At American Crane & Equipment Corporation (ACECO), we believe that understanding the intricacies of crane types and their components is essential for efficient and safe operations. Cranes are indispensable in construction, manufacturing and logistics, enabling the lifting and moving of heavy loads with precision. This guide provides an overview of crane types, basic terminology and key structures involved.
Types of Cranes
Overhead Crane: Features a movable bridge carrying a hoisting mechanism that travels on an overhead fixed runway structure.
Gantry Crane: Similar to overhead cranes, but with the bridge supported on two or more legs running on fixed rails or runways.
Jib Crane: Has a bridge girder (boom) fixed at one end, often hinged to allow rotation, providing flexibility in small spaces.
Single Girder Crane: Runs on a single bridge girder, suitable for lighter loads.
Double Girder Crane: Utilizes two bridge girders, ideal for heavier loads and longer spans.
Bridge Girder: The primary horizontal beam of the crane bridge.
Box Section: A rectangular cross-section of girders, enhancing strength and stability.
Camber: An upward curve in the girder to counteract deflection.
End Tie: Connects the ends of the girders to maintain structural integrity.
Load and Capacity
Capacity: The maximum load a crane is designed to handle, measured in tons.
Rated Load: The safe maximum load a crane can handle.
Critical Load: Any load whose uncontrolled movement could compromise safety systems.
Crane Movement
Reeving: The path the hoist rope takes around various pulleys and sheaves.
Span: The horizontal distance between runway rails.
Hook Approach: The minimum horizontal distance between the runway rail and the hook.
Safety Features
Anti-Collision: Prevents cranes from contacting each other.
Single Failure Proof: Design features ensuring that a single component failure won’t result in load loss.
Holding Brake: Automatically prevents motion when power is off.
Regenerative Braking: Uses electrical energy to control speed and feed it back into the power system.
Glossary of Terms
Adjustable Frequency Drive: Motor controller converting fixed frequency AC power for speed control.
Auxiliary Hoist: A secondary hoist for lighter loads at higher speeds.
Bogie: Short end truck distributing crane wheel loads.
Clearance: Minimum distance from crane extremity to nearest obstruction.
Collectors: Devices collecting current from conductors for the bridge and trolley.
Festooning: Power supply method for a traveling hoist.
Sheave: A grooved wheel or pulley guiding the hoist rope.
Top Running Crane: End trucks supported on rails atop runway beams.
Under Running Crane: Movable bridge running on the lower flanges of a fixed runway structure.
Wheel Load: The load on any wheel without vertical inertia force.
Understanding these terms and structures is crucial for anyone involved in crane operation, maintenance, or purchasing. At ACECO, we are committed to providing high-quality cranes and equipment, and we believe that informed customers are empowered customers. Proper knowledge ensures the safe and efficient use of cranes, contributing to overall project success. To learn more, visit our Glossary Guide for Cranes.
Aerospace manufacturers regularly lift, turn, and position large components when assembling their products. These lifts are deemed critical since the items being hoisted are usually cumbersome, sensitive to damage, and extremely expensive. The margin for error in these applications is slim, and any mistakes can result in significant production delays.
With so much at stake, aerospace cranes tasked with lifting must be carefully selected and specially designed to meet the stringent standards of the industry. In recent years, American Crane has proudly supplied several prominent companies in the industry with lasting solutions to these difficulties.
How NASA Used a Double Girder Crane
Lockheed Martin contracted American Crane to design an assembly crane for The National Aeronautics and Space Administration (NASA) Orion, its first spacecraft designed for long-term manned space flight and exploration. NASA faced the challenge of lifting the vessel’s spacecraft crew module to its final position atop the service module.
To successfully lift and install the crew module, NASA needed a crane suited to the job. Since the Orion capsule weighs 22,899 pounds (about 11.45 tons), its crane needed enough capacity to handle to the weight of the module, with additional capacity as a safety margin.
Mounting aerospace components is a delicate process that requires highly accurate equipment. NASA’s crane needed to accommodate precise movements to ensure the proper alignment of the separate components during installation. In addition, sensitive handling was required to minimize the possibility of damage due to improper handling or falling debris.
With NASA’s specifications in mind, American Crane designed a top-running double girder crane with a 25-ton capacity, more than twice the weight of the capsule. To provide NASA with greater control over movement during assembly, the crane also featured micro speed movements.
Our crane included specific ‘clean room’ features such as self-locking stainless steel fasteners to prevent the loosening of bolts, walkways equipped with kick plates to capture falling debris, and runway conductor bars enclosed in a plastic housing. Special coatings were applied to prevent corrosion.
NASA successfully uses the double girder crane to lift the Orion module to its final position. Permanently installed at the Kennedy Space Center, the double girder crane continues to be used for other sensitive hoisting applications such as telescope arrangement, lens management, and spacecraft maintenance.
Other Cranes for Aerospace Industry
Double girder cranes are just one of the many types of cranes used in the aerospace industry. Facility size, maximum lifting weights, and clearance heights are some of the factors that need to be taken into consideration when searching for an aerospace crane.
In another example of our work, Boeing hired American Crane to produce a material handling system for its manufacturing plant in North Charleston, SC, where it constructs the 787 Dreamliner. The system needed to be able to access all areas of the 460,000 square foot facility while allowing users to intricately and precisely lift any component.
For this particular application, we created an 80-ton underhung crane consisting of multiple bridges. To promote access to the entire facility, the crane was designed without columns so that the bridges could be interlocked, allowing the trolley to cross from one bridge to the other. Its precision control design further enables Boeing to safely lift objects with difficult centers of gravity regardless of their size.
For more than four decades, American Crane has proudly worked with Lockheed Martin, Boeing, and other authorities in the aerospace industry to solve their manufacturing challenges. Specializing in start-to-finish design and fabrication, we’re pleased to be recognized as the leading provider of crane and hoist solutions in the industry.
