SAFETY
1-14 / Mid-Mount Ascendant Aerial Tower
© 2021 Pierce Manufacturing Inc. All Rights Reserved.
1-9.4
Cribbing and Blocking
Aerial Stabilizer Cribbing and Blocking
You may set up your aerial on a surface that requires cribbing or blocking to maintain the apparatus within the safe
level limits.
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Blocking - Provides a foundation that spreads the load from an outrigger pad or foot over a larger area than the
foot itself.
•
Cribbing - Blocking materials that are used to increase the bearing area and height.
Only use cribbing or blocking if you are trained in the proper methods, have cribbing that will support at least 100
psi of ground contact pressure, and follow these guidelines:
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Place cribbing or blocking material on a firm level base or foundation to properly disperse the weight of the load.
•
Ensure no debris is under the cribbing or blocking which may prevent it from resting firmly on the ground or
surface.
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Place cribbing or blocking directly beneath the outrigger and stacked to avoid slipping.
Figure 1-8: Blocking and Cribbing on a Sloped Surface
RL010
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When using cribbing or blocking on a sloped surface, level the stack on the first layers so that the jack foot sits
on a level surface.
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Always use the apparatus stabilizer pads as the top layer of the block, directly under the jack foot.
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Cribbing and blocking should cover at least as much areas as the stabilizer pads.
•
Frequently inspect cribbing and blocking during operation for settling, slippage, cracking, bending, crushing or
shear failure.
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Cribbing should never be taller than twice the width of the blocking base.
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Use only undamaged hardwood blocking appropriate for the load.
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