- Electric Worker
- Welding and cutting worker
- Grinding worker
WORK AT ELEVATED PLACE
- Scaffolding components
- Scaffolding terms
- Working place-general
- Construction common to all scaffolds
- System scaffolding
- Independent tied Scaffolds
- Slung scaffolding
- Tank Scaffolding
- Safety net
- Ladders and step ladders
- Material handling
- Transformer bank
- Circuit Breaker
- Switch box
- Wielding machine
- Movable wiring
- Erection by crane
- Erection by gin pole
- Winch work
- Rigging work
- SAFETY device
- Pressurized equipment
- Grinding tools
- Pneumatic tools.
- Welding work
- Gas work
- Classification of personnel
- Methods of work
- Maximum permissible doses
- SAFETY equipment
- Scaffolding Erection and Inspection
- Safety Devices.
- Safety Watchman
- Gas Test Inside the Tank
The following procedures shall be referred to as necessary when using this procedure.
- Construction Execution Plan.
- OWNER/CONTRACTOR’S SAFETY Requirement and Procedures.
The SAFETY PROGRAM covered in this safety procedure shall be carried out by the safety organization shown in Appendix-1
CONTRACTOR shall organize a safety committee consisting of CONTRACTOR’S site manager, CONTRACTOR’S safety engineer, and the subcontractor’s superintendents. The committee shall cover security and health committee. The purposes of the safety committee are;-
- To carry out the safety programs.
- To Instruct and direct the safety programs
- To perform the work safety
A safety meeting presided over by CONTRACTOR shall be held weekly. This meeting shall be attended by all members of the safety committee. The safety meeting shall bee held immediately after a safety patrol is made to make the meeting effective. The findings of the safety patrol, review of work plans, etc. shall be discussed at the safety meeting. The members of the safety committee may be assigned as members of the security and health committee.
A safety patrol shall be conducted around the jobsite by the members of the safety committee every Saturday morning. The safety patrol shall inspect and check any violations against the stated safety rules. Particulars attention shall be paid to disclosing hazards or critical working condition due to alack of awareness by inexperienced workers. A file of the safety patrol reports ( Appendix-2) shall be kept at the jobsite during the entire construction period.
Every employee in a CONTRACTOR must be aware of his CONTRACTOR’S SAFETY policy and attitude towards the control of injury, damage and fire, and of the part he as an employees, supervisors, and management must be stated in writing by the CONTRACTOR’S management. Each employee should satisfactorily discharge the responsibilities allocated to him and be left in no doubt that his safety record will be taken into account when bonus and promotion are being considered. The abroad responsibilities of various members of the constructions team are cited in the following.
- Initiate the CONTRACTOR’S policy for the control of injury, damage, and fire.
- Administer the policy himself or appoint a senior member of his staff to do so.
- Know the requirements of OWNER’S SAFETY REQUIREMENTS and the relevant parts of LOCAL GOVERNMENT WORKMEN’S REGULATIONS, and ensure they are observed by his personnel and labor.
- Ensure that all levels of supervision are qualified and receive adequate and appropriate training.
- Make sure that in tendering at planning stages, and throughout the contract, allowance is made for suitable and sufficient equipment to enable the jobs to be done with minimum risk.
- Coordinate safety activities between CLIENT, sub-contractors, and any other individual contractors who may be working on the same site.
- Institute proper system for reporting, investigation, and estimating the cost of injury, damage, and fire. Promote action to prevent recurrence and initiate analysis to discover accident trends.
- Reprimand any member of supervision for failing to discharge satisfactorily the responsibility allocated to him.
- It a personal example.
- Understand the CONTRACTOR’S policy and appreciate the responsibility allocated to each grade of supervision.
- Know the requirements of OWNER’S SAFETY REQUIREMENTS and relevant part of LOCAL GOVERNMENT WORKMEN’S REGULATIONS, and ensure that they are observed.
- Ensure that tenders are adequate to cover sound working methods and reasonable welfare facilities.
- Determine at the planning stage:-
- The most appropriate order and method of working.
- Allocation of responsibilities with OWNER, Sub contractors, and other contractors.
- Storage areas, access, etc.
- Facilities for welfare, first aid, an sanitation.
- Work permit procedures and requirements.
- Basic fire precautions.
- Provide written instructions to establish work methods, to explain the sequence of operations, to outline potential hazards at each stage, and to indicate precautions to be adopted.
- Check over work methods and precautions with supervision before work starts.
- Create safety awareness by promoting safety meetings and talks and by encouraging safety training.
- Set a personal example on site by wearing appropriate protective clothing and equipment at all times.
Advice site management on :
- Preventing injury to personnel damage to plant and equipment and fires.
- Ways to improve existing work methods.
- Legal and contractual requirements affecting safety, health, and welfare.
- Provision and use of protective clothing and equipment.
- Suitability, from a safety viewpoint, of new or hired equipment.
- Potential hazards on new contracts before work starts and on the safety organization and fire precautions required.
- Changes in safety requirements.
- Carry out site surveys to see that only safe work methods are in operation, that health and safety requirements are being observed, and that welfare and first aid facilities are adequate and properly maintained.
- Determine the cause of any accident or dangerous occurrence and recommend means of preventing recurrence.
