World Cement - July 2020

a method than a compliance issue. It should be

posted in plain sight, clearly understood and

washed when dirty or replaced when faded. Like

most lower-tier methods, signs do not remove the

hazard and are easily ignored.

Installing systems such as engineering controls

that allow remote monitoring and control of

equipment – or guards such as gates and

inspection doors that obstruct access – greatly

reduce exposure, but again, do not remove the

hazard. Some operators go as far as installing

interlocking guards connected to switches to

discourage removal or proximity sensors to

detect workers who break the safety plane of the

conveyor.

Using the substitute method replaces something

that produces a hazard with a piece of equipment

or change in material that eliminates the hazard.

For example, the process of manually clearing of

a clogged hopper could be replaced by installing

remotely triggered air cannons. However, operators

may find that this method is not a practical solution

for all belt conveyor systems. In most cases, it is

difficult to achieve the same volume of throughput

when replacing a belt conveyor with another type of

system, such as an enclosed pipe conveyor.

Examples of ‘eliminate by design’ are longer, taller

and tightly sealed loading chutes to control dust

and spillage or heavy-duty primary and secondary

cleaners to minimise carryback. By using hazard

identification and risk-assessment methods early

in the design process, engineers can create the

safest, most efficient system for the space, budget

and application. These designs alleviate several

workplace hazards, while minimising cleanup and

maintenance, reducing unscheduled downtime and

extending the life of the belt and the system itself.

Economic analysis of prevention

through design (PtD)

Another way of saying ‘eliminate by design’ is PtD

(prevention through design),

the term used by The National

Institute of Occupational Safety

and Health (NIOSH). As a

department of the US Centers

for Disease Control (CDC),

the organisation spearheaded

the PtD initiative.

In its report,

the institute points out that,

while the underlying causes

vary, studies of workplace

accidents implicate ‘system

design’ in 37% of job-related

fatalities.

Although injuries are the

focus of the NIOSH report,

the prevention aspect of

design also greatly impacts

production. In most cases,

workplace hazards produce

consequences such as

downtime, product loss and

reduced efficiency from

spillage, dust and early

equipment failure. The cost

of operation is dramatically

influenced by the efficiency

of the system, but is unique

to each application. Cost is

most often the main inhibitor to

PtD, which is why it is best to

implement safer designs in the

The return on better design and quality is

realised over the extended life and safety of the

system.

Rather than meeting minimum compliance standards, conveyor

systems should exceed code, safety and regulatory requirements.

World Cement

July 2020