Monday 4 April 2011

health and safety

HEALTH AND SAFETY


Introduction:
As it would be necessary with in any occupation or in any working environment, health and safety is a major concern in dealing with the mechanical side of the marine engineering.
Having a safe environment is vital for well being of everyone involved in the work environment, besides, legislation requires employers/employees, institutions/students to provide and practice safety environment as per The Health and Safety in Employment Act 1992 came into effect in April 1993.
Potential hazards:



In this (marine engineering) work environment hazzards are many. Some examples are
Mechanical forces (collisions and impact forces)
Danger of getting struck by objects,
Confined spaces around the equipment,
Slips and trips due to lubricant spillages etc,
Potential dangers of falling on a pointed object,
Potential danger of Entanglement etc.
Equipment related injuries can be such as Cutting,abrasion, crushing, shearing, fraction puncture and Stabbing etc...
How do you prevent work place injuries/accidents in this environment?
Work place safety is ensured by adhering to safe environment procedures and by implementing Safety Practices
There are 4 crucial elements in a work environment to ensure safety
A.Always use safety protection gear
The following safety equipment/gear must be worn by the individuals. They are
Protective Overalls (Cotton fabric material is recommended)
Steel Capped leather boots:(essentially non slippery ones)
Safety goggles: essential to prevent any foreign objects causing injury to eyes. safety goggles must be worn all the time specially using lathe, grinder, and drill.
Ear muffs: essential especially where sound decibel levels are high.
hat, hair net or a hair tie, For restraining long hair
Personnel jewellery that could come entangled/entrapped in the equipment or prevent the equipment to function appropriately must be removed prior to handling.
In addition, other associated measures must be in place such as having ready access first aid kit and fire extinguishers etc.
B. Maintain workshop area clean and tidy at all times. This not only helps to prevent slips, trips, spills but also ensures the equipment are available as needed and to prevent working in a disorganised/disorderly fashion.
Always use the appropriate personal protective devices and check that they are clean and in good order if required repair before and after use. .
C. Ensure the object/equipment used/fitted are as per the instructions.
Only use machines and tools intended for their purpose
each machine should be inspected prior to commencement of work to ensure that all guards are fitted correctly.
plant,Machinery, and equipment should be installed so as to ensure that sufficient space and safe to operate.
provision for footholds around an individual machine to allow for normal operation.
Where machine guards are necessary, they must be in place, a function of a guard is to protect the person and equipment from danger, to keep the operator's ,clothing, arms,fingers and body away from the danger point,and also to prevent a hazardous piece of material from striking the operator e.g. a grinding wheel guard. These guards must of be of aproproite shape and of sufficient strength to prevent the hazard from being flung out at the operator. This may also prevent the fitting of an unsafe attachment e.g. an oversize wheel to a lathe.
Ensuring having Machine controls more clearly visible e.g. stop buttons coloured red and start buttons coloured green indicating STOP/START on or near the button,having easy to locate stop buttons are handy.
Ensuring to have easy operable machine controls such as Start-stop controls are of the push button type.
Starting levers and handles must have a provision for automatic retention to the "off" position.
Each machine should have a stop control for disconnecting power and the control should be readily and safely accessible to the user from the normal operating position.
Having a ready access emergency stop buttons which are prominently and well labelled, and these are installed at selected positions so that pressing any one of these buttons should immediately stop the power supply from the machines.
Avoid distracting attention of another member when that person is operating equipment.
D. If you are to drill,file or using lathe, the object must be placed and tightened properly in the vice grip ( This was personally experience by me in the lab as a solid metal slipped out of wise grip and fell on my foot thanks to my steel capped boots no damage was done:-)
While using the hack saw, object must be properly fitted and hack saw is held in a 90 degree angle ensuring safe distance is maintained.do not wear jewellery ie hand bracelet, and keeping close watch on every stroke holding the hack saw with two hands.
Always use the appropriate personal protective devices and check that they are clean and in good condition and if needed repair before and after use.
Do not use unauthorized measures or practices
Report all damaged equipment and refrain from using until it has been repaired by a qualified technician.
It is vital to remember that safety of the person is a priority to the safety of the machine itself.
Ensure all unsafe conditions and work practices are needed to be reported.

To ensure safety procedures are followed the basic principle is to remember all safety practices and to be adhered to appropriately and strictly.

