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Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558 1
Keeping your crew safe,effective, and productive in thenew regulatory environment
Wirelesscommunicationand crane safety
Keeping your crew safe,effective, and productive in thenew regulatory environment
800.833.4558
www.soneticscorp.com
White Paper No. SO12-02.01
Wirelesscommunicationand crane safety
Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558 3
CONTENTS
Executive summary .....................................................................................................................................5
Overview ....................................................................................................................................................7
A brief note on scope ..................................................................................................................................8
A nation of cranes ......................................................................................................................................9
Types of construction cranes .....................................................................................................................10
Are crane injuries a big problem?...............................................................................................................10
Subpart CC in general: A new focus on crane safety ...................................................................................13
How are people injured in crane accidents?............................................................................................... 14
Communication: The key to safety .............................................................................................................15
Wireless communication for crane safety .................................................................................................. 17
Hearing protection: An added benefit .........................................................................................................18
How to choose a wireless headset system ................................................................................................ 19
Safety and crane regulation: Some final thoughts .......................................................................................22
Notes ..................................................................................................................................................... 23
References...............................................................................................................................................25
Appendix A: Wireless system requirements ............................................................................................... 27
4 Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558
Apart from their obvious benefits for OSHA compliance,wireless headset systems are a convenient and reliablemethod of ensuring clear communication among workcrews when operating in construction, utility, and otherdangerous, high-noise environments.
Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558 5
EXECUTIVE SUMMARY
OSHA’S NEW CRANE RULES FOR CONSTRUCTION (29 CFR §1926, eff. Nov. 8, 2010) are the most sweepingoverhaul of crane safety regulations in more than 40 years. Of particular importance are new rulesgoverning communication between the crane operator, signal person, and spotter. These three individuals
are absolutely essential to safe crane operation, but until now have had to rely on hand signals or two-way radiosto communicate.
Although “universal” hand signals have been established, the system is complex and the visible differencesbetween some of the signals are subtle at best. Hand signals also require line-of-sight visibility, which is notalways feasible, particularly in darkness or inclement weather. Although two-way radios do not require line ofsight, they tie up one hand for operation and are subject to electronic interference. OSHA recognizes theselimitations by setting forth new and stringent requirements forsignals conveyed electronically. These include:
• The device(s) used to transmit signals must be testedon site before beginning operations to ensure that thesignal transmission is effective, clear, and reliable.
• Signal transmission must be through a dedicatedchannel.
• The reception of signals must be by a hands-freesystem.
These requirements make self-contained wireless communicationheadsets a better option than two-way radios for OSHAcompliance since radios typically do not offer a dedicatedchannel or completely hands-free operation. In the case of craneoperations, wireless headsets are becoming the best practice forensuring clear and reliable communication among the crane operator, signalperson, and spotter. If desired, wireless headsets can be integrated easilywith existing two-way radio systems to enable remote communication.
The basic building blocks of a wireless communication system are straightforward: two or more wirelessheadsets; base station to allow communication between and among headsets; and an optional radio-transmitinterface to allow communication between the worksite and remote users over a mobile radio.
The benefits of wireless communication headsets are substantial. DECT-based wireless headset systems utilize adigitally encoded, dedicated channel. Wireless headset systems also provide full-duplex, hands-freecommunication within the local audio network. Full-duplex systems allow conversations to take place in bothdirections simultaneously, similar to a telephone. This is an important safety feature for crane operationsbecause, unlike a walkie-talkie, it allows verbal warnings to be delivered instantly, even if someone else is talking.Wireless headset systems can also be integrated with existing radio systems to enable monitoring of multipleradios and push-to-talk transmit capabilities. Wireless headsets offer the additional advantage of hearingprotection, typically 24dB or more of noise reduction, a major concern in virtually all crane environments.
Apart from their obvious benefits for OSHA compliance, wireless headset systems are a convenient and reliablemethod of ensuring clear communication among work crews when operating in construction, utility, and otherdangerous, high-noise environments. Clear communication is an essential element in every team’s effectivenessand productivity. For crews who must work around cranes, it could even save a life.
Dedicated spotter
Signal person
Crane operator
LocalAudioNetwork
• 1,600-foot line-of-sight range• Hands-free• Dedicated channel
Basic Wireless Headset Communication System
Optional mobile radio interfacefor communication with remote users
6 Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558
Wireless communication is a cost-effective methodof keeping your entire work crew safe, effective,and productive — especially if they are workingwith or around cranes.
Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558 7
Overview
On November 8, 2010, the Occupational Safety and Health
Administration’s (“OSHA”) new crane and derrick rules (“Rules”) for
construction took effect.1 Weighing in at over 275,000 words, the Rules
represent the first major regulatory overhaul of crane operations since
OSHA’s initial regulations were enacted in 1971. Considered by many in
the construction industry to be long overdue,2 the Rules also have some
serious teeth. No longer are words like “should” or “shall” used in the
text; indeed, the word “must” is used over 800 times.
In this white paper, Sonetics Corporation examines several key
components of the Rules, particularly with respect to communication
among the crane operator, signal person, and spotter. Sonetics proposes a
wireless voice communication solution that greatly enhances the safety,
effectiveness, and productivity of crane operations, while simultaneously
complying with OSHA’s two important new requirements for electronic
signaling: hands-free communication and the need for a dedicated
transmission channel.
The crane operator, signal person, and spotter are absolutely essential to
safe crane operation, but until now have had to rely on hand signals or
*Sonetics Corporation of Portland,Oregon designs and manufacturesproven communication solutions forwork teams in construction, publicworks, aviation, firefighting, marine,construction, and industrial operations.Twice named by Inc. magazine as one ofAmerica’s 500 fastest-growing privatecompanies, Sonetics, together with itsFirecom and Flightcom divisions, helpsmore than 500,000 customers in 90countries hear and be heard underchallenging circumstances.
