Crawler Cranes

A crawler crane is a mobile crane mounted on a tracked undercarriage. Instead of tyres and outriggers, it stands and travels on two crawler tracks, which spread its weight over a large area and let it move around a site while carrying a load. Most crawler cranes have a lattice boom assembled from sections, although telescopic boom versions are also common in the smaller and middle classes. The range goes from compact machines of a few tens of tonnes to the largest land-based cranes in the world, rated at several thousand tonnes.

Crawler cranes are used where loads are heavy, lifts are many and the crane stays on the same project for weeks or months: power stations, refineries, bridges, wind farms, large buildings and infrastructure. They are slower to transport and set up than wheeled mobile cranes, but once assembled they offer high capacity, long reach and the ability to “pick and carry” loads on prepared ground.

Brief History of Crawler Cranes

The first cranes on tracks were cable-operated machines derived from steam and later diesel excavators, in the early twentieth century. Many manufacturers built convertible machines that could be fitted as a shovel, a dragline, a clamshell or a crane, all on the same crawler base. American companies such as Manitowoc, Bucyrus-Erie, American Hoist and Link-Belt were important names in this period, and lattice boom crawler cranes became standard equipment on heavy construction sites after the Second World War.

From the 1960s and 1970s, the demand for ever-heavier lifts in the power, petrochemical and offshore industries drove the development of very large crawler cranes with additional counterweight systems, derricks and ring attachments. Liebherr built its first crawler crane, the LR 1300, in the late 1970s for nuclear power plant construction in the United States. Later decades brought full hydraulic drives, electronic load moment limiters, self-assembly features and, at the top of the range, machines such as Liebherr’s LR 13000, rated at about 3,000 tonnes. Chinese manufacturers have become major players since the 2000s.

How a Crawler Crane Works

A crawler crane combines an undercarriage, a slewing superstructure and a boom system.

Crawler undercarriage. Two tracks carry the crane, driven by hydraulic motors. On larger cranes the crawlers are removed for transport and fitted on site, and many machines can extend the track gauge to increase stability.
Superstructure. The engine, hydraulic pumps, winches, cab and counterweight sit on a slewing ring and rotate through 360 degrees.
Boom. A lattice boom is built from bolted or pinned sections, with the length chosen for the job. A telescopic boom extends hydraulically and needs no assembly of sections.
Luffing jib. Many cranes can be fitted with a luffing jib on top of the main boom, giving more reach over obstacles and a higher hook height close to the crane.
Counterweight and superlift. Counterweight on the superstructure balances the load. For heavy lifts, an additional ballast system (often called superlift, MAX-ER, VPC or similar) with a mast and extra counterweight increases capacity substantially.
Controls and safety systems. A load moment limiter continuously compares the load and radius with the crane’s rated capacity and stops movements that would overload the machine.

Types of Crawler Cranes

Lattice Boom Crawler Cranes

The classic form, with a lattice boom and often a luffing or fixed jib. Capacities range from roughly 50 tonnes to several thousand tonnes. The lattice structure is light for its strength, which gives long booms and high capacity at radius.

Telescopic Crawler Cranes

These cranes combine a telescopic boom with a crawler undercarriage. They are quicker to set up, need no boom assembly and can work on uneven ground. Capacities are usually up to about 300 tonnes, and they are popular for foundation work, bridge beams and general construction.

Heavy Lift and Ring Configurations

For the heaviest lifts, crawler cranes are fitted with derrick masts, large ballast trays and, in some cases, ring systems where the crane runs on a circular track. These configurations are used in refineries, power stations and offshore module yards.

Duty-Cycle Crawler Cranes

Heavy-duty machines designed for continuous work with grabs, draglines, vibratory hammers and diaphragm wall tools. They have strong winches and cooling systems for repeated cycles.

Compact Crawler Cranes

Smaller lattice or telescopic crawler cranes are used on building sites and in industrial plants where space is limited. Mini crawler cranes, used for glazing and interior work, are covered in a separate entry.

Size Classes

Class	Typical maximum capacity	Typical use
Small	about 40 to 100 t	Building sites, foundations, steel erection
Medium	about 100 to 300 t	Bridges, precast, industrial plants
Large	about 300 to 800 t	Wind turbines, power and process plants
Very large	about 800 t and more	Refineries, heavy modules, major infrastructure

Figures are indicative and depend on configuration, radius and counterweight.

