That the crew on the Vessels / seafarers are often required to live away from home for extended periods thereby making their workplace their place of temporary stay. During such time of stay, they are at times subjected to harsh circumstances due to unfavourable environmental conditions, hull motions and many other factors which are beyond their control.

Therefore, keeping in mind the objective of the overall safety of all crew members and with the aim of improving the quality of crew member’s performance, comfort by improving working and living environments in terms of accommodation, area design and ambient environmental qualities, the American Bureau of Shipping (ABS) has laid down a guide which speaks of the criteria and measures which are required to be undertaken in order to provide means and ways to reduce crew fatigue, improve performance and safety and to assist with crew recruiting and retention. ABS has produced a Guide for Crew Habitability on Workboats in order to provide a single source for habitability criteria suitable for workboats.

Application and Scope of the Guide

The Guide applies to all the new and existing Vessels. This Guide may be applied to those vessels which are falling under the categories of off shore support vessels, tug boats, tow boats, dredgers, research vessels, anchor handling vessels or other vessels providing services to offshore oil and gas exploration and production. The Guide does not apply to vessels such as oil and chemical tankers, bulk or combination carriers, container carriers, multi-purpose cargo vessels, or mobile offshore drilling units (MODUs). These types of vessels are covered and discussed in other ABS Habitability Guides.

Types of Metrics

The scope of the Guide is to provide an extensive guidance in the areas of accommodations’ design, whole-body vibration, noise, indoor climate and lighting. The Guide further offers’ the designer specific metrics against three levels of habitability –
HAB ++

The Guide addresses two major aspects of the vessel design: accommodation and the ambient environment. The Accommodation criteria are provided for living and some work areas. The ambient environment is concerned with whole-body vibration, noise, indoor climate, and lighting.

At the request of the owner, a vessel complying with the minimum criteria for accommodation areas and the ambient environment provided in this Guide may be assigned a notation of HAB(WB).

A vessel complying with the HAB(WB) criteria and the more stringent criteria with respect to accommodation, whole-body vibration, noise, and indoor climate may be distinguished in the Record by the notation HAB+(WB).

A vessel satisfying all the criteria in the Guide may be distinguished in the Record by the notation HAB++(WB).


Accommodation Areas Requirement for Accommodation Areas Requirement for Accommodation Areas Requirement for Accommodation Areas
Whole Body Vibration Level of vibration- reducing discomfort and promoting job performance Lower level of vibration- promoting job performance and increased comfort Lowest Level of Vibration- promoting job performance and increased comfort
Noise IMO Code on Noise with modifications HAB(WB) with additional requirements HAB+(WB) with additional requirements
Indoor Climate No provision for individual temperature adjustment Aimed at enhancing crew comfort by making provisions for individual adjustments of indoor climate temperature.
Lighting No differences among the notations.


The HAB+(WB) and HAB++(WB) notations have more stringent criteria than the HAB(WB) notation with the objective of providing enhanced living and working conditions to improve seafarer safety and comfort.
This includes enhanced criteria for work space design, crew cabins, and recreation/leisure areas. The HAB+(WB) notation requires meeting the accommodation area criteria of HAB(WB) and HAB+(WB). To achieve a HAB++(WB) notation requires meeting the criteria for both HAB(WB) and HAB+(WB), as well as the HAB++(WB) requirements.

The Guide provides for requirements for accommodation areas and functional requirements for accommodation areas and assessment techniques with regards to the ambient environmental factors.


One of the major factors that effects the crew’s notion of habitability is the accommodation area. The accommodations criteria fall into the following categories:

• Access/Egress          • Berthing
• Sanitary Spaces        • Office
• Food Service           • Recreation Areas
• Laundry                • Medical

Ambient Environmental Conditions:

Whole-body Vibration:

Working and/or living aboard workboats can subject workers to human whole-body vibration. These vibrations will be transmitted to crew members via the vessel’s structure. There are many varieties of potential vibration sources including wave and wind actions, on-load and offload act operations, machinery (main engineers of dynamic positioning thrusters) operations, or vessel motions. Prolonged vibration to the human body can result in a variety of problems. Mechanical vibration may interfere with the crew’s work quality, productivity, and safety. Vibrations resulting from wind, waves, or vessel operations which results in motions that are more likely to affect a crew member’s sense of comfort and can cause motion sickness. For this reason, the ABS Guide specifies vibration limits for the frequency ranges that relate to both mechanical vibration and vessel motions.
Using national and international standards on human performance as well as the consideration of factors such as vessel loading conditions for transit verses circumstances relating to staying on station, which may greatly influence the vibration conditions, were used to help set the criteria levels. Whole-body vibration limits were chosen that would support crew member performance on visual and manual tasks, increase the potential for crew comfort.


