types of overhead cranes & components

CRANE TYPES FROM A-Z

At Ace we like to say “the sky’s the limit” and that’s just what you’ll find when you shop for a crane with us. A consultation with an Ace representative will cover every aspect of your overhead lifting needs and facility to determine the best fit for a crane product.

What is the amount of space you’ve got to work with? How many lifts per hour or day will your crane be performing? How heavy is the load you’re lifting? How far will it travel? These questions and more will help us help you select the right type of crane for your application.

Cranes come in a variety of models that handle different kinds of production, lifting anything from car engines on an assembly line to tons of steel in a manufacturing plant to marine components in a shipyard.

about overhead bridge cranes

An overhead crane, also known as a bridge crane, is typically found close to the ceiling in industrial environments, and is used for manufacturing, storage or maintenance applications to aid in the lifting, maneuvering, and unloading of materials. Overhead cranes can be directed by an operator either manually or with wireless controls. They tend to have low maintenance costs comparatively and offer the most lifting height for higher vertical stacking and efficient use of space and because they don’t occupy floor space, they provide better visibility for operators than forklifts.

Buyer Tips for Bridge Cranes

Choosing the lowest price crane bid without understanding the variances in equipment quoted, may result in additional long term maintenance costs to you. Selecting the proper equipment for the application is important. Prior to compiling specifications for RFQ submittal, here are some basic points to consider:

• What type of “Service” will the overhead crane be used for?
• What is the “Frequency” or how often will the bridge crane be used?
• What “Speed” of the bridge, trolley and hoist is necessary to match production efforts?
• Does the buyers’ budget match the specifications desired?

Why do minor changes in the length, width or height of a system impact the overall cost?

Steel comes in standard lengths. Beams: 30’, 40’, 50’ & 60’ angle: 20’ & 40’ tube steel: 40’ & 48’.

Adding another foot of lift or increasing the length of just one bay, could change the design and therefore, the cost.

TYPES OF OVERHEAD BRIDGE CRANES

Additional Buyer Considerations

• What are the long term maintenance costs associated with less expensive crane systems and components?
• Are replacement motors and other parts readily available from multiple suppliers or just one?
• Does the crane provider meet your company’s minimum liability insurance requirements?
• Does the crane provider adhere to all CMAA manufacturing guidelines and specifications?
• Does the crane provider have engineering and manufacturing capabilities or do they outsource these services?
• Are the replacement components readily available, to eliminate potential long lead times and increased costs?
• Does the crane provider have their own installation team or do they outsource installation?
• Not having a qualified crane company install the runway? Make sure the runway is installed to meet the CMAA runway tolerance specifications. An improperly installed runway will either delay installation of the bridge crane or create future problems and add additional costs.
• Are you considering whether or not you will be able to increase the capacity of the crane or add a 2nd bridge in the future? If so, verify if the runway beam size and rail quoted is adequate for future upgrades.

TOP RUNNING SINGLE GIRDER CRANES

An overhead traveling crane that utilizes a single bridge beam attached to the two runway/end trucks that are attached to the top of the crane runways. This bridge beam or single girder supports a lifting mechanism or hoist that "runs" on the bottom flange of the bridge beam. The top running crane achieves greater lifting height compared to under running systems and installation and service are easy.

UNDER RUNNING SINGLE GIRDER CRANES

Under running bridge cranes are an efficient solution to free up floor space as this type of system is typically supported directly by the building roof structure and does not require columns. This type of crane is an electric overhead traveling with the end trucks supported on tracks attached to the bottom flanges of the beam; or supported on bottom flanges of beams. These beams make up the crane runway.

TOP RUNNING DOUBLE GIRDER CRANES

Typically, a top running bridge crane, a double girder system utilizes two girders as the bridge structure and a hoist trolley unit that traverses across rails mounted atop the two bridge girders. The hook from the hoist "falls" between the two bridge beams. Headroom under the crane is increased by utilizing this hoist/crane configuration. A hoist/trolley variation might configure an underhung hoist trolley unit attached to bottom of the bridge girders.

MONO AND DOUBLE BOX GIRDER CRANES

Instead of the typical steel I-beam make-up of the bridge, the box girder crane’s bridge is specially engineered and constructed as a hollow box. This structure can withstand more tension and rotating forces, allowing for some of the largest load capacities of all overhead cranes. A free-standing box crane provides the strength needed to lift heavy equipment without the need of columns or posts. Provides extra strength for longer spans and girder depth can be designed to improve hook height.

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LIGHTWEIGHT OVERHEAD CRANES

Compact, lightweight, industrial quality overhead cranes are ideal for lifting equipment, machines and heavy parts in more confined spaces or on assembly lines for either manual or powered hand-operated applications. When you’re looking for a portable option that can be moved around your facility easily, lightweight overhead cranes might be the smartest and safest lifting solution.

LIGHTRAIL/WORKSTATION CRANES

Lightrail or workstation cranes are an ideal solution for light duty lifting in applications with specific work areas like manufacturing with workers positioned at stations who perform precision lifts. They consist of a moving bridge that runs across parallel runways with a hoist or other lifting device traveling its span. These systems are cost-effective and modular, allowing easy expansion and relocation as lifting needs change.

