The need for machine guarding, practices and devices and includes information on hazardous machine components, motions, and actions,Safety Awareness, It is sharing of knowledge. By Bimal Chandra Das, Rtd. AGM (Safety), Bokaro Steel Plant,/ Bokaro. Kolkata

1. Machine Guarding
Prime Mover
Any engine motor or other appliance which generates or otherwise provides
power
Transmission Machinery
Any shaft, wheel, drum, pulley, system of pulleys, coupling, clutch, driving belt or
other appliance or device by which the motion of a prime mover is transmitted to
or received by any machinery or appliance.
Machinery :
Includes prime movers, transmission machinery and all other appliances where
by power is generated, transformed, transmitted or applied.
Securely Fenced :
• Not to be interpreted as little securely fenced, or reasonably fenced or
moderately fenced. The employer is not be able to defend himself by saying
that it is impossible for commercial or mechanical reasons to fence the
machine or part of a machine.
• The obligation imposed by Sec. 21 is absolute (complete, free from
controls & conditions), it is not for court to water down the absolute
character of the obligation by imposing considerations as to practicability of
the requirement or possible substantial loss of efficiency or utility of
machinery
• The carelessness, the indolence (negligence), the inadvertence (laziness),
the weariness (tiredness) and even the disobedience of a worker are things
which an occupier of a factory can and is expected to foresee and should,
therefore, provide against such happenings, fencing of machinery must be
secured.
• Constantly maintained and kept in position - Sect. 94 Applies
Basic Requirement of Mechanical Guard
• It must be sturdy to prevent damage to the guard from external source or
interference.
• It must permit required maintenance, operation without necessitating
excessive labour for dismantling and assembling the guard.
• It must be properly mounted. The mounting must be rigid to objectionable
rattle or interference with working parts.
• It should be designed so that there are no detachable parts, which if
removed and replaced would reduce guarding effectiveness.
• It should be easy to inspect.
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2. Dangerous
A machinery or part thereof is dangerous if in the ordinary course of its working
danger may reasonably be anticipated from it when working without protection,
taking into account the various factors incidental to its working, including
carelessness of the workmen.
Default as to make the employer liable to a penal consequence
The obligation of the employer is absolute and it does not require the proof of
existence of men’s area. When of a proper safeguard is provided and someone not
known to the employer, removes it without his knowledge or consent, still the
employer would be made liable for penal consequence.
Machine Guarding
A guard is a device to prevent injury to a person working on or near a moving
machinery.(e.g. Coupling guards, V-belt guard, Conveyor tail end guard etc.)
Where dangerous parts of machinery are not made safe at the design stage by
construction or by position, they should be guarded or protected in such a way as to
prevent access at all times when danger exists.
Machinery Hazards
• The violent ejection of a work piece.
• Contact with the revolving wok piece.
• Contact between a work piece.
• The free fall of a part which is at rest?
• Contact with hot substance.
• Entanglement in materials.
• Entanglement of loose clothing, hair or materials
• Projected from pockets.
Dangerous Machinery Parts
• Rotating shafts & spindles.
• Trap or nips at ingathering rotating parts.
• Nips between belts and pulleys.
• Projection on moving parts.
• Discontinuous rotating parts.
• Revolving drums or cylinders with dangerous surface.
• Worms and spirals.
• Surface of fast running parts.
• Band type cutting tools.
• Revolving cutting & abrading tools.
• Reciprocating tools of the press or punch type.
• Misc. shearing and trapping hazards.
Principles of Machine Guarding
• Provide positive protection.
• Prevent all access to the danger zone during operation.
• Cause no inconvenience to the operator.
• Be suitable for the job & the machine.
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3. • Constitute a built-in feature.
• Allow for m/c oiling, inspection, adjustment & repair.
• Withstand long use & normal wear & shop with minimum maint
• Protect against unforeseen operational conditions, not only against normally
expected hazards.
• Must be properly mounted.
Factories Act 1948
Sec. 21(Fencing of Machinery)
In every factory dangerous parts of machinery, e.g. Every moving part of a
Prime Mover & every Fly Wheel connected to a Prime Mover. The headrace
& tailrace of every water wheel & water turbine Every parts of transmission
machinery. Every parts of electric generator, a motor etc. Every dangerous
parts of any other machinery.
Shall be securely fenced by safe guards of substantial construction which
shall be constantly maintained and kept in position, while the parts of
machinery, they fencing, are in motion or in use.
Sec 22 (Work on or near Machinery in motion)
When it becomes necessary to examine any part of machinery, while the
machinery is in motion, such examination or operation shall be carried out
only by a specially trained adult male worker wearing tight fitting clothing,
whose name has been recorded in the register prescribed in this behalf.
No woman or young person shall be allowed to clean, lubricate or adjust any
part of a prime mover or any part of transmission machinery while the
machine is in motion.
Sec 26 (Casing of New Machinery)
In all machinery driven by power and installed in any factory after the
commencement of this act:- Every set screw, bolt or key on any revolving
shaft, spindle, wheel or pinion. All spur, worm and other toothed or friction
gearing which does not require frequent adjustment, while in motion, shall
be completely encased.
Sec 23 : Employment of young persons on dangerous machines
No young persons shall be required or allowed to work at Any machines
which is in motion, unless he has been fully Instructed as to the dangers
arising in connection with the machine & the precaution to be observed and
a) has received sufficient training in work at the machine or
b) is under adequate supervision by a person who has a thorough
Knowledge & experience of the machine.
Rule 59(B) of BFR – 1950 also specifies the same.
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