Another factor that can significantly influence a crew member’s task performance is noise. Prolonged exposure to noise can interfere with speech communications, impair concentration, and result in a sensation of annoyance. While international and national rules exist with regard to hearing conservation, the ABS Guide provides noise criteria aimed at supporting crew member task and communications needs. To accomplish this, noise limits were set for each type of space that could possibly be expected to exist on a workboat. For the noise measurement methodology, the ABS Guide adopted the techniques and conditions outlined in ISO-2923, Acoustics–Measurement of Noise on Board Vessels. Meeting the ABS criteria allows a vessel to provide an environment where crew members should find tasks that require communication or concentration easier to accomplish.

Indoor Climate:

The Indoor climate is another factor that can influence crew members’ performance. Generally, inappropriate indoor climate levels are only perceived when conditions change or become extreme. The reason for this is that the human body has the capacity to thermo-regulate itself in various environments by producing or losing heat to maintain a comfortable core temperature level. However, this capacity has limits. As a result, it is important to regulate and control indoor conditions such that crew members do not become aware of noticeable changes (ANSI/ASHRAE 55a). The ABS Guide provides criteria for each of these factors. Limits were chosen to facilitate crew member task performance and comfort. The ABS Guide sets forth clear criteria for selecting measurement locations for indoor climate. By meeting the criteria in the ABS Guide, the vessel owner or operator can create a climate that is satisfactory to most crew members and supportive of task performance.


For most activities, vision is a main sensory channel for receiving information. Proper illumination is therefore a critical design element. Lighting is a powerful tool for creating an atmosphere with regards to the desired activity levels within a space. Visual discomfort can reduce concentration, the ability to read or see, or even result in confusion. Human errors can result from visual discomfort by making visual tasks difficult, leading the crew to under and overestimation of distances, or to simply misread a chart or a display. Considering the potential impact that inappropriate lighting levels can have with regards to crew members, ABS personnel decided that it was necessary to include lighting criteria as a part of the comprehensive set of habitability criteria. By using the ABS Guide’s lighting criteria, the vessel operator or owner can ensure that an appropriate lighting environment is provided. While the ABS Guide only requires adherence to the minimum levels, it also offers preferred lighting levels to allow the vessel operator or owner to further enhance lighting aboard their installation.

Obtaining Habitability Notion:

The ABS Guide provides for the assessment criteria and further describes the measurement methodology for obtaining workboat habitability notion. It is intended for use by the shipowners or companies requesting for optional notations of workboat habitability (HAB (WB)) or workboat habitability (HAB+ (WB)). Habitability criteria is provided for vessels of less than or equal to 60m (200ft) and for craft greater than 60m (200ft) in length.

In order to obtain proper habitability notion, the vessel Owner shall certify the operational status of the vessel as being fully operational and/or inclusive of all the equipment’s and fittings. If the Vessel is not fully furnished or operational, a complete list of all the deficiency of services, components, equipment’s etc, shall be submitted to ABS for review. ABS shall review and make a determination and thereafter notify the vessel Owner or shipyard as to whether accommodation area verification activities or ambient environmental testing can commence. The intent is to conclude all ambient environmental testing by the end of the sea trials.

To be awarded the HAB WB or HAB+ WB notation, a vessel must meet the appropriate criteria across the various habitability categories. A summary of the differences between each of the notations is given below.

