ATB (Anti-Two-Block) Systems for Crane Safety & Equipment Use

ATB systems are essential safety devices for cranes, truck-mounted lifting equipment and similar heavy-duty machinery. At Custom Truck One Source, our ATB Systems category features heavy-duty, reliable ATB components — including switches, sensors, and alarm systems — designed to prevent dangerous two-blocking events and protect both operators and equipment.

What Is an ATB System and Why It Matters

An ATB system (also referred to as A2B) prevents the hook block or load block from colliding with the crane boom tip — a hazardous condition known as “two-blocking.”
Without an ATB system, a too-high hoist could cause the block to contact the boom tip, potentially snapping the hoist line, damaging crane structure, dropping the load, or injuring personnel on the ground.
Because of this danger, ATB systems are considered a key safety indicator and often a regulated requirement for cranes and lifting equipment.

How ATB Systems Work: Wired and Wireless Options

ATB systems typically rely on a limit-switch or sensor mounted at the boom tip connected to a display and alarm inside the operator cab. When the load block approaches dangerously close to the tip, the switch triggers the alarm — alerting the operator to stop the hoist before impact.

• Wired ATB systems: use cable-linked switches and are common for fixed-boom cranes where cable routing is manageable.

• Wireless ATB systems: employ a boom-tip switch that transmits a signal wirelessly to the cab display — ideal for telescopic booms or mobile cranes where cable routing is impractical.
  Both versions provide visual and audible alarms; some also integrate with lockout controls to prevent further hoisting once a “two-block alert” is triggered.

Benefits of Installing ATB Systems

• Personnel safety: Prevents load-block collisions and reduces the risk of dropped loads or cable failure — protecting crew and bystanders.

• Equipment protection: Helps avoid boom damage, hoist-line failures, and expensive crane repairs due to over-hoist or hook-tip contact.

• Compliance & reduced liability: ATB systems are widely recognized as a minimum safety aid and, in many cases, mandated by safety standards for crane operations.

• Reduced downtime and cost savings: Preventing accidents and equipment damage avoids costly repairs or work stoppage and supports more predictable job-site operations.

Maintenance Tips & Replacement Indicators

To ensure your ATB system remains reliable:

• Regularly test the tip-switch and cab alarm before each lift cycle — ensure wiring integrity (for wired systems) or battery/ signal strength (for wireless units).

• Inspect the switch, chain/weight mechanism and mounting hardware on the boom tip for wear, damage or corrosion.

• Replace or service any ATB component showing signs of wear, delayed alarm response, intermittent signal, or physical damage — never rely on a compromised ATB system.

• Document maintenance and test history to support safe lifting practices and regulatory compliance audits.

Why Choose Custom Truck One Source for ATB Systems

• We stock a comprehensive selection of heavy-duty ATB components suitable for cranes, truck-mounted lifts, and equipment booms — including wired and wireless variants.

• As a full-service parts and equipment supplier, we support fast order fulfillment and nationwide distribution to minimize downtime.

• Our parts-specialist team has deep experience with heavy equipment safety systems — helping you select the correct ATB configuration, ensure fitment, and integrate alarms or lockout controls properly.

• Competitive pricing, strong inventory, and a user-friendly online catalog make it easy to locate the right ATB solution for your application.

Browse & Order Today

Explore our full selection of ATB systems — filter by type (wired / wireless), crane or boom compatibility, switch & alarm kit, or part number. Order online or contact our parts specialists at 877-831-0572 for help matching the right ATB to your crane or equipment setup.