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ALERT
Preventing
Injuries and Deaths from Falls during Construction and Maintenance
of Telecommunication Towers
July 2001
DHHS (NIOSH) Publication No. 2001-156 |
Disclaimer
Preventing Injuries and Deaths from Falls
during Construction and Maintenance of Telecommunication Towers
WARNING!
Workers involved in construction and maintenance of telecommunications towers
are at high risk of fatal falls.
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WORKERS
should take the following steps to protect themselves from falls
during tower construction and maintenance:
- Use 100% fall protection when working
on towers at heights above 25 feet.
- Participate in all training programs
offered by your employer.
- Follow safe work practices identified
by worker training programs.
- Use OSHA-required personal protective
equipment and make sure you are trained in its proper use.
- Inspect equipment daily and report
any damage or deficiencies to your supervisor immediately.
EMPLOYERS
should take the following steps to reduce the risk of worker injuries
and deaths from falls during tower construction and maintenance:
- Comply with OSHA Compliance Directive
2-1.29.
- Ensure that hoisting equipment used
to lift workers is designed to prevent uncontrolled descent and
is properly rated for the intended use.
- Ensure that hoist operators are
properly trained.
- Ensure that workers use 100% fall
protection when working on towers at heights above 25 feet.
- Provide workers with a 100% fall-protection
system compatible with tower components and the tasks to be performed.
- Ensure that gin poles are installed
and used according to the specifications of the manufacturer or
a registered professional engineer.
- Ensure that tower erectors are adequately
trained in proper climbing techniques, including sustaining three-point
contact.
- Provide workers with OSHA-required
personal protective equipment and training in its proper use.
- Ensure that workers inspect their
equipment daily to identify any damage or deficiencies.
- Provide workers with an adequate
work-positioning device system. Connectors on positioning systems
must be compatible with the tower components to which they are
attached.
- Supplement worker training on safe
work practices with discussions of FACE case reports.
- Know and comply with child labor
laws that prohibit hazardous work by workers under age 18.
For additional information:
see NIOSH Alert: Preventing Injuries and Deaths from Falls
during Construction and Maintenance of Telecommunication Towers
[DHHS (NIOSH) Publication No. 2001-156].
Single copies of the Alert are available free from the following:
NIOSH--Publications Dissemination
4676 Columbia Parkway
Cincinnati, OH 45226-1998
Telephone: 1-800-35-NIOSH (1-800-356-4674)
Fax: 513-533-8573
E-mail: pubstaft@cdc.gov
or visit the NIOSH Web site at www.cdc.gov/niosh
Department of Health and Human Services
Centers for Disease Control and Prevention
National Institute for Occupational Safety and Health |
Preventing Injuries and Deaths from Falls during Construction and Maintenance
of Telecommunication Towers
WARNING!
Workers involved in
construction and maintenance of telecommunications towers
are at high risk of fatal falls.
|
The National Institute for Occupational
Safety and Health (NIOSH) requests assistance in preventing deaths
and injuries from falls of workers during construction and maintenance
of telecommunication towers. Recent NIOSH fatality investigations
suggest that employers, supervisors, workers, tower owners, tower
manufacturers, and wireless service carriers may not recognize or
appreciate the serious fall hazards associated with tower construction
and maintenance. As a result, they may not follow safe work practices
for controlling these hazards. This Alert describes seven deaths
resulting from falls during construction and maintenance of telecommunication
towers. The Alert also includes recommendations for preventing similar
incidents. The seven deaths were investigated by the NIOSH Fatality
Assessment and Control Evaluation (FACE) Program.
The widespread use of wireless communication
services has resulted in the construction of telecommunication towers
to hold transmitting devices for cellular phones, personal communication
services, and television and radio broadcast antennas. The Federal
Communications Commission (FCC) estimates that at least 75,000 telecommunication
towers have been constructed in the United States, and industry
groups indicate that more than 1,000 telecommunication towers are
erected each year [Chiles 1997]. The Telecommunications Act of 1996
(Public Law 104-104) is expected to promote more tower construction
to meet the increased demand for wireless communication services
[OSHA 1998].