JIB CRANES

Jib cranes have a boom arm that supports a moving hoist and are compact, ideal for operations with limited space. Similar to workstation cranes, jib cranes provide a great application specific solution where precise load positioning is required, are simple to operate and require less maintenance than overhead cranes. The cantilevered boom lengths run up to 30’ standard with longer spans available. Jibs come in motorized and articulating options.

GANTRY CRANES

Gantry cranes are very versatile and can be built to your specifications no matter what size or capacity. Most motorized or higher capacity gantries, those above 5 ton and 30 foot span, are custom designed for a customer’s unique application. Gantry cranes are made light-weight, portable and adaptable for varied uses. Both fixed and adjustable heights are available.

DAVIT CRANES

A Davit crane consists of an angled beam which pivots over a vertical axis. They are a light duty, versatile, lifting system typically used in applications where lifting from an elevated position is required (e.g. lifting an object from below an elevated platform or from within a pit). Davits come in manual or motorized options and have fixed or adjustable lengths.

CUSTOM DESIGNED CRANES AND LIFTING APPARATUSES

Ace Industries employs a full in-house, quality-driven team of engineers who routinely create innovative solutions for a variety of difficult, application specific problems for our customers. If standard crane systems don’t resolve your equipment needs, our skilled and seasoned engineers can take your specifications and design a fully customized, site specific, workable solution for your facility from the ground up, taking into account any architectural obstacles or existing equipment to work around.

Ace engineers specialize in systems design. When working with your space to design the perfect crane or under the hook apparatus for your unique requirements and challenging business demands, our team can help ensure you are getting the most from your investment, and provide a cohesive and efficient solution, following all OSHA and ANSI regulations.

LOAD TESTING

OSHA requires rated load tests for any new or altered crane. Ace has a fully equipped service department that can help you schedule and perform crane load tests with the results provided as a certificate of proof for your records. Whether you have a large, heavy duty crane requiring the use of massive water weights or a smaller scale crane where test weights will suffice, no load test is too big or too small for Ace Service.

Per OSHA requirement (OSHA 1910.179 (k) Testing), load tests are performed on cranes after new installations or after any modifications or alterations have been made to the lifting equipment, prior to its first use. Trained Ace service technicians perform load tests between 100-125% of the crane’s capacity to ensure the system can handle the maxiumum weight capacity during standard operations. A certificate of proof is provided for you records when completed.

CRANE COMPONENTS

RUNWAYS

A runway is the assembly of rails, girders, brackets and framework on which the crane operates. The crane type will dictate whether the end trucks ride on top of the runway rail or on the bottom flange of the runway beam. Your crane’s runway design and ASCE rail size will determine whether it’s feasible to use the existing structure for any future crane support or the cost associated with increasing its capacity, if necessary. Runways should be installed per CMAA runway specifications and tolerances. Runways that are not installed per CMAA runway specifications or are misaligned due to wear and tear may cause premature wheel wear and other crane and component issues. An engineered runway survey is recommended, if you have abnormal wheel wear, bridge skewing, loud scraping sounds or other indications of a potential runway problem.

TYPES OF RUNWAYS AND RUNWAY COMPONENTS

Runway System using Sister Columns and Tied Back to Building

Runway on Haunches

Free Standing Runway System

Moment Columns

Ceiling Mounted

Rail

END TRUCKS

End trucks ride on the runway rail and move the bridge crane. The two types of end truck designs are the fixed axle and the rotating axle.

Fixed Axle

Rotating Axle

ELECTRIFICATION TYPES

Most hoists and cranes are powered by electricity. Electrification components of hoist and crane systems are relatively simple. There are two circuits in most hoist electrification systems, power and control.

POWER SYSTEMS

The power circuit provides the energy to lift loads and run other motors.

Rigid Bar

Potential Concerns

• Voltage drop on long runs
• Requires hangers every five (5) feet
• Collectors & bar require replacement over time

Festoon

Potential Concerns

Cable Reel

Potential Concerns

• Limited on length
• Cable sag
• Reel spring can pull manual trolleys
• Must have slip ring for 360 degree rotation

CONTROL SYSTEMS AND VARIABLE FREQUENCY DRIVES (VFDS)

The control circuitry activates the devices that turn the main motors on and off. The control circuit operates at lower voltage and current than the power or primary circuit.

Pendant Control Stations

POWERED CHAIN HOISTS

Electric chain hoists, simply put, use an electric motor and controller to vertically lift or lower a load. Because they are motorized and have the lifting strength of a machine, they have a high carrying capacity, are efficient, cost-effective, versatile and durable.

POWERED WIRE ROPE HOISTS

Steel wire ropes are more suitable for very heavy lifting than chains, have a higher strength to weight ratio and can lift up to three times the load. Steel wire ropes are made up of multiple steel wires wound into cables, which are then wound around a central core into the final wire rope. Steel ropes are extremely resistant to corrosion, rust and abrasion and come in a range of sizes and materials.