Engineered Overhead Bridge Cranes - Single Girder and Double Girder

Overhead bridge cranes are a proven solution for heavy industrial lifting applications, as they provide the safest and most efficient way possible of lifting and moving materials from one location to another. They significantly improve the workflow and manufacturing process in warehouses or facilities, especially in industries such as steel fabrication, coil handling, power, defense, railroad, automotive, and paper milling.

Top Running Single Girder Cranes

Top Running Double Girder Cranes

Under Running Single Girder Cranes

Under Running Double Girder Cranes

Why choose Tri-State Overhead Crane and Hoist to design and build your next overhead crane and runway?

Tri-State Overhead Crane and Hoist has been providing American Made cranes and hoists throughout the Midwest and beyond for over 60 years. This experience has helped us become a leader in the design and manufacturing of overhead bridge cranes, will all of our cranes fabricated in house at our 40,000 square foot state of the art facility located in St. Louis, MO.

Because TSOC's sales and engineering teams work so closely together, it’s easier for us to consult, design, and fabricate an EOT (electric overhead traveling) crane for your specific application. So whether you’re looking for a simple single girder bridge crane or a custom-engineered double girder bridge crane, Tri-State Overhead Crane is your go-to source for all your overhead bridge crane needs.

Our equipment is used in traditional industries such as steel fabrication, coil handling, power, defense, railroad, automotive, paper milling as well as specialized environments such as medical, semi-conductor, biotechnology and food production. Check out some of our overhead crane installations here on our Case Studies page.

What is an Overhead Bridge Crane?

Bridge cranes, sometimes referred to as electric overhead traveling (EOT) cranes, are a type of overhead crane system that consist of two overhead runways, the crane bridge (the horizontal beam that rides along the runways), a hoist, and a trolley. A standard design will feature one or two load-bearing beams, also known as girders, that are mounted to either the top or bottom of the runway.

Overhead Bridge Crane Components

Below is a drawing of a top running double girder bridge crane, where we've labeled some of the common overhead crane components. You can learn more about these and other overhead crane terms here on our Overhead Crane Definitions page.

Common Overhead Bridge Crane Terms:

Bridge - the load bearing beam which the hoist and trolley ride on.
Runway - parallel beams that allow the bridge to travel from one end to another.
End Truck - drives the bridge down the runway.
Control Panel - used to control the end truck.
Hoist - this is mounted to the bottom of the bridge and moves the hook.
Hook - attaches the load to be moved.
Trolley - allows the load and hoist to be moved from side to side.

Overhead Bridge Crane Classifications

The Crane Manufacturers Association of America, Inc. (CMAA) classifies bridge cranes based on their duty cycles and the type of service they will be used for. These classifications are listed in the chart below:

CMAA Crane Class	Description
A	Standby or Infrequent Service
B	Light Service - 2-5 lifts hr.
C	Moderate Service - 50% capacity, 5-10 lifts hr.
D	Heavy Service - 50% capacity, 10-20 lifts hr.
E	Severe Service - near capacity, 20+ lifts hr.
F	Continuous Severe Service - near capacity and continuous service throughout day

Bridge cranes can be provided for CMAA Class A, Class B, Class C, Class D, Class E and Class F with capacities to 200 tons and spans to 150 feet. Modular Cranes can be used off the shelf and are normally classified as A, B or C with up to 5-10 lifts per hour at 40% capacity (e.g. machine shops, sawmills). Process Cranes are engineered for a specific need with continuous use and are classified as D, E or F. They are used for 10+ lifts per hour at 50-75% capacity (e.g. auto industry, steel mills).

We provide different types of overhead cranes for any usage, including single girder overhead cranes for general service or custom built double girder overhead cranes for heavy duty service. Let our team help you with the selection of the correct industrial overhead crane for your application.

Types of Overhead Bridge Cranes

Overhead bridge cranes can be provided in multiple configurations depending on the need. These crane types can be identified by how many bridge girders they have, how they are mounted to the runways, and how they were engineered. Construction can be from Standard I-Beams, Wide Flange Beams, Patented Track, Monobox, and Box Girder Design.

Tri-State Overhead Crane is your go-to source for all types of electric overhead traveling cranes (EOT crane) or ceiling mounted bridge cranes including:

Single Girder Crane - single beam on top of or under the runway/end trucks.
Double Girder Crane - 2 bridge beams on top of or under the runway/end trucks.
Top Running Crane - crane end trucks mounted to the top of the runways.
Under Running Crane - crane end trucks mounted to the bottom of the runways.