Telecommunication towers may be of several types
and range in height from 100 to 2,150 feet or more [OSHA 1998]. Three
general forms of telecommunication towers are
monopoles that consist of tapered steel tubes that fit over each
other to form a stable pole,
guyed towers that are stabilized by tethered wires, and
self-supporting towers that are free-standing lattice structures
(Figure 1).
Figure 1. Tower Types
Telecommunication towers are generally manufactured as sections and
constructed onsite by hoisting each section into place and bolting
sections together. Some models of shorter towers are self-erecting.
For most towers that are constructed onsite, cranes and gin poles
attached to the tower being erected are generally used to hoist each
section into place. A gin pole is a device unique to the telecommunication
tower industry. The gin pole is used to raise successive sections
of steel, equipment, or workers into position. This temporary lifting
device uses cables and pulleys to allow enough head room to accommodate
the length of the next tower section or equipment being installed
(Figure 2).
The exact number of workers
involved in tower construction and maintenance is unknown. Workers
are categorized in a variety of occupational subgroups for which
employment data are collected. These groups include communications
workers, painters, steel erectors, and electrical and electronic
equipment repairers. This type of work also occurs in several industrial
subgroups such as the following:
- SIC (Standard Industrial Classification)
623Water, sewer, pipeline, and communications
and power line construction (subcategory--radio transmitting tower
construction)
- SIC 1731Electrical
work (subcategory--telecommunications equipment installation)
- SIC 1791Structural
steel erection
- SIC 1799Special trade
contractors not elsewhere classified (subcategory--antenna installation,
except household type)
In addition to telecommunication towers, transmitting
devices for wireless communication services are often mounted on
the roof perimeters of buildings, exposing workers to fall hazards.
However, the mounting and maintenance of these devices on buildings
require fall protection measures that are not addressed in this
document.
Figure 2. Gin pole attached to
communication tower.
The Census of Fatal Occupational Injuries (CFOI)
is a multisource data system maintained by the Bureau of Labor Statistics
to identify work-related deaths in the United States. A NIOSH review
of the CFOI data identified 118 deaths associated with work on telecommunication
towers from 1992 through 1998. These deaths included 93 falls, 18
telecommunication tower collapses, and 4 electrocutions. However,
the number of deaths identified here should be considered a minimum
because identification methods are not exact [NIOSH 2000a].
Estimates vary greatly about the number of workers
in telecommunication tower construction and maintenance. In 1993,
estimates ranged from 2,300 to 23,000 workers in this field [OSHA
1998]. These estimates suggest fatality rates of 49 to 468 deaths
per 100,000 workers--nearly 10 to 100 times the average rate of 5
deaths per 100,000 workers across all industries.
OSHA
The Occupational Safety and Health Administration
(OSHA) safety standard for fall protection in the construction industry
[29 CFR (Code
of Federal Regulations) 1926, Subpart M]
excludes steel erection activities on nonbuilding structures such
as towers. Subpart R of the OSHA fall protection standard in construction
[29 CFR 1926] has a proposed effective date of September 18, 2001,
and does not apply to transmission towers, communication and broadcast
towers, and tanks.
Compliance Directive
To address hazards associated with telecommunication
tower construction and maintenance, OSHA formed a multiagency Tower
Task Force in August 1997. The Task Force (with representatives
from Regional and Federal OSHA offices, the Federal Aviation Administration,
the U.S. Army Corps of Engineers, NIOSH, the U.S. Navy, and others)
has worked with the National Association of Tower Erectors (NATE)
to develop a compliance directive to protect workers from hazards
in the tower construction industry.
