Tower Crane Accidents:Causes, Concerns, and Correct Procedures

Presented By: Jim Getting, Ph.D. Consultation Education & Training (CET) Division

Michigan Occupational Safety & Health Administration Michigan Department of Energy, Labor & Economic Growth

www.michigan.gov/miosha(517) 322-1809

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MIOSHA Training InstituteCertification

What is it?

Through this certification you will begin the process of developing a safety and health management system while becoming familiar with MIOSHA Standards and other relevant topics.

MIOSHA Training InstituteCertification

What are the benefits?

• Conducted by credible MIOSHA consultants• CEUs, CSPs, Maintenance points• Validation of a set of knowledge• Standardized curriculum path• Increased recognition for employee & employer• Tracking of course completion

Objectives

• Analyze the scope and magnitude of the problem.• Summarize recent tower crane accidents.• Describe specific actions that can prevent tower

crane accidents.

Tower Cranes: Defined

Luffing Jib

Hammerhead

How many tower crane accidents?

• Short Answer: Nobody knows exactly.• Web sites inconsistent, not comprehensive.• Industry sources are not comprehensive.

• Bureau of Labor Statistics (BLS)Census of Fatal Occupational Injuries (CFOI)– Commonly used and widely accepted.– Limitations.

• Fatalities only.• Data sometimes incomplete, little accuracy checking.

– McCann (2008) cites 632 crane related fatalities from 1992 – 2006.

– First report from CPWR cited 323 crane related fatalities from 1992 – 2006*.

* As reported in Greene, M.V. (Sept 2008) Many sided problem. Safety and Health Magazine. National Safety Council.

BLS Classifications

Two Groups May Apply:• Portal, tower, and pillar

(grouping comes from ASME B30.4).

• Hammerhead cranes.

Portal Crane(portalcranes.com)

Pillar crane (hoists.apluswhs.com)

Hammerhead Crane (freefoto.com)

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•1992 – 2007 Bureau of Labor Statistics Census of Fatal Occupational Injuries•2008 data summarized from news sources

Tower Crane-Related Deaths in Construction by Year, 1992-2008

Crane-Related Deaths in Construction by Year, 1992-2006

Original Source: U.S. Bureau of Labor Statistics Census of Fatal Occupational Injuries Research File.

Data summarized by: McCann (2008) Crane Related Deaths and Injuries in Construction. Center for Construction Research and Training.

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•1992 – 2007 Bureau of Labor Statistics Census of Fatal Occupational Injuries.•2008 data summarized from news sources.

Tower Crane Versus All Crane Deaths in Construction by Year, 1992-2008

Expected Frequency of Tower Crane Accidents and Fatalities

• 2.1% of cranes are tower cranes.– 2000 tower cranes and 96000 cranes total*.

• 5% of crane accidents are tower cranes – (16 of 306)**.

• 42 crane related fatalities per year (average)**. • Expect .84 tower crane fatalities per year, if

accidents were proportional.• Actual for 1997-2008 = 34 fatalities or 2.83 per year.

•OSHA press release (2008)•McCann (2008)

Is it just recently that tower cranes have started having accidents?

• No.• Crane type has changed:

– internal vs external to the structure.

• Far more tower cranes in use.• There appears to be an increasing incident

rate.

What Does It All Mean?

• Increased rate has been happening for years, but barely noticed.

• Still very infrequent compared to:

– 5 fatal falls in Michigan in 2008.

– 3 electrocutions in Michigan in 2008.

– Crane accidents in general.

• Digital cameras, 24 hour news:

– Sometimes cause us to over-estimate dangers.

– In this case, it made us more aware of an important problem!

Recent Tower Crane Accidents

1. New York, (3/15/2008), 7 dead.– Rigging failed, collar dropped, crane fell.

2. Miami, FL, (3/25/2008), 2 dead, 5 injured.– Dropped section of crane while “jumping” crane

3. New York, NY, (5/30/2008), 2 dead.– Weld on turntable fails, jib and cab fall.

4. New York, NY, (9/4/2008), 1 dead.– Guardrail removed. Erector falls.

5. Annapolis, MD, (4/30/2008), 1 dead.– Crushed between boom sections while disassembling.

6. Bellevue, WA, (11/16/2006), 1 dead.– Inadequate base. Collapse onto apartment.

Review of accidents:Bellevue, Washington, 11/16/2006

• Crane severed 15’ from base.• No load on crane.• Landed on 3 buildings.• One bystander killed.• Minor injuries to operator.• Operator drug use?• Excessive leaning? 3 feet. • Proper weathervane prior to

incident? 80 mph winds.

Photo courtesy: Andrea James and John Iwasaki (Nov 17, 2006) Seattle Post Intelligence

Bellevue, Washington, 11/16/2006

Bellevue, Washington, 11/16/2006

Citations:

• $5,600 – Magnusson Klemencic Associates – Engineering firm that designed the foundation. – The base did not meet manufacturer requirements.

• $9,200 – Lease Crutcher Lewis – The general contractor.– Not ensuring the crane was maintained and used properly.– Not inspecting the tower.– Hanging two large banners on it that could affect the crane's operations.

12/1/2006Near Miss

• Another Bellevue, Washington.