800.833.4558
www.soneticscorp.com
Wireless communicationand crane safetyKeeping your crew safe, effective, andproductive in the new regulatoryenvironment
8 Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558
two-way radios to communicate. Although “universal” hand signals exist,
the system is complex and the differences between some of the signals
are subtle. Hand signals also require line-of-sight visibility. While two-way
radios do not require line of sight, they tie up one hand for operation and
are subject to interference. OSHA recognizes these limitations by setting
forth new requirements for signals conveyed electronically:
• The device(s) used to transmit signals must be tested on site before
beginning operations.
• Signal transmission must be through a dedicated channel.
• The reception of signals must be by a hands-free system.
These requirements make self-contained wireless communication
headsets a far better option than two-way radios for OSHA compliance
since radios offer neither a dedicated channel nor hands-free operation.
DECT-based wireless headset systems use a digitally encoded, dedicated
channel. Wireless headset systems also provide full-duplex, hands-free
communication within the local audio network. Full-duplex systems allow
conversations to take place in both directions simultaneously. This is an
important safety feature for crane operations because, unlike a walkie-
talkie, it allows verbal warnings to be delivered instantly, even if someone
else is talking. Wireless headset systems can also be integrated with
existing radio systems to enable communication with remote locations.
Wireless headsets offer the additional advantage of hearing protection, a
concern in virtually all crane environments.
A brief note on scope*
The Rules discussed in this white paper apply to cranes and derricks used
in “construction,” which OSHA defines as “work for construction,
alteration, and/or repair, including painting and decorating.”3 In addition to
construction, cranes are addressed in a separate set of regulations for
“general industry,” such as marine and overhead cranes. Typically, OSHA’s
construction regulations are stricter than general industry regulations,4
and employers may be covered by one or both sets of standards,
depending on the type of work being done.
It is estimated that
more than 300,000
cranes are in use
worldwide, and half of
those are used in
construction
*This article is for informationalpurposes only and not for the purpose ofproviding legal advice. While informationin this article has been gathered fromsources believed to be reliable, SoneticsCorporation does not guarantee theaccuracy or currency of this information.If you have questions regardingregulatory compliance, you shouldconsult your own attorney for adviceregarding your specific situation.
Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558 9
A precise definition of what constitutes “construction” vs. “general
industry” has been the subject of much regulatory activity.5 It is not
necessary for an employer to be a “construction company” in order to be
classified as doing “construction work.”6 OSHA has also stated that
construction work is not limited to new construction; it includes the repair
of existing facilities, as well as the replacement of structures.7
Even if your company is not typically subject to OSHA’s construction rules,
there are still two compelling reasons to employ a wireless communication
system in your crane operations. First, a single construction-related
activity — even one incidental to your main purpose — could trigger
compliance requirements under the more stringent construction rules.
Second, wireless communication is a cost-effective method of keeping
your entire work crew safe, effective, and productive, regardless of the
type of work they may be doing. Compared to the costs of injuries and lost
work days, wireless communication systems provide an excellent return on
investment and can easily pay for themselves in a matter of weeks.
A nation of cranes
Gaze across the skyline of any city and the chances are you will see at
least one crane. It is estimated that more than 300,000 cranes are in use
worldwide, and half of those are used in construction.8 Besides being the
most conspicuous feature of a work site, cranes have become a mainstay
of the construction industry itself, due in part to the increased
mechanization of construction techniques.9 In the past, structural
elements — such as walls, flooring, and roofs — were often built on the
construction site out of raw materials. In modern construction, structural
elements are usually fabricated elsewhere and delivered to the work site
for installation, often with the aid of a crane. As a result, today’s building
contractors tend to be less concerned with equipment for production, and
focused more on equipment for materials handling. Several observers
have also noted that crane selection is one of the most important
decisions a contractor makes, and the choice of cranes often influences
the selection of other equipment.10
Crane selection is one
of the most important
decisions a contractor
makes, and the choice
of cranes often
influences the selection
of other equipment
10 Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558
Types of construction cranes
Construction cranes are of two types: tower cranes and mobile cranes.
Tower cranes are fixed to the ground on a concrete slab, rise hundreds of
feet into the air, and can reach out equally as far. The mast consists of
large triangulated lattice sections that can be bolted into place atop one
another, allowing the crane to “grow” in height along with the structure it is
helping to build. Tower cranes can be used to lift steel, concrete, large
items like cement mixers, and other equipment. They can typically lift up to
20 tons, grow to an unsupported height of 265 feet, and extend a reach
up to 230 feet, although these maximums can vary greatly in actual
practice.11 Mobile cranes are self-propelled machines that can move freely
around a construction site. Mobile cranes vary greatly in size, from models
that fit in the back of a small truck to gigantic machines capable of lifting
1000 tons or more. Mobile cranes are used to set up tower cranes at the
beginning of a job and dismantle them when the job is finished.12
OSHA intended the new Rules to apply to a wide range of cranes. Cranes
are defined as “power-operated equipment, when used in construction,
that can hoist, lower, and horizontally move a suspended load.”13 For
purposes of illustrating the types of machinery to which the Rules apply,
the definition goes on to specify a non-exhaustive list of 17 types of
cranes.14 Excluded items include things like power shovels, excavators,
wheel loaders, backhoes, dedicated drilling rigs, automobile wreckers,
forklifts, tow trucks, and tree trimming equipment.
OSHA’s own cost-benefit analysis shows that the Rules will affect over
267,000 businesses and more than 4.7 million employees nationwide.15
Remember that those figures are just for construction activities. OSHA’s
general industry crane regulations, although less stringent, are applicable
to virtually every business.
Are crane injuries a big problem?
Crane operation is a dangerous business. Tons of material is suspended
in mid-air, personnel are working in close proximity on the ground,
OSHA’s own cost-
benefit analysis
shows that the new
crane rules will
affect over 267,000
businesses and
more than 4.7
million employees
nationwide
Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558 11
overhead hazards such as power lines are frequently present, the crane
operator is often unable to see exactly where the load is traveling, and
even a slight error in rigging or load calculation can cause the entire
assembly to buckle. Moreover, because cranes are such a highly visible
component of many operations, they are likely to draw extensive and
unflattering media attention when accidents do occur. Several recent
events in the Puget Sound region of Washington state illustrate this point.
