A tower crane is a fixed crane with a tall vertical mast and a rotating horizontal jib, used to lift and place heavy materials like structural steel, concrete, and equipment high above a construction site. Its height and reach make it the backbone of most high-rise and large structural projects, which is why a tower crane is often the first piece of equipment up and the last one down.
Key Takeaways
- A tower crane is a fixed crane with a vertical mast and a rotating jib that lifts and places heavy materials at height, common on high-rise and large structural projects.
- The four main types are hammerhead (saddle jib), flat top (topless), luffing jib, and self-erecting, each suited to different site conditions and space constraints.
- Most tower cranes are erected with the help of a mobile assist crane, then grow with the building by adding mast sections. Self-erecting models raise their own mast and unfold hydraulically.
- Luffing jib and flat top cranes work well on tight urban sites and where several cranes share airspace. Hammerheads suit open sites with room to operate.
- Lifting capacity and working height vary by make, model, and configuration, so the crane is matched to the heaviest lift and the longest reach the job requires.
- Maxim Crane offers tower crane rentals with or without operating crews, backed by in-house engineering and project management.
Types of Tower Cranes
The four main types of tower cranes are hammerhead (saddle jib), flat top (topless), luffing jib, and self-erecting. They differ mainly in how the jib is built and moves, how much room they need to set up, and the kind of site they suit best.
Tower cranes are the fixed, or static, members of a broader family of construction cranes. The table below compares the four main tower crane types at a glance.
| Type | Defining feature | Best for | Assembly | Relative capacity |
|---|---|---|---|---|
| Hammerhead (saddle jib) | Fixed horizontal jib with a trolley; a tower-top assembly and pendant lines support the arm. | Heavy lifting and high-rise work on sites with room to operate. | Raised and dismantled with the help of a mobile assist crane. | High; a workhorse for heavy lifting where there is room to set up. |
| Flat top (topless) | The same fixed horizontal jib without the tower-top cap or pendant lines, so a lower, simpler head. | Sites where several cranes share airspace or overhead clearance is limited. | Quicker and simpler to transport and erect than a hammerhead. | High; comparable to a similar hammerhead. |
| Luffing jib | A jib that raises and lowers to change reach, instead of a long fixed arm. | Tight, congested urban sites with neighboring structures and shared airspace. | Raised with an assist crane; setup is more involved. | High; trades working radius for the ability to work in tight space. |
| Self-erecting | A smaller crane that raises its own mast and unfolds its jib using hydraulics. | Shorter-term jobs, residential, and tight or fast-moving sites. | Erects without a separate assist crane. | Lowest of the four. |
Hammerhead (saddle jib): the classic tower crane, with a fixed horizontal jib and a trolley that moves the load in and out along the arm. It is a workhorse for heavy lifting and high-rise work where there is room to set up.
Flat top (topless): a hammerhead-style crane without the tower-top cap and pendant lines, giving it a lower, simpler head. That lower profile helps on sites where several cranes share airspace or overhead clearance is limited.
Luffing jib: a crane whose jib raises and lowers to change reach, instead of relying on a long fixed arm. It is the common choice for tight, congested urban sites with neighboring structures.
Self-erecting: a smaller crane that raises its own mast and unfolds its jib using hydraulics, with no separate assist crane needed. It suits shorter-term jobs, residential work, and fast-moving or space-limited sites.
Parts of a Tower Crane
A tower crane is built from a handful of core parts that work together to lift, balance, and place a load: the base, the mast, the turntable, the operator’s cab, the jib, the trolley and hook block, the counter-jib, and the counterweight.
- Base: the heavy foundation, usually a reinforced concrete pad or a ballasted chassis, that anchors the crane and provides stability.
- Mast (tower): the tall vertical lattice structure that gives the crane its height and supports everything above it.
- Turntable (slewing unit): the rotating assembly that lets the jib swing a full circle around the mast.