The OSHA compliance directive (CPL 2-1.29, Interim
Inspection Procedures During Communication Tower Construction Activities)
became effective January 15, 1999 [OSHA 1999]. The directive addresses
fall protection and safe tower access during construction. Specifically,
the directive does the following:
- Establishes uniform policies and procedures
for OSHA compliance officers when conducting inspections of towers
under construction
- Describes best practices for use by the industry
- Requires telecommunication tower workers
to maintain 100% fall protection when working 25 feet or more
above the ground (this requirement applies to workers ascending,
descending, or moving from point to point)
- Specifies procedures and allowable conditions
under which workers may access the tower by "riding the line"
(a practice in which workers are directly lifted up a tower by
a hoist line)
- Prohibits
riding the line for work at heights less than 200 feet above the
ground. Requires instead that workers access workstations at these
heights using conventional methods such as climbing with fall
protection or use of a personnel platform
- Permits
up to two tower erectors at a time to ride the line for work at
heights more than 200 feet above the ground when (1) towers
are erected with gin poles, (2) conditions preclude the use of a
personnel platform, and (3) other conventional methods of climbing
using a ladder or other approved climbing devices might create a
greater hazard from fatigue or repetitive stress
- Specifies minimum requirements for allowing
workers to be hoisted on the hoist line, such as the following:
-
Worker training
- Use
of hoisting equipment that has been approved, certified, and/or
inspected by a registered professional engineer or other designated
professional
- Trial
lift and proof-testing procedures
- Pre-lift
meetings
- Documentation
of procedures used
- Continuous
communication between hoist operator and workers being hoisted
- Consideration
of environmental conditions
- Specifications
and maintenance for hydraulic hoists and gin poles
Addendum on the
Use of Gin Poles
The OSHA Tower Task Force may develop an addendum to the OSHA compliance
directive (CPL 2.129) or a new directive specific to the use of
gin poles. Such a directive would draw on guidelines that already
exist or are under development [NATE 1998, 1999]. For example, NATE
has developed industry guidelines for the use of gin poles. In addition,
the Telecommunications Industry Association/Electronic Industries
Association (TIA/EIA) is developing a gin pole standard [TIA/EIA
2001]. OSHA is considering components from both the NATE gin pole
guidelines and the TIA/EIA standard for use in any future compliance
directive addressing gin poles.
At a minimum, any future directive on gin poles
would require that a registered professional engineer's drawing
be available at the site. The drawing must
-
show the gin pole and its track (if any) and indicate
lifting capacity and the manner of attachment to the tower,
- indicate
track attachment to at least two places (top and bottom), and
- indicate
how high the gin pole can be raised above its uppermost attachment
to the tower.
In addition, any future directive would require
inspection records, documented worker training, and an anti-two
block device (a device that prevents contact between the lower load
block or hook assembly and the gin pole head assembly).
Fair Labor Standards
Act and Youth Employment
The Fair Labor Standards Act (FLSA) [29 USC (United
States Code) 201 et seq.] includes work declared hazardous for youth
by the Secretary of Labor. Hazardous Order No. 7 Power Driven Hoisting
Apparatus Occupations prohibits workers under age 18 from work in
all occupations involved in the operation of a power-driven hoisting
apparatus, including riding on a manlift. The Act defines the term
manlift as "a device intended for the conveyance of persons which
consists of platforms or brackets mounted on, or attached to, an endless
belt, cable, chain, or similar method of suspension; such belt, cable,
or chain operating in a substantially vertical direction and being
supported by and driven through pulleys, sheaves, or sprockets at
the top and bottom."