On February 16, 2012, a 40-ton crane at a Seattle shipyard collapsed into
the water with the operator still inside it. Rescuers were able to pull the
man from the water and get him to the hospital, where he was treated for
serious injuries. The aftermath of the incident, with the top of the crane
protruding from the waters of Elliott Bay, was captured on video by local
news helicopters and quickly made the evening news across the Pacific
Northwest.16 Barely a week later, on February 23, the Seattle Fire
Department responded to an incident aboard a construction barge, where
a female in her late 30s had suffered a head injury after being hit by a
crane. The patient was transferred to the hospital with life-threatening
injuries.17 Two months’ prior to these incidents, a crane was badly
damaged during the demolition of the roof at the University of
Washington’s Husky Stadium. Although no one was injured, the crane
suffered so much damage it had to be removed. Unfortunately for the
crane operator, the incident was caught on video and posted to YouTube,18
resulting in an investigation by the Washington State Department of Labor
and Industries.19 For Seattle residents, all of these incidents punctuated
the memory of a horrifying accident in 2006, in which a 210-foot
construction crane collapsed on Seattle’s east side, killing a 31-year-old
Microsoft employee in his apartment, injuring several others, and causing
severe structural damage to three high-rise buildings.20
Reliable statistics on crane accidents are difficult to obtain, primarily due
to underreporting.21 OSHA estimates 84 persons are killed in construction
crane accidents each year, but there is evidence that this figure is
artificially low.22 Data on crane fatalities from the Bureau of Labor
Because cranes are such
a highly visible
component of many
operations, when
accidents do occur, they
are likely to draw
extensive and
unflattering media
attention
12 Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558
Statistics (BLS) show a high of 113 fatal accidents in 1992 to a low of 36
in 2010 (mean= 74), but there are problems with BLS data as well.
Recent studies have documented significant injury undercounts in
comparisons of BLS reports, state workers’ compensation data, and
OSHA injury logs.23
A third source of accident data is available from www.craneaccidents.com,
a privately run Web site that specializes in photos of crane mishaps.
Craneaccidents.com offers its own statistics, based on reports submitted
by Web site visitors. As shown in Figure 1, craneaccidents.com reports
significantly higher accident numbers than either OSHA or BLS, ranging
from a low of 74 deaths in 2000 to a high of 347 deaths in 2006. This
results in a mean accident rate of 162 per year, approximately twice as
high as that reported by OSHA and BLS.24
While annual statistics may vary, it is clear that hundreds of people have
lost their lives and many more have been seriously injured in crane
accidents over the past few years. In fact, a Google search for “crane
accident lawyers” yields more than 100,000 results for law firms that
specialize in this type of injury. It is also worth noting that none of the
preceding data sources report “near misses.” If these were included, the
picture of crane safety would undoubtedly look even grimmer. As the
authors of one study succinctly observed, “Crane-related fatalities are
substantial, representing more than 8 percent of all construction fatalities
investigated by OSHA, and most, if not all are preventable.”25
Crane-related fatalities
are substantial,
representing more
than 8 percent of all
construction fatalities
investigated by OSHA,
and most, if not all are
preventable
Craneaccidents.com
050
100150200250300350400
1 2 3 4 5 6 7 8 9 10
Figure 1Fatalities reported at craneaccidents.com: 2000-2009
2000 01 02 03 04 05 06 07 08 09
Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558 13
Subpart CC in general: A new focus on crane safety
In promulgating the new Rules, OSHA attempted to address several critical
components of crane safety. A discussion of all the changes is beyond the
scope of this paper; however, the major impacts are as follows:26
• Federal requirements for the training and certification of crane
operators, and requirements for third-party crane operator certifiers.
Employers must train their crane operators and signal persons in
accordance with a new national standard for certification. Prior to this
requirement, there was no national standard for crane operations
training, although 15 states and six cities had their own licensing
requirements.27
• New requirements for communication between the crane operator,
signal person, and spotter. Because OSHA recognizes that two-way
radios require a free hand to operate and are subject to interference,
the Rules set forth new and stringent requirements for signals
conveyed electronically. These include:
• The device(s) used to transmit signals must be tested on site
before beginning operations.
• Signal transmission must be through a dedicated channel.
• Signals must be received through a hands-free system.
These unique requirements make self-contained wireless
communication headsets a far better option than two-way radios for
OSHA compliance since radios offer neither a dedicated channel nor
hands-free operation.
• Increased crane inspection requirements. Crane inspections are
required prior to each shift, as well as ongoing monthly and
comprehensive annual inspections. Records must be kept of monthly
and annual inspections.
• Requirements for working near electricity. Employers are required to
ensure that cranes maintain a safe distance (typically no less than 20
feet) from a power line. A dedicated spotter is usually employed to
observe the clearance and the spotter must maintain continuous
contact with the operator.
• New rules for assembling and disassembling cranes. Employers must
The requirement of hands-
free communication over
a dedicated channel
makes self-contained
wireless headsets a far
better option than two-way
radios for OSHA
compliance since radios
offer neither of those
features
14 Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558
It is readily apparent that
many incidents could
have been prevented with
better communication
and the ability to warn
the crane operator in real
time
ensure that proper procedures are followed during crane assembly and
disassembly and supervised by a competent person.
• New requirements for inspecting ground conditions prior to a lift. The
“controlling entity” must inform the crane operator of known ground
conditions and underground hazards that might affect safe crane
operation, such as voids, tanks, utilities, and the like. A “controlling
entity” is a prime contractor, general contractor, construction manager,
or any other legal entity that has the overall responsibility for project
construction. “Known” hazards include those identified in documents
such as site drawings, as-built drawings, and soil analyses. Acceptable
“ground conditions” mean ground that is firm, drained, and graded to
the manufacturer’s specifications for support and leveling.
• Qualifications for riggers and signal persons. A qualified signal
person must be used when the operator’s view is obstructed or if, in
the operator’s judgment, a signal person is necessary for safe
operation..
