Overhead Crane

Overhead Crane

This article will give you everything you need to know about overhead cranes. You will learn about what is an overhead crane, how overhead cranes operate, how they are used, and types of overhead cranes.  Before your company looks at the cost of building cranes in your factory, you should find your measurements for the spans, girder type, and usage to be able to see what construction will cost before you buy.

What is an Overhead Crane?

An overhead crane, sometimes referred to as a bridge crane, industrial crane, and overhead traveling crane, is a heavy duty machine capable of moving extremely heavy objects from one location to another using the overhead space to perform the loading and unloading of applications. Overhead cranes lift loads multi-directional, allowing for the movement of materials in manufacturing and storage inside or outside a facility. These cranes cover an area that moves loads from side to side and backwards and forwards. This rectangular area is mounted with a hoist on a trolley that runs on an elevated track parallel to the runway. 

Types of Overhead Cranes

The different types of overhead cranes include jib, gantry, workstation, monorail, top-running, and under-running. Choosing the correct overhead crane can make work more efficient and improve the production and assembly in a work space. The crane’s capacity may be limited to the type of overhead crane selected or may be specifically designed for different systems. Additional equipment such as a hoist and trolley may be required to your lifting needs. 

JIB

A jib crane is a type of overhead crane that is often used in smaller work cell environments for recurring lifting tasks. If you visualize a jib crane, they look like a upside down letter L, and are usually mounted to the floor from a support system or support beam from the building. It's horizontal member, known commonly as a boom or jib, extends horizontally and supports a movable hoist fixed to the wall or mounted on the floor. The jib crane’s length typically reaches 20 feet and can handle a capacity of 6,000 pounds. The boom of the crane is able to rotate 360 degrees, allowing for great flexibility when positioning the load by hand. These cranes are used for tasks such as machine loading, unloading, and die changing.

Gantry

A gantry crane is very similar to an overhead bridge crane, the main difference is that the girder, single ort double, rests upon ridgidA gantry crane is very similar to an overhead bridge crane, the main difference is that the girder, single or double, rests upon legs instead of runways that can be built into the structure. These legs may have casters that allow the user to roll the gantry crane along the floor. This gives a gantry crane greater mobility as it can be moved around the facility to be used. Overhead gantry cranes can also be constructed with either steel or lightweight aluminum. Aluminum gantry cranes are transportable compared to steel gantries because of its lightweight design that significantly reduce the weight of rigid steel legs that are immobile.

The height and span of a gantry crane may be adjustable or fixed. A fixed height gantry is the most common type, being suitable for fixed and repetitive tasks while adjustable gantry cranes can be altered for the application. 

Workstation

A workstation crane is designed to work with a specific machine or assembly line. It typically has an I-beam that runs the length of the machine and a hoist that moves up and down the beam. This crane is bolted directly to the machine or workstation and provides lifting capability within that area. The advantage of using a workstation crane is that it eliminates the need to install into the foundation, with most workstation cranes needing little when it comes to the installation process.

Monorail

A monorail crane is similar to a gantry crane, but it is most commonly installed in breezeways or hallways. This type of overhead crane has two tracks that are under the bridge that are attached to support columns. The hoist trolley typically runs up one track and down the other, allowing the monorail crane to be multi-directional. This complex path allows for curved configurations of the I-beam and can also include switches and branches to transport items though the monorails assembly line.

Top Running overhead crane

Top-running overhead cranes have a fixed track system or rail system on the top of each runway beam, which allows the end trucks to carry the hoist and bridge along the top of the runway system. The trolley rides on these rails and has the hoist mounted to it. This type of overhead crane is best suited for low-bay areas where headroom is limited as the rails take up less space then the bottom and side running cranes. Girder top running overhead crane's have no limiting capacity, which allows them to handle small capacity loads and much heavier large loads. Top running overhead bridge cranes can be built to capacities from 1/4 ton for lighter loads or 100 tons for construction and material handling.

Under Running overhead crane

Under-running overhead cranes, commonly named “underhung” crane, uses a fixed track or rail system on the bottom of each runway beam, which allows the end trucks to carry the hoist and bridge along the bottom of the runway system. The trolley rides on these rails and has the hoist mounted to it. This type of overhead crane is best suited for low-bay areas where headroom is limited as the rails take up less space then track or rails mounted on top of the runway beams.

Most modern overhead cranes are typically equipped with electric chain-driven hoists which run along floor-mounted metal guide-ways known as “tracks” (commonly referred to as “runways"). The trolley is supported by two wheels directly below it.

Bridge Cranes

A bridge crane can be easily visualized, they consist of two runways that are elevated and run parallel along the length of the bridge crane. A runway can be built into the supporting structure of the building, or in the case of a free standing bridge crane, it can be supported by columns that are floor mounted instead. The beam connecting the runways is a movable single girder or double girder beam that (when supported by an end truck on each side) moves the girder back and forth along the runway. Girders have a long life in the heavy service industry, maximizing floor space and only requiring repair and servicing if damaged. The choice between a single girder system and double girder system depends on the span between runways, weight of load lifted, and lifting height. Single girder bridge cranes are the most cost-effective solution for various lifting applications, they typically use less material and this can significantly reduce cost, saving money on material, freight, and installation. Single girder cranes will rarely be seen rated higher than 15 tons, making a double girder crane a better choice for heavy loads and single girder cranes better for medium-sized to light loads. 

Single Girder overhead bridge crane

Single-girder overhead bridge cranes use a single I-beam as the bridge, typically this beam is made of steel. A single girder I-beam can also be made out of aluminum. The crane’s trolley rides on top of the beam and the hoist hangs below it. This type of crane has a more limited range than a double girder overhead bridge crane but is much lighter

Double Girder overhead bridge crane

A double-girder overhead bridge crane uses two I-beams as the bridge, typically these beams are made of steel. A double girder I-beam can also be made out of aluminum. The crane’s trolley rides on top of the beam and the hoist hangs below it. This type of crane can span greater distances than a single girder overhead bridge crane and can lift heavier loads

Below the hook equipment and attachments to overhead cranes

Below the hook equipment, or end effectors, are a variety of application-specific attachments that can be used on a overhead crane to handle the lifting and position of loads for facilitating load lift. Below-the-hook lifting devices include coil hooks, coil grabs, mechanical lifters, spreader bars, and magnet lifts. A coil hook used in conjunction with a crane and hoist allows for overhead cranes to transport of steel and other 

Industries using overhead cranes

Overhead cranes are vital to the safety and success of many industries. Because they are such adaptable tools, they can be customized for almost any space, including environments where headroom or space is a limiting factor. Overhead cranes lift and move heavy loads, and the different types, such as bridge cranes, gantry cranes, jib cranes, perform their job in your business and company work area.

Overhead cranes are being used in many different industries around the world because they can lift heavy objects up to extended heights quickly. Industries that usually use overhead cranes include material handling and factories. Industries such as Storage, Automotive, metal manufacturing, shipbuilding, aviation, seaports, goods assembling, construction, power plants, and many more rely on the the right overhead crane for your facility and application. Our company will service you anywhere in America.

Manufacturers of Overhead Crane Hoist

A gantry crane on it’s own is not able to lift an object. You’ll need an electric hoist or manual hoist in order to lift the load, using the gantry crane as a lifting point. A Overhead crane system may require electric chain hoists for more repetitive lifting or electric wire rope hoists for a job site that does heavy duty lifting. Here is a list of popular hoists to use on overhead bridge cranes. 

Electric Chain Hoist

CMCO Electric Chain Hoists

 

Harrington Electric Chain Hoists by KITO group

 

 

Lever Hoist

 

Hand Chain Hoist