The cases presented here were investigated by
the NIOSH FACE Program. The goal of this program is to prevent occupational
fatalities across the Nation by (1) identifying and investigating
work situations that involve high risk for worker injury and (2)
formulating and disseminating prevention strategies
Case 1
On December 3, 1999, the 40-year-old owner of
a tower-painting company, his 16-year-old stepson, and a 19-year-old
employee died after falling 1,200 feet to the ground. The company
had been at the site for 2 weeks repairing the beacon light at the
top of a 1,500-foot radio broadcast tower, painting the tower, and
installing rest platforms. On the day of the incident, the owner
had planned to work on the beacon light at the top of the tower
while the other two workers continued painting the tower. A 3,000-foot
length of ¾-inch nylon rope and a 1,000-pound-capacity portable
electric capstan hoist were used to raise the workers up the outside
of the tower. Three loops were tied into the hoist line approximately
6 feet apart. The workers used these loops to help them ride the
hoist line. The stepson was first on the line, followed by the 19-year-old,
and then the company owner. Using a length of woven rope, the workers
had attached one of the rest platforms to the end of the nylon rope
62 inches below the last loop. The company owner's wife was operating
the capstan hoist using a foot pedal located on the ground. As the
wife was hoisting the workers up the side of the tower, the hoist
line began to slip around the capstan. The wife was unable to hold
the rope and the workers fell to the ground. The hoist used in this
incident was not manufactured or rated for lifting people. In addition,
the load was likely to have exceeded the lifting capacity of the
hoist [NIOSH 2000b].
Case 2
On December 8, 1998, a 21-year-old male tower erector
died after sliding approximately 1,000 feet down a supporting
guy wire. The victim and coworkers were attaching dampeners to the
tower guy wires when the incident occurred. The tower being constructed
was a 1,040-foot, high-definition digital television tower. When the
incident occurred, the victim was at the 1,000-foot level and was
wearing a positioning safety belt with a T-bar attached to the D-rings
on his belt. Attached to one end of the T-bar was an adjustable-length
lanyard with a large hook as its terminal device. Attached to the
other end of the lanyard was a large hook. The victim placed the large
hook over the guy wire but did not attach the adjustable lanyard to
the tower before sliding out on the guy wire. Although he had one
foot draped over the wire, he could not keep himself from sliding.
The victim slid rapidly down the wire, striking the anchor point of
the guy wire. He was pronounced dead at the scene [Missouri FACE 1998].
Case 3
On November 13, 1998, a 41-year-old male tower
erector fell 240 feet from a 260-foot telecommunication tower while
attempting to install a new phone service device on the tower. The
victim and a coworker attached their lanyards to the cable climb positioned
on one leg of the tower and climbed to the 240-foot level of the tower.
The owner and a third tower erector remained on the ground. Both workers
wore two 6-foot lanyards attached to the side D-rings on their body
harnesses. The terminal devices on the coworker's lanyards were two
large pelican hooks. The terminal device on one of the victim's lanyards
was a large pelican hook, but the other lanyard had a smaller snaphook
as a terminal device. The victim began to attach a coaxial phone cable
to an antenna arm while the coworker, with his back to the victim,
was attaching cable tray components to the tower. A short time later,
the victim fell, unwitnessed, from the tower to the ground. The coworker
stated that two pelican hooks were necessary because the smaller snaphook
could not be attached to the larger tower components [NIOSH 1999].
Case 4
On July 16, 1998, a 23-year-old male tower erector
died after falling 200 feet from a telecommunication tower while
attached to an 80-foot section of cable tray. He was a member of
a nine-man crew erecting a 240-foot, three-sided telecommunication
tower. The crew bolted a 140-foot section of the tower together
on the ground. Next this section was set in place by a crane. The
workers then erected the final 100-foot section on the ground, and
three tower erectors climbed the 140-foot section. The final section
was set in place by the crane, and the workers bolted the two sections
together. The crane then lifted an 80-foot section of cable tray
to the top of each side of the tower. As each section was lifted
into place, an erector began to attach it to the tower using four
J bolts every 10 feet. The victim began working down the tower,
attaching the cable tray and tightening all bolted connections as
he descended. After approximately 1 hour, the victim was at the
200-foot level of the tower. The victim then repositioned himself
and connected both of his lanyards to the partially attached cable
tray. Shortly thereafter, the section of cable tray gave way, falling
to the ground with the victim attached [NIOSH 1998a].
