Discussion: View Thread

​We members of the ASCE Construction Institute Crane Safety Committee attempt to assist fellow members (and others) in understanding the issues and difficulties involved with lifting with cranes or alternative methods. The new OSHA crane safety rules cite several instances where qualified engineers should be involved and the lifting standards (if any) by owners and general contractors will also mandate additional rules that are site specific. In addition there are other standards, many of which are ASME standards, that are important- such as the design of below-the-hook lifting devices.

In order to better fulfill our mission and assist fellow members, I would appreciate feedback from those engineers who have had to become involved, whether it was to review (or develop) a lift plan, design rigging components, analyze ground bearing, or any other aspect of lifting. We would like to know what problems you had, where you received advice and references, and what assistance, if any, you needed the most.​

Our committee members represent a wide range of experience and knowledge in this field. 


Jim Worrell
Chairman, ASCE Construction Institute Crane Safety Committee

------------------------------
James Worrell
Mostly Retired
PE, RLS (retired)
Raleigh NC
[jimworrell@...]
------------------------------

I've done reviews of crane track/mat bearing pressures on large diameter pipelines. It's always good to confirm that the underground pipelines can take the loads that will impact the pipe at depth, and to talk to the pipeline owner about this. This is a classic reason to require crane mats when working over or near underground pipelines. This issue is not always on the minds of those deploying the crane, so a good thing for the engineers involved to be aware of.

------------------------------
David Hook P.E., M.ASCE
CIVIL ENGINEER
San Jose CA
(408) 226-1728
------------------------------

Original Message:
Sent: 05-11-2018 08:02
From: James Worrell
Subject: Engineers and crane lifts

​We members of the ASCE Construction Institute Crane Safety Committee attempt to assist fellow members (and others) in understanding the issues and difficulties involved with lifting with cranes or alternative methods. The new OSHA crane safety rules cite several instances where qualified engineers should be involved and the lifting standards (if any) by owners and general contractors will also mandate additional rules that are site specific. In addition there are other standards, many of which are ASME standards, that are important- such as the design of below-the-hook lifting devices.

In order to better fulfill our mission and assist fellow members, I would appreciate feedback from those engineers who have had to become involved, whether it was to review (or develop) a lift plan, design rigging components, analyze ground bearing, or any other aspect of lifting. We would like to know what problems you had, where you received advice and references, and what assistance, if any, you needed the most.​

Our committee members represent a wide range of experience and knowledge in this field.


Jim Worrell
Chairman, ASCE Construction Institute Crane Safety Committee

------------------------------
James Worrell
Mostly Retired
PE, RLS (retired)
Raleigh NC
[jimworrell@...]
------------------------------

Thanks for your reply. What you did was very important and frequently overlooked. I may be overly cautious, but I believe in always matting- whether it is a crawler or an outrigger crane. A minor problem is that there is no generally accepted method for determining the way the load is transferred through the matting and this is especially true for crawler cranes. What lies under the matting is also of concern. A related cause of failure is close proximity to a slope- especially on a recently back-filled one.

There are several crane accidents around the world each week and a notable percentage of them are caused by a ground bearing failure- sometimes combined with overloading. Until recently, there was no good book on the market that addressed ground bearing.

------------------------------
James Worrell
Mostly Retired
PE, RLS (retired)
Raleigh NC
[jimworrell@...]
------------------------------

Original Message:
Sent: 05-12-2018 11:25
From: David Hook
Subject: Engineers and crane lifts

I've done reviews of crane track/mat bearing pressures on large diameter pipelines. It's always good to confirm that the underground pipelines can take the loads that will impact the pipe at depth, and to talk to the pipeline owner about this. This is a classic reason to require crane mats when working over or near underground pipelines. This issue is not always on the minds of those deploying the crane, so a good thing for the engineers involved to be aware of.

