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Why Your Crane Needs an Anti-Two Block Warning System

In 2011, a crane accident took place in Naples Maine; while working on a highway bridge project, the crane operator accidentally engaged the main hoist of the crane with the hook block, which caused the lattice boom to bend over to the back. Fortunately, no fatalities were caused by the accident; however, the crane sustained severe damage.



This kind of crane accident is called ‘two-blocking.’ It occurs when a crane’s hook comes in contact with its boom tip, putting extra stress on the hoist line. This is a dangerous scenario that can cause the hoist to snap and the load to drop, wreaking havoc on the work site.

According to statistics, 2% of all crane-related deaths in the US construction industry between the years of 1984 to 1994 were caused by two-blocking.


How Can You Prevent Two-Blocking?

Two-blocking can be prevented in cranes by installing a safety device called the anti-two-blocking system. In fact, the American National Standards for Mobile and Locomotive Cranes (ASME) have made it compulsory for cranes manufactured after February 1992, to have an anti-two-blocking system installed.


What’s an Anti-Two-Blocking System?

An anti-two-blocking system is a technologically advanced electrical device with a built-in sensor that helps the crane operator prevent two-blocking incidents.


Two of the most popular variations of this safety device are wireless ATB systems and hardwired ATB systems.


The wireless device is easy-to-install and use and is compatible with lattice and telescopic boom cranes. The audio-visual alarms on the display alert the crane operator when the hook has reached the maximum safe height. Moreover, the hardwire ATB systems work best with fixed boom cranes and help the operator ensure that the hook doesn’t come in contact with the boom tip.

Why Should You Get An Anti-Two-Blocking System?

The benefits of installing an ATB warning system on your crane are many. First off, it ensures the safety of your crew, which gives them a sense of security and in turn leads to increased productivity and efficiency at work.


Moreover, an ATB warning system helps you ensure that a lift operation is conducted safely and the load is transported in a secure manner, without any damage to the property.

Lastly, installing an anti-two-blocking system on your crane is  important because its required by OSHA, in most cases and if you have a crane accident without an ATB system installed, your insurance claim may be rejected.


Looking for a high-quality yet cost-effective Anti two Block warning systems for your crane? Get in touch with Crane Warning Systems Atlanta today! We’re the leading distributor of technologically advanced Rayco Wylie crane safety devices in the U.S.


Besides Anti Two Block Warning Systems, we’ve also been providing safe load indicator systems, crane Wind Speed Indicator system, two-way-radios and camera systems, to clients for the past two decades!


Contact us today for more information.

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