- Supervise the recording and analysis of information on injuries, damage, and production loss. Assess accident trends and review overall safety performance.
- Assist with training employees at all levels.
- Take part in discussions on injury, damage, and loss control.
- Keep up-to-date with recommended codes of practice and safety literature circulate information applicable to each level of employees.
- Foster within the CONTRACTOR an understanding that injury prevention and damage control are an integral part of business and operational efficiency.
- Attend job progress meetings where safety is on item on the agenda. Report on job safety performance.
- Understand the requirements of OWNER’S SAFETY REQUIREMENTS and the CONTRACTOR’S loss prevention policy.
- Inspect the work site daily and report and correct unsafe acts and conditions.
- Keep a permanent record of all injuries and damage at the site.
- Keep a record of weekly safety meeting on site with subject and attendance.
- Set a personal example.
- Ensure that all equipment purchased or hired is safe and fully efficient, is guarded and equipped with safety devices, and has been subjected to all necessary tests.
- Make certain that operators and attendants are employed only on equipment for which they have been thoroughly trained.
- Check that periodic tests, inspections, and maintenance are carried out when due.
- Attend promptly to all equipment and advise site management of the need for any dangerous equipment to be taken our of service until properly repaired.
- Organize sites so that work is carried out to the required standard with minimum risk to men, equipment, and materials.
- Know the requirements of OWNER’S SAFETY REQUIREMENTS.
- Be familiar with WORK PERMIT PROCEDURES.
- Give precise instructions on responsibilities for correct work methods.
- Ensure that new employees are properly instructed in precautions to be taken before they are allowed to start work.
- Commend men who by action or initiative eliminate hazards.
- Report unsafe conditions and defects in equipment.
- Set a personal example
- Use the correct tools and equipment for the job. Use the protective clothing and equipment provided.
- Do nothing to endanger self or workmates.
- Keep tools in good conditions.
- Refrain from horseplay and abuse of safety devices, equipment, and welfare facilities.
Anybody on jobsite shall wear a SAFETY helmet. CONTRACTOR shall provide its personnel working at job site with SAFETY helmet and SAFETY shoes/boots having built-in steel toe-caps and reinforced soles. Any unsafe operation shall stopped immediately on request of SAFETY ENGINEER of OWNER and remedied to their satisfaction.
Electric workers for live lines shall be required to wear linemen’s belts and rubber gloves.
Welding and cutting worker.
- Workers engaged in gas welding, cutting, and brazing shall be required to wear goggles or face masks to protect themselves from injury.
- Workers engaged in electric welding cutting, and other similar operations shall be required to wear helmets or shields fitted with filters of appropriate shade, and gloves as necessary.
Workers engaged in grinding, and other similar work shall be required to wear goggles fitted with SAFETY filter for eye protection, or face masks for the same protection purpose and protective gloves.
- All excavation made by CONTRACTOR must be fenced and/or barricaded to protect persons form slipping or falling into the excavations.
- At night the excavations must be provided with red or amber warning lights approved by OWNER.
- A thorough inspection of the protective device of the excavations shall be performed by CONTRACTOR, and corrective measures must be taken when any insufficient protection is found.
- The ladders shall be provided for the working areas deeper than 15 meters or more below ground level.
WORK AT ELEVATED PLACE
Where the work cannot to done safety on the ground or form part of a building or permanent structure, and adequate level of working area supported by scaffolds, ladders or other means must be provided, in order to carry out the work safety.
Scaffolding components Tube
Ordinary scaffold tube is 1 29/32 inches in diameter and is usually referred to as two-inch tube. Tubes shall be free form cracks and surface flaws, laminations, excessive rust, and other defects. The ends shall be cut cleanly and square with the axis of the tube. Tube shall not deviate from a straight line by more than 1/600 of its length measured at the center of its length.
All fittings (couplers, clamps etc.) shall be approved type. They shall be examined regularly and care must be taken to ensure that moving parts of fittings are sound and well lubricated and that threads are not stripped.
Board shall be of rough timber, minimum 35mm thick and not less than 200mm wide, and shall conform to following specifications:
- Looking at the face of the board, not more than one-third the width of the board in any one place shall be knot wood.
- Looking at the face of the board, the ends shall not be split up more than 300mm, with the hoop iron fixed or the end bolted through.
- Looking at the edge of the board, not more than half the depth shall be knot wood.
- Looking at the edge of the boards, the grain shall not cross from face to face in a distance of less than 300mm.
- Looking along the aboard from one end, the board must not be twisted by more than 12mm. Board shall not be painted or treated on any way that may conceal defects.
- Boards Which are split, decayed or wrapped shall not be used, but the parts affected may be cut off to procedure shorter boards with the ends banded or bolted through.
- Scaffold boards shall not be used for such other purposes as form plate for concrete pouring, side stopper for trench or sole plate for scaffolding.
- Standard: (Also known as an upright or column) A tube used as a column or vertical in the construction of scaffold, and transmitting a load to the ground via baseplate.
- Ledger: A tube spanning horizontally and tying a scaffold longitudinally. It may also act as a support for putlogs, transoms for board bears.
- Transom: A tube spanning across ledgers to tie a scaffold transversally, which may also support a working platform.