------------------------------
David Hook P.E., M.ASCE
CIVIL ENGINEER
San Jose CA
(408) 226-1728

Original Message:
Sent: 05-11-2018 08:02
From: James Worrell
Subject: Engineers and crane lifts

​We members of the ASCE Construction Institute Crane Safety Committee attempt to assist fellow members (and others) in understanding the issues and difficulties involved with lifting with cranes or alternative methods. The new OSHA crane safety rules cite several instances where qualified engineers should be involved and the lifting standards (if any) by owners and general contractors will also mandate additional rules that are site specific. In addition there are other standards, many of which are ASME standards, that are important- such as the design of below-the-hook lifting devices.

In order to better fulfill our mission and assist fellow members, I would appreciate feedback from those engineers who have had to become involved, whether it was to review (or develop) a lift plan, design rigging components, analyze ground bearing, or any other aspect of lifting. We would like to know what problems you had, where you received advice and references, and what assistance, if any, you needed the most.​

Our committee members represent a wide range of experience and knowledge in this field.


Jim Worrell
Chairman, ASCE Construction Institute Crane Safety Committee

------------------------------
James Worrell
Mostly Retired
PE, RLS (retired)
Raleigh NC
[jimworrell@...]
------------------------------

One more clarification. What I should have said is that there needs to be an engineering evaluation of whether the underground facility or nearby structure can take the load imposed by the crane tracks. This is needed for a number of reasons, including protection of the underground facility/structure, the public, and the construction workers. And as noted by Michael Yerion, a dirt bridge can serve the same function as crane mats - to spread the load and reduce the forces at the underground facility level.

------------------------------
David Hook P.E., M.ASCE
CIVIL ENGINEER
San Jose CA
(408) 226-1728
------------------------------

Original Message:
Sent: 05-14-2018 08:00
From: James Worrell
Subject: Engineers and crane lifts

Thanks for your reply. What you did was very important and frequently overlooked. I may be overly cautious, but I believe in always matting- whether it is a crawler or an outrigger crane. A minor problem is that there is no generally accepted method for determining the way the load is transferred through the matting and this is especially true for crawler cranes. What lies under the matting is also of concern. A related cause of failure is close proximity to a slope- especially on a recently back-filled one.

There are several crane accidents around the world each week and a notable percentage of them are caused by a ground bearing failure- sometimes combined with overloading. Until recently, there was no good book on the market that addressed ground bearing.

------------------------------
James Worrell
Mostly Retired
PE, RLS (retired)
Raleigh NC
[jimworrell@...]

Original Message:
Sent: 05-12-2018 11:25
From: David Hook
Subject: Engineers and crane lifts

I've done reviews of crane track/mat bearing pressures on large diameter pipelines. It's always good to confirm that the underground pipelines can take the loads that will impact the pipe at depth, and to talk to the pipeline owner about this. This is a classic reason to require crane mats when working over or near underground pipelines. This issue is not always on the minds of those deploying the crane, so a good thing for the engineers involved to be aware of.

------------------------------
David Hook P.E., M.ASCE
CIVIL ENGINEER
San Jose CA
(408) 226-1728

Original Message:
Sent: 05-11-2018 08:02
From: James Worrell
Subject: Engineers and crane lifts

​We members of the ASCE Construction Institute Crane Safety Committee attempt to assist fellow members (and others) in understanding the issues and difficulties involved with lifting with cranes or alternative methods. The new OSHA crane safety rules cite several instances where qualified engineers should be involved and the lifting standards (if any) by owners and general contractors will also mandate additional rules that are site specific. In addition there are other standards, many of which are ASME standards, that are important- such as the design of below-the-hook lifting devices.

In order to better fulfill our mission and assist fellow members, I would appreciate feedback from those engineers who have had to become involved, whether it was to review (or develop) a lift plan, design rigging components, analyze ground bearing, or any other aspect of lifting. We would like to know what problems you had, where you received advice and references, and what assistance, if any, you needed the most.​

Our committee members represent a wide range of experience and knowledge in this field.


