Which Overhead Crane Service Class is Best for Your Business

There are six (6) different classifications for overhead cranes, specified by the Crane Manufacturers Association of Mỹ (CMAA). Each CMAA crane classification takes the following criteria into consideration:

Service:

How frequently will the crane be used?

Speed:

How quickly can the crane transfer materials or equipment? How many lifts per hour can the crane perform?

Maintenance Requirements:

Will the crane need to be serviced regularly?

Distance:

How far does the crane need to move material in your facility?

Rated Capacity:

What is the average rated load of the materials that your crane will be moving? How often will the crane be lifting fully-rated loads?

Service Conditions:

What type of environment will the crane be operating?

Different Types of Overhead Crane Classifications

If you can answer or define each of the criteria above, it will be much easier to determine the type of crane system that works best for your business or industry. Below we’ll identify and define the six types of overhead crane classes and provide types of businesses or industries that match up the best with each classification.

CRANE CLASS A (STANDBY OR INFREQUENT SERVICE)

This service class covers cranes where precise handling of equipment at slow speeds with long idle periods between lifts are required. Capacity loads may be handled for the initial installation of equipment and for infrequent maintenance. Typical examples are cranes used in powerhouses, public utilities, turbine rooms, motor rooms, and transformer stations. This is the lightest crane as far as the duty cycle is concerned.

CRANE CLASS B (LIGHT SERVICE)

This service class covers cranes where service requirements are light and the speed is slow. Loads may vary from no load to occasional full-rated loads with 2 to 5 lifts per hour, averaging 10 feet per lift. Typical examples are cranes in repair shops, light assembly operations, service buildings, light warehousing, etc.

CRANE CLASS C (MODERATE SERVICE)

This service covers cranes where service requirements are deemed moderate, handling loads which average 50 percent of the rated capacity with 5 to 10 lifts per hour, averaging 15 feet, with not over 50 percent of the lifts at rated capacity. Typical examples are cranes used in machine shops, paper mill machine rooms, etc.

CRANE CLASS D (HEAVY SERVICE)

In this type of service, loads approaching 50 percent of the rated capacity will be handled constantly during the work period. High speeds are desirable for this type of service with 10 to 20 lifts per hour averaging 15 feet, with not over 65 percent of the lifts at rated capacity. Typical examples are cranes used in heavy machine shops, foundries, fabricating plants, steel warehouses, container yards, lumber mills, etc., and standard duty bucket and magnet operations where heavy-duty production is required.

CRANE CLASS E (SEVERE SERVICE)

This type of service requires a crane capable of handling loads approaching the rated capacity throughout its life with 20 or more lifts per hour at or near the rated capacity.

Typical examples are magnet, bucket, magnet/bucket combination cranes for scrap yards, cement mills, lumber mills, fertilizer plants, container handling, etc.

CRANE CLASS F (CONTINUOUS SEVERE SERVICE)

In this type of service, the crane must be capable of handling loads, approaching rated capacity continuously under severe service conditions throughout its life. Typical examples are custom-designed specialty cranes essential to performing the critical work tasks affecting the total production facility, providing the highest reliability with special attention to ease of maintenance features.