Crawler Cranes

Crawler cranes ride on wide steel tracks and often have long lattice booms and heavy counterweights. They lift huge loads on steel erection, bridges, industrial plants and pile driving. Their strength comes with big risks: ground failure, boom collapse, overloading and wind, plus the hazards of assembling and disassembling a giant machine.

• Crane Operators
• Assembly Crews
• Riggers
• Lift Directors
• Steel Erectors

Features that matter

• Crawler tracks spread the load, but the ground bearing pressure is still high under the track ends when lifting.
• Lattice boom and jib sections are pinned together on site, with boom hoist cables, pendants and luffing jibs.
• Counterweights and car body weights must be assembled correctly. Capacity depends on the boom length, radius and counterweight configuration. See Load Charts.
• Boom stops, backstops and anti-two-block devices prevent the boom from tipping backward or the hook block from hitting the boom tip. See Crane Safety Devices.

Main hazards

• Ground failure and tipping: soft or uneven ground, buried utilities or voids, and track edge pressure can cause the crane to tip. See Crane Setup.
• Boom collapse or backward tip: overloading, side loading, wind, boom angle too high without backstops, two-blocking and structural defects.
• Assembly and disassembly accidents: pinned booms falling, unsecured sections, crushing and falls from the boom or crane.
• Struck-by and crushed: loads, counterweights, tracks and crane parts. Workers are caught between the crane and obstacles.
• Power line contact. See Cranes & Power Lines.
• Wind: long booms and large loads catch wind. See Lift Wind Limits.
• Travel hazards: traveling with loads on slopes and uneven ground can tip the crane.

Ground and setup

• Verify ground bearing capacity using geotechnical information, and use crane mats (timber, steel or composite) engineered for the crane weight and track pressures. Place mats on compacted, level ground, and replace damaged ones. Check the mat arrangement, spacing and overlap.
• Make sure the site is level within the manufacturer's limits and watch for settlement, drainage and ground softened by rain or thaw.
• Check for buried utilities, tanks, culverts and voids beneath the crane's path and set-up area. Don't travel or set up over them without engineering approval.
• Adjust the track gauge as specified and set the counterweights and car body per the lift configuration.
• Set the load moment indicator and boom angle and length indicators properly, and test the anti-two-block and limit devices.

Assembly and disassembly

• A qualified person and competent person must direct assembly and disassembly (as OSHA's crane rule requires), following the manufacturer's procedures. Hold a pre-job meeting. See Crane Basics.
• Use proper cribbing, blocking and support for boom sections during assembly, and verify all pins, locking devices and pendants are installed correctly.
• Control fall hazards for workers on the boom: use fall protection and safe access methods. See Personal Fall Arrest Systems.
• Use assist cranes within their capacity, with qualified riggers and signal persons.
• Never use unapproved pins, bolts or parts, and keep workers out from under raised sections. Inspect all parts for damage.
• Check boom stops and backstops and that the boom angle limits work before raising the boom.

Operating safely

• Operators must be qualified or certified, and the crane inspected daily by a competent person and periodically as required. See Crane Inspections.
• Use the lift plan with load weight, radius, configuration, wind limits and exclusion zones. See Lift Planning.
• Make smooth movements, avoid shock loading and two-blocking, and don't exceed boom angles or load chart. Don't lift loads with the boom near its maximum angle without backstops.
• When traveling with a load, keep the boom aligned with the tracks, the load close to the ground and the speed low, and follow the manual and engineering plan. Avoid turns, slopes and soft ground.
• Use qualified signal persons and riggers and clear communication. Keep workers away from the swing radius, tracks and counterweight swing. Barricade the tail swing. See Signal Person Qualification.
• Lower the load and stow the boom if wind or weather exceeds limits, and secure the crane at the end of the day (boom lowered or secured as the manual says).

Crawler crane checklist

• Ground bearing capacity is verified and engineered mats are in place
• Assembly is directed by qualified and competent persons per the manual
• Boom stops, backstops, LMI and anti-two-block devices are tested
• The lift plan accounts for load weight, radius, wind and power lines
• Nobody is under the load or in the swing and tracks area

Last updated: October 5, 2026