heil" icon screened on the face. The inside of the rear plate has the "Sieg Heil" icon stamped between the hammer and anvil. "02-04038LM" is stamped on the back.
Except for adding the lever lock, the Yates Rocker is functionally identical to the Troll Rocker. The lever lock works, but one needs to be careful not to bump it so that it accidentally disengages. A carabiner in the upper hole can help prevent this. When the lever lock is disengaged, it blocks access to the upper hole.
The instructions on the Rocker warn against using it with soft or loose-sheathed ropes. The same warning should apply to other fall arrests as well; at least Yates tells people about this.
The following rope grabs are all variations of the same basic design:
|Image||Rope Grab||Manufactured||Side Plates||Locking Tab|
|ISC Rocker||2006 (?)||3.9 mm. Anodized Aluminum||Yes|
|Proverti AC080||4/2015||4.4 mm. Anodized Aluminum||Yes|
|Proverti AC081||4/2015||2.5 mm Stainless Steel||Yes|
|Singing Rock Locker||1/2008||4 mm. Anodized Aluminum||Yes|
|Troll Rocker||~2001||4.3 mm. Anodized Aluminum||
|Xinda Rocker||~2014||4 mm. Anodized Aluminum||Yes|
|Yates Rocker||~2003||4.3 mm. Anodized Aluminum||Yes|
Each of these is a compact, lightweight (except for the stainless steel Proverti AC081) fall arrest that can also be used as a ratchet when hauling loads over a pulley. I'm not sure when the second carabiner hole is necessary - none of these came with instructions showing it in use.
These have no sharp teeth to cut the rope sheath. Some informal testing suggests that, lacking teeth, these can slide before engaging, but normally the slippage is less than a foot. The cases where I observed this were somewhat contrived (i.e., I held the grab in a specific position and carefully dropped the load straight down), and so I'm not too worried about the slippage. I would be far more concerned if they had sharp teeth and didn't slip at all.