Employers who operate cranes on a construction site are responsible for
complying with all aspects of the standard, but other on-site employers
have responsibilities as well. OSHA’s multi-employer policy imposes
compliance duties on employers who create or control hazards, expose
their employees to hazards, or have general supervisory authority over a
work site. Thus, even if an employer is not operating a crane itself, that
employer is still responsible for protecting its employees against
reasonably foreseeable hazards if they are working around cranes.
How are people injured in crane accidents?
OSHA’s regulatory initiatives are designed to address the major causes of
crane accidents, which, as shown in Table 1, can arise from a variety of
factors. Beavers et al. examined crane accidents reported in OSHA’s
Integrated Management Information System (IMIS) for the period 1997-
2003 and determined that struck-by-load and electrocution were the
leading causes of crane fatalities.28 Other frequent causes include
crushed-by incidents, boom failure, crane tip-over, struck by cab or
counterweight, and falls. Other researchers have reached similar
Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558 15
conclusions, although the ordering
of factors varies slightly from study
to study.29
In reviewing the “contributing
factors” in Table 1, it is readily
apparent that many accidents could
have been prevented with better
communication. In particular,
factors such as improper clearance
with power lines, potential for
striking other objects, and
unbalanced loads could easily be
more evident to a signal person
than to a crane operator. In these,
and probably many other cases,
tragedy could have been avoided if
the signal person and crane
operator had been able to
communicate clearly and verbally
warn each other in real time.
Indeed, the professional literature
in occupational safety is replete
with examples of how poor
communication adversely affects
construction work sites.30
Renowned safety specialist Gordon
Dupont, whose famed “Dirty Dozen” list of human factor errors have been adopted as a model for occupational
safety in industries ranging from aircraft maintenance to medicine, states the argument in no uncertain terms.
According to Dupont, “lack of communication” is the number one cause of accidents.31
Communication: The key to safety
As previously noted, many of the new Rules are concerned with the proper training and certification of crane
operators, signal persons, and power line spotters, all of whom are required to maintain continuous contact with
Table 1Contributing factors and communication failures related to crane fatalities
Proximal cause Contributing factors Events
Struck by load (not boom failure) 40
Rigging failure 24
Unbalanced load 3
Load dropped 10
Accelerated movement 1
Equipment damage 5
Electrocution 34
Failure to maintain required clearance 34
Boom contact 15
Cable contact 12
Headache ball/sling contact 5
Jib contact 1
Load contact 1
Crushed during assembly/disassembly 15
Improper assembly 3
Improper disassembly – pin removal 10
Improper boom support 6
Failure of boom/cable 15
Boom buckling 2
Boom collapse 5
Overload 6
Equipment damage 5
Incorrect assembly 3
Cable snap 3
Two blocking 1
Crane tip-over 14
Overload 5
Loss of center-of-gravity control 3
Outrigger failure 2
High winds 2
Side pull 1
Improper maintenance 1
Struck by cab/counterweight 4
Intentional turntable turning 3
Bridge crane in motion 1
Falls 3
Missing hand rails 1
Improper operation 1
Improper maintenance 1
Source: Beavers, et al. (2004)
16 Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558
each other.32 During crane operations, the ability to transmit signals
between the operator and ground personnel must be maintained. If that
ability is interrupted, the operator must stop operations until signal
transmission is reestablished and a proper signal is given.33
Under the new Rules, three or more people could be simultaneously
involved in crane operation:
• the crane operator;
• the signal person; and
• a dedicated spotter, whose sole responsibility is to make certain the
crane maintains the required clearance from power lines.
Dedicated spotters receive the same training as signal persons. This
ensures that the spotter is knowledgeable about crane dynamics and is
able to recognize situations in which the minimum clearance distance may
inadvertently be breached if, for example, the load is stopped quickly while
it is being moved near a power line.34
Traditionally, crane operators, signal persons, and spotters have had to
rely on hand signals or two-way radios to communicate. Both of these
“solutions” have serious drawbacks. Although the construction industry
has developed universal hand signals,35 the resulting system is still very
complex and the visible differences between some of the signals are
subtle at best. Hand signals also require line-of-sight visibility between the
crane operator and signal person, which is not always feasible, particularly
in darkness, inclement weather, or in the operation of tower cranes where
great distances may separate the crane operator and signal person. Two-
way radios do not require line of sight, but they tie up one hand for
operation and are subject to electronic interference.36
Recognizing the importance of clear communication during crane
operations, the Rules place strict requirements on the methods used to
communicate among the crane operator, signal person, and spotter. Four
types of signals are allowed: hand signals, voice signals, audible signals
(other than voice), and so-called “new” signals.37
“Universal” hand
signals are complex and
the visible differences
between some signals
are subtle at best
Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558 17
Wireless communication for crane safety
Because OSHA recognizes that two-way radios require a free hand
to operate and are subject to interference, the Rules set forth new
and stringent requirements for signals conveyed electronically.
These include:
• The device(s) used to transmit signals must be tested on site
before beginning operations to ensure that the signal
transmission is effective, clear, and reliable.
• Signal transmission must be through a dedicated channel.
• The operator’s reception of signals must be by a hands-free
system.38
Recent advances in technology have made self-contained wireless
communication headsets a far more attractive option than two-way
radios.39 In the case of crane operations, they are rapidly becoming the
best practice for ensuring clear and reliable communication among the
crane operator, signal person, and spotter. Although an infinite variety of
configurations are possible, the basic building blocks of a wireless
communication system are fairly straightforward, as shown in Figure 2:
• Two or more wireless headsets
• Base station to allow communication between and among headsets
• Optional radio-transmit interface to allow communication between the
worksite and remote users over a mobile radio.
The benefits of wireless communication headsets over two-way radios are
substantial. Wireless headset systems, particularly those equipped with
Digital Enhanced Cordless Telecommunications (DECT) technology, utilize
a digitally encoded, dedicated channel. Pairing the headsets to a base
station creates a closed-loop audio network, eliminating the possibility of
other devices “breaking in” or interfering with the conversation. Although
some inexpensive, consumer-grade systems utilize Bluetooth, DECT is far
preferable for crane operations because it has nearly 30 times the range
and is far less subject to interference than Bluetooth. DECT transmissions
also have multi-pathing capability, meaning that the signal will bounce up,
over, and around obstructions to establish the best possible connection.