- Board bearer : A tube incorporated diagonally across two or more members in a scaffold and fixed to them to afford stability.
- Brace: A tube incorporated diagonally across two or more members in a scaffold and fixed to them to afford stability.
- Tie : A tube used to connect a scaffold to a rigid anchorage.
- Guardrail : A tube erected at the edge of platforms and other places to prevent persons falling from the platform or place.
- Handrail : A tube used on stairs before permanent handrails, banisters etc. are fitted to prevent the fall of persons.
- Scaffold fittings Base Plate: A steel plate providing a flat bearing surface for long distributions form standards. It has an integral spigot and fixing holes for the with sole plates.
- Adjustable base plate: Base plate used for compensating variations in ground levels. Also used for strutting and shoring.
- Fixed coupler : (Also known as a Right Angle or 90 coupler) A load-bearing coupler used for connecting two tubes together at fixed right angles.
- Universal Coupler: (Also known as a Band and plate coupler) A load bearing coupler used for connecting two tubes together at right angles or in parallel.
- Swivel coupler : Coupler used for connecting two tubes together at any angle through 360 deg. Not designed for load-bearing purposes.
- Joint Pin : (Also Known as a spigot) A pin used for connecting two tubes end to end. Fitted internally it expands to apply grip against the wall of the tubes.
- Sole plate:(Also Known as a spigot ) A timber or other member of adequate size and suitable quality used to distribute the load from the baseplate over an area of ground, floor joists, etc.
- Toe board : ( Also Known as a kicking Board) A board positioned at the edge of a platform or place so as to prevent persons, tools and materials falling from the platform or place.
- Decking : A close boarded scaffold platform.
- Longitudinal Bracing : (Also known as face on façade Bracing) Tubes secured diagonally across the face of a scaffold to ensure stability.
- Lift :The height from the ground or floor to the lowest ledger or the vertical distance between two adjacent ledgers.
- Ledger bracing : Tubes secured diagonally between lifts from ledger to ledger or standard to standards ensure suitability.
- System scaffolding : ( Also known as unit or frame scaffolding) Tubular welded frame, or patent scaffolding composed wholly or part of purpose made frames or units.
- Scaffold, ramps, ladders, and platforms shall be provided for all work be done 2 meters or more above the ground to prevent falling getting damaged or injured.
- Construction, replacing and dismantling of scaffolds, ramps and work floors shall be directed by supervisor.
- Unauthorized persons shall be prohibited from entering the construction area of scaffolds, ramps, and platforms, caution signs like “NO ENTER” , “DANGER OVERHEAD” shall be displayed during construction, and area shall be rope off.
- Scaffold, ramps and platforms shall be kept free from grease, mud or material or equipment.
- Maximum allowable load and name of person responsible for scaffold , ramps and working floors shall be displayed.
- Wood material used for construction of ramps, platforms and runway shall be good quality. Synthetic or natural fibre rope or other sitting flexible material shall not be used as guardrails.
- SAFETY net shall be provided where scaffolds are infeasible , unavailable, such as when assembling pipe rack, stack., piping structure. In such case, worker shall use SAFETY belts.
- All openings and ends of platforms located at more than 2 meters at the ground shall be barricaded or covered to prevent falling.
- All scaffolds, ramps, and platforms shall be inspected regularly every month, and damaged or unsafe portions shall be repaired or replaced.
- Every working place shall be safe and of great dimensions. When tolls or material could fall 1.8meters of more, guardrails and toe boards shall be provided. Should the provision of these safeguard impracticable, other means of prevention such as SAFETY belts cradles, etc shall be used.
- Guardrails and toe boards shall be fitted at edges of decking from which men or materials could fall a distance of more than 1.8 meters. Guardrails shall not be less than 920mm and not more than 1.15meters high and the space between toe boards and guardrails shall not exceed 760mm.
- Guardrails and toe boards shall be securely fixed to the inside of standards to prevent outward movement.
Access to a working platform is best achieved by providing a separate ladder tower or cantilevered access platform so as not to obstruct the platform and to minimize he possibility of persons falling through the gap in the guardrail or decking.
System scaffolding, also known as unit frame, tubular welded frame, or patent scaffolding, is composed wholly or partly of prefabricated sections. There are many type of system scaffolding available which vary a great deal in design and methods of erection, however the same basic principles set out in 3.5 construction common to all scaffolds apply and the following matters require particular attentions.
- To be erected and dismantled by experienced workmen under the direction of a competent supervisor in accordance with manufacturer’s specification.
- Periodic inspection shall be executed of all parts and accessories. Broken, bent, altered, excessively rusted or otherwise structurally damaged frames of accessories shall not be used.
- Scaffold legs shall be pitched on steel base plates and on timber sole plates or as necessary. Adjustable base plates shall be used to compensate for variations in ground levels.
- Scaffolds shall be properly by cross braces or diagonal braces or both, and the cross braces shall be of such length as will automatically acquire and align vertical members so that the erected scaffold is always plumb, acquire, and right. All brace connection shall be made secure.
General requirement for erection shall be in accordance with 35 construction common to all scaffolds.
Design Loading and dimensions :
A general purpose independent tied scaffold may have up to four working platforms in use at any time. The maximum distributed load on each platform shall not exceed 180Kg/cm2 and the standards shall not be more than 2.1 in apart longitudinally. Not more than one other platform may be boarded out for the purpose of erection, dismantling or access.
