Physical Factors at Work

External physical factors affect us, humans. We are affected both physically and mentally, directly and indirectly by our physical work environment. Those who work at sea work on a surface in constant motion with the sea and vibrations. Noise is present in many places on board and can affect health in several ways. We will look closer at how noise, vibration, lighting and workplace design affect us. This part of the course will give you insight into what applies to the living environment and knowledge of personal protective equipment (PPE).

Noise and Loud Sounds

Prolonged, intense exposure to noise can cause permanent hearing damage, but even sudden, loud sounds can damage your hearing. Lower noise levels can cause discomfort and mental fatigue for a long time. This, in turn, can lead to an increased risk of injuries due to accidents but also reduced efficiency at work. Noise can also cause muscle tension and increased secretion of stress hormones.

If you work on board and are at a place where the equivalent noise level (the average value) for 24 hours exceeds 80 dB, hearing protection must be used. If you are unsure that your workplace's noise level is within approved limit values, talk to your supervisor and ask for noise measurement. The employer is obliged to provide you with information about noise areas and the right type of hearing protection. Hearing protection has its limitations, so make sure you use the right type with sufficient sound attenuation for the environment you are staying in. If plug protection is used, they must be well adapted to the size and shape of the outer ear canal. The hearing protectors used should provide higher attenuation than required concerning prevailing limit values as individuals are differently sensitive to noise. Sometimes it is advisable to combine plugs and covers.

Noise Reduction

• Hard surfaces are covered with acoustic tiles or insulating screens.
• Enclosure auxiliary motors or other small machinery.
• Soundproof workrooms and living rooms so that noise does not penetrate where the crew is staying.
• Install silencers in, for example, the ventilation system's ducts.
• Elastic arrangement. Made by machines and other sound-generating devices and prevents sound and vibration from spreading as structural noise.
• Well-thought-out purchases. Always strive to buy the least noisy machines and tools.
• You can read more about noise and hearing protection in the Swedish Work Environment Authority's brochure (ADI 344).

Premises and Lighting

The design of the premises is vital for the environment and well-being on board. International recommendations primarily regulate these. Detailed regulations on the design of different types of onboard premises can be found in the Swedish Transport Agency's and the Swedish Maritime Administration's regulations. When a ship is built, the Swedish Transport Agency reviews and approves drawings and other construction descriptions. During construction, onboard employees must be given the opportunity to comment on, for example, the crew's housing. Safety representatives must participate in the planning of new or changed premises.

To Keep In Mind When Planning:

• Switch between standing and sedentary working position to prevent neck and back problems.
• Vary the work tasks as much as possible, too much one-sided work can result in wear and tear.
• Instruments and control panels should be logically and ergonomically designed and centrally located.
• Floor covering must be shock-absorbing and non-slip.
• Plan storage of the products, paint cans, or tools that are used most to make them accessible and prevent unnecessary lifting.
• Identify risks and evaluate your workplace by talking to the safety representative or supervisor.

Lighting and Sight

Vision is an interplay between the eye, lighting, visual objects, and immediate surroundings. When assessing lighting, all these factors must be taken into account. The lighting must not dazzle, and the luminaire must be placed so that reflections in work objects and windows are avoided. It must be adjustable and can be directed so that shadows are avoided and provide sound color reproduction. It is especially crucial that lighting on the bridge does not interfere with night vision. The eyes get tired faster if they are often forced to switch between light and dark surfaces. Over the years, the need for lighting increases, and a 60-year-old is considered to need significantly stronger light than a 40-year-old to achieve the same visual effect. It is important that the lighting is maintained. In one year, lighting in a relatively clean environment, such as an office, can be soiled and the light output deteriorates by 20%. In a workshop, the deterioration can be as much as 75% in one year.

• Poor work lighting that dazzles or has the wrong direction, strength, or color, can cause a stinging feeling in the eyes and impair night vision.
• Poorly designed computer workstations and monitors that cause reflections, glare, dazzle, have too small text, or are improperly placed can cause the same problems as poor work lighting.
• Bridge windows should be equipped with blinds and sun protection film.

