Crew Habitability: What you need to know

12 Dec 2013 Bulletin: Issue 34 - Habitability Resource

The main goals of designing for habitability are to provide a design that will enhance human performance, mental alertness, the quality of life for seafarers, and quite possibly crew recruiting and retention.

What is crew habitability? There are many different possible answers but key components of any definition will likely include the acceptability of the conditions of a vessel in terms of ambient environmental qualities (noise, whole-body vibration, indoor climate, and lighting) and the physical, spatial, and outfitting characteristics of the accommodations provided to the crew.

The main goals of designing for habitability are to provide a design that will enhance human performance, mental alertness, the quality of life for seafarers, and quite possibly crew recruiting and retention. Designing to habitability goals allows for improvement of productivity, morale, safety, and comfort as well decreasing the potential for fatigue and human error. Looking at habitability from a human factors perspective, designing for appropriate levels of ambient environmental factors are crucial to work task performance, whether that task is communicating on the bridge, viewing displays in a control room, or resting and trying to sleep in your cabin. Here are some reasons why:


Inappropriate levels of noise can degrade vigilance during watchkeeping tasks, interfere with complex mental tasks, delay the onset of sleep or awaken one from sleep, and generally interfere with rest.

Whole-body Vibration

Controlling levels of whole-body vibration can establish a safe environment with respect to human response to excessive vibration, including; motion sickness, vibration induced injury/illness and motion induce instabilities and interruptions. Vibration can also alter worker perception (e.g., reading text and instruments, depth perception) and influence control movements (e.g., tactile sense, head/ hand movements, manual tracking).

Indoor Climatic Qualities

The objective here is to provide conditions that are suitable to facilitate human performance with regard to factors such as increases in energy expenditure, decreases in work capacity, reduced hand/arm control manipulation capability, and a decreased capacity for cognitive functioning.


Vision is essential to information transfer, as well as general safety. Inappropriate lighting levels can result in visual task difficulty, distraction, perceptual confusion (such as misreading a display) and failure to detect visual targets. Improperly designed lighting systems can also contribute to eye fatigue, human error, unsafe conditions, and increases in reaction/ response times.

The intent of good habitability design is to apply appropriate criteria or limits that will provide the best overall shipboard or structure conditions for the crew, given design constraints and budget. Additionally, it is crucial that all habitability design characteristics be considered concurrently and early in the design to help meet potential resource constraints.

Until recently, little comprehensive statutory (or regulatory) guidance has been offered related to habitability. Although a few class societies have been quite active in this area, compliance with their guidance is optional. Now we have the International Labour Organization’s Maritime Labour Convention (MLC). The MLC covers owner/ operator related management systems and the vessel’s accommodations design. The MLC, as it relates to habitability, institutes minimum standards of living through the provision of crew accommodation areas that:

1. are free from hazardous levels of noise and vibration;

2. provide appropriate levels of lighting and indoor climatic qualities;

3. offers improved crew accommodation’s design.

The MLC establishes a new (and improved) baseline related to crew accommodation requirements, while replacing requirements that date back to the 1940s and 1970s. The crew will have for example fewer or no cabin- mates, a larger cabin floor area (almost double previous ILO Crew Accommodation Convention requirements), and more convenient access to showers, water closets, and lavatories.

Even though the MLC is basically a health and safety conservation standard, it is a definite step forward for seafarers.

Accommodation areas: Access and egress, crew cabins, sanitary spaces, offices, food services, recreation areas, laundry, medical spaces

Whole-body vibration: Low frequency mechanical vibration (vessel motions), high frequency vibration (rotating machinery)

Noise: Speech communication, hearing loss, sleep, concentration, ‘annoyance’ factor

Indoor climate: Heating, ventilation, air conditioning

Lighting: Illuminance, task duration, visual fatigue, task criticality, veiling reflections