Case 5
On December 8, 1997, a 32-year-old male tower
erector was working with a crew of two others on a 160-foot cellular
phone tower. The crew had completed the tower erection and was in
the process of lowering the gin pole (the lifting device used to
hoist tower sections into place) to the ground. The tower erector
had removed two choker cables securing the upper section of the
gin pole to the tower and was attempting to ride the hoist cable
down to the two lower chokers. The terminal device on the victim's
lanyard was a pelican hook with a 4-inch-wide by 7¼-inch-long interior
opening. The terminal device on the hoist cable was a 3-inch clevis.
Either the victim tried to hook to the cable and missed or the larger
opening of the pelican hook on his lanyard slipped off the hoist
cable. He fell 130 feet to the ground [NIOSH 1998b].
These incidents suggest that employers, workers,
tower owners, tower manufacturers, and wireless service carriers
may not fully appreciate or recognize the serious hazards associated
with the construction and maintenance of telecommunication towers
and the need to follow safe work procedures that include the use
of 100% fall protection.
FACE investigations identified the following contributing factors
in fatal falls from telecommunication towers:
- Hoist failure
- A hoist that is not rated to hoist workers
- Truck-crane failure
- Inadequate fall protection
- Failure to attach the lanyard to the tower
- Terminal devices on the lanyard that are
not compatible with tower components
- Attachment of lanyard to unstable tower components
- Failure to ride the line under prescribed
conditions
- Inadequate worker training
- Potential fatigue and repetitive strain
- Failure by employers, workers, tower owners,
tower manufacturers, and wireless service carriers to address
these factors could result in future fatalities.
Failure by employers, workers, tower owners, tower
manufacturers, and wireless service carriers to address these factors
could result in future fatalities.
NIOSH recommends that employers and workers
comply with OSHA directives, maintain equipment, and take the following
measures to prevent injuries and deaths when constructing or maintaining
telecommunication towers.
Employers
Employers should take the following steps to reduce
the risk of worker injuries and deaths during tower construction and
maintenance:
- Comply with OSHA Compliance Directive 2-1.29
Interim Inspection Procedures During Communication Tower Construction
Activities. OSHA inspectors use these guidelines in tower
inspections. Employers should ensure that workers follow these
guidelines.
- Ensure that hoisting equipment used to lift
workers is designed to prevent uncontrolled descent and is properly
rated for the intended use.
- Ensure that hoist operators are properly
trained.
- Ensure that workers use 100% fall protection
when working on towers at heights above 25 feet.
- Provide workers with a 100% fall-protection
system compatible with tower components and the tasks to be performed.
- Ensure that gin poles are installed and used
according to the specifications of the manufacturer or a registered
professional engineer.
- Ensure that tower erectors are adequately
trained in proper climbing techniques, including sustaining three-point
contact.
- Provide workers with OSHA-required personal
protective equipment and training in its proper use.
- Ensure that workers inspect their equipment
daily to identify any damage or deficiencies.
- Provide workers with an adequate work-positioning
device system. Connectors on positioning systems must be compatible
with the tower components to which they are attached. (Note that
a work-positioning device system does not constitute 100% fall
protection.)
- Supplement worker training on safe work practices
with discussions of FACE case reports to help assure that workers
fully appreciate the serious hazards involved with their tasks
and the need for strict safe work practices.
- Know and comply with child labor laws that
prohibit hazardous work by workers under age 18. An example
of hazardous work is any task involving power-driven hoisting
apparatus.
Tower Owners and Manufacturers
Tower owners should take the following steps:
- Use contracts requiring that workers adhere
to OSHA-required safety measures (including Compliance Directive
2-1.29) while construction or maintenance is being performed on
your towers.
- Require contractors to have a formal safety
and health program relating to tower construction and maintenance.
- Include a provision in your contracts for
frequent and regular jobsite inspections by a competent person
who has expertise in tower erection and worker fall protection.
Both manufacturers and tower owners should install
fall-protection fixtures for workers to use as anchor points on
tower components during fabrication or erection.
Workers
Workers should take the following steps to protect
themselves during tower construction and maintenance:
- Use 100% fall protection when working on
towers at heights above 25 feet.
- Participate in all training programs offered
by your employer.
- Follow safe work practices identified by
worker training programs.