The working platforms between standards should not be more than five boards wide (each board 200 mm wide) and it is permissible to place one of these boards between the inner standards and the building if space allows.
Generally ledgers shall be vertically spaced at 1.8m to 2.1m centers o give adequate headroom along the platforms. The first pair of ledgers, however, may be up to a maximum height of 2.6m.
General purpose independent tied scaffolds erected in accordance with the foregoing directions with not more than four working platforms, may be used up to a maximum height of 45m. General purpose independent tied scaffolds departing from these directions shall be specially designed.
Heavy duty independent tied scaffolds General requirements
For general requirements are section 35 construction common to all scaffolds.
Design Loading and dimension:
A heavy duty independent tied scaffold may have up to two working platforms in use at a maximum distributed loading of 290 kg/m2 on each platform and further two platforms used for access or light duty at a loading of 180 kg/cm2 on each platform. The standard shall be at not more than 1.8m apart longitudinally. Not more than one other platform may be boarded out for the purpose of erection, dismantling or access.
Heavy duty independent tied scaffolds erected in accordance with the foregoing directions with not more than two load carrying platforms and two access or light duty platforms are specified, may be used up to a maximum height of 45 m. Heavy duty independent tied scaffolds departing from those directions shall be specially designed.
A slung scaffold shall be suspended by wire ropes or chain from roof or other structural members where scaffolding from the ground is impracticable. Generally, it is used for painting and other work of a light nature.
Design loading and dimensions
A slung scaffold shall only has a single working platform and maximum distributed loading on the platform shall be taken as 73 kg/m2 with ledgers at 2.4m centers and 120 kg/m2 with ledgers at 1.9 m centers.
Working platforms may be suspended by chains, but wire ropes are more commonly used. Wire ropes to be sued for suspension of slung scaffolds should be at least 1/8” (9 mm) in diameter. The •••” or 3/8” scaffold lashing must never be used as a means of suspension. Wire ropes or chains shall be vertical and secured to ledgers as close as possible to transoms. Wire ropes should be secured by two full round turns and three wire rope clamps, chains shall be secured by shackles. Where wire ropes pass round a sharp edged member, packing shall be provided to avoid high point loads and to prevent chafing. The weight supported by a single wire shall not be greater than the safe working load of the rope or of the member to which the rope is attached
Ledgers shall span the suspension points and be spaced at 1.9m centers.
Transoms shall be secured on top of ledgers with load bearing couplers at centres not exceeding 1.2 m.
The working platform shall be close boarded over the whole working area and boards secured to prevent displacement.
Guardrail and toe board:
Guardrails and toe boards shall be fitted at edges from which persons could fall a distance of more than 1.9 m
The stability of the platform shall be ensured by securing adequate and suitable guy lines between the platform and suitable anchorage points. Guy lines shall be as near horizontal as possible and kept taut. A main rope for the SAFETY belts shall be provided.
- Structural steel, steel straps, and steel bars used for brackets, books and hanger shall be free from any damage or corrosion.
- It is essential that the brackets, straps, and welds of sufficient strength to support the weight of the scaffold, men, tools and materials.
- The weld shall be made with the same electrode as is used for main weld joints. The end must be backed up to fill the crater.
- Before the bracket is attached to the strap, the weld shall be inspected by a competent welding or welding supervisor who will mark the weld as passed by circling it with wax crayon.
- Brackets shall be inspected prior to each use and damaged or defective brackets removed from service. Brackets shall be vertical and spacing shall notexceed 2.4 m.
- Rigid guardrails and mid rails shall be securely fixed to the uprights of the brackets at 1 m and 0.5 m from the platform respectively. Alternatively 3/8” wire ropes may be used in place of guardrails and mid rails providing that they are securely fixed and kept taut by the use of turn buckles.
- Work requiring SAFETY net protection shall not be undertaken until the net is in place. SAFETY net shall be extended 2 meters beyond the edge of the work area when workers are exposed to the hazard of falling.
- SAFETY net shall be suspended by chains or links with hooks at least at the four corners, Nets shall be lapped I meter at the edges instead of being butt jointed.
- SAFETY nets shall be inspected daily for damage from abrasion chemicals, or heat. Any damaged portions shall be mended.
- Debris shall be removed from SAFETY nets at least daily, and combustible materials removed before welding , cutting or doing other work emitting sparks, slag, or other ignition sources.
- Spacing between SAFETY net and work shall not exceed 6 meters in height.
- Spacing between bottom of hanging SAFETY net and lower floor level or machinery shall not be less than 3 meters in height.
- SAFETY nets shall be of the following specification :
- Material : Nylon Standard : 4mm(dia.)x3 (standard)/45(number)x1260 (Denier=fibre vol. : wt/length), or equal
The SAFETY of a ladder depends on four important factors : Selection condition, position, and use.
- ladder must be of the proper length for the job to be done. If it is used as a means of access or as a working place, it shall rise to a height of at least 0.9 m above the landing place or above the highest rung to be reached by the feet of the person using the ladder.
- Metal ladders, ladders with metal reinforced side rails, and ladders which are wet, shall not be used near electrical equipment with exposed live conductors.