Many factors need to be considered when deciding which type of crane will be best for your application: What is the weight being lifted? What span will the overhead crane need to be? How often will it be in use? Will this be indoors or outdoors? What is the size of the building? Our in-house engineering can provide a complete package of footing design, runway design and bridge crane design. Our sales engineers can provide the expertise to help you choose the correct piece of equipment for your application.

Depending on your application, you may choose a top running single girder crane, a under running single girder (under hung) crane, a double girder top running crane or a double girder under running crane.

Top Running Single Girder Bridge Cranes

Tri-State Overhead Crane is your go-to source for top running single girder bridge cranes. Top running single girder bridge cranes can be provided for CMAA Class A, Class B, Class C and Class D with typical capacities up to 35 ton and spans to 90 feet. Higher capacities and spans are available. Typically, these single girder cranes are designed from standard I-Beams or Wide flange but can be provided with custom fabricated monobox, patented track or truss construction.

Advantages of Top Running Single Girder Cranes:

Cost effective due to less dead weight and thus less load on runway and building structure and foundations.
Less cost on freight to job site.
Easier installation thus less install costs.
Ease of maintenance.
All Tri-State Overhead Cranes (TSOC) are designed to CMAA specifications.

Under Running Single Girder Bridge Cranes

This style is also referred to as underrunning, under hung or under slung. Under running bridge cranes are especially versatile when properly applied and can be provided in spans exceeding 75 feet and capacities up to 25 tons, although typical spans do not exceed 60 feet with capacities not exceeding 15 tons. These can be provided in CMAA Class A (standby or infrequent service), Class B (light service), Class C (moderate service), or Class D (heavy service).

The construction of these single girder cranes allows interlocking systems where a transfer of the load is required from one bay to the next, transfer to monorail and then onto another crane, or onto a spur. Typically, these are provided as patented track design but can also be done with wide flange or standard I-beam construction.

Under running bridge cranes typically use electric chain hoists or electric wire rope hoists but can be provided with a pneumatic hoist or a manual hand chain hoist.

These single girder cranes can be provided with pushbutton from the hoist, from an independent traveling pushbutton or radio control.

Special construction for spark resistant, explosion proof or food grade applications are available. A special class of under running bridge cranes are workstation bridge cranes. These are under running and are typically provided for lighter loads (up to 4000 pounds) and are manually pushed but normally have an electric or air chain hoist.

Advantages of Under Running Single Girder Cranes:

Hoist trolley can go underneath runway providing best end approach.
System can be integrated into building design for cost saving on runway structure.
Freestanding workstation bridge crane systems are especially rigid due to connection of columns to headers, and headers to the runway.
Can be provided interlocking to another crane or monorail.
Low headroom design especially with notched bridge beams taking advantage of the depth of the runway.
Easier installation thus less install costs.
Ease of maintenance.

Top Running Double Girder Bridge Cranes

50-Ton Double Girder Top Running Bridge Crane

60-Ton Double Girder Top Running Bridge Crane

5-Ton Double Girder Top Running Bridge Crane

Double girder top running bridge cranes are a proven solution for many of industries toughest applications.

They are typically used in heavy industrial applications ranging from aerospace, steel fabrication, steel processing, steel mills, repair of heavy construction/industrial equipment, defense, railroad construction, energy, plastics, ship construction, heavy chemical, heavy electrical, mining, scrap handling, refuse handling, oil refining to name a few. In addition, these can be provided for special environments such as molten metal handling, explosion proof or spark resistant, clean room, nuclear or food processing.

Double girder top running cranes can be provided for CMAA Class A, Class B, Class C, Class D, and Class E with typical capacities up to 500 tons and spans to 200 feet or more. Typically, these cranes are designed from Wide flange, reinforced wide flange or box girder construction. Trolleys run on ASCE rail or square bar. End trucks can be provided in 4 wheel or 8 wheel (bogey construction) for increased spans and capacities.

Double girder bridge cranes can be provided with many options. Some available options include dual hoist, radio remote control, independent traveling pushbutton station, anti-collision, limits for travel on hoist, bridge or trolley motion, variable frequency control with up to 1000:1 speed control, service and full man platforms, air conditioned controls, cab control, dummy cab, visual and auditory signals, and weight readout. Other specialized options can be provided such as powered bottom block, closed loop variable frequency drive control, magnets, cable reels, stacker mast, and stacker mast for boats.

