Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Related Articles


Cribbing under crane outrigger feet or chock feet

Cribbing under crane outrigger feet or chock feet

Cribbing under crane outrigger feet or chock feet

I need at least3'x3' cribbing under outrigger pad to transfer the load to supporting slab
Question is if feet has rubber (with ribs like car tires) pads as load transferring surface, the damping can reduce impact load or the cribbing requirements?
Thanks for help.

RE: Cribbing under crane outrigger feet or chock feet

Crane support loads are not significantly dynamic. With a good operator, there should be no or negligible impact while the crane is stationary and operating.

As such, the cribbing requirements would not decrease.

The name is a long story -- just call me Lo.

RE: Cribbing under crane outrigger feet or chock feet

On the other hand, if the ribs were pointed down (under the square 3x3 foot pad), they would compress a softer ground or dirt until sufficient area were resisting compression forces under each of the 4x cranes pads. If large gravel or asphalt or concrete, you'd expect less compression of the surface, but the ribs would compress.

Having ribs under the pads (facing down) would essentially reduce the initial contact area by 1/2 the pad nominal size.

RE: Cribbing under crane outrigger feet or chock feet

It's the crane outrigger pads and not the cribbing that has the rubber ribbed surface, is that correct? I've been in a few heavy lifts with injection mold machines, and honestly I've never seen cribbing pads with rubber surfaces. This should not affect your cribbing surface as it relates to the slab, the pads are already sized with compression of any elastomeric material factored in to the crane capacity. The operator will load the outriggers prior to lift, likely enough that the undercarriage and chassis of the crane will no longer be load bearing through to the road tires.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

RE: Cribbing under crane outrigger feet or chock feet

My thoughts would be to still use the required cribbing area and do not decrease due to rubber pads. The rubber pads are just for decreasing vibration and prevent damage to surfaces.

RE: Cribbing under crane outrigger feet or chock feet

I am going to keep cribbing for the job.
Thanks for all support and clarification.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Research Report: State of IoT Adoption in Product Development 2019
This research report, based on a survey of 234 product development professionals, examines the current state of Internet of Things (IoT) adoption by product design teams, its perceived importance, and what features and capabilities teams consider important when making decision about adding IoT functionality to their products. Download Now
Research Report: Augmented Reality for Maintenance, Repair and Overhaul (MRO)
The term Industry 4.0 denotes a cluster of technologies that’s poised to fundamentally reshape manufacturing and bring about a new industrial revolution. These include 3D printing (AM), the Industrial Internet of Things (IIoT), artificial intelligence (AI) and mixed reality technologies, more commonly known as virtual reality (VR) and augmented reality (AR). Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close