Notation Accommodations Ambient Environment
Vibration Noise Indoor Climate Lighting
HAB WB No difference between HAB WB and HAB + WB Must meet performance-based criteria No difference between HAB WB and HAB + WB This Criteria provides for a set temperature within limits No difference between HAB WB and HAB + WB
HAB+ WB Must meet comfort-based criteria This Criteria provides for adjust-ability for comfort


Step by Step Chart:

Importance of obtaining Habitability Notion:

The importance of obtaining HN is to make sure that while operating in harsh and extreme conditions like the Polar Regions or otherwise appropriate working and living conditions are satisfied for the vessel to operate in such conditions. In the circumstances during sea trials, where the criteria were either not met, or passed by a small margin, the ABS Surveyor in conjunction with the designer and Owner, may request additional confirmatory tests to be carried out in the actual area of operation. The testing shall be in accordance with the submitted Test Plans reviewed and approved by ABS Engineering in advance of the testing. Testing shall be witnessed by an ABS Surveyor. If the criteria specified in this Guide have been satisfied, then the appropriate notation may be confirmed. The testing shall be in accordance with the submitted Test Plans which are reviewed and approved by the ABS Engineering in advance of the testing.

Safety Culture and Indicators of Safety:

The need to assess the existing safety culture is to identify the areas of strength that can be built upon and weaknesses that afford opportunities and for improvement against operational accidents and personal injuries. Its purpose is to identify the safety metrics which are strongly associated with the safety performance. The Safety Culture requires the seafarers / crew to answer categories of statements into eight aspects of safety viz. Communication, Empowerment, Feedback, Mutual Trust, Problem Identification, Promotion of Safety, Responsiveness, Safety Awareness.


There are challenges that should be considered during the decision-making process of determining whether or not to proceed with a safety culture (SC) survey. Undertaking a survey can be costly, so the costs and benefits should be carefully appraised before proceeding. Once the decision has been made to carry out a survey, the details of the questionnaires should be completely finalized, the distribution format needs to be determined, and employees should be prepared well before beginning the survey. The choices of distribution are paper-based, electronic or a mixture of both (e.g., a web-based electronic distribution for shoreside staff and spreadsheet or paper-based for vessels). There are numerous considerations that are need to be addressed before a web-based survey for shipboard personnel can be a viable option. Some of these considerations include web access of crewmembers, bandwidth, security and confidentiality.


The importance of human element in maritime safety is recognised by the shipping and off shore communities. They still receive continuous attention due to the significant efforts and by the United States Coast Guard (USCG), the United Kingdom’s Health and Safety Executive (HSE), the International Labor Organizations (ILO) and the International Maritime Organization (IMO). Classification societies have also responded, generating guidance and rules for the application of ergonomic data and principles to the design of marine structures, their maintenance, and to the readiness and skills of the people who operate and live on those structures.

The notations will give the owners a clear way to indicate to prospective crew the quality of shipboard life aboard their vessels.


  • What Is The ABS Guidance Note For?

The Guidance Notes are intended to serve as a reference for maritime organizations when planning, developing, implementing, and maintaining procedures and technical manuals. They describe general concepts, provide design considerations, and offer content suggestions.
The intent of the Guidance Notes is for the procedure writer to tailor the provided information to the organization’s own unique needs and preferences, so long as the concepts of clarity, accuracy, and completeness are maintained while promoting safety.

  • Is It Necessary To Abide By The Guide And Obtain Notions?

Yes, for maintaining and monitoring the safety of the seafarers and for conducting Human performance (e.g., safe, efficient, and reliable task performance) it is incumbent to abide by the Guide. An inadequate level of human performance can adversely impact operations. The primary objective for influencing human performance is the reduction of errors. Written procedures and manuals can influence human performance by reducing variation in work performance. This is accomplished by documenting standard work processes.

  • What All Factors Should Be Taken Into Consideration While Determining The Limit And Criteria Of Noise For Adhering To The Guide?

The main factor that’s acts as a precedent to determine is the type of space that could possibly be expected to exist on a workboat is one of the guiding factors. Other Factors such as the types of activities typically take place in the space, the frequency of occupation of the space (unmanned, intermittently, or continuously manned), the communication requirements in the space are taken into consideration for fixing noise limits.

  • Where Are The Conditions And Techniques Enumerated For Noise Measurement?

The conditions are outlined in ISO-2923, Acoustics–Measurement of Noise on Board Vessels.

  • What Is The Key Document For The Identification Of Appropriate Lighting Levels?

ISO 8995 (2005), Lighting of Indoor Work Place.

Leave a Reply