Crew Habitability: What You
Need to Know
Dr. Kevin McSweeney
Manager - Human Factors Department
ABS, Corporate Technology, Houston Texas
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What is Habitability?
• The acceptability of a vessel (or facility) as determined by its physical arrangements, as well as the ambient environmental qualities of vibration, noise, indoor climate, and lighting
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Why Habitability?
• Proper facility design and ambient environmental conditions are influential factors for enhancing human performance and reducing human error
• Ambient environment conditions where the crew work, sleep, eat, rest and relax can influence overall sense of comfort (habitability), well-being and perhaps crew recruiting and retention
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Guide for Crew Habitability on Ships
• Crew Habitability– Basic notation (HAB)
aimed at supporting task performance
– Higher notation (HAB+) aimed at enhancing crew habitability
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Guide Contents
Crew Habitability
Accommodations Design
Checklists for Various Spaces
Compliance Criteria& Measurement Methods
Ambient Environmental
Qualities
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Accommodations Design
• Access/egress• Berthing• Sanitary spaces• Offices• Food services• Recreational
facilities • Laundry• Medical spaces
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Ambient Environment
• Human Whole-
Body Vibration
• Noise
• Indoor Climate
• Lighting
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Human Whole-Body Vibration
• Criteria included for:– Crew task performance– Enhanced habitability
• Basis of measurement methodology:– BS 6841
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Vibration Frequencies of Interest
• 0.5 Hz to 25 Hz
– Motion induce instability (MII) modest discomfort and fatigue
– Internal body parts resonate
• 25 Hz to 80 Hz– Performance degradation due
to decay in sensations and perceptions
z-axis
y-axis
x-axis
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Interference with Crew Activities
• Vibration Frequency range (Hz)– Reading (instruments) 0.5 - 12
– Reading (text) 0.5 - 50
– Control manipulation 0.5 - 30
– Speech 1 - 20
– Depth perception 25 - 40
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Noise
• Criteria based on:– Normal activities in a
space– Frequency of occupation
of a space– Communications needs– Crew’s expectations
• Basis of measurement methodology: – ISO 2923
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Noise Levels
• Adverse / improper levels can:– Cause speech interference
– Interfere with concentration and thought processes
– Disrupt sleep
– Cause fatigue and aggression
• Appropriate noise levels can:– Provide an environment for improved human
performance
– Have a positive psychological effect on people
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Big Contributor – HVAC Noise
• Potential Solutions:– Configurations including largest feasible duct
diameter, gradual turns– Use of HVAC
silencers / resonators– Tuning of resonators
to the blade frequency– Reduction of pressure
changes– Proper Supports for
Exhaust and Piping Systems– Secure ventilation ductwork piping systems will
reduce vibration against shipboard structures
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Indoor Climate
• Criteria based on human performance data
• Basis of measurement methodology :
– ANSI / ASHRAE 55a
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What Determines Comfort?
• Environmental factors– Air temperature– Air speed– Humidity
• Individual factors– Activity– Clothing insulation
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Lighting
• Criteria based on supporting tasks via general and activitylighting
• Basis of measurement methodology:
– IESNA RP-12
– ISO 8995
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Lighting Requirements
• Relationship between age and lightrequired for readinggood print
Source: Phillips Lighting
Ligh
t R
equi
rem
ent
(x 1
00 L
ux)
~ 3x greater
~7x greater
Age (years)
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Lighting
Visual performance vs. Light level (in Lux) for an assembly task
Young
Older
Source: Phillips Lighting
~7x greater
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HAB and HAB+ Notation HAB and HAB+ Notation
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Habitability Data Gathering
• Data collection efforts started in 2001 and continues today
• Data has been obtained from multiple sources:– Offshore installations– Commercial ships– Workboats
(OSV’s and crew boats)– Passenger vessels
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Data Gathering
• Data from Pacific, Europe, and Americas
• Review of accommodations design and layout
• Focus on ambient environment characteristics (noise and vibration)
• Informal (but informative) interviews with crew members