Self-contained wireless
communication
headsets are rapidly
becoming the best
practice for ensuring
clear and reliable
communication among
the crane operator,
signal person, and
spotter
Dedicated spotter
Signal person
Crane operator
LocalAudioNetwork
• 1,600-foot line-of-sight range• Hands-free• Dedicated channel
Figure 2Basic Wireless Headset Communication System
Optional mobile radio interfacefor communication with remote users
18 Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558
Properly configured, wireless headset systems also provide full-duplex,
hands-free communication within the local audio network. Full-duplex
systems allow conversations to take place in both directions
simultaneously, similar to a telephone. This is an important safety feature
for crane operations because, unlike a walkie-talkie, it allows verbal
warnings to be delivered instantly, even if someone else is talking.
Although many of these systems include a push-to-talk button on the
headsets, the latter is used only to break away from the local audio
network and communicate with remote users over an optional mobile
radio interface. All communications within the crane crew itself are
seamless, continuous, and hands-free – just like normal conversation.
Hearing protection: An added benefit
In addition to complying with OSHA’s requirements for electronic signals,
wireless headsets can also offer a significant amount of hearing
protection, an important consideration for all construction sites and most
crane deployments. The National Institute for Occupational Safety and
Health estimates that approximately 30 million American workers are
exposed to hazardous levels of noise on the job. Industries with
particularly high numbers of exposed workers include: construction,
agriculture, mining, manufacturing, utilities, transportation, and the
military.40
OSHA regulations require hearing protection when the time-weighted
average noise exposure over an eight-hour period equals or exceeds 85
In addition to
complying with
OSHA’s requirements
for electronic signals,
wireless headsets
can also offer a
significant amount of
hearing protection,
an important
consideration for all
construction sites
and most crane
deployments
Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558 19
If the system you are
considering is billed as
“wireless,” it should be
truly wireless and not
require a belt pack.
decibels.41 “Time-weighted average” takes into account the fact that the
louder the noise, the shorter the exposure time before hearing protection
is needed. As shown in Table 2, as the decibel level increases, the
allowable exposure time without mandated hearing protection decreases.
As shown by the column of corresponding sounds, these standards are
routinely exceeded in construction environments; hence, the need for
hearing protection.
How to choose a wireless headset system
Wireless headset systems are available in a wide variety of configurations
and price ranges. To ensure a system meets your needs, particularly when
purchasing a system for crane operations, consider the following factors
carefully.
• Is the system truly wireless? A number of so-called “wireless”
systems actually require a wire from the headset to a radio or belt
pack. While these systems allow freedom of movement, the use of a
belt pack or radio wire creates many of the same problems inherent in
hardwire systems, particularly tangled cords. Moreover, belt packs
generally have less transmission range than self-contained systems
worn on the head.
• Does the system use DECT technology? Transmission technology can
dramatically affect how well wireless systems perform in the field.
Systems that employ Bluetooth technology generally have a limited
range and are subject to interference from nearby communication
devices, especially those operating on the 2.4 GHz or 5 GHz channels.
Look for systems with the most recent version of Digital Enhanced
Cordless Telecommunications (DECT) technology. DECT 6.0 units offer
up to 30 times more coverage and are less subject to interference in
the 30MHz – 1.8GHz spectrum. DECT transmissions also have
multipath capability, meaning that the signal will bounce up, over, and
around objects in order to establish the best possible connection. For
enhanced security, DECT signals are digitally encoded to ensure
privacy in the transmission of sensitive information.
• Is the system full-duplex or half-duplex? Half-duplex systems allow
20 Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558
communication in both directions, but only one direction at a time,
similar to a walkie-talkie. Once a party begins transmitting, all other
transmissions are essentially “locked out” until the first transmission
is over. Full-duplex systems allow communication in both directions
simultaneously, similar to a telephone. (The term “multiplexing” is
sometimes used to describe full-duplex communication between more
than two parties.) Full-duplex or multiplex capabilities are an
important safety consideration because the parties can speak and
hear others at the same time, allowing verbal warnings to be delivered
instantaneously.
• Is the system radio-compatible? Wireless systems should have the
capability of interfacing with mobile radios to allow communication
with remote users. Given that there are hundreds of radio makes and
models available, look for a system with maximum interface flexibility.
• Can the duplex capabilities be configured to your specific needs? To
maintain an orderly flow of communication and minimize the chance of
“cross-talk,” or multiple conversations taking place simultaneously,
the system should allow you to establish a hierarchy of who can talk
to whom — especially which crew members are allowed to broadcast
over the radio.
• Is the system scalable? As your needs expand, your wireless system
should be able to expand with you. Advanced wireless systems should
be able to accommodate up to 60 users.
• Is the system comfortable to wear and easy to use? Before buying,
physically try on a headset. It should fit snugly, but comfortably, over
the ears. If you are purchasing hard hat-compatible headsets, try one
on while actually wearing a hard hat to ensure a comfortable fit. The
controls should be readily accessible, preferably with a simple push-
to-talk button or toggle-to- talk switch for accessing the radio and
allowing complete hands-free communication with the team. And if the
system is billed as wireless, it should be truly wireless and not require
a belt pack.
• What is the system’s Ingress Protection Rating? The Ingress
Protection Rating, or IP Code, is an international standard that rates
Full-duplex or multiplex
capabilities are an
important safety
consideration because
they allow the parties
to speak and hear
others at the same
time
Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558 21
the degree of protection against the intrusion of solids and liquids
into an electrical unit. A wireless headset should have a minimum
rating of IP65, which indicates that the unit is completely impervious
to dust and is capable of withstanding a stream of water for three
minutes without damage to the interior components.42
• What is the range of the system? The greater the range, the more
effective the system will be for your application, since obstacles and
vehicles may reduce range. Look for a minimum 1500-foot line-of-sight
transmission capability, bearing in mind that system performance may
deteriorate at the outer limits of the range.