- Aluminium ladders shall not be used where there is likelihood of contact with materials harmful to aluminium such as caustic liquids, clamp lime, wet cement and sea water.
- Each ladder shall be examined before use. Those with split or broken side rails, missing, broken, loose, decayed or damaged rungs of cleats or with other faulty equipment shall not be used.
- Rungs shall be properly mortised into side rails, cleats shall be uniformly spaced 300 mm from top to top.
- The side rails of a ladder shall be equally supported on a firm level surface. Boxes, blocks, barrels etc, shall not be used as a means of support. The area at the base of a ladder must be kept clear.
- Ladders shall not be supported on their rungs or cleats. Rungs or cleats shall not be used to support scaffold planks.
- Wherever possible, ladder shall be set at an angle of 75 deg. (one horizontal to four vertical)
- Metal reinforcing shall be on the underside of the rungs and where reinforcing is provided on one side of the side rails, that too shall be on the under side.
- Both stiles of a ladder shall be evenly supported at the upper resting place and securely lashed to prevent any movement.
- Where lashing at the upper resting place is impracticable, other measures must be taken to prevent movement of the ladder by securing it at the base/using side guys, or stationing a man at the base.
- It must be understood, however, that a man stationed at the base will only be able to controls ladder up to 6m in height.
- Where there is a possibility of a ladder being struck by moving vehicles or equipment, a man should be placed on guard or a space at the base of the ladder securely fenced off.
- A ladder should always be placed so that there is space behind each rung or cleat for a proper foothold. There should be no obstruction in the way of a man’s foot, particularly at the landing platform. Here the rung or cleat should be level with the platform.
Where an extension ladder is used fully extended the minimum overlap of sections shall be four rungs. Splicing or lashing ladders together to obtain an extension shall not be permitted. Single rung and single cleat ladders should be used by only one man at a time. When ascending or descending, the user should face the ladder. Man ascending or descending ladders should not carry tools and materials in their hands. Tools maybe carried in pockets or special belts provided those do not impair movement. Where a ladder is carried by one man, the front end should be kept high enough to clear men’s heads and special care shall be taken at corners and blind sports.
- Materials, rubbish and tools shall not be thrown from upper levels to lower levels or to the ground.
- When lowering, or moving materials to the ground, suitable devices such as chute, bag, or container with a rope, or a device tied securely with rope shall be used. During the work the foreman shall carefully keep watch, providing NO ENTERING and CAUTION OVERHEAD signs, and rope off the related work are a for SAFETY.
- Excess materials shall not be placed no the platform or runway.
- Materials, tools and equipment which may be displaced or full shall be secured adequately.
- All electrical work shall be performed by qualified and experienced workers. Equipment shall be locked or secured to prevent starting by unauthorized persons.
- Live parts of apparatus and wiring shall be effectively guarded to protect all workers or objects from coming in contact.
- All equipment and wiring shall be checked daily by the operator before starting work. All electrical circuits shall be grounded.
- Warning signs or posters such as “DANGEROUS”, “NO ENTRY” shall be displayed at dangerous places, such as substations, switch boxes and overhead or underground cables.
Transformer Banks or high voltage equipment shall be barricaded with a fence. The entrance shall be locked. For transformer banks, warning signs of “DANGER”, “NO ENTRY “ and “ NO WATER SPRAYING” shall be posted. Posters shall show the name of the supervisor or maintenance ENGINEER. Primary and secondary voltage and capacity shall also be displaced.
- Circuit breaker shall be provided for all electrical construction equipment such as conveyor, winch, pump grinder and similar equipment, to prevent workers from being injured by electrical shock.
- Automatic leakage breakers installed in switch boxes are preferable.
- Temporary switch boxes shall be constructed of metal with a waterproof roof and door which can be locked.
- Switch boxes shall be installed adjacent to the work area at a height of 80cms or more above the ground or platform.
- An ample number of switch boxes shall be provided wit adequate capacity. Switches and fuses shall be of proper capacity for the circuit, protected. Overloading beyond the rated capacity shall be prohibited.
- Name of person responsible for inspection and maintenance of the switch box shall be marked on every switch box.
- Switch boxes shall be grounded with vinyl insulated copper wire.
- Use of copper or steel wire instead of fuses shall strictly be prohibited.
- Multi- connection of cables from one switch shall be prohibited.
- During inspections or repairing, switches shall be cut off and the switch box locked.
- Before welding machines are used, insulation shall be tested to ensure that the machines are in safe operating condition.
- All exposed terminals shall be covered safely with insulation tape.
- Flexible cable having ample capacity shall be used for the secondary cable of the welding machine.
- Name of responsible person and name of CONTRACTOR providing welding machine shall be painted with above attached to it.
- Automatic anti-electric shock device shall be provided for all welding machines, and tested every day before work is started.
- Welding machines shall be installed 30cms or more away from the switch box.
- Wiring shall be cab-type cable having a dielectric strength of not less than rated voltage of 600 volts.
- Cable having ample capacity for the load shall be used.
- Cable with any external damage shall not be used.
- All cables shall be installed away from any steel materials, such as wire rope, steel frame scaffold, etc.
- To present short circuits of electric or electric shock, special precaution such as grounding shall be taken for wiring work where metal scaffolds or steel structures are erected.
