from the following CMAA 70 service classifications:
1. Class A (Standby or Infrequent Service): This
service covers cranes which may be used in
installations such as powerhouses, public utilities,
turbine rooms, motor rooms and transformer stations
where precise handling of equipment at slow speeds
with long, idle periods between lifts are required.
Capacity loads may be handled for initial
installation of equipment and for infrequent
maintenance.
2. Class B (Light Service): This service covers
cranes which may be used in repair shops, light
assembly operations, service buildings, light
warehousing, etc., 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 3 m (10 feet) per lift.
3. Class C (Moderate Service): This service covers
cranes which may be used in machine shops of paper
mill machine rooms, etc., where service requirements
are moderate. In this type of service the crane
will handle loads which average 50 percent of the
rated capacity with 5 to 10 lifts per hour,
averaging 4.5 m (15 feet), not over 50 percent of
the lift at rated capacity.
4. Class D (Heavy-Duty): This service covers
cranes which may be used in heavy machine shop,
foundries, fabricating plants, steel warehouses,
container yards, lumber mills, etc., and standard
duty bucket and magnet operations where heavy-duty
production is required. In this type of service,
loads approaching 50 percent of the rated capacity
will be handled constantly during the working
period. High speeds are desirable for this type of
service with 10 to 20 lifts per hour averaging 4.5 m
(15 feet), not over 65 percent of the lifts at rated
capacity.
5. Class E (Severe Service): This type of service
requires a crane capable of handling loads
approaching rated capacity throughout its life.
Applications may include magnet, bucket,
magnet/bucket combination cranes for scrap yards,
cement mills, lumber mills, fertilizer plants,
container handling, etc., with 20 or more lifts per
hour at or near the rated capacity.
6. Class F (Continuous Severe Service): This type
of service requires a crane capable of handling
loads approaching rated capacity continuously under
severe service conditions throughout its life.
Applications may include custom designed specialty
cranes essential to performing the critical work
tasks affecting the total production facility.
These cranes must provide the highest reliability
SECTION 14630A
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