• What is the Noise Reduction Rating? Noise Reduction Rating (NRR)
is the measurement, in decibels, of how well a hearing protector
reduces noise as specified by the Environmental Protection Agency.
The higher the NRR number, the greater the noise reduction. While
wearing hearing protection, your exposure to noise is equal to the
total noise level minus the NRR of the hearing protectors. For
example, if you were exposed to 95dB of noise but were wearing a
headset with an NRR of 24, your actual noise exposure would be
71dB. Look for an NRR of at least 24.
• What is the operational temperature range? Extreme temperatures
can affect battery life and headset operation.
• Are all components necessary for operation included in the purchase
price? The price you pay should deliver a complete system that is
ready for operation. Accessories such as battery chargers and
charging cables should be included, not “added on” as options.
• What is the manufacturer’s track record and how knowledgeable are
its representatives? Not all wireless headset systems are equally
reliable and durable over the long term. Make sure the system is
designed for use in your operating environment, ask about warranty,
repair, and replacement policies, and try out the manufacturer’s
technical support prior to making a decision. If you purchase your
system from a dealer, he or she is a critical link in ensuring the final
solution meets your needs. Look at the dealer’s longevity and
reputation in the industry and do not hesitate to ask for references.
Make sure the system
is designed for use in
your operating
environment, ask
about warranty, repair,
and replacement
policies, and try out
the manufacturer’s
technical support prior
to making a decision
22 Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558
Reputable manufacturers choose their dealers carefully and educate
them to act as “problem- solvers,” not just “order takers.” Problem-
solving dealers ask lots of questions, and will attempt to thoroughly
understand your situation before recommending a solution. Advanced
wireless headset systems offer a wide variety of configuration options
that allow customization to your specific application. Your dealer
should be fully informed and aware of what options are available.
• How long is the warranty? A two-year limited warranty is standard in
the industry and some vendors provide extended plans of up to five
years. In addition to length, also look at breadth of coverage.
Safety and crane regulation: Some final thoughts
Apart from their obvious benefits in terms of OSHA compliance, wireless
headset systems are a safe and convenient method of ensuring clear
communication among work crews when operating in construction, utility,
and other dangerous, high-noise environments.
In the final analysis, clear communication is an essential element in every
team’s effectiveness and productivity. If your company employs cranes its
operations, whether for construction or other purposes, Sonetics
Corporation encourages you to explore the benefits of wireless
communication headsets. For crews who must work around cranes, clear
communication could well mean the difference between life and death.
For crews who must
work around cranes,
clear communication
could save a life
Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558 23
1 Federal Register, August 9, 2010, pp. 47906-48177. EffectiveNovember 8, 2010 and codified at 29 CFR §1926, Subpart CC.
2 C. O’Neill, et al., The hidden human and environmental costs ofregulatory delay. (Washington, D.C.: The Center for ProgressiveReform, 2009), pp. 13-16. See also D. Cole, “Crane safety gets alift: The long and winding road to update OSHA’s crane safetyregulations,” EHS Today, August 2009, pp. 240-241.
3 29 CFR §1926.32(g) and 29 CFR §1910(b)(2). These terms arealso used in section 1 of the Davis-Bacon Act (40 U.S.C. §276a) andsection 1 of the Miller Act (40 U.S.C. §270a), which OSHA notes“have considerable precedential value” in determining whatconstitutes construction work. See 29 CFR §1926.13(a).
4 Codified at 29 CFR 1910.
5 J. Stanley, “Construction vs. Maintenance,” OSHA interpretivememorandum, August 11, 1994. www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=21569
6 See New England Telephone & Telegraph Co., 4 OSHC 1838,1939 (1976); and New England Telephone & Telegraph Co. v.Secretary of Labor, 589 F.2d 81 (1st Cir. 1978).
7 For example, in Pacific Gas & Electric Co., 2 OSHC 1962 (1975),the Occupational Safety and Health Review Commission held thatthe replacement of a wooden utility pole is covered by theconstruction industry standards. The utility had argued that thereplacement of the pole was “maintenance work,” rather than“construction work.” The Commission, however, concluded that polereplacement is “improvement” and, therefore, construction work.Similarly, construction work is typically performed outdoors, ratherthan at a manufacturing plant. This factor is another hallmark ofconstruction work. See Cleveland Electric Co. vs. OSHRC, 910 F2d1333 (6th Cir. 1990).
8 J. Keller, “Crane safety: What you need to know when having acrane on site and what it takes to keep your site safe,” Columbus,OH: Presentation to the American Society of Safety Engineers, April17, 2009.
9 A. Shapira and B. Lyachin, “Identification and analysis of factorsaffecting safety on construction sites with tower cranes,” Journal ofConstruction Engineering and Management, January 2009, pp. 24-32.
10 A. Shapira, G. Lucko, and C. Schexnayder, “Cranes for buildingconstruction projects,” Journal of Construction Engineering andManagement, September 2007, pp. 690-700.
11 M. Brain, “How tower cranes work,”www.science.howstuffworks.com/transport/engines-equipment/tower-crane2.htm. Accessed February 15, 2012.
12 Shapira, 2007, p. 694.
13 27 CFR § 1926.1400.
14 The list includes, without limitation: articulating cranes; craneson monorails; crawler cranes; dedicated pile drivers; derricks;floating cranes and cranes on barges; industrial cranes; locomotivecranes; mobile cranes; multi-purpose machines configured to hoist,lower, and horizontally move a suspended load; overhead and gantrycranes; pedestal cranes; portal cranes; service/mechanic trucks
with a hoisting device; sideboom cranes; straddle cranes; and towercranes.
15 Department of Labor, Occupational Safety and HealthAdministration, “Cranes and derricks in construction; final rule.”Federal Register, August 9, 2010, pp. 48080-48082.
16 www.komonews.com/news/local/Crane-collapses-into-water-at-Seattle-shipyard-139468853.html
17 http://seattletimes.nwsource.com/html/localnews/2012197549_crane25m.html
18 http://www.youtube.com/watch?v=mY7Lh0Rl81Y. A quicksearch of YouTube reveals hundreds of such accidents caught onvideo.