- Grounding shall be insured connecting the wire to an earth rod buried firmly in the ground.
- Brass or steel be belts and nuts shall be used for grounding terminals of all electric equipment.
- The erection work plan procedure shall be checked thoroughly by Field supervisors.
- Warning signs of NO ENTRY and SAFETY rope shall be provided CONTRACTORS at the instructions of SAFETY ENGINEER.
- The strength of the road and any obstacles on the route of the crane shall be checked. The road shall be reinforced and obstacles removed where required.
- The strength of the ground where the crane is to be placed shall be examined. It necessary, reinforcements, such as installation of steel plate, shall be made.
- Only authorized persons with a license shall be permitted to operate the crane, or do singing for lifting equipment.
- The foreman and signal man shall be assigned for each erection work. They shall stand where they can observe the loading operation and be clearly visible to the crane operator during the crane work.
- A uniform signal system shall be used with flags, transceivers and whistles for signaling.
- Total lifting weights and the center of gravity of equipment shall be carefully rechecked before commencing erection work.
- As a preliminary check the equipment shall be lifted and held 10cms from the ground. In this state, all the elements shall be checked and inspected to see if they are functioning properly. If risky conditions are detected the lifting work shall be stopped immediately.
- Lifting work shall not be carried out during bad weather, such as strong winds or rains.
- All cranes and winches shall be tested and inspected regularly each month.
- Cranes and winches shall be locked or braked when not in operation.
- Any pressurized equipment or systems confirmed to be unsafe shall be tagged OUT OF SERVICE, DO NOT USE, and use of such equipment shall be prohibited until the unsafe condition is corrected.
- Pressurized equipment shall be operated and maintained only by qualified and designated personnel.
- It is advisable that SAFETY valve setting does not exceed 110 percent over the working pressure. The discharge from SAFETY valves, relief valves, and blow offs shall be directed away from persons.
- SAFETY appliances or devices shall not be removed, except when repairing.
- Compression and related equipment shall be placed to provide safe access to workers for equipment operation, maintenance and repairs.
- All air compressors shall automatically stop before the discharge pressure exceeds the maximum working pressure allowable on the weakest portion of the system.
- A stop valve shall be installed at each outlet for the air hoses. The stop valve on the air lose shall be closed when a tool is being changed or repair work is in progress.
- The driven valve on the air receiver shall be opened before commencing work.
- All hand tools shall be kept in satisfactory condition and used only for the purpose for which they are designed.
- Prior to use, power tools shall be inspected and tested to ensure safe operating conditions.
- Defective top shall not be used.
- When work is being carried out at an elevated position, tools not in use shall be secure or placed in holders.
- Hurling tools or materials form one location to another , from one worker to another, or dropping them to lower levels shall be prohibited.
- Only non-speaking tools shall be used in locations where hazardous vapours exist which may initiate a fire or explosion.
- Power tools shall be operated only by designated personnel.
- Flexible rubber cable shall be used for all portable electric tools. Waterproof connectors shall be used for cable connections.
- Wearing gloves shall be prohibited during drilling or grinding work.
- Electric hand tools shall be grounded.
Use of cracked or damaged grinding wheels shall be prohibited.
- Compressed air shall be exhausted from the line before disconnecting tools from the line.
- Air house shall be pressure rated by the manufacturer, and this pressure shall not be exceeded. Defective hoses shall not be used.
- Hose shall not be left on ladders, steps, scaffolds or walkways.
- The use of compressed an for blowing dirt from the hands, face or clothing is prohibited.
- All welding and cutting apparatus shall be inspected duly. Defective apparatus and equipment shall be repaired.
- Combustible materials equipments such as gas cylinder, rubber hose and debris shall be removed or shielded from heat, sparks and from welding and cutting.
- Welding or cutting work at elevated place shall be conducted only in safe conditions. A SAFETY belt shall be worn.
- Welding or cutting in an area where inflammable vapour may be present shall be carried out carefully after, under the supervision of SAFETY ENGINEER, confirming wire a gas detector that the area is safe.
- When welding or cutting is cutting out in confirmed areas for a long time the space shall be well ventilated. During the work the concentration of oxygen in air must be greater than 18 percent. When working in a confined area, the workers should at least be in pairs to avoid accidents.
- Welding machines shall be placed 15 cm above the ground to keen them dry.
- Welding machines shall be placed level and secured with a suitable wedge to keep them in a horizontal position.
- All electric welding machines shall be effectively grounded. The ground load for the welding machines shall be mechanically strong and electrically adequate for the service required.
- Approved connectors shall be used to connect the welding cable with the welding machine and electric holder.
- Only electrode holders that have passed the inspection shall be used.
- Whenever welding work is suspended of the welder leaves the construction area, the switch shall be turned off and the welding rod disconnected from the holder.
- Cylinders shall be stored in a well ventilated location and shielded from direct sunlight with steel plate or incombustible canvas.
- It is preferred to have the cylinders in service secured in portable racks or hand carts.
- Cylinders transported by crane, hoist, or derrick shall be loaded on cradles, net or skid pans, but never in slings or chains or by magnets.
- Cylinder caps shall be in place when cylinders are in storage in transit, and whenever the regulator is not in place.
