Design of

Below-the-Hook Lifting Devices

AN A MERICAN NA TIONAL S T AND ARD

Errata to

ASME BTH-1–2014

Design of Below-the-Hook Lifting Devices

On page 13, in the nomenclature for eq. (3-17), the second definition for CLTB has been corrected by errata to replace the square root sign in the numerator with parentheses. The correct equation is shown below.

CLTB p

2.00 (EIx/GJ) (Lb/bf)2

+ 0.275  1.00

THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS

Two Park Avenue, New York, NY 10016-5990 January 2015

J0175E

ASME BTH-1–2014

(Revision of ASME BTH-1–2011)

ASME BTH-1–2014

(Revision of ASME BTH-1–2011)

Design of Below-the-Hook Lifting Devices

AN AMERICAN NA TIONAL S T AND ARD

Two Park Avenue • New York, NY • 10016 USA

Date of Issuance: October 29, 2014

The next edition of this Standard is scheduled for publication in 2017. This Standard will become effective 1 year after the Date of Issuance.

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THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS

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CONTENTS

Foreword v

Committee Roster vi

Correspondence With the BTH Committee vii

Summary of Changes viii

Nonmandatory Appendices

1. Commentary for Chapter 1: Scope, Definitions, and References 45

2. Commentary for Chapter 2: Lifter Classifications 49

3. Commentary for Chapter 3: Structural Design 51

4. Commentary for Chapter 4: Mechanical Design 60

5. Commentary for Chapter 5: Electrical Components 63

FOREWORD

There have been many formal requests for interpretation of the limited structural design criteria stated within ASME B30.20, Below-the-Hook Lifting Devices, a safety standard. As a consequence, industry has for quite some time expressed a need for a comprehensive design standard for below-the-hook lifting devices that would complement the safety requirements of ASME B30.20. All editions of ASME B30.20 have included structural design criteria oriented toward the industrial manufacturing community requiring a minimum design factor of three, based on the yield strength of the material; recent editions have also included design criteria for the fatigue failure mode. However, members of the construction community expressed the need for design criteria more suitable to their operating conditions, including a lower design factor, and the necessity to address other failure modes such as fracture, shear and buckling, and design topics such as impact and fasteners.

A Design Task Group was created in 1997 to begin work on a design standard as a companion document to ASME B30.20. The ASME BTH Standards Committee on the Design of Below-the- Hook Lifting Devices was formed out of the Design Task Group and held its organizational meeting on December 5, 1999.

ASME BTH-1–2005, Design of Below-the-Hook Lifting Devices, contained five chapters: Scope and Definitions, Lifter Classifications, Structural Design, Mechanical Design, and Electrical Components. This Standard, intended for general industry and construction, sets forth two design categories for lifters based on the magnitude and variation of loading, and operating and environmental conditions. The two design categories provide different design factors for determining allowable static stress limits. Five Service Classes based on load cycles are provided. The Service Class establishes allowable stress range values for lifter structural members and design parameters for mechanical components. ASME BTH-1–2005 was approved by the American National Standards Institute on October 18, 2005.

ASME BTH-1–2008 incorporated editorial revisions and two new mechanical design sections for grip ratio and vacuum-lifting device design. ASME BTH-1–2008 was approved by the American National Standards Institute on September 17, 2008.

ASME BTH-1–2011 incorporated revisions throughout the Standard and the addition of a new mechanical design section for fluid power systems. ASME BTH-1–2011 was approved by the American National Standards Institute on September 23, 2011.

This revision of ASME BTH-1 includes a section on lifting magnets that has been incorporated into Chapter 4. Other technical revisions include new requirements for fluid pressure control and electrical system guarding. Along with these technical changes, the nonmandatory Commentary for each chapter was moved to its own respective Nonmandatory Appendix. ASME BTH-1–2014 was approved by the American National Standards Institute on June 24, 2014.

