Crane Types by Structure: How Reach and Rated Capacity Decide the Right Lift

Bridges, high-rise frames, highways and industrial plants have one thing in common: none of them go up without a machine that can hold a load in the air and place it accurately. Cranes have been doing that work for a very long time — the earliest recorded examples date to ancient Greece around 515 BC, and irrigation records from Mesopotamia point to lifting gear used thousands of years before that. Several structures still standing from antiquity would need a crane of some kind if anyone tried to build them today.

What has changed is not the principle. Ropes, pulleys and mechanical advantage still do the work, and an operator can still move loads far beyond human strength. What has changed is the variety: modern cranes solve the same physics problem in a handful of very different structural forms, sometimes in environments where no crew could safely stand.

This article sorts the five common construction types by structure, because structure is what sets the two numbers that actually decide a lift — how far the hook can reach, and how much it can hold at that distance.

Two properties decide every lift

Every crane is a compromise between how it is supported and how far it must extend. Support determines where the machine can work and how much setup it needs; extension determines the radius, the height and the capacity left at that radius. A crane's headline lifting figure is only valid at a stated configuration, so comparing two machines by a single tonnage number tells you almost nothing.

• Fixed support (a foundation or a tied mast) buys height and radius, at the cost of assembly time and a site that stays put.
• Rail support buys precision and repeated coverage of a rectangular area, but keeps the machine indoors and on a defined path.
• Wheeled support buys road speed and fast rigging, at the cost of ground bearing and outrigger space.
• Tracked support buys flotation and stability on poor ground, at the cost of transport weight and travel speed.

With that framework, the five types below fall into place.

1. Tower cranes: radius from a fixed mast

The tower crane is the silhouette most people associate with a city under construction, and its logic is vertical. A mast is anchored to a concrete base or tied back to the structure being built, and a long jib rotates at the top to sweep material across the footprint.

Structure and lifting envelope

Height comes from the mast, radius from the jib, and balance from counterweights placed on the opposite side of the slew. Because the machine is fixed, it can be erected well above the work and left there for the duration of the project. Capacity is highest close to the mast and reduces as the hook travels out along the jib — which is why the placement of the loading deck matters as much as the crane's selection.

Where it is used

• High-rise construction: hoisting steel, concrete, formwork and plant to floors that no mobile machine can reach.
• Infrastructure: bridges, towers and other tall structures where a fixed working radius covers the whole site.

Why projects accept the setup cost

Nothing else matches the combination of height and coverage from a single position. The rotating jib serves the entire footprint without repositioning, and the machine can stay in place for months. The trade-off is that erection, climbing and dismantling are engineering operations in their own right.

2. Mobile cranes: telescopic reach on a road-going chassis

Mobile units ride on a truck chassis or a wheeled platform, which is exactly why this class dominates general construction work. The machine drives to the lift, sets up, works, and leaves.

Structure and lifting envelope

Reach comes from a telescopic boom that extends to the length the lift requires. Because the boom can be retracted, the machine travels legally and rigs quickly; because it can be extended, it covers lifts that would otherwise need a different machine. The envelope is smaller than a tower crane's, and ground conditions plus outrigger spread set the practical limit.

Where it is used

• General construction: smaller projects and residential builds where a fixed crane cannot be justified.
• Material handling: unloading and distributing deliveries around a site.
• Confined sites: a compact chassis can work where a larger machine cannot position itself.

Why operators choose it

Portability between jobs, short rigging time and flexibility across light to medium lifts. For a contractor working on several locations, that combination often outweighs a higher capacity available elsewhere.

3. Crawler cranes: capacity on tracks

When the load is heavy and the ground is poor, the crawler crane takes over. It runs on tracks rather than wheels, and that single change alters what the machine can do.