19 http://www.seattlepi.com/local/komo/article/State-investigating-crane-incident-at-Husky-2418373.php
20 http://www.komonews.com/news/4673926.html
21 A. Shapira and M. Simcha, “Measurement and risk scales ofcrane-related safety factors on construction sites,” Journal ofConstruction Engineering and Management, October 2009, pp. 979-989.
22 For example, a study by Suruda et al. attempted to examine thecauses of crane-related deaths for the 1984–1994 period throughan analysis of OSHA’s Integrated Management Information System(IMIS) data. For the years in question, they found 479 accidentsinvolving 502 fatalities. However, the authors noted that data forCalifornia, Michigan, and Washington State were not available for1984–1989; the proportion of fatal accidents investigated by OSHAwas unknown; and some of the investigation reports were notsufficiently detailed to allow the authors to determine the cause ofthe accident or the type of crane involved. See A. Suruda, M. Egger,and D. Liu, Crane–related deaths in the U.S. construction industry,1984-94. (Silver Spring, MD: The Center to Protect Workers’ Rights,1997); and A. Suruda, M. Egger, and D. Liu, “Fatal injuries in theUnited States Construction industry involving cranes 1984–94,”Journal of Occupational and Environmental Medicine, December1999, pp. 1052-1058.
23 See J. Ruser, “Examining evidence on whether BLS undercountsworkplace injuries and illnesses,” Monthly Labor Review, August2008, pp. 20-32; Workplace safety and health: Enhancing OSHA’srecords audit process could improve accuracy of worker illness anddata. GAO Report 10-10. (Washington, D.C.: GovernmentAccountability Office, 2009); and N. Nestoriak and B. Pierce,“Comparing workers’ compensation claims with establishments’responses to the SOII,” Monthly Labor Review, May 2009, pp. 57-64.
24 Craneaccidents.com draws from a global base of visitors; thus,some of the reported accidents may have occurred outside theUnited States. It may also be that craneaccidents.com receivesreports of accidents that are not reported to government regulators.Whatever the reason, the fact that craneaccidents.com draws onaccident reports from a self-selected sample of respondentsindicates that its numbers, too, are likely to be significantlyunderreported – at least on a global scale.
25 J. Beavers, J. Moore, R. Rinehart, and W. Schriver, “Crane-related fatalities in the construction industry,” Journal of
NOTES
24 Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558
Construction Engineering and Management, September 2006, pp.901-910.
26 See Occupational Safety and Health Administration, Small entitycompliance guide for the final rule for cranes and derricks inconstruction. (Washington, D.C.: Occupational Safety and HealthAdministration, 2011), pp. 7-8.
27 K. Hunt, Accidents highlight crane safety issues; update ofdecades-old federal rule sought,” Business Insurance, June 16,2008.
28 Ibid.
29 See G. Shepard, R. Kahler, and J. Cross, “Crane fatalities – ataxonomic analysis,” Safety Science, February 2000, pp. 83-93; andA. Suruda, M. Egger, and D. Liu, “Fatal injuries in the United StatesConstruction industry involving cranes 1984–94,” Journal ofOccupational and Environmental Medicine, December 1999, pp.1052-1058.
30 See F. Campbell, Occupational Stress in the ConstructionIndustry, (Berkshire: Chartered Institute of Building, Berkshire,2006; and R. Haslam, “Contributing factors in constructionaccidents,” Applied Ergonomics, July 2005, pp. 401-415.
31 G. Dupont, “The dirty dozen errors in aviation maintenance,”Proceedings of the Eleventh Federal Aviation Administration Meetingon Human Factors Issues in Aircraft Maintenance and Inspection:Human error in aviation maintenance (Washington, DC: FederalAviation Administration/Office of Aviation Medicine, 2007), pp. 45-49.
32 Federal Register (2010), p. 47961.
33 Ibid., p. 47997.
34 Ibid., p. 47948.
35 See American National Standards Institute B30.5-1968,“Crawler, Locomotive and Truck Cranes” and American Society ofMechanical Engineers B30.5-2007, “Mobile and LocomotiveCranes.”
36 Federal Register (2010), p. 47997.
37 27 CFR §1926.1419 et seq. Paragraph (d) of this sectionallows “new” signals other than hand, voice, or audible signals to beused if certain criteria are met. To ensure that any new signalsdeveloped by a particular employer are as effective as hand, voice,or audible signals, §§ 1926.1419(d)(1) and (d)(2) require theemployer to empirically demonstrate that the new signals are aseffective as existing signals for communicating.
38 29 CFR §1926.1420
39 R. Stager, “Wireless communication selection and use toimprove team safety,” Professional Safety: Journal of the AmericanSociety of Safety Engineers, March 2012, pp. 60-61.
40 National Institute for Occupational Safety and Health, Work-related hearing loss, NIOSH Publication Number 2001-103, 2001.www.cdc.gov/niosh/docs/2001-103.
41 29 CFR §1910.95
42 Water projected by a 6.3mm nozzle, 12.5 liters per minute, at apressure of 30 kN/m2 from a distance of 3m.
43 HDH Group, How to avoid OSHA fines. (Pittsburgh, PA: HDHGroup, n.d.), p. 5.
NOTES
Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558 25
REFERENCES
American National Standards Institute B30.5-1968, Crawler, Locomotive and Truck Cranes.
American Society of Mechanical Engineers B30.5-2007, Mobile and Locomotive Cranes.
Beavers, J., Moore, J., Rinehart, R., and Schriver, W. “Crane-related fatalities in the construction industry,” Journal of ConstructionEngineering and Management, September 2006: 901-910.
Bello, D., et al., “OSHA issues guidance on cranes and derricks,” Safety & Health, May 2011: 16.
Brain, M. “How tower cranes work,” www.science.howstuffworks.com/transport/engines-equipment/tower-crane2.htm. Accessed February 15,2012.
Campbell, F. Occupational Stress in the Construction Industry. Berkshire: Chartered Institute of Building, Berkshire, 2006
Cleveland Electric Co. vs. OSHRC, 910 F2d 1333 (6th Cir. 1990).
