Modern Design of Machinery Guarding Presence Sensing Safety Devices

Running head: ESSAY
Modern design of machinery guarding presence sensing safety devices
Name of the Student
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Author Note

1ESSAY
Introduction
Every year, significant number of employees are found to incur bodily injuries that
occurs from the use of machines, particularly those that have exposed moving parts. These
injuries can be attributed to the fact that the machines are not adequately designed for safe
use and the companies fail to implement sufficient safe work related procedures (Vallmuur et
al. 2016). Machine guarding refers to the safety feature that is present on or around certain
engineering or manufacturing equipment that consist of a device or shield, which cover
specific hazardous areas of the machines. The primary purpose of machine guarding is to
eliminate all kinds of contact with the body parts, thereby preventing a range of hazard such
as, sparks or chips from the machine. Machine guarding also provide a definite means of
protecting humans from severe injuries, while operating an instrument or working nearby any
equipment.
This form of guarding is often considered as the first line of defence, with the
objective of providing protection to the operators from minor or fatal injuries, while they
work on or around some industrial machinery, during normal operations of an industry.
Moving parts of a machine have been identified to hold the potential of resulting in severe
workplace injuries, namely, amputations, crushed hands or fingers, blindness, or burns
(Parker et al. 2015). Thus, safeguards or machine guarding equipment are crucial for
protecting the workers from such avoidable injuries. Any part of a machine, process or
function that might lead to injury of the individuals working on them must be safeguarded.
When operation of some machinery or an accidental contact injures the operators/workers in
the vicinity of the instrument, efforts must be taken for immediate elimination or control of
the workplace hazards. The essay will elaborate on the designs of machinery guarding safety
sensing devices.

2ESSAY
WSH Singapore
Occupational health and safety in the country of Singapore is under the direct
governance of the Singapore Ministry of Manpower, which is considered as a responsible
authority for the same. The Workplace Safety and Health Act 2006 was formulated and
enforced with the aim of addressing a set of specific requirements for the safety and health of
people, in workplaces in Singapore. This act replaced the previous Factories Act on 1 March
2006. The Workplace Safety and Health Council is an industry-led Statutory Body that was
formed on 1 April 2008 (Safety 2013). The act can be defined as a legislation that is related
to the health, safety and welfare of all people in their workplaces.
The principles of the act are focused on reducing risks at the source, facilitated by
asking all stakeholders to minimise the risks created. The act also aims to encourage several
industries for adopting an ownership of the health and safety of their workers. Furthermore, it
also imposes penalties for poor management of safety. Some of the equipment identified by
the WSH Act includes scaffolds, forklifts, bar-blenders, lifting equipment, power presses,
piping containing flammable or corrosive substances, and welding machinery, among others
(Ministry of Manpower 2007). Subject to the functional check of all safety devises before
declaring a machine as safe, some of the safety devices identified by the WSHC include
machine guards, presence-sensing device, sensors, emergency stop buttons and warning
devices.
Machine guards
The machine guards are generally defined as rigid physical barriers, having the
capability of enclosing hazardous or unsafe machine parts, in addition to restricting the access
of the operators to areas that are identified dangerous. Machine guards also have the
capability of partially covering the areas of operation, while allowing limited or negligible

3ESSAY
access to the operators (Parker et al. 2016). The machine guards are designed in a way that
takes into consideration certain aspects namely, (1) all intended applications of the machines,
(2) realistically foreseeable unfitting use of all machines, and (3) all kinds of involuntary and
voluntary movements of the workers/operators (Wshc.sg 2018). The WSH guidelines take
into account the fact that all machinery guards should be positioned in a way that creates no
obstruction to the view of the operator and also does not interfere with the machine’s normal
operations. Situations that demand removal of the guarding from the machines, during their
maintenance or servicing, must also ensure that the measures of energy lockout are in put into
effect, before the work is started. Machine guarding should be immediately re-installed, after
the maintenance work or servicing is completed.
Types of machine guarding
Fixed guards are physical barriers that are found permanently attached with the help
of screws to the instruments and help in preventing any access to the zone of danger, from all
possible directions. Fixed guarding are typically designed in a way that makes it difficult to
remove them without the use of tools, specific for the equipment (Chinniah 2015). Thus,
modern devices with fixed guards are safer than others. Their preference can be attributed to
their permanence and relative simplicity.
Modern machines also have adjustable guards that can be reconfigured or moved
according to the dimensions of the work being performed. These allow the machines to
handle different sized materials, while providing protection to the users present in the danger
zone. Guards that cover the operation point of circular band saws are one type of adjustable
guarding (Wshc.sg 2018). Guards are also designed in a way that cover the danger region,
until some work gets pushed to the area of operation and move the guard. Movement of the
work piece determines the gap between the danger zone and self-adjusting guards, installed