Civil Engineering Reference
In-Depth Information
• over-frequent or over-prolonged physical effort involving in particular the spine
• an insufficient bodily rest or recovery period
• excessive lifting, lowering, or carrying distances
• a rate of wo
rk imposed by a process which cannot be altered by the worker.
5.
Individual Risk Factors
The worker may be at risk if he/she
• is physically unsuited to carry out the task in question
• is wearing unsuitable clothing, footwear, or other personal effects
• does not have adequate or appropriate knowledge or training.
TABLE 10.8
Guidelines for Lifting According to
the Health and Safety Commission (1991)
Height
Less than Half Arm's
Length (kg)
Between Half Arm's
Length and Full Arm's Length (kg)
Below knee height
10
5
Knee height-knuckle height
20
10
Knuckle height-elbow height
25
15
Elbow height-shoulder height
20
10
Shoulder height-full length
10
5
work posture with a nontwisted trunk. Under such circumstances the guideline figures are
assumed to provide reasonable protection to nearly all men and between one-half and
two-thirds of women. There are also correction factors for stooping and twisting the
body. For example, for 90° stooping the weight should be reduced by 50%, and for 90°
twisting it should be reduced by 20%. One major advantage of these guidelines is that
they are very easy to use.
10.7
MATERIAL HANDLINGS AIDS
In an industrial facility there are many different needs for materials handling:
transportation of goods to and from the facility; unloading of materials at the receiving
department; transportation of materials to workstations until the product has been
assembled, tested, and inspected; and transportation of the product to packaging and to a
warehouse for final distribution to customers. In addition to these primary transportation
needs, there are also secondary transportation requirements, such as removal of waste
products and housekeeping. Transportation and materials handling in manufacturing
constitute a major expense. We therefore have a dual interest in designing an effective
materials handling system:
• To reduce manufacturing costs.
• To reduce ergonomic costs and injuries.
The planning for materials handling and smooth transportation should start at the product
design stage (Grossmith, 1992). One important aspect of product design is “design for
ease of handling and transportability.” Thus a product could have a smooth bottom,