- Operator’s cab: the control station where the operator runs the crane, often positioned at the top of the mast.
- Jib (working arm): the horizontal arm that extends out from the mast and carries the load.
- Trolley and hook block: the trolley travels along the jib to set the load radius, while the hook block raises and lowers the load.
- Counter-jib: the shorter arm that extends opposite the jib to help balance the crane.
- Counterweight: the ballast at the rear of the counter-jib that offsets the weight of the load on the jib.
How Does a Tower Crane Work?
A tower crane works by combining a fixed mast with a jib that rotates around it. The trolley moves the load in and out along the jib, the hoist raises and lowers the hook, and a counterweight on the counter-jib balances the load so the crane stays stable.
Three basic movements let a tower crane reach almost any point within its working circle:
- Slewing: the jib rotates around the mast, up to a full 360 degrees.
- Trolleying: the trolley travels along the jib to move the load closer to or farther from the mast.
- Hoisting: the hoist line raises and lowers the hook block and its load.
Balance is everything on a tower crane. The load on the jib is offset by the counterweight on the counter-jib, and the whole crane sits on a wide base weighted down with concrete or anchored to the structure. Tower cranes are designed to handle high winds, with the counterbalanced arm and heavy base keeping the structure stable.
How a Tower Crane Is Erected and Climbs
A tower crane is assembled on site in stages. First, a reinforced concrete foundation (or a mounting to the building structure) anchors the base. Then the mast is built up from steel lattice sections, usually with the help of a mobile assist crane, and the jib and counterweights are added at the top.
From there, many tower cranes grow taller as the building grows. There are two common ways this happens:
- External climbing: the crane stays on its foundation and adds mast sections at the top using a climbing frame, or collar, that jacks the crane up and makes room for each new section.
- Internal climbing: the crane sits inside the building, often in an elevator shaft or a dedicated opening, and jumps up floor by floor as the structure rises, supported by the completed floors below.
Self-erecting tower cranes are the exception. They arrive folded, then raise their own mast and unfold their jib hydraulically, so no separate assist crane is needed to stand them up.
Erecting, climbing, and later dismantling a tower crane is not a plug-and-play job. It involves foundation engineering, tie-ins to the structure, space and traffic planning for the assist crane, and careful sequencing against the construction schedule. That is why this work is planned and carried out by a provider’s engineering and project teams rather than handled on the fly.
Inside Maxim’s Tower Crane Division
On the right project, a tower crane does more than lift. It sets the pace for the entire site. As Matt Hyden, Vice President of Maxim Crane’s Tower Crane Division, puts it:
“Usually, if there’s a tower crane on the sites that are suited for a tower crane, that is the main lifeline for the whole job site.”
Maxim Crane runs a large tower crane fleet that skews toward hammerhead cranes, a configuration widely used on North American jobsites. Maxim operates more than 50 locations across the United States with coast-to-coast coverage, and its tower crane rentals can reach final hook heights in excess of 1,000 feet.
Tower cranes can be rented with or without operating crews. Because crane work in construction is tightly regulated, and OSHA requires operators to be trained, certified or licensed, and evaluated, many contractors choose operated and maintained rentals so a qualified operator comes with the crane.
The Evolution of the Tower Crane
Tower cranes have shaped construction since the mid-20th century. The modern, transportable tower crane traces back to 1949, when Hans Liebherr built the first mobile tower crane, the TK 10, which could be moved between sites and erected quickly.
Before that, cranes were heavy, fixed, and slow to assemble, so they were used only occasionally. The mobile tower crane made fast, repeatable lifting practical on everyday building sites, and the design has been refined ever since into the hammerhead, flat top, luffing, and self-erecting machines on jobsites today.
Selecting the Right Tower Crane
Choosing a tower crane comes down to matching the crane to the job: the weight and reach of the heaviest lifts, the space available to set up and climb, the crane’s position relative to everywhere it needs to reach, and the site’s constraints. Getting this right early prevents expensive surprises later.