WELDING SAFETY PRECAUTIONS: Fusion welding and cutting process involve intense heat, either from an electric arc or a gas flame.
In the arc welding process , rays are given off that are high in infrared and ultravoilet emmisions. If we look at an eye without proper eye protection , we are prone to an condition called arc eye. This is painful condition causing irritation of the eyes which can last upto 48 hours in severe cases and should seek medical advise.
the welders eyes and face must therefore be protected from these rays and also intense heat and light comming rays comming from the arc.The shield should cover the sides of the face and have a slpecial filter lens.
The filter glass of the shield is protected by a plain cover glass which should kept clean and replaced when spatter damage makes it difficult to see through.
For heavy duty welding a leathet apron is usually worn on top of the overalls.Industrial boots to protect the feet from particles of hot metal and sparks .leather glove are recommended.
For gas welding it is not neccesary to wear a helmet.Goggles must be worn to protect from sparks,heat and light radiated from the work.Goggles must be replaced when they are damaged  to avoid obscure vision.
Precautions to avoid electric shock: when changing the electrodes always wear gloves to avoid comming in contact with the electrodes with bare hands
Wearing thick soled industrial boots and standing on dry boards in damp conditions will minimise the risk of getting electrocuted.All metal casings on electrical equipment should be connected to earth so that electricity is safely discharged.
Precautions to avoid the risk of fire and explosion: Acetylene can form potetially explosive mixture with air with in the range of 2-82 percent of acetylene.This range can could be achieved merely from a leakage.
Oxygen is non flammable but will support and increase combustion in flammable materials, the atmosphere surrounding the work must not be allowed to become enriched with oxygen,from a leak from a hose or pipe the slightest spark under these conditions can cause flash fire.oxygen can ignite oil so all the premises should be clean.
All  fusion welding process produce sparks and hot metal all the combustbles stored away.
Using and storing cylinders of compressed gas:
!.keep full and empty cylinders  separalely in a clealy marked storage area.
the storage room should be fireproof and have flame proof electrical fittings.It should be well ventillated.
2. Never smoke, wear oily or greesy cloathing
3. In storage and in use never allow cylinder to come in contact with ice and also direct sunlight.
4.Acetylene cylinders should be kept in upright position.
5.Oxygen and combustable gases such as acetylene propane should not be stored toghether.
6.Keep cylinders away from the heat as heat increases the pressure of the gas and can weaken cylinder wall.
7.Use cylinder trolly to transport  the cylinders to avoid dropping bumping etc.
8.In use always protect the cylinder from sparks and flames of welding and cutting operations and ensure that they are clear of electrical apparatus if there is a danger of stray arcing.
9.Never test for leaks with a naked flame always use soapy water.
10.Always shut off the gas supply when the cylinders are not in use, do not over tighten the valve when shutting off tighten enough to prevent the leakage.
!!.Never use fittings made of copper or copper alloy with more than 70 percent copper; copper can form an explosive compound when in contact with acetylene.
12.Blow out the cylinder outlet by quickly opening  and closing  the cylinder valve to clear out any dirt or du
st,before fitting. the regulator. Do not use oil or greese on valves or  gas welding equipment.
13.Always ensure the cylinders are secure and will not fallover,either in use or in storage.
14.If the cylinder spindle valve should become frozen thaw it out slowly with warm water,never use flame.
15.If the acetylene cylinder becomes heated for any reason ,take it outside and immerse in water or spray  it with water .Open valve and keep it as cool as possible until the cylinder is empty.
Welding and cutting vessels that have held combustibles
Never perform a welding on  vessel that has contained in a inflammable liquid unless proper precautions are taken.
VENTILATION AND FUME EXTRACTION WHEN WELDING: Most of the fumes are potentially hazardous and some even can be fatal.particular care and specific control measures have to be taken specially   when using electrode coatings containing flourides.Also when welding usi ng low hydrogen electrodes such as monel nickel and stainless steel or any metal with a high chromium content.
welding and cutting of materials that have been painted ,brass and galvanised or cadmium plated metals should be carried out in a well ventilated  area with fume extraction at the point of work.
If the welder exposed to the fumes seek medical assistance immidiatly.
Nitrogen oxides can be formed by the action of heat and ultra voilet radiation.These oxides can irritate the lungs and in high concentrations,can cause cyanosis this condition can be fatal.
Argon and carbon dioxide both are widely used shielding gases are heavier than air and can settle at floor level and if they ade not extracted can build up into a stagnant blanket of asphyxiating gases an extractor duct at the floor level and a fan blower replenishing fresh air into welding area will avoid this situation.
Methods of fume extraction:  The atmospehere in the welder's helmet can be controlled by replenishing with fresh air constantly.Special helmets can be obtained for this purpose.
2.Small extractor ducts: These can be placed near the welding   operation can be very effective as they extract fumes at the source.
3.Roof extractor hoods.will help to keep the fumes in a workshop down to acceptable level.