Advantages of Top Running Double Girder Cranes:

Maximum hook height.
Ease of maintenance especially with control on a catwalk.
Ultra-Low Headroom designs possible.
Durable construction for maximum up time-Less maintenance.
Longer spans and capacities available.
Modular easily repaired components such as brakes, motors, controls for ease of maintenance.
All trolley and end truck loads are on top of ASCE rail or bar so no lower flange loads creating peening or failure as on single girder cranes.
NEMA rated components available.
Faster travel speeds.
Longer spans.
Higher duty cycle.

Under Running Double Girder Bridge Cranes

Double girder under running bridge cranes are an ideal solution for especially tight headroom clearances. The inherent design allows the hoist to be mounted in-between the girders utilizing the girder headroom for optimum high hook. Under running girder cranes are typically supported from a runway structure that has been integrated into the building design.

Double girder under running cranes can be provided for CMAA Class A, Class B, Class C, and Class D with typical capacities of up to 25 tons and spans to 100 feet or more. Typically, these double girder cranes are designed from Standard I-beam, Wide flange, reinforced wide flange, or box girder construction. End trucks can be provided in 4-wheel or 8-wheel (bogey construction) for increased spans and capacities.

Double girder cranes are typically provided with electric wire rope trolley hoists but can also be provided with electric chain hoists depending on the application and customer preference. Although it is not common double girder under running bridge cranes can be provided with top running trolley hoists.

Double girder under running bridge cranes are typically used in light to heavy industrial applications ranging from mining, steel processing, steel mills, railroad equipment, equipment repair, farm implement repair, coal, electricity, defense, and aerospace. Special applications include spark resistant or explosion proof, clean room, and food processing environments.

Some available options for these overhead bridge cranes include but are not limited to dual hoist, radio remote control, custom variable frequency control with up to 1000:1 control ratio, full or service platform, horns and lights, overload protection, stacker masts, and travel limits. All Tri-State overhead cranes are designed to CMAA specifications.

Advantages of Under Running Double Girder Cranes:

Minimum headroom required.
Ease of maintenance (especially when installed with control on a catwalk.)
Can be designed with your building for an integrated system.
Durable construction for maximum uptime and less maintenance.
Ultra-low headroom designs are possible.
Longer spans and capacities are available.
Modular, easily repaired components are available such as brakes, motors, and controls for ease of maintenance.
NEMA-rated components are available.
Faster travel speeds.
Longer spans.
Higher duty cycle.

Single Girder Cranes vs Double Girder Cranes

Single Girder Bridge Cranes - Single girder bridge cranes consist of a single bridge beam attached to the runways. These cranes are a proven solution for many material handling challenges and can provide years of service when properly maintained. They are also highly customizable, offering maximum flexibility for your work area. They can be supplied with manual chain hoists, electric chain hoists, or electric wire rope hoists. Optional features include radio remote control, independent traveling pushbutton stations, anti-collision systems, travel limits for bridge and trolley, variable frequency control, bridge lights and warning bells or horn, and weight readout.

Double Girder Bridge Cranes - Double girder bridge cranes consist of two bridge beams attached to the runways. These cranes are typically provided with top running electric wire rope trolley hoists but can also be provided with top running electric chain hoists depending on the application. Although it is not common, double girder top running bridge cranes can be provided with underrunning trolley hoists as well. Our most popular capacities are: 5-Ton, 10-Ton, 15-Ton, 20-Ton, 25-Ton, 30-Ton, 50-Ton, 75-Ton, and 100-Ton.

Top Running Cranes vs Under Running Cranes

Top Running Bridge Cranes - EOT (electric overhead traveling) crane mounted to the top of the runways. Top running cranes are ideal for maximizing hook height.

Under Running Bridge Cranes - EOT crane with the end trucks attached and supported to the flanges on the bottom of the runway beams, making them ideal for situations with low headroom clearances. Under running bridge cranes are especially versatile when properly applied. This style is also referred to as underrunning, under hung, or under slung.

TSOC distributes and manufactures overhead bridge cranes, including top running single girder cranes, under running single girder cranes, top running double girder cranes and under running double girder cranes. We serve clients from coast to coast, Canada, Mexico, and are especially focused in Missouri, Illinois, Indiana, Iowa, Kansas, Nebraska, Arkansas, Mississippi, Tennessee, Kentucky, South Carolina, Florida, and Oklahoma.