• Cracks in the tower. • Cause: Water collected

inside. Weepholes were clogged. Water froze and burst the steel.

Photo courtesy: Scott Eklund (Dec 1, 2006) Seattle Post Intelligence

12/1/2006 Near Miss

• Duct Tape???• Note: same company erected

this one as the crane that fell in Bellevue.

• Note – 2 other cranes were found to have 2’ long hairline cracks in the next week in the same city.

Photo courtesy: Scott Eklund (Dec 1, 2006) Seattle Post Intelligence

Review of AccidentsNew York: March 15, 2008

New York: March 15, 2008

Photo courtesy: New York Times

• Seven Fatalities.• Rigger offered FOUR new

slings by construction manager.

• No inspection of slings.• Used FOUR slings.

Manufacturer said use EIGHT.• Did not use softeners.

New York: March 15, 2008

Photo courtesy: New York Times

The Red Flag That Got OverlookedNew York: December 15, 2007

Photo courtesy: Jin Lee (Dec 14, 2007) New York Times

• Load dropped. One worker injured.• Lifting over construction office trailers.• Sling failure – 14K load with a 19K nylon sling.

Review of AccidentsMiami: March 25, 2008

• Two Fatalities.• Dropped section of mast while

“jumping” crane.• Crashed through house being

used for storage.• One deceased was insurance

safety inspector.

Review of AccidentsNew York: May 30, 2008

• Two Fatalities.• Failure of a repair weld

on turntable.• Jib and cab fall.• Crane was a Kodiak,

1982 or older.

Photo courtesy Associated Press, Dima Gavrysh

Canada Tower Crane Accident Review

Includes: Near Miss, Property Damage, Injury, and Fatality Accidents

Year Number of Incidents2005 192006 152007 192008** 19Total 72

* WorksafeBC.com** Through September of 2008

Canada Tower Crane Accident Type

* WorksafeBC.com

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Dropped Load

Electrical

Collision - other crane

Crane malfunction

Crushed by / Struck By

Collision

Other

Assembly / Disassembly

What Do We Learn: The 331 Rule Applies

Fatal/Catastrophic

Injury/Property Damage

Near Misses

What Do We Learn?Causes of Accidents

• Lack of sufficient crane inspections.• Improper repairs.• Failure to follow manfacturers’ procedures.

– Operators, riggers, erectors, crane owners, general contractors.

• Failure to follow OSHA/MIOSHA rules.– Operators, riggers, erectors, crane owners, general

contractors.• Human error.

– Miscalculation.– Forgetting.– Misunderstanding, miscommunication

• Failure to act:– If something looks wrong, DO SOMETHING about it!

So is it Over-hyped?

• NO!!!!• Accident severity warrants the

attention.• Many non-fatal accidents.• Increased use in the future.• Changing nature of use:

– self erecting.

• World market: use some places is scary!

Photo from Dubai

What Can I Do to Help?

General Contractors

• Know the crane inside and out.– Read the manual.– Meet with the owner, erector, operator.– Learn history of the crane.

• Age.• Repairs/modifications/replacement/damage.• Strengths/weaknesses with crane model.• Where/how it has been used.• Previous inspection history.

• Third party inspections before erecting.• Qualified erectors.

What Can I Do to Help?

General Contractors

• Operator certification and more.• Don’t push the schedule.• Process in place to verify correct procedures

at every step.• Widen public barriers.• Watch for the near misses.

What Can I Do to Help?

Subcontractors on site:• Know crane limits.• Stay on schedule – when plans change

accidents happen.• Plan ahead – need to give operator and riggers

advance information.• Keep job-site orderly – less visual distraction.• Observe “no lifting over” rules.• Report near misses.

What Can I Do to Help?

Everybody: • Stay out from under loads.• No rigging or landing loads unless trained.• Be an inspector: keep an eye on the crane.• Report near misses, even the little things.• Help the operator, rigger, erector:

– Remember they are humans who;• WILL make mistakes – forgets, misunderstands.• Get tired, frustrated, distracted.

– Do not distract, interrupt their routines.– State things twice, have them repeat it back.– Keep site clean, orderly.– Keep job on schedule.

Sources of Additional Info

• ANSI Standard B30.3 – 1996 Construction Tower Cranes• Tower Crane Management: Avoiding Problems Through Proper

Selection, Erection, Testing, Maintenance, Operation, and Dismantling (1985) D. E. Dickie; Construction Safety Association of Ontario.

• http://towercraneaccidents.blogspot.com/ - Listing of tower crane accidents world wide.

• http://www.craneoperator.com/index.htm - Listing of many crane accidents.

• http://edocket.access.gpo.gov/2008/pdf/E8-21993.pdf - Proposed new OSHA rule: Cranes and Derricks in Construction.

• http://www.liftlink.com/ - Lift and Crane Magazine.• http://www.cpwr.com - Research articles on safety, including

McCann (2008) Crane Related Deaths and Injuries in Construction. Center for Construction Research and Training.

Thank You for Attending

Michigan Occupational Safety & Health Administration

Consultation Education & Training Division

7150 Harris Drive, P.O. Box 30643

Lansing, Michigan 48909-8143

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