Attachments and Equipment

Besides the hook block, crawler cranes can work with a wide range of equipment. Lattice boom cranes are fitted with fixed or luffing jibs, heavy-lift adapters and runner jibs. Duty-cycle machines carry clamshell buckets, draglines, vibratory hammers, diaphragm wall grabs and demolition balls. For precise lifting, riggers use spreader bars, lifting beams, load equalisers and remote-controlled rotating hooks. On wind farms, special blade and tower lifting yokes are common.

Main Manufacturers

Liebherr, with the LR lattice and LTR telescopic ranges.
Manitowoc, one of the historic names in lattice boom crawler cranes.
Sany, XCMG and Zoomlion, the main Chinese manufacturers, active across all classes.
Kobelco, Sumitomo and Tadano, the main Japanese manufacturers.
Link-Belt, a long-established American crane builder.
Sennebogen, with telescopic and lattice crawler cranes and duty-cycle machines.

Main Uses of Crawler Cranes

Erection of wind turbines, including towers, nacelles and blades.
Construction of power stations, refineries and petrochemical plants.
Bridge building, including girders, segments and steel spans.
Structural steel and precast concrete in large buildings.
Port and offshore module handling.
Foundation work, piling and diaphragm walls in duty-cycle versions.

Planning and Operating Tips

Ground bearing pressure. A crawler crane spreads its weight, but heavy lifts can still exceed the capacity of the ground. Mats, crane pads and ground surveys are essential.
Transport and assembly. Large lattice cranes can need dozens of truckloads and an assist crane to assemble. Transport, assembly space and time should be planned early.
Choose the right configuration. Boom length, jib, counterweight and superlift options change the load chart. The lightest configuration that covers all lifts saves transport and assembly.
Pick and carry. Many crawler cranes can travel with a load, but capacity is reduced and the ground must be level and firm. The manufacturer’s travel chart applies.
Wind. Long booms are sensitive to wind. The permitted wind speed depends on the load’s surface area as well as the crane configuration.
Lift plans. Critical and tandem lifts need a written lift plan, including crane positions, radius, ground preparation and communication between crane operators and riggers.

Safety

The main hazards with crawler cranes are overturning, structural failure of the boom, ground failure under the tracks, contact with power lines, dropped loads and accidents during assembly and dismantling. Many serious incidents occur during boom assembly, when workers are under or inside boom sections, or when pins are removed from a boom that is not properly supported. Operators must follow the load chart for the exact configuration, keep the load moment limiter correctly set and never bypass it. Exclusion zones, trained riggers and signallers, checked lifting accessories and wind monitoring are standard practice on professional sites.

Trends and Technology

Crawler crane design is moving in several directions. At the top end, capacities keep rising to lift larger wind turbine components and prefabricated modules. In the middle classes, manufacturers are adding variable counterweight systems, self-assembly features and quick connections to reduce the number of trucks and the time needed for setup. Telescopic crawler cranes are becoming more capable. Electric and hybrid drives are appearing, allowing some cranes to work from a mains supply on sites with emission limits. Telematics, lift planning software and camera systems help both operators and fleet managers.

Key Terms

Lattice boom: a boom made of steel sections with a triangulated structure, assembled on site.
Luffing jib: a jib mounted on top of the main boom whose angle can be changed under load.
Superlift: a common name for an additional counterweight system with a mast that increases capacity.
Load moment limiter: an electronic system that prevents the crane from exceeding its rated capacity.
Track gauge: the distance between the two crawlers, often adjustable for stability.
Tandem lift: a lift carried out by two cranes together.

Frequently Asked Questions

What is the difference between a crawler crane and a mobile crane? A crawler crane stands and travels on tracks and usually needs to be transported in pieces. A wheeled mobile crane drives on the road and uses outriggers for stability. Crawler cranes are generally used for longer, heavier jobs.

Can a crawler crane move with a load? Yes, many crawler cranes can travel with a suspended load on firm, level ground, at reduced capacity and according to the manufacturer’s charts.

How long does it take to assemble a large crawler crane? It depends on the size and configuration. A small crawler crane can be ready in hours, while the largest machines can take several days or weeks.

Why are crawler cranes used for wind turbines? They combine high capacity with very long booms and can move between turbine positions on prepared roads without being fully dismantled.