Review the lighting. The light must not be reflected in the bridge windows, and computer screens must not dazzle. The workshop lighting must be cleaned at regular intervals.

Vibrations and Hand Tools

Whole-body vibrations can cause low back pain. Partial vibration damage to hand-held machines is common on board. Vibrations can spread up to the wrists and cause damage to muscles, nerves, bones, and joints. The most noticeable type of vibration damage is the so-called white fingers caused by disturbing the blood circulation in the tissues. The fingers become numb, sting, and ache, and the symptoms can be aggravated by smoking and cold. Vibrations can also cause vascular and nerve damage as well as decreased sensation and poorer motor skills. The injuries usually occur in the hands. Examples of tools that can cause vibration damage are chisel hammers, needle guns, grinders, and striking nutrunners. Always consider an alternative working method such as blasting instead of a needle gun. If it is not possible to work with anything other than the hand tool, make sure it is used correctly and not for too long.

Measures to Prevent Injuries:

• Calculate the approved working time with the hand tool, for example, the vibration calculator 2.0 on amv.se.
• Avoid cold machines and wear gloves.
• Let the machine do the work, do not press the tool against the workpiece.
• Check the vibration level when purchasing new tools. Ideally, the vibration level should be below 2.5 m/s2.
• Keep in mind that the so-called vibration gloves do not allow longer exposure time than prescribed.
• Always wear safety goggles, hearing protection, and a filter mask (additional gloves and a mask may be required when removing thermosets).

Enclosed Spaces

Serious accidents, several of them fatal, have occurred after entering enclosed spaces onboard. An enclosed space is a space that:

• Has limited openings for entry and exit.
• Lacks insufficient ventilation and lighting.
• Not designed for continuous work.

Enclosed spaces onboard include cargo spaces (in some cases), double bottoms, fuel tanks, ballast tanks, cargo pump-rooms, cargo compressor rooms, boilers, engine crankcases, drain tanks, and adjacent connected spaces. This list is not exhaustive, and a list of enclosed spaces onboard must be on the vessel.

Keep in mind that this also applies to stairwells and storage in connection with tanks and cargo holds. Oxygen content and the presence of toxic and suffocating gases must be measured before entering. Personal protective equipment must be used, and it can include respiratory protection to provide you with fresh air. Before each commenced work in a closed space, a permit shall be issued by the responsible officer and the signature of the persons who are to carry out the work. There must also be a guard adjacent to space whose only task is to monitor and keep in touch with those who perform the work.

Fall from Height

Fall accidents are the most common workplace accidents. In the long run, this means an increased workload for the rest of the work team as well as costly sick leave. The statistically most vulnerable department onboard are curators in ferry traffic.

Fall To the Same Level

Still, there are also risks in the engine rooms with steep ladders and oil spills and during the winter at the mooring stations. Make sure to:

• Always wear approved work shoes with anti-slip protection.
• Paint jetties and floors with anti-slip protection in the paint.
• Wipe up oil spills.
• Mop wet floors in the galley.
• Be aware of slippery decks and jetties in winter.
• Avoid running.

Fall To a Lower Level

There are clear guidelines for using collective fall protection or personal fall protection when you work at a higher level. Simply described, some form of fall protection or fall prevention system must be used if there is a risk of falling from a higher level to a lower one. Collective fall protection means a fence or railing that limits the work area to a fenced workplace. In some cases, collective fall protection can be enough, and no personal fall protection is needed. In some cases, there is no possibility of collective fall protection due to a lack of space.

Fall Protection

There are two different types of personal fall protection; fall prevention and fall arrest. Fall prevention is intended to limit the person's work area so that he or she cannot end up in a situation where he or she falls to a lower level. The rope must be static and without fall arresters. A fall arrest protection must, as it allows, dampen the jerk in the event of a fall. A full-body harness must be used in combination with a fall arrester, and the free fall height must be calculated. The manufacturer states in the operating instructions how the free height is to be calculated for the equipment.

Those who use personal fall protection must have training in how these are used, how they are inspected, and know about the location and strength of the anchor points. There must also be an agreed rescue plan if someone falls since the person can not be left hanging in the harness.