Subpart 1. [Repealed, 32 SR 7]
Subp. 2. [Repealed, ]
IBC section 1607.13.2 is amended to read as follows:
1607.13.2
Vertical impact force.
The maximum wheel loads of the crane shall be increased by the
percentages shown below to determine the induced vertical impact or vibration
force. Impact load shall be applied to one hoist system at a time for multiple
hoist or bridge systems.
A. Monorails,
underhung bridge cranes and pendant operated top running bridge cranes:
15 percent minimum for hoist lift speeds of less than 30 feet
per minute. Percentage equivalent to 0.5 times the hoist lift speed, for lift
speeds of 30 to 100 feet per minute.
50 percent maximum for hoist lift speeds greater than 100 feet
per minute.
50 percent for magnetic pickup or vacuum lift type
systems.
No impact load is required for hand chain (non-powered)
hoists.
B. Cab operated or
remotely operated top running bridge cranes: 25 percent minimum.
Subp. 3. [Repealed, ]
IBC section 1607.13.3 is amended to read as follows:
1607.13.3
Lateral force. Top
running powered bridge cranes.
A. The lateral
force on top running crane runway beams with powered trolleys shall be
calculated as 20 percent of the sum of the rated capacity of the crane and the
weight of the hoist and trolley. The lateral force shall be assumed to act
horizontally at the traction surface of a runway beam, in either direction
perpendicular to the beam, and shall be distributed according to the lateral
stiffness of the runway beam and supporting structure. The runway beams shall
be designed for the lateral and torsional loads, as well as for the maximum
lateral deflection limit of Span/800.
B. Monorails and underhung bridge cranes. The
bridge girder, underhung bridge crane runway beam and monorails shall be
designed with sufficient strength and rigidity to prevent detrimental lateral
deflection. The lateral deflection should not exceed span/800 based on 5
percent of maximum wheel load(s) without vertical impact factor.