- Use OSHA-required personal protective equipment
and make sure you are trained in its proper use.
- Inspect equipment daily and report any damage
or deficiencies to your supervisor immediately.
The principal contributors to this Alert were
Virgil Casini and Dawn N. Castillo of the NIOSH Division of Safety
Research, and T.J. Lentz of the NIOSH Education and Information
Division. Cases presented in this Alert were contributed by the
NIOSH FACE Project and by Thomas D. Ray of the Missouri State-Based
FACE Project. Additional reports from FACE investigations are available
at the NIOSH internet site:
www.cdc.gov/niosh/face/
Please direct comments, questions, or requests
for additional information to the following:
Dr. Nancy A. Stout, Director
Division of Safety Research
National Institute for Occupational Safety and
Health
1095 Willowdale Road
Morgantown, West Virginia 26505-2888
Telephone: 304-285-5894
For further information about occupational
safety and health topics, call 1-800-35-NIOSH (1-800-356-4674),
or visit the NIOSH Web site at www.cdc.gov/niosh.
We greatly appreciate your help in protecting the safety and health
of U.S. workers.
Kathleen M. Rest, Ph.D., M.P.A.
Acting Director
National Institute for Occupational
Safety and Health
Centers for Disease Control and
Prevention
CFR. Code of Federal regulations. Washington,
DC: U.S. Government Printing Office, Office of the Federal Register.
Chiles, JR [1997]. We got us some sky today, boys.
Smithsonian 28:44-52. Missouri
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from television tower. Jefferson City, MO: FACE Investigation No.
98MO161.
NATE [1998]. NATE Gin Pole Procedures. San Diego,
CA: National Association of Tower Erectors. February 6.
NATE [1999]. NATE Large Gin Pole Procedures.
New Orleans, LA: National Association of Tower Erectors. February
19.
NIOSH [1998a]. Tower erector dies after falling
200 feet from telecommunication tower--North Carolina. Morgantown,
WV: U.S. Department of Health and Human Services, Public Health
Service, Centers for Disease Control and Prevention, National Institute
for Occupational Safety and Health, FACE Report No. 98-20.
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U.S. Department of Health and Human Services, Public Health Service,
Centers for Disease Control and Prevention, National Institute for
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WV: U.S. Department of Health and Human Services, Public Health
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for Occupational Safety and Health, FACE Report No. 99-01.
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Division of Safety Research. Unpublished. NIOSH
[2000b]. Three tower painters die after falling 1,200 feet when
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of Health and Human Services, Public Health Service, Centers for
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J-9-F-4-0013, Jack Faucett Associates, Bethesda, Maryland.) Washington,
DC: U.S. Department of Labor, Occupational Safety and Health Administration.
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during communication tower construction activities. Washington,
DC: U.S. Department of Labor, Occupational Safety and Health.
OMB [1987]. Standard industrial classification
manual. Washington, DC: Executive Office of the President, Office
of Management and Budget.
TIA/EIA [2001]. Draft Standard, TIA/EIA-PN-4860-Gin
Poles. Structural standards for steel gin poles used for the installation
of antenna towers and antenna supporting structures. Telecommunication
Industry Association/Electronic Industries Association, TR 14.7
Sub-committee, Safety Facilities Task Group.
USC. United States code. Washington, DC: U.S.
Government Printing Office.
This
document is in the public domain and may be freely copied or
reprinted. |
DISCLAIMER
Mention of any company or product does not constitute
endorsement by NIOSH.
ORDERING INFORMATION
To receive documents or other information about
occupational safety and health topics, contact the National Institute
for Occupational Safety and Health (NIOSH) at
NIOSH-Publications
Dissemination
4676 Columbia Parkway
Cincinnati, OH 45226-1998
Telephone: 1-800-35-NIOSH
(1-800-356-4674)
Fax: 513-533-8573
E-mail: pubstaft@cdc.gov
or visit the NIOSH Web site
at www.cdc.gov/niosh
DHHS
(NIOSH) Publication Number 2001-156
July
2001
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