Cole, D. “Crane safety gets a lift: The long and winding road to update OSHA’s crane safety regulations,” EHS Today, August 2009: 240-241.
“Cranes: Minimize the risk,” Safety & Health, January 2011: 51-52.
Dalrymple, W. “Self help: in the world of self-erectors, operator training and certification has not been taken sufficiently seriously ... untilnow.” Cranes Today, September 2003: 36-40.
Damato, R. “Pay attention to new rules for Cranes and Derricks,” Roofing Contractor, September 2010: 6
Department of Labor, Occupational Safety and Health Administration, “Cranes and derricks in construction; final rule.” Federal Register,August 9, 2010: 48080-48082.
Dupont, G. “The dirty dozen errors in aviation maintenance,” Proceedings of the Eleventh Federal Aviation Administration Meeting on HumanFactors Issues in Aircraft Maintenance and Inspection: Human error in aviation maintenance. Washington, DC: Federal AviationAdministration/Office of Aviation Medicine, 2007.
“Economic Analysis of Crane Rule Complete,” Professional Safety, July 2008: 17-23.
Haslam, R. “Contributing factors in construction accidents,” Applied Ergonomics, July 2005: 401-415.
HDH Group, How to avoid OSHA fines. Pittsburgh, PA: HDH Group, n.d.
Hunt, K. Accidents highlight crane safety issues; update of decades-old federal rule sought,” Business Insurance, June 16, 2008.
Keller, J. “Crane safety: What you need to know when having a crane on site and what it takes to keep your site safe,” Columbus, OH:Presentation to the American Society of Safety Engineers, April 17, 2009.
Kime, L. “Key Elements of OSHA’s Cranes & Derricks Standard,” Occupational Health & Safety, August 2011: 34-38.
National Institute for Occupational Safety and Health, Work-related hearing loss, NIOSH Publication Number 2001-103, 2001. www.cdc.gov/niosh/docs/2001-103.
Nestoriak, N. and Pierce, B. “Comparing workers’ compensation claims with establishments’ responses to the SOII,” Monthly Labor Review,May 2009: 57-64.
New England Telephone & Telegraph Co. v. Secretary of Labor, 589 F.2d 81 (1st Cir. 1978).
New England Telephone & Telegraph Co., 4 OSHC 1838, 1939 (1976).
O’Neill, C., et al., The hidden human and environmental costs of regulatory delay. Washington, D.C.: The Center for Progressive Reform, 2009.
Occupational Safety and Health Administration, Small entity compliance guide for the final rule for cranes and derricks in construction.Washington, D.C.: Occupational Safety and Health Administration, 2011.
Occupational Safety and Health Administration. Cranes and Derricks in Construction; Final Rule. Federal Register, August 9, 2010: 47906-48177.
OSHA clarifies info in cranes and derricks, hazcom rules. Safety & Health, January 2012: 12-19.
Pacific Gas & Electric Co., 2 OSHC 1962 (1975).
Ruser, J. “Examining evidence on whether BLS undercounts workplace injuries and illnesses,” Monthly Labor Review, August 2008: 20-32.
26 Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558
Shapira, A. and Lyachin, B. “Identification and analysis of factors affecting safety on construction sites with tower cranes,” Journal ofConstruction Engineering and Management, January 2009: 24-32.
Shapira, A. and Simcha, M. “Measurement and risk scales of crane-related safety factors on construction sites,” Journal of ConstructionEngineering and Management, October 2009: 979-989.
Shapira, A., Lucko, G. and Schexnayder, C. “Cranes for building construction projects,” Journal of Construction Engineering and Management,September 2007: 690-700.
Shepard, G., Kahler, R., and Cross, J. “Crane fatalities – a taxonomic analysis,” Safety Science, February 2000: 83-93.
Snowdy, G. “Cranes & derricks in construction,” Professional Safety, February 2011: 64-65.
Stager, R. “Wireless communication selection and use to improve team safety” Professional Safety: Journal of the American Society of SafetyEngineers, March 2012, 60-61.
Stanley, J. “Construction vs. Maintenance,” OSHA interpretive memorandum, August 11, 1994. www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=21569.
Suruda, A., Egger, M., and Liu, D. “Fatal injuries in the United States Construction industry involving cranes 1984–94,” Journal ofOccupational and Environmental Medicine, December 1999: 1052-1058.
Suruda, A., Egger, M., and Liu, D. Crane–related deaths in the U.S. construction industry, 1984-94. Silver Spring, MD: The Center to ProtectWorkers’ Rights, 1997.
Van Hampton, T. “Enforcing the New Rule,” ENR: Engineering News-Record, May 16, 2011: 14-15.
Workplace safety and health: Enhancing OSHA’s records audit process could improve accuracy of worker illness and data. GAO Report 10-10.Washington, D.C.: Government Accountability Office, 2009.
REFERENCES
Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558 27
Feature Sonetics
Truly wireless? Completely self-contained wireless headsets; no belt pack or radio wire is necessary
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DECT or Bluetooth? DECT 6.0, interference-free communication with 30 times the coverage area of Bluetooth
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Configurable duplex? Fully configurable with a variety of push- and toggle-to-talk options
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Comfortable? Designed for comfort with ComLeather-over-memory-foam ear seals
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Customer support Dealers receive extensive training; expert technical phone support is available 10 hours per day, five days per week
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Microphone Noise-cancelling electret on flex boom for crystal clear communications
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Warranty Two-year standard; expandable to five years with ComCare™ service
When looking for a wireless headset system, it is helpul to understand the key features and functionalities ofeach system. The following table provides a top-level look at the major recommended requirements for wirelesssystems used in crane operations, and how Sonetics’ solutions address these recommendations.
APPENDIX AWireless System Requirements
28 Sonetics Corporation White Paper No. SO12-02.01_final | www.soneticscorp.com | 800-833-4558
7340 SW Durham Rd. • Portland, OR 97224 USA800.833.4558 • www.soneticscorp.com • [email protected]
Copyright ©2012 by Sonetics Corporation.