ASME BTH STANDARDS COMMITTEE

Design of Below-the-Hook Lifting Devices

(The following is the roster of the Committee at the time of approval of this Standard.)

STANDARDS COMMITTEE OFFICERS

D. R. Verenski, Chair

D. Duerr, Vice Chair

M. R. Gerson, Secretary

STANDARDS COMMITTEE PERSONNEL

S. Barton, Doc Magnet

G. A. Bond, Wood’s Powr-Grip Co., Inc.

P. W. Boyd, The Boeing Co.

D. Duerr, 2DM Associates, Inc.

J. D. Edmundson, Konecranes/P&H

A. Faris, Ibberson Engineering Co.

M. R. Gerson, The American Society of Mechanical Engineers

K. M. Jankowski, Walker Magnetics

T. C. Mackey, Washington River Protection Solutions

D. L. McCabe, Babcock and Wilcox Co.

D. T. Rebbin, Bradley Lifting Corp.

J. E. Rea, Alternate, Bradley Lifting Corp.

J. W. Rowland III, Consultant

R. S. Stemp, Lampson International, LLC

P. D. Sweeney, General Dynamics, Electric Boat

P. E. Van Every, Tecnomagnete, Inc.

D. R. Verenski, Hunter Lift Ltd.

T. J. Brookbank, Alternate, Hunter Lift Ltd.

HONORARY MEMBERS

R. A. Dahlin, Walker Magnetics

J. W. Downs, Jr., Downs Crane and Hoist Co.

CORRESPONDENCE WITH THE BTH COMMITTEE

General. ASME Standards are developed and maintained with the intent to represent the consensus of concerned interests. As such, users of this Standard may interact with the Committee by requesting interpretations, proposing revisions, and attending Committee meetings. Corre- spondence should be addressed to:

Secretary, BTH Standards Committee

The American Society of Mechanical Engineers Two Park Avenue

New York, NY 10016-5990

https://go.asme.org/Inquiry

Proposing Revisions. Revisions are made periodically to the Standard to incorporate changes that appear necessary or desirable, as demonstrated by the experience gained from the application of the Standard. Approved revisions will be published periodically.

The Committee welcomes proposals for revisions to this Standard. Such proposals should be as specific as possible, citing the paragraph number(s), the proposed wording, and a detailed description of the reasons for the proposal, including any pertinent documentation.

Interpretations. Upon request, the BTH Standards Committee will render an interpretation of any requirement of the Standard. Interpretations can only be rendered in response to a written request sent to the Secretary of the BTH Standards Committee at go.asme.org/Inquiry.

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Subject: Cite the applicable paragraph number(s) and the topic of the inquiry.

Edition: Cite the applicable edition of the Standard for which the interpretation is being requested.

Question: Phrase the question as a request for an interpretation of a specific requirement suitable for general understanding and use, not as a request for an approval of a proprietary design or situation. The inquirer may also include any plans or drawings that are necessary to explain the question; however, they should not contain proprietary names or information.

Requests that are not in this format may be rewritten in the appropriate format by the Committee prior to being answered, which may inadvertently change the intent of the original request.

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Future Committee meeting dates and locations can be found on the Committee Page at https://cstools.asme.org/.

ASME BTH-1–2014 SUMMARY OF CHANGES

Following approval by the ASME BTH Standards Committee and ASME, and after public review, ASME BTH-1–2014 was approved by the American National Standards Institute on June 24, 2014.

ASME BTH-1–2014 includes editorial changes, revisions, and corrections identified by a margin note, (14).

qualified person; stress, maximum; and

stress, minimum revised

1-5.2 Definitions of brittle fracture revised and

unbraced length deleted

1-5.3 Definitions of grip ratio and gripping force

deleted

4–7 1-6.1 Nomenclature for Fu, Lb, M1, M2, N, Nd, and Neq revised, and Ix added

1-6.2 Nomenclature for FH revised, GRmin and

SF deleted, and Fs added