Safety in industries , Precautions , Causes , Engineering drawing and safety , UPSC ESE

 Common hazards:

Hazard	Effect	Cause	Precaution
Slip	injuries	It is due to lack of friction	Clean wet surfaces, check before walking, Anti slip boots
Trip	Injuries	Due to hindrance in the path of movement	Remove all the obstacles like scattered cables , open workbooks , etc from the path
fall	Injuries	It is due to unbalance of the body	Proper lighting , proper dress , proper steps , provide guard rails.

Working on elevated surfaces:

• Scaffolds are temporary structures means for construction , repair and decoration .
• Scaffolds can be of 3 types : fixed scaffolds , rolling scaffolds , suspended scaffolds.

Hazard	effect	Precaution
Falling	Injury or death	Every scaffold must have toe board mid rails and guard rails. Working above 6 feet a fall arrest system like anchors , connecting wire should be worn. Always follow safe working load parameters.
Collision	Unbalance of scaffold	Use outriggers and barricade the premises.

Mobile elevated work platform:

It is of two types:

1. Vertical ascending type
2. Boom type
   
   
   

Hazard	effect	Precaution
Entrapment	Serious injuries	Riggers and workers must be dynamic
Falling	Injuries or death	Use fall arrest system
Overloading	Overturn	Always work in SWL condition which is written in platform
collision	MEWP unbalances	Use outriggers and barricade the area

Portable ladder: 

• It is made of aluminium or timber or fibre glass 
• It is of two types : extension /straight ladder , step ladder

Hazard	Effect	Precaution
Falling	Injuries	Always maintain 3 point contact rule, always follow 4:1 rule, do not step at top 3 rungs of straight ladder and 2 rungs of step ladder, check the footing rungs etc. before use.
collision	Ladder unbalances	Barricade the area

Trenching :  it is excavation in which depth of excavation is greater than the width of excavation.

Hazard	Effect	Precaution
Entrapment under soil	Injury or even death	Slopping , shoring , shielding

1. Slopping :
   
   
   
2. Shoring: it is primary done to avoid collapse.
   
   
   
3. Shielding: it is primary done for safe guard worker.
   
   
   

PPE : personal protective equipment

• It is a cloth or equipment that protects the body of worker from hazard.
• It must be provided by employer free of cost.
• It must be kept along with employee all the time and should not be shared

Types of  PPE:

1. Non respiratory type:

• Face and eye protection : eg safety glass , face mask
• Foot protection: eg anti slip boots
• Hand protection : eg gloves
• Head protection: eg hard hats

Types of hard hats:

a) Class B/E : it is hardest and can withstand a voltage of 20KV
b) Class A/G :it is medium hard and can withstand a voltage of 2200KV
c) Class C : it is hard enough to withstand a impact but does not provide any insulation.

• Ear protection: eg earphone
• Fall arrest system : eg vests
• Approns : 

1. Provides visual aid
2. It supports body safety by enclosing overhanging clothes
3. It also protects form radiations

2. Respiratory PPE

• Oxygen cylinder: used where insufficient oxygen like marine , mining , etc.
• Masks: it provides safety from toxic  gases , fumes ,etc

Safety in demolition:

Demolition can be done in three ways:

1. Manual
2. Explosives
3. Ball wreck

Precautions while demolition:

• Barricade the building or site to be demolished
• Use the glowing ribbons around the barricades on which danger or caution word is written.
• During night there should be red signal that must glow around barricades.
• There must not be trees passing
• Use proper  PPE

Methods to demolish:

• Always demolish the structure from to bottom.
• The demolition must ensure stability of structure after each demolition.
• For demolition of any structure remove glaze shash , doors , loose plasters , at first hand .
• For elimination of building the demolition step is 

1. Outward wall / balconies /cantilever beams
2. Secondary beam
3. Primary beam
4. Pillars or column

• Always use water jets while demolition to ensure safety from dust.
• Material chutes can be used for high rise structures for dumping waste material.

Safety in metal  or wood cutting industry.

• Protection of worker from machine.
• Four ways of machine protection:

1. Fully guarded machine: it is done when machine parts are not used for maintenance frequently.
2. Interlock grard; it is accessable frequently by removing grards.
3. Adjustable guards: it can be adjusted depending upon the size of stock.
4. Self adjustable guards: it adjust automatically according to the size of stock.

Highway safety:

1. Dilinearities

• It provides visible aid to the drivers during day or night.

2. Spotter:

• It aids the worker for performing jobs safely.
• For safety of spotters , PPE is provided and signages are used.

3. Sign boards:

• It aids safety to drivers as well as workers working on roads.
• It also provides safety for animals.

4. Barricades:

• To check the overspeeding or drink and drive case.

5. Channelizers:

• To provide temporary pathway for moving traffic.

6. Guard rails:

• It provides protection of vehicle from deviation falling.
• It also checks the crossing of animals or person.