Jim Worrell
Chairman, ASCE Construction Institute Crane Safety Committee

------------------------------
James Worrell
Mostly Retired
PE, RLS (retired)
Raleigh NC
[jimworrell@...]
------------------------------

I couldn't agree more that there should be an analysis of any subsurface structure to insure that the crane track/outrigger loads are appropriately distributed over the structure.  However, in the industry there is no consensus on how that analysis should be performed.  There is no guidance on how the steel/wood mats, or even earth bridges, distribute the load.  Geotechnical engineers will have their opinions.  Rigging engineers, such as myself, have our own opinions.  No accepted criteria is in place to guide those not inherently familiar with the loadings on how to perform this evaluation.  You have books you can refer to (Duerr or Shapiro, for example), but no ASME standards on ground bearing or load spreading.  If you ask me, this is a major issue in our industry.  As cranes get larger and lifted loads get heavier, the loads imposed on the soil are increasing at an alarming rate.  Our industry really needs to step up and create design/usage/inspection guidelines for load spreading.

------------------------------
Timothy L. Parker, PE, PMP, M.ASCE
Principal
Parker Consulting Engineers, LLC
North Charleston, SC
843-514-3640
tim@...
------------------------------

Original Message:
Sent: 05-14-2018 11:46
From: David Hook
Subject: Engineers and crane lifts

One more clarification. What I should have said is that there needs to be an engineering evaluation of whether the underground facility or nearby structure can take the load imposed by the crane tracks. This is needed for a number of reasons, including protection of the underground facility/structure, the public, and the construction workers. And as noted by Michael Yerion, a dirt bridge can serve the same function as crane mats - to spread the load and reduce the forces at the underground facility level.

------------------------------
David Hook P.E., M.ASCE
CIVIL ENGINEER
San Jose CA
(408) 226-1728

Original Message:
Sent: 05-14-2018 08:00
From: James Worrell
Subject: Engineers and crane lifts

Thanks for your reply. What you did was very important and frequently overlooked. I may be overly cautious, but I believe in always matting- whether it is a crawler or an outrigger crane. A minor problem is that there is no generally accepted method for determining the way the load is transferred through the matting and this is especially true for crawler cranes. What lies under the matting is also of concern. A related cause of failure is close proximity to a slope- especially on a recently back-filled one.

There are several crane accidents around the world each week and a notable percentage of them are caused by a ground bearing failure- sometimes combined with overloading. Until recently, there was no good book on the market that addressed ground bearing.

------------------------------
James Worrell
Mostly Retired
PE, RLS (retired)
Raleigh NC
[jimworrell@...]

Original Message:
Sent: 05-12-2018 11:25
From: David Hook
Subject: Engineers and crane lifts

I've done reviews of crane track/mat bearing pressures on large diameter pipelines. It's always good to confirm that the underground pipelines can take the loads that will impact the pipe at depth, and to talk to the pipeline owner about this. This is a classic reason to require crane mats when working over or near underground pipelines. This issue is not always on the minds of those deploying the crane, so a good thing for the engineers involved to be aware of.

------------------------------
David Hook P.E., M.ASCE
CIVIL ENGINEER
San Jose CA
(408) 226-1728

Original Message:
Sent: 05-11-2018 08:02
From: James Worrell
Subject: Engineers and crane lifts

​We members of the ASCE Construction Institute Crane Safety Committee attempt to assist fellow members (and others) in understanding the issues and difficulties involved with lifting with cranes or alternative methods. The new OSHA crane safety rules cite several instances where qualified engineers should be involved and the lifting standards (if any) by owners and general contractors will also mandate additional rules that are site specific. In addition there are other standards, many of which are ASME standards, that are important- such as the design of below-the-hook lifting devices.

In order to better fulfill our mission and assist fellow members, I would appreciate feedback from those engineers who have had to become involved, whether it was to review (or develop) a lift plan, design rigging components, analyze ground bearing, or any other aspect of lifting. We would like to know what problems you had, where you received advice and references, and what assistance, if any, you needed the most.​

Our committee members represent a wide range of experience and knowledge in this field.


Jim Worrell
Chairman, ASCE Construction Institute Crane Safety Committee

------------------------------
James Worrell
Mostly Retired
PE, RLS (retired)
Raleigh NC
[jimworrell@...]
------------------------------