SAFETY ON CONSTRUCTION SITESPART-I

BY AK GUPTA EE(TRG)

INTRODUCTION

• Construction industry employs around 250 million people and contributes 7% of global employment.

• The industry is tarnished for its reputation as "Dirty, Difficulty and Dangerous – the three Ds”

• According to International labour organization, the industry which accounts 7% of the global employment is responsible for 30 to 40 percent of world’s fatal injuries

Construction Workers in INDIA• Construction industry in India is the second largest

industry . • It employs 32 million people and its market size is

worth about Rs. 2,48,000 crores. • It comprises of 55% of the unskilled, 27% skilled

labour and rest consists of support and technical staff .• The report from ILO, 2009, revealed that every year

nearly 50,000 Indian die from illness or work related accidents

• On an average, 165 workers per 1000 are injured.

Accident Causation Theories

• Accidents are unplanned, undesired unexpected and uncontrolled that may result in damage to property and injury to person

• Heinrich---Five Dominoes-(1) Social Environment and ancestry,(2)fault of person,(3)unsafe act/unsafe condition,(4)accident and (5)injury

• Inherited traits---stubbornness,greed.recklessness,bad tempered,inconsiderate

• Unsafe act or unsafe condition is the central factor

Unsafe Conditions

• Rough, sharp or slippery work• Defective equipment• Overloaded tools/equipment• Defective ladders/scaffolds• Improper clothing• Inadequate aisle space, inadequate

ventilation, improper illumination• Protruding ends of reinforcements,nails

Unsafe acts

• Not wearing helmets, safety glasses• Working while intoxicated• Working with insufficient sleep• Moving electrically energized or pressurized

equipment• Failure to use safety belt, fall arresters and

safety net• Using hands instead of hand tools

Foundation of Major Injury

• Foundation of Major injuries (Heinrich 1959)

1 MAJOR

injury1 out of 330

accidents

29Minor Injury

29 out of 330 accidents

300 NO injury

300 out of 330 accidents

Foundation of major accidents

• Foundation of Major accidents/injuries (bird and loftus 1982, cited in Mining Safety Handbook)

1 Serious or disabling injuries

10 Minor injury, i.e., any reported

injury less than serious

600No visible injury or damage

30Property-damage

accidents of all types

Causes of fatalities• Fall from height-------------32%• Mechanical impact---------10%• Fall/hit by objects-----------10%• Accidents involving vehicles------------9%• Electrocution-----------------------8%• Collapse of structures --------------7%• lifts---------------------------------------2%• Drowning------------------------------1%• Fire--------------------------------------1%• combined-------------------------4%• Others--------------------------16%

Prevention of Accidents

• Initial job instructions• Priority to engineering• Stressing the after-effects of accident• Appeal to the workers to care for his family• Showing disapproval of unsafe acts• education

SITE PLANNING AND LAY OUT

• Badly planned and untidy site : cause of many accidents

(a)From fall of materials (b)Collision between workers and plant or

equipment• Space constraints the biggest limiting factor in

urban areas

Planning before work begins

• The sequence in which work is to be done• Note the hazardous operations and processes• Access for workers on and around site• Routes free from obstruction , falling

materials and equipments• Suitable warning notices to be posted• Routes to welfare facilities to be clear and

marked

Edge Protection• Edge protection required at the edge of floor

openings and stairs and where there. is drop of 2 meters.

Edge Protection

Edge protection: Guard-rails and toe boards at open edges of floors and working platforms to prevent workers from falling

TYPICAL EDGE PROTECTION

VEHICULAR TRAFFIC• Vehicular movement to be “one-way” as far as

practicable• Traffic congestion prejudices safety of workers when

impatient drivers unload goods hurriedly• Materials to be stored close to work stations• Construction machinery on operational requirement• suitable locations for workshops and medical

facilities• Sanitary facilities for both sexes at several locations• Artificial lighting where workers pass after dark.s

SITE SECURITY

• site to be fenced to keep out unauthorized persons.

