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CMAA
Crane Duty Classifications
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CMAA
Class
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Description
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Further
Explaination
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Class
A
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Standby
or Infrequent Service
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This
class normally includes installation and
maintenance cranes. This equipment usually
operates at slow speeds for precise handling
with long idle periods between lifts. Maximum
capacity lifts are sometimes required. |
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Class
B
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Light
Service
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This
class of crane is used in repair shops,
light assembly operations, service buildings,
light warehousing, etc. Service requirement
is light and speeds are slow. Loads vary
from none to occasional full capacity. Lifts
per hour would range from 2 to 5, and average
10 feet per lift. |
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Class
C
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Moderate
Service
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In
terms of numbers, most cranes are built
to meet Class C service requirements. This
service covers cranes that may be used in
machine shops or papermill machine rooms.
In this type of service, the crane will
handle loads that average 50% of the rated
capacity with 5 to 10 lifts per hour averaging
15 feet. Not over 50% of the loads at rated
capacity. |
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Class
D
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Heavy
Service
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This
service covers cranes which may be used
in heavy machine shops, foundries, fabricating
plants, steel warehouses, container yards,
lumbermills, 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 15 feet, not over 65 percent
of the lifts at rated capacity. |
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Class
E
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Severe
Service
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This
type of service is reserved for top riding
bridge and gantry type multiple girder electric
overhead traveling cranes and 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. |
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Class
F
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Continuous
Severe Service
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This
type of service is reserved for top riding
bridge and gantry type multiple girder electric
overhead traveling cranes and requires
a crane capable of handling loads approaching
rated capacity 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,
with special attention to ease of maintenance
features. |
