Front	Top

Side	Open for Rigging

Technical Details

I acquired this box from cptnamerica2003 in 2021.

This box is 98 mm. wide, 80 mm. high, 41 mm. thick, and weighs 268 g. It is a double channel chest box milled from an aluminum alloy block. It has two 16 mm. rope channels with two long QR pins. Each pin passes through both channels, one from the left and one from the right. The pins are held by 1.6 mm. steel cable keepers attached to the top of the box. There are two 56 mm. tall vertical slots for attaching the box to a chest harness, and a 12.7 mm. carabiner hole on the central rib.

The bottom of the box is hand stamped with "PATENT PENDING."

Comments

This box resembles the Gossett Block, but the dimensions are quite different. This box has a carabiner hole that the Gossett Block lacks. The hole location is unfavorable, since a carabiner placed here would interfere with both the main line and the upper ascender slings.

The QR pin choice is unusual, and I have two reasons to dislike this arrangement. First, inserting or removing the rope or an ascender sling requires opening both QR pins. In either case, t is possible to remove one only half-way so that the other side channel remains closed, but this is requires some care and could easily be missed, with undesirable results. The other is that the rope and sling run directly on the QR pin rather than on a roller. This places a sharper bend on the rope and sling, increases friction, and increases QR pin wear compared to a roller arrangement. Overall, I give this design a lemon award .

I was not able to find a U.S. patent matching this box. Perhaps the idea was abandoned because of the existence of the Gossett Block, a design that was deliberately left in the public domain rather than being patented.