US-based ground support giant Jennmar has introduced two new high-capacity cable truss systems. The manufacturer said both products, JMM and JMS, had patents pending, were “mine proven” and offered better protection than normal roof bolting.
The products also eliminated cribbing. The JMM cable truss uses a Jennmar INSTaL J-bar angle bolt with an expansion shell and resin. Featuring two truss shoes, U-bolts, bearing blocks and housings with wedges for tensioning the horizontal cable, the truss is said to accommodate three grade 270 cable diameters.
“The JMM provides proven superior roof support,” Jennmar said. “It is ideal for primary support on longwall gate road development. With fewer parts than competitors’ products, the system is easy and fast to install.
“It controls uneven and potted out roof, and adjusts to varying entry widths.”
The JMS is described as an all-cable truss system with two truss plates and splice tubes each with two housings and wedges. “It is an economical system and great for low seams,” Jennmar said.
“Cable is easily tensioned for narrow or wide entries (and) birdcages at the anchor end of the cable improve alignment and resin mixing, and offer immediate anchorage.”