Category Archive: Double Girder Cranes

Single vs Double Girder Cranes: Which One Is Right for Your Needs?

Single vs Double Girder Cranes: Which One Is Right for Your Needs?

When it comes to selecting the right crane for your operations, understanding the differences between single and double girder cranes is essential. At American Crane & Equipment Corporation, we offer a variety of crane solutions tailored to meet your specific lifting requirements. Let’s explore the key differences between single vs double girder cranes to determine which one is right for your needs and application requirements.

Single Girder Cranes

Single girder cranes are designed with one main girder and are ideal for lighter lifting applications. Here are some of the key advantages. 

  1. Efficiency in Smaller Spaces: Single girder cranes are compact, making them perfect for facilities with limited space. Their streamlined design allows for efficient operation in smaller areas without compromising performance.
  2. Cost-Effective Solution: Due to their simpler construction, single girder cranes are generally less expensive to manufacture and install. This makes them a budget-friendly option for many businesses.
  3. Reduced Structural Stress: With less deadweight, single girder cranes place minimal stress on building structures and foundations. This reduced load minimizes wear and tear on runway beams, leading to lower maintenance costs over time.
  4. Ease of Installation and Maintenance: The simpler design of single girder cranes translates to easier installation and maintenance, reducing downtime and increasing productivity.

Double Girder Cranes

Double girder cranes, on the other hand, are equipped with two main girders and are built to handle more demanding lifting tasks. This makes them suitable for industries that require moving large, heavy materials.

  1. Higher Load Capacity: Double girder cranes are capable of lifting heavier loads compared to single girder cranes. This makes them suitable for industries that require moving large, heavy materials.
  2. Increased Hook Height: With the hoist and trolley positioned between the girders, double girder cranes offer greater hook height. This allows the load to be lifted higher, which is crucial for applications requiring significant vertical clearance.
  3. Wider Span and Additional Features: Typically, double girder cranes have a wider span and can accommodate additional features such as walkways, maintenance platforms, operator cabs, and lighting. These enhancements improve operational efficiency and safety.
  4. Versatility and Customization: Double girder cranes offer customization to meet operational needs, including the integration of advanced control systems and automation features. This versatility makes them a preferred choice for complex lifting operations.

Choosing the Right Crane for Your Needs

When deciding between single and double girder cranes, it’s important to consider your specific operational requirements. For lighter loads and smaller spaces, a single girder crane offers a cost-effective and efficient solution. However, for handling heavier loads, achieving higher hook heights, and accommodating additional features, a double girder crane is the better choice.

At American Crane, we offer a wide range of single and double girder cranes that enhance safety and efficiency in your operations. Visit our store or contact us today to learn more about our crane solutions and how we can support your lifting needs. 

Crane 101: Types of Cranes, Basic Terms and Structures

Crane 101: Types of Cranes, Basic Terms, and Structures

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.

Learn more: The Basics of Cranes and Hoists

Basic Terms

Crane Components

  • Bridge: The main horizontal structure that supports the trolley and travels parallel to the runway.
  • Trolley: Carries the hoisting mechanism and moves along the bridge.
  • Hoist: The mechanism used for lifting and lowering loads.
  • End Trucks: Support the bridge girders and house the wheels that travel on the runway rails.

Learn more: The Four Key Crane Components

Structural Elements

  • 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.

Cranes in Aerospace: A Challenging Lift for NASA

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

NASA Used a Double Girder CraneLockheed 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.

To learn more about the various types of overhead cranes used in the aerospace industry, download our eBook, Building Toward the Sky: Overhead Cranes for Aerospace.