|Left||Right||Open for Rigging|
I acquired my GET International Lineboss in 2017 as part of Bob Thrun's collection.
The Lineboss is 122 mm. tall, 89 mm. wide, 63 mm. thick, and weighs 494 g.
Lineboss consists of a fixed plate, a pivoting plate, and a number of items mounted on the fixed plate. Each of these plates is about 6.3 mm. thick, milled from aluminum with rounded edges, has a 16 mm. attachment hole near the top right, and is hard anodized.On the inside of the fixed plate, to the left of the attachment hole, is a 25.3 mm. diameter, 12.8 mm. high cylinder consisting of a central core and a 1.8 mm. thick shell held in place by a button-head hex screw. A button-head post in the center of the cylinder provides a stop for the front plate, which is notched to clear the shoulder in the post. Below the cylinder are four small tapped holes. Farther down and to the right is another cylinder, like the first, but without a post. Finally, below this is the "brake bar," a lever that pivots on a bolt on the lower left corner of the fixed plate. The pivoting side plate also rotates on this bolt. The left end of the lever has a 13.5 mm. attachment hole, while the right side has a post that supports a 22 mm. diameter, 6.8 mm. thick bearing roller that sits behind the plane of the fixed plate. A cam and attached lever arm ob the outside of the fixed plate rotate on an axle behind the second cylinder. The cam pushes against the roller on the brake bar. A small Allen screw (a.k.a. the "governor") on the cam can be set to limit how far the cam can travel to open the brake bar. The governor screw can be set to hit a screw ("stop bolt") placed in one of the four tapped hole. Choosing one of the holes provides a coarse selection, and turning the governor screw provides fine adjustment. The stop bolt was missing when I acquired the lineboss; however, marks indicate that it was originally in the lower hole.
The front of the Lineboss is printed with ""▲,"" above "UP," "LINEBOSS®" a Reading-is-Dangerous icon beside the word "WARNING," "PROPER TRAINING IS VATAL BEFORE USE," "MBS 11250 lbF/50kN," "exceeds test for ANSI Z359.1," "PAT. & PAT. PEND,""GET INTERNATIONAL," "MADE IN USA", "11AT.02" (indicating 2002 manufacture), a rigging illustration, "11-13mm ROPE," and "LINEBOSS.COM."
The Lineboss was marketed as an ascender/descender progress capture and top-rope belay device. It was designed for arborists, and since I don't swing through trees, I'll let them evaluate it for their applications. For cavers and climbers, it is heavy and far enough off the mainstream of designs that I cannot recommend it in those applications.
The Lineboss is a heavy, complex device that requires careful study before use. It looks and feels rugged, as a working tool should. A notice with the Lineboss says that the maximum breaking strength of 11250 lbF/50kN has been changed to 6070 lbF/27kN to conform to ANSI Z359.1.