- Capacity and reach: the crane has to handle the heaviest lift at the longest radius it will work at, not just its maximum near the mast. Load charts show what a given crane can lift at each radius and configuration.
- Space to set up and climb: tower cranes take up little ground space once they are up, but assembly, climbing, and dismantling need room and support equipment, so the footprint has to be planned.
- Position on the site: most tower cranes are fixed once installed, so placement has to let the crane reach every area where lifting is required, sometimes alongside a mobile crane.
- Site and ground conditions: foundation design, ground bearing, height clearance, neighboring structures, and shared airspace with other cranes all shape which type and size of crane will work.
Cost follows the same variables. Tower crane rental pricing is shaped by the type and size of crane, how long it stays on site, whether it is rented bare or operated and maintained, and the transport, assembly, and permitting the job requires.
On some projects a mobile crane is the better fit. Tower cranes are fixed, with strong height and stability, while mobile cranes like a crawler crane can move around or between sites with more flexibility but less height and stability. For lighter or shorter lifts, or work spread across a site, a mobile crane (or a tower crane paired with one) often makes more sense. A broader walk-through of choosing the right crane for a project can help weigh the trade-offs.
Because so much rides on these calls, crane selection is rarely a solo exercise. Maxim Crane’s engineering and project management teams evaluate load, reach, terrain, and site constraints as part of planning a lift.
Ideal Uses and Projects
Tower cranes earn their place on tall, dense, or long-running projects where height, reach, and repeated lifting matter more than mobility.
- Hospitals and educational facilities: large, multi-phase builds that run for months or years.
- Multi-family and mid- to high-rise construction: residential and commercial towers where materials have to reach many floors.
- Bridges and infrastructure: heavy, repeated lifts over a fixed footprint.
- Parking garages: repetitive placement of large precast and structural elements.
- Industrial and commercial development: plants, facilities, and large commercial buildings with heavy structural lifts.
Frequently Asked Questions About Tower Cranes
What is the difference between a hammerhead and a luffing jib tower crane?
A hammerhead tower crane has a fixed horizontal jib with a trolley that moves the load in and out along the arm. A luffing jib crane instead raises and lowers its jib to change reach, which lets it work in tighter spaces and makes it the common choice for congested urban sites where a long fixed arm would not fit.
What is a self-erecting tower crane?
A self-erecting tower crane is a smaller tower crane that raises its own mast and unfolds its jib using hydraulics, so it does not need a separate assist crane to stand it up. Its quick setup suits shorter-term jobs, residential work, and tight or fast-moving sites, though it carries less than larger hammerhead, flat top, or luffing cranes.
How does a tower crane climb or build itself?
Most tower cranes are first erected with a mobile assist crane, then grow taller as the building rises. With external climbing, the crane adds mast sections at the top using a climbing collar that jacks it up. With internal climbing, the crane sits inside the structure and jumps up floor by floor. Self-erecting models are the exception and raise their own mast.
What is the lifting capacity of a tower crane?
It depends on the make, model, and configuration. Maxim Crane’s tower crane rentals range from 4 to 66 tons. Across the industry, capacities run from roughly 2 tons for small self-erecting cranes up to about 100 tons for large luffing models, with specialized cranes going higher.
How do tower cranes stay upright and withstand high winds?
A tower crane stays stable through balance and ballast. The load on the jib is offset by a counterweight on the counter-jib, and the crane sits on a wide base weighted down with concrete or anchored to the structure. Tower cranes are designed to handle high winds, and crews stop lifting when winds climb past safe limits for the crane.
Plan Your Next Tower Crane Rental
The right tower crane keeps a project moving; the wrong one slows everything down. If a tower crane is on the table for your next build, Maxim Crane can help you weigh the type, capacity, and setup against your site and schedule. Request a quote from Maxim Crane to get started, or contact the team to talk through your project requirements.
