CMAA Releases Updates To Overhead Crane Specifications 70 And 74

The Crane Manufacturers Association of America (CMAA) has released the latest updates to two of its technical specifications:

  • CMAA Specification 70 – Specifications for Top Running Bridge & Gantry Type Multiple Girder Electric Overhead Traveling Cranes
  • CMAA Specification 74 – Specifications for Top Running & Under Running Single Girder Electric Traveling Cranes Utilizing Under Running Trolley Hoist

The two documents’ updates include new technical standards for multiple and single girder cranes, respectively. The mechanical section of Specification 70 also features a revision of the hoisting ropes section to include consideration of additional rope constructions, as well as a new keys and keyways section to address allowable stresses, and significant additional information regarding drum design. In both Specifications 70 and 74, a section on wind restraints has been added. Further, the electrical sections in both Specifications have been revised.

Last updated in 2015, these modifications are the first substantial changes to the publications since that time. The new updates were proposed, written, evaluated and implemented by CMAA’s engineering committee. The group includes more than 50 experts divided across three sub-committees — structural, electrical and mechanical — each dedicated to the safe design and use of overhead cranes. More than 50 volunteers from CMAA’s 45-plus member companies have spent countless hours researching and debating the finer points of crane design to ensure that end users receive a technical specification that is thoroughly vetted and backed by the leading manufacturers in North America.

CMAA members represent the industry’s leading suppliers of overhead crane systems. They design, manufacture, assemble, install and service overhead cranes and components. CMAA members, with the combined experience of more than 30,000 crane installations in North America in the last decade, are committed to providing products which focus on safety and innovation. The organization offers a variety of resources—including buyers’ guides, engineering specifications, OSHA Alliance safety tip and fact sheets, inspection and maintenance checklists, safety seminars and more—via its website at

Want to purchase the latest CMAA Specifications? The full technical specifications library — including the two updated documents — is available now.