Two block is a situation there the hook block comes in contact with the boom head of a crane. This situation can have serious consequences. Damage to the crane could result, or more seriously, the wire rope could break causing the load to drop.

Anti Two blocking, therefore is a system that alerts the operator that he is nearing this condition. The alarm, is usually in the form of an audio buzzer or horn. Visual alarms are not practical due to the fact that the operator is concentrating on the lift in progress.
Options:

• Designed to be easily mounted in the cab or outside the crane.
• Comes with built in fuse, on/off switch, LED light, buzzer, wiring harness, and connectors.
• Remote antenna ensures proper communication with switch.
• Each Tx and Rx unit have there own unique frequency.
• Transmitter uses a high energy, inexpensive 12 volt battery.
• Switch is made of high strength, light weight plastic.
• Bob weight weighs 18 lbs.
• bob weight can be fitted without weaving through or removing pins.