- Acetylene cylinders shall be in an upright position during use and secured to prevent displacement.
- Oxygen cylinders and fittings shall be kept away from oil or grease and not handled by oily hands or gloves.
- All cylinders shall be tagged “FULL” or “EMPTY”, and empty cylinders shall be returned immediately to the storage area.
- All connections between houses, hose and force, and hose and regulator shall be tightened rigidly with hose bands.
- Pressure gages with cracked glass or damaged regulators shall be renewed.
- Before starting work, a leakage test shall be made at all connections with soap solutions.
When work is completed, the cylinders block valve shall be closed and regulators and hoses shall be removed and put in the tool box.
Present daily quality control requirements demand that radiography be conducted at any time of the day or night in a variety of places in construction site for non-destructive testing, i.e., testing or welds sin pipes, pressure vessels, etc without damaging the materials. The use of gamma emitting isotopes and x-ray equipment presents potential risk to health, both to on-classified persons and to classified persons, and SAFETY precautions must be observed at all times.
Classification of personnel
It must be understood that the classification of personnel does not grant immunity against radiation.
Competent person must have sufficient technical knowledge to exercise special supervision with regard to the requirements of the regulations and to assist in enforcing their observance. In general he should be made responsible for working out protective measures and safe working techniques and seeing that they are observed.
Persons who in their employment are involved in the used of sealed source and/or operation of X-ray machines and whose work at any time takes them into a radiation area (i.e. and area where the radiation dose rate is liable to exceed 0.75 millions per hour) must be designated” classified workers”. Classified workers must be at least 18 years of age, and are subject to medical supervision.
Classified persons can receive the maximum permissible close of 25 mr/hr to 100 millirems per 40 hours week, but the cumulative dose must not exceed 3 rems per calendar quarter or 5 rems per calender year. A classified person must wear a film badge, which is changed at regular intervals, and a personal dosimeter at all times when using radioactive material. Non-classified persons are members of the general public who are not exposed to ionizing radiation as a part of their jobs. These persons must not be exposed to more than 0.75 millirems per hour at any time.
- All equipment should be maintained in good, clean, working order, and be checked frequently by a responsible person at construction site.
- A record of these checks should be kept, showing details or any defects and action taken to remedy them.
- Isotopes equipment should be examined annually by the manufacturer or his agent.
- All equipment should be provided with means of preventing unauthorized use.
- In order to minimize the radiation doses received by classified workers the control panel should be placed as far as possible from the X-ray tube head. It should be not less than 10 meters for X-ray less than 200KV and 20 meters for X-ray over 250KV.
- All X-ray equipment shall conform to adequate electrical safe standard, and in particular shall be earthed while in use.
- For storage of X-ray equipment special storage facilities are required. However, from the SAFETY viewpoint they shall be kept in lockable storeroom or cupboard.
- Exposure container shall be so designed as a scaled source consists of a small sealed metal capsule inside which the radioactive substance is completely contained.
- The source must be housed in a suitable container and exposed only to the extent that is necessary to produce a satisfactory radiography.
- The exposure containers shall be following three types which are commercially available at present.
- Shutter type : The radiation beam is exposed without the source leaving the body of the container.
- Manual Extraction type : The source is removed from the container on a handling rod that can be one of two types. -Touch type (most commonly used ) where the handling rod incorporates some shielding. -Long handling rod for use with small sources.
- Project type : The source is projected along a guide tube to an external working position.
- The exposure container should be provided either with an integral lock, or preferably with hasps through which a separate padlock can be fitted.
- The choice of a suitable exposure container has a significant effect on the dose received by a classified worker, and its correct selection is important.
- Types of work, frequency and duration of exposures, and in particular accessibility of the working position.
- Type and activity of the source.
- Dose rates outside the container when not in use.
- Provision of suitable means to hold the equipment securely in its operating position.
- When not in use, the exposure container must be kept in a locked store reserved exclusively for radio active materials, so as to minimize the risk of its coming into the possession of unauthorized and untrained persons.
- There must be warning notices on the outside of the store stating the nature of contains. The notices should include the internationally agreed symbol of ionizing radiations.
- The store should be under the supervision or a responsible person, and it is convenient if this is the same person as the one authorized to keep the source records.
- The storage area of exposure container shall not be located where constructional excavations affect it.
- One a technician fully experienced in the practical aspects of radiography and SAFETY.
- The other an assistant with sufficient knowledge to act in a emergency. Knowledge of the following facts will be useful for actual field operation of radiography. An X-ray machine under normal operation condition does not present a prolonged danger from radiation once the pre-set time has clasped. Gamma emitting isotopes, however, are generally dependent upon manual timing and operation and in the event of a accident the operator may lie injured in a high radiation area and shall be in considerable danger if he has no assistance.
- Distance, time and shielding are the methods of reducing radiation exposure.
- Distance : This is an effective method of protection for radiation, because gamma and X – radiation omitted by point sources obey the inverse square law, that is, the radiation intensively decreases with the square of the distance. Conversely, does rates at close distances can be extremely high even for small sources. It is essential, therefore that sealed sources are nover handled directly, but only by remote controls.
