So what is a crane?

The standard definition of a crane is “a device used for lifting and lowering a load and moving it horizontally and laterally.”

That’s only part of the story. A crane is an anti-gravity device. Gravity is a powerful force that wants to pull everything to the ground. But where Star Trek and Hollywood use special effects to lift dead weight, the crane industry uses wire ropes, couplings, motors, gears and brakes. Much like your car. And like your car, a crane wears and requires maintenance.

How are cranes classified?

CMAA (Crane Manufacturers Association of America) groups cranes into six broad classes, based on their service capacity.

• Class A (Standby or Infrequent Service) cranes are used in the precise handling of equipment at necessarily slow speeds, where full capacity lifts are rare. Class A cranes tend to have long, idle periods between lifts.
• Class B (Light Service) cranes are used in repair shops and light assembly operations, at slow speeds. Though Class B cranes usually handle light loads and service requirements, they may lift an occasional full-rated load, with two to five lifts per hour at an average of 10 feet per lift.
• Class C (Moderate Service) cranes are frequently used in machine shops or steel service centers. Loads can average 50 percent of rated capacity, with 5 to 10 lifts per hour at an average of 15 feet per lift.
• Class D (Heavy Service) cranes are used in heavy machine shops, foundries, container yards, lumber mills, and standard duty bucket and magnet operations where heavy production is required. Class D cranes regularly handle loads approaching 50 percent capacity, at 10 to 20 lifts per hour at high speeds.
• Classes E and F (Severe and Continuous Severe Service) cranes handle rated capacity, under extreme service conditions, for their life span. They may operate at 20 or more lifts per hour. Class E and F cranes provide the highest reliability, and are designed with special attention to ease of maintenance features.