Structure and lifting envelope

Tracks spread the machine's weight across a long, wide contact patch, so the crane stays stable on soft or uneven ground without outriggers. The long boom extends the radius, and the heavy counterweight and wide base allow lifts that wheeled machines of similar size cannot attempt. The price is transport: crawler cranes arrive on trailers, in pieces, and take time to assemble.

Where it is used

• Industrial construction: power plants, refineries and large process facilities.
• Infrastructure: bridges, highways and dams.
• Remote sites: off-road and rugged locations with no prepared hardstanding.

Why projects accept the logistics

Terrain tolerance, very high load capacity and no outrigger requirement. On a site where the ground would swallow a wheeled machine's stabilisers, that is decisive.

4. Rough-terrain cranes: mobility where the ground is the problem

The rough-terrain crane is built for sites that are not flat and not clear. Four-wheel drive and robust tyres let it move across broken ground, and a compact chassis lets it position close to the work.

Structure and lifting envelope

Outriggers provide the stability during the lift; a single engine powers both the crane upper and the carrier, which simplifies maintenance and operation. Reach is limited compared with a long-boom crawler, but the machine can reposition between lifts faster than almost anything else on this list.

Where it is used

• Oil and gas construction: remote energy sites where access is rough and lifts are frequent.
• Outdoor projects: large-scale work in demanding environments.
• Frequent repositioning: jobs that move the crane several times a day across uneven ground.

Why operators choose it

Manoeuvrability in difficult terrain, stability on outriggers during the lift, and a build that tolerates rough handling. It is the class that keeps working when the access road is the constraint.

5. Overhead cranes: span instead of radius

Overhead cranes, also called bridge cranes, work indoors in factories and warehouses. Their geometry is different in kind: instead of a rotating jib sweeping a circle, a horizontal bridge travels along two parallel runways and a hoist moves along the bridge.

Structure and lifting envelope

Coverage is rectangular and defined by the runway length and the bridge span, so the crane serves the whole bay rather than a radius around a mast. Lifting height is set by the building, and the hoist position gives precise placement along both axes.

Where it is used

• Manufacturing: moving heavy components along assembly lines.
• Warehouses: handling goods in storage and dispatch areas.
• Repetitive handling: continuous, accurate movement of the same load types.

Why buildings are designed around them

Precision, throughput and the use of overhead space that would otherwise be wasted. The crane is part of the building structure, which is why it is specified during design rather than hired for a season.

Reading the five types on one axis

• Tower crane — fixed mast, rotating jib; huge height and wide circular coverage; slow to erect, permanent for the project.
• Mobile crane — truck or wheeled chassis, telescopic boom; moderate radius, fast deployment, road-legal travel.
• Rough-terrain crane — four-wheel drive, outriggers, single engine; moderate radius, best mobility on bad ground.
• Crawler crane — tracks, long boom, no outriggers; high capacity and long reach, heavy transport and assembly.
• Overhead crane — runways and a travelling bridge; rectangular coverage indoors, fixed to the building.

Five questions that narrow the shortlist

• What is the heaviest single piece, including rigging? The load plus slings, spreader and hook block is the number the chart is read against.
• How far from the machine is the furthest pick point? Radius, not height alone, governs what the crane can hold.
• What height and what obstacles? A jib or boom must clear the structure, and the clearance changes the configuration.
• What will the ground carry? Outrigger loads on made ground, or track flotation on soft fill, decide whether the machine can set up at all.
• How often will it move? Frequent moves favour wheeled machines; a single long campaign favours a fixed or tracked one.

Choosing with MechLink

MechLink holds a broad selection of quality used cranes ready for upcoming projects, including mobile, crawler and offshore units from manufacturers such as Liebherr, Grove, Tadano Faun and Terex Demag. Each machine's specification is checked against the work it is being bought for, and every crane is inspected and tested before shipment. If the requirement is more specialised, describe the lift and the site and the team will set out to source the right machine. Start from the crane listings to compare current availability, or look specifically at crawler cranes for heavy lifting on poor ground.