- When X-ray and gamma emitting source is used in the construction site, the area should be isolated and guarded as follows:-
- The are a should be suitably marked and encircled by rope barrier or “bunting” set up at 0.75 millirems per hour distance from the source.
- In all cases adequate warning to all persons in the vicinity should be given by lamp or audible signal or both.
- In the case of X-ray machine operation it is mandatory that the means for giving warning should be integrated with the control circuitry so that they operate automatically and it is recommended that the equipment should be unable to function unless they are so connected.
- In the case the gamma ray exposures the warning lamps are generally used and those must be kept in good writing order. They must be positioned so that they are clearly visible to all persons in the vicinity.
- Barriers or “ bunting” identifying radiation area shall be erected before starting radiography and not during an exposure when there may already be people in the area.
- A shield plate shall be provided around the source of radiation to reduce the dose of radiation.
- During radiation work, close of radiation at the area which was encircled by the barriers or bunting shall be measured and recorded.
- For classified workers the sum of doses of gamma or X-rays shall not exceed 2 rems in any calendar quarter to parts of the body other than eyes, hand, forearms, feet and ankles.
- The maximum permissible case stated in above is subject to an overriding limit depending on the workers age such that his total cumulative dose expressed in rems year. I.e 5 x (N-180 rems where “N” equals the individual’s age in year from his first birthday, and persons who are 18 years old shall note 19 instead. c) The maximum permissible dose rates outside closed containers shall be :
- At a distance of 5 cm from surface of container, maximum 100 millirems per hour.
- At 1 meter from source position, maximum 10 millirems per hour.
- Although the dose rates outside closed containers should be kept to a minimum it is far more important to limit the dose rates to which persons may be exposed when the container is in actual use.
- The operating dose rate is a function of the type of equipment, size of source, time exposed, etc, and the work load must be consistent with a dose of no more than 20 millirems per day.
- If the dose rate with a particular equipment exceeds this criterion a stated in above one of the following courses of action should be taken:
- Use a container and accessories which provide more shielding for the operator.
- Reduce the strength of the sealed source.
- Use a projection type container.
- As last resort, reduce the work load of the individual operator so that he shall not receive an excessive dose.
- All tools, machines and other equipment shall be kept in safe condition.
- The area where blast cleaning will be performed shall be defined by warning signs.
- The persons performing blast cleaning shall be protected by helmets with fresh air supply and dust protected overalls.
- For blast cleaning in defined areas sufficient measures for ventilation and dust collection shall be protected.
- The hoses and the nozzles of the blast cleaning equipment shall be sufficiently grounded.
- Written permission is required for surface preparation work as soon as a welding permit is required for the specific object.
- The SAFETY precautions of the solvent manufacturer shall be protected by warning signs.
- The working area shall be kept clean and safe. Used abrasive shall be removed without delay.
- Flammable casting materials shall be mixed under sufficient fresh air circulation only.
- Explosion proof agitators shall be used for mixing of flammable coating materials.
- Warning signs shall be provided for all areas where flammable coating materials will be stored mixed or applied. The sign shall define that area as hazardous zone and shall prohibit smoking open fire and welding.
- Explosion proof electrically powered equipment shall be used when using flammable casting materials (especially in confined areas)
- In closed areas ( eg inside of tanks. Etc) a sufficient ventilation shall be prohibited.
- The installation of the ventilation unit shall prevent unventilated corners. Special precautions shall be taken for all vapours heavier than air.
- The air circulation shall be so designed that the solvent vapour contents will be at least 20% below the explosion limit. The contents of solvent vapour shall not exceed 25% of the air volume.
- The ventilation unit shall be designed and installed in such a manner that condensation on the treated surfaces is prevented.
- Project Planning & schedule
- Cost / Man – Hour Control
- Project Administration & Documentation
- Project Coordination
- Quality Control
- Reporting system & progress Measurement.
- Electrical / Instrument Engineering.
- Mechanical /Piping Engineering.
- Civil / Architecture Engineering.
- Buying Activities Worldwide.
- Quality Assurance
- Inspection & Expediting
- Shipping & Delivery to job sites
- Traffic & Clearance.
- Construction Supervision.
- Schedule Control.
- Quality Control
- Safety Control
- Quantity Survey
- Site Administrative & Labor Control
- Planning & Scheduling for Construction
- Field Engineering.
Operator SAFETY is prime importance, therefore it is strongly recommended that at least two persons are employed on every job :
For a given job the source strength sold be selected to give reasonable exposure times compatible with acceptable doses to the operator. For example if a strong source is used for radiography of small pipe the exposure times may be too short to enable the operator to work in a safe manner.
Safety equipment Radiation does rate meters
The most important single item of SAFETY equipment is a radiation does rate meter. One should be generally available to each classified worker and readily available to each competent person, and be in the possession of each person in charge of radiography on a site.
Audible alarm monitors.
These instrument that indicate the presence of radiation by an audible signal, and are small enough to be carried in a pocket. One should be provided for the personal use of each classified worker, who should keep it switched on during the whole period that he is exposed to ionizing radiations.
Film badges obtained from an approved laboratory are required to be worn by all classified personnel engaged on work involving the use of ionizing radiations. It is essential that film badge results are recorded in a person’s dose record as soon as practicable.
TANK INTERNAL PAINTING.
Commissioning Start- up Assistance