The quick guide to crane types
You've probably heard the old real estate mantra: location, location, location. Well, for overhead cranes it's application, application, application. Where you're using a crane and what you need it to do for you will dictate the type of crane you'll need to ensure reliable, safe operation and a productive workplace. This article highlights the critical differences between the four major types of cranes. We also explore sub-categories of cranes within each type.
OVERHEAD (OR BRIDGE) CRANE
This type of crane has two overhead runways built into the building’s support structure. A single girder bridge crane design consists of one girder beam supported on each side by an end truck. In a double girder bridge crane design, the bridge consists of two girder beams supported by an end truck on either side. Double girder bridge cranes are used in situations that require heavier capacities and longer spans. Bridge cranes can have the trolley and hoist running on the bottom flange of the runway beam (under running) or on top of the runway beam (top running). Bridge cranes are also known as “girder cranes.”
Top running overhead crane. This is the most common overhead crane solution. Top running cranes run on rails mounted atop a runway beam, giving them more lifting height than an under running crane can offer. (The compromise is they require more overhead space to operate.) The runway system is supported by either engineered columns or building columns. Top running cranes can be designed as either single-girder or double-girder systems. A single-girder top running crane has a typical load capacity up to 20 tons and a typical span of less than 65 ft. A double-girder top running crane has a typical load capacity of up to 400 tons and can typically span more than 65 ft.
Under running overhead crane. An under running crane is usually supported by the building’s structure and has the trolley and hoist running on the bottom flange of the bridge. The crane is bolted to the I-beam, which gives the crane additional stability. Under running cranes are available in single and double girder designs (single is more common) and with profile or box beam construction. In multi-span applications, more end trucks can be added to reduce the weight of the crane structure. These cranes are also known as “underhung.”
Process crane. A process crane is a way to describe any heavy duty bridge crane that is carefully engineered to perform a specific function, such as constant high capacity lifts. Process cranes are typically double girder top running bridge cranes designed to high specifications (CMMA, AIST #6) and are Class E and F cranes. They maximize reliability and safety, so are often called for when the task the crane will perform is critical to production. They can also be highly customized with state-of-the-art functionality, such as automated drives, collision avoidance systems, overload sensors, remote monitoring and below-the-hook lifting devices. Process cranes are sometimes called "custom engineered cranes."
Modular crane. This is a term used to describe any lighter duty overhead crane that’s suitable for applications that don’t require much customization or special add-ons. They’re usually Class A, B or C cranes and consist of a base-level hoist, trolley and bridge. They can be top running or under running, depending on headroom. The bridge, which is fabricated to meet the requirements of the application, can be single or double girder. The modular crane is an economical solution for smaller manufacturing, mills and machine shops. These cranes are also known as "pre-engineered" or “kit cranes,” phrases we find slightly misleading. All cranes require at least some engineering and assembly, even if the majority of the components are off-the-shelf, to ensure they’re properly matched to their application.
Workstation crane. A workstation crane is an overhead crane designed to assist workers in moving or lifting loads ergonomically in a smaller, rectangular work area. The goal is to minimize worker effort, increase productivity and improve workflow. These cranes range from light duty and capacity systems that use light extruded structures to heavy, higher capacity systems that use hollow structural section or hot rolled beams. Typical capacities are from 150 to 4,000 lbs. Lighter capacity systems can be basic push-pull systems that are partially or fully powered in all directions.
A gantry is a structure that’s used to straddle an object or area. A gantry crane uses legs to support the bridge, trolley and hoist; it’s the legs that move, traveling on rails that are at floor level. Gantry cranes are some of the heaviest-duty cranes available, yet they’re portable and lightweight.
Full gantry crane. Full gantry cranes, which are available as single or double girder designs, have their tracks at ground level. These cranes are used most often in shipyards, railyards and steel mills to move extremely heavy loads of up to 20,000 tons but smaller full gantry cranes are used in warehousing, maintenance applications and manufacturing. They’re ideal for outdoor applications and when overhead space is an issue.
Semi-gantry crane. This gantry hybrid has a single overhead runway and a single track that runs on the shop floor. A semi-gantry crane has capacities of up to 20,000 lbs. An advantage of a semi-gantry crane is it can be installed below an existing overhead bridge crane. It’s also ideal for centralized workstations and when an existing building can’t accommodate a bridge crane.
Adjustable gantry crane. The height, span and tread is adjustable on an adjustable gantry crane, making it ideal for use in any situation that requires moving material through aisles and doorways or where there’s obstacles. Welding and fabrication shops use adjustable gantry cranes to lift parts and equipment into position.
Portable gantry crane. If efficient disassembly and reassembly is key, a portable gantry may be a good option. Portable gantry cranes are ideal for plant maintenance applications, pulling heavy equipment and if the crane needs to be transported by service truck.
Track-mounted gantry crane. This gantry crane lifts and moves heavy loads over a fixed route, in a manual or motorized manner.
A monorail crane uses a trolley to carry the hoist along a single stationary beam which can be curved, branched, use switches, and change elevation. Monorail cranes are used for moving lifting devices along a single axis (and therefore won’t be an effective crane system if you need side-to-side trolley movement). Monorail cranes are most effective in production applications where materials are repetitively moved from one point to another over long distances in a straight line.
These space-saving, economical cranes are attached to a mast that is mounted to a wall, column or floor, giving them a rotation of 180 to 360°. This makes jib cranes ideal for moving materials in a smaller, semi-circular or circular area. Jib cranes come in a wide range of capacities, heights and spans. The application, including usage, spans, height clearances and support structure, will determine which style and type of jib crane will work best. They’re little powerhouses, with even small jib cranes being able to lift several tons of material.
Freestanding jib crane. This is the most common type of jib crane. It can be used indoors or outdoors, under an existing bridge crane, and in conjunction with other jib cranes. Jib cranes can offer 360° of rotation, 40 ft. boom heights, spans of 50 ft. and capacities up to 15 tonnes—greater than any other type of jib crane. The trade-off is their expense and the permanence of their mounting.
Foundationless jib crane. Quick to install and relatively portable, these jib cranes don't require a special concrete foundation. Their capacity is up to 1 tonne, boom height is up to 20 ft. and spans are from 9 to 16 ft., with 360° rotation.
Mast-type jib crane. These jib cranes offer some of the robustness of a freestanding jib (40 ft boom, 10 tonne capacity, 10-40 ft span) with the cost-effectiveness and ease of installation of a foundationless jib (only a 6 in. concrete foundation is required). They do need an overhead beam or structure to support the lifts, however.
Wall-mounted jib crane. Because it doesn't require any floor support and can be mounted very close to overhead obstructions, this crane saves space. Because it's attached to a wall, its maximum rotation is 180° to 200°. It can be designed for spans from 8 to 30 ft. and capacities up to 5 tonnes, but the support it's attached to must be able to withstand the load. It can swing to avoid obstacles and fold out of the way if required.
Articulating jib crane. This jib crane has two arms with different degrees of rotation, allowing operators to lift loads around obstacles and into or under containers or machinery. They can be mounted to the floor, wall, ceiling or to a bridge or track crane system. The span of an articulating jib (up to 16 ft.) and capacity (up to 1 tonne) make it best suited for lighter duty operations.
Now that we’ve covered the main types and sub-types of cranes, we’d like to make one final point. It’s important to not lose sight of the main point of any overhead crane system—to give the crane operator the ability to move a desired load from one point to another, safely and efficiently. It takes considerable experience to select the right crane for a particular application. Knowing the types of cranes that are available is a great way to start the conversation, but we never want our customers to feel like they need to be crane experts.