• Protect children and public from site hazards• Fencing to be 2 mtr high without gaps and holes• Overhead protection to public necessary if tower

crane load passes over public thoroughfares• Low voltage electrical power for temporary

lighting

SITE TIDYNESS

• Accidents occur due to tripping ,slipping and stepping over on nails

• Clean as you go• Keep gangways, working platforms and stairways

clear of equipments• Cleanup spilled oil and grease• Deposit waste material at a recognized disposal

point• Remove or hammer down any projecting nails

gangways

TIDYNESS

Clean up spilt oil or grease

NAILS : HAMMER DOWN

Hammer down any nails projecting from timber

EXCAVATIONCauses of accidents

• Workers trapped and buried due to collapse of sides• Workers struck by the material falling into the

excavation• Workers falling into excavation• Unsafe means of access and insufficient means of

escape• Vehicles driven too close to excavation while reversing• Asphyxiation or poisoning---exhaust fumes from diesel

and petrol engines

Preventing collapse of excavation

• Sides of excavation to be sloped to a safe angle of repose, usually 45 degree

• Excavations 1.2m or more to be provided with adequate timbering or sheeting

• Close boarding or sheeting is required if the ground is unstable or lacks cohesion

• Never work ahead of the trench support• Erect suitable barriers to prevent falls into the

trench

SHORING

Shoring to prevent the collapse of the sides of an excavation consisting of timber or steel frames with close boarding between frames

Barriers

Barriers along the sides of an excavation to prevent workers falling into it

Inspection

• To be inspected by a competent person before work begins

• At least once in a day when work is in progress• Thoroughly examine once in a week• Keep record of such inspections

Adjoining Buildings

• Excavation should not be so close and deep to undermine any adjacent structure

• Shoring or other measures to ensure safety of adjoining structure

• Not to store or move material and equipment near the edge of an excavation

• Spoil and waste heaps to be kept away from edges of excavation.

BUILDING PROTECTION

Excavation near a building: Shoring required to prevent collapse of the building

Miscallaneous• Well anchored stop blocks to be provided on the

surface to prevent vehicles reversing into an excavation while tipping.

• provide safe means of access and egress such as secured ladder ex. In the event of flooding.

• Adequate lighting around the area of excavation. • Appearances can be deceptive, most accidents

happen in trenches less than 2.5 m deep• Always wear a safety helmet while working in an

excavation

Stop Blocks

Stop block to prevent vehicles being reversed into an excavation while tipping

Underground services• Electrical cables, water and sewer lines ,gas

pipes, telephone lines • Severe burn injuries due to live electrical cables• Ask from electrical authority, local authority

about the lay out of cables• Even if plan exists, some cables may not be laid

according to available plan• Look for traffic signs, street lights and substations

around• Use cable locators

Marking Electrical Cable

Locating buried electrical cables from a plan and marking their position

Points to remember

• Hand dig with care as cables may be just below the surface

• Use a shovel or spade and not a fork or pick-axe. Do not spear the tools into the ground

• if cable is embedded in concrete , do not break it but seek advice

• If cable is damaged , keep well clear• Do not work bare chested. Work clothing

provide protection from flash burns.s

Gas pipes

• Do not use mechanical excavators within half a meter of a gas pipe

• In case of gas smell, make sure thre are no source of ignition nearby such as a lit cigarette, or running vehicle engines

• Keep the people away and call gas authority• While backfilling a trench with gas pipe , do

proper compaction beneath the pipe to prevent settlement which may lead to pipe fracture.

Ladders• make sure there are no overhead power lines with

which the ladder might make contact;

• wooden ladders with wire-reinforced stiles should be used

• the ladder should extend at least 1 m above the landing place, or above the highest rung on which you have to stand. This is to stop the risk of over-balancing when you step off and on at the top

• never use a ladder which is too short, and never stand it on something such as a box, bricks or an oil drum to gain extra height

Ladders• place the ladder at a safe angle of about 75° to the

horizontal, that is about 1 m out at the base for every 4 m in height

• face the ladder when climbing or descending • ensure that there is sufficient space behind the rungs

to provide a proper footing; • for extension ladders, make sure you leave an

overlap of at least two rungs for sections up to about 5 m in length and at least three rungs for sections of more than 5 m in length

LADDERS• always raise and lower extension ladders from the ground and

make sure that hooks or locks are properly engaged before you start to climb;

• make sure that your footwear is free from mud or grease before you begin to climb a ladder

• if possible carry your tools in your pockets or in a holster or bag when you climb ladders.

• try not to carry materials while you are climbing ladders – use a hoist line instead;

• a common cause of accidents is overbalancing or overreaching, so

do not be tempted to stretch too far instead move the ladder

OVERREACHING

SECURING THE LADDER

Ladder secured at its upper end, extending above the landing place

Securing the ladder

Ladder secured at its foot to stop movement

Safe use of Ladders

Safe use of ladders – allow sufficient overlap of extension-ladder sections; carry tools safely; don’t overreach