While crane operators, riggers and signalers work to improve jobsite communication, some of the electronic safety devices inside cranes are getting connected in new ways as well.
Monitors are starting to appear on new cranes.
Load indicators, which compute an overload situation, alert operators to danger and, in some cases, restrict movement. They typically use long strands of cable strung up and down the crane's boom to keep several sensors talking to each other. Troubleshooting and replacing these cables can be very difficult and time consuming, but new wireless technology, coupled with long-life batteries, is starting to make crane work much safer and easier.
Wireless monitors and limiters are common retrofits for older cranes. Thousands are installed every year, each costing between $200 and $15,000, according to Dave Smith, president of Houston-based supplier Load Systems International Inc. He says the units come precalibrated and provide up to one month of battery life.
Many have questioned the safety of wireless load monitors, but the controls are "turning out" to be more reliable than mechanical ones because of fewer moving parts, says Dave Ritchie, a risk-control specialist for St. Paul Travelers in Bastrop, Texas.
Wireless monitors also are becoming standard equipment on new cranes. In October, Lexington, Ky.-based Link Belt Construction Equipment Co. became one of the first vendors to do so on a new 45-ton telescopic crawler. "I think it's really the wave of the future," says Chuck Martz, Link-Belt president. He says that more wireless-equipped units are on the way.