Occupational Safety II

1. 6 Mechanical handling hazards
1

2. 2
Mechanical handling hazards 1/4
The mechanical handling equipment
 Must be capable of lifting and/or moving the load
 Must be fault-free, well maintained and inspected on a regular
basis
 Collisions between people and the equipment
 Personal injury from being trapped in moving parts of the
equipment (such as belt and screw conveyors)

3. 3
Mechanical handling hazards 2/4
The load
 Should be prepared for transportation in such a way as to minimize
the possibility of accidents
 The nature of the load: substances which are flammable or
hazardous to health
 The security and stability of the load: collapse of bales or
incorrectly stacked pallets

4. 4
Mechanical handling hazards 3/4
The workplace
 Should be designed so that, whenever possible, workers and the
load are kept apart
 Collisions between people and the moving load

5. 5
Mechanical handling hazards 4/4
The employees
 The employees and any other people who are to use the equipment
must be properly trained and competent in its safe use
 Errors made by operators cause accidents involving mechanical
handling equipment

6. 6
Cranes 1/9
Types of cranes: tower cranes

7. 7
Cranes 2/9
Types of cranes: jib cranes
Jib tower crane Crawler type crane

8. 8
Cranes 3/9
Types of cranes: overhead/gantry travelling crane

9. 9
Cranes 4/9
What can go wrong?
A German Liebherr top-slewing tower crane toppled through three buildings and killed a man
in Bellevue, WA, US, 2006

10. 10
Cranes 5/9
Failures of wheel-mounted cranes

11. 11
Cranes 6/9
A specific accident 1/2

12. 12
Cranes 7/9
A specific accident 2/2

13. 13
Cranes 8/9
The principal failures of cranes
Overturning Caused by weak support, operating outside the crane’s capabilities, by
striking obstructions or strong winds
Overloading By exceeding the operating capacity or operating radii or by failure of
safety devices
Collision With other cranes, overhead cables or structures;
Support failure Can occur due to placing of crane over cellars and drains outriggers
not extended, made-up or not solid ground or failure of structural
components of the crane
Operator
errors
Errors from impaired or restricted visibility, poor eyesight, inadequate
training
Loss of load From failure of lifting equipment, lifting accessories or slinging
procedure

14. 14
Cranes 9/9
Control of hazards
Identification
and testing
Every crane should be tested and certificate should be issued;
the safe working load clearly marked, etc.
Maintenance Cranes should be inspected regularly with any faults repaired
immediately; records of inspections should be kept
Safety
measures
A number of safety measures should be incorporated for the safe
operation of the crane: automatic safe load indicator, dead-man controls
Operating
area
All nearby hazards, including overhead cables and bared power supply
conductors, should be identified and removed or re-routed;
solid support should be available;
the possibility of striking other cranes and structures should be examined
Operator
training
Crane operators and slingers should be fit and strong enough for the
work;
training should be provided for the safe operation of the particular
equipment

15. 15
Hoists 1/5
Hoists: platforms or cages for goods and passengers

16. 16
Hoists 2/5
Hoists: another types
Manual chain hoist and manual lever hoist
Electric rope hoists

17. 17
Hoists 3/5
What can go wrong?
Failure of a hoist crane

18. 18
Hoists 4/5
The principal failures of hoists
Collapse Inadequate ties or other support
Structural failure Operating outside the hoist’s capabilities
Striking obstructions Structures and equipment improperly projecting into the space
of movement of hoist’s platform/cage
Overloading By exceeding the operating capacity or by failure of safety
devices
Collision With overhead cables, electrically loaded platforms
Operator errors Errors from impaired or restricted visibility, poor eyesight,
inadequate training, wrong operating position
Loss of load From failure or bumping of the hoist platform

19. 19
Hoists 5/5
Control of hazards
Identification
and testing
Every hoist should be tested and certificate should be issued;
the safe working load clearly marked, etc.
Maintenance Hoists should be inspected regularly with any faults repaired
immediately; records of inspections should be kept
Safety
measures
A number of safety measures should be incorporated for the safe
operation of the crane: load capacity information indicator, overtravel
switches, safe access to platform/cage, clear visibility for operator, etc.
Operating
area
Solid supports should be placed under the ground level hoistway and
approach areas
Operator
training
Hoist operators and slingers should be fit and strong enough for the
work;
training should be provided for the safe operation of the particular
equipment

20. 20
Fork-lift trucks 1/7
Types of trucks: rough terrain counter-balanced lift truck

21. 21
Fork-lift trucks 2/7
Types of trucks: pallet trucks

22. 22
Fork-lift trucks 3/7
Types of trucks: fork-lift trucks in warehouses
Pallet stacker truck Very narrow aisle truck

23. 23
Fork-lift trucks 4/7
What can go wrong?

24. 24
Fork-lift trucks 5/7
The principal failures of fork-lift trucks
Overturning From manoeuvring with load elevated, driving at too high speed,
sudden breaking, striking obstructions, driving down the ramp with the
load, etc.
Overloading By exceeding the maximum lifting capacity of the truck
Dangerous
stacking
Dangerous stacking or de-stacking technique can destabilize a
complete racking column
Floor failure Because of uneven and unsound floors, or by exceeding the load
capacity of the floor
Loss of load Can occur if devices are not fitted to stop loads slipping from forks
Silent
operation
Silent operation of the electrically powered fork lift truck – can make
pedestrians unaware of its presence

25. 25
Fork-lift trucks 6/7
Physical hazards related to the use of fork-lift trucks
 Noise caused by poor silencing of the power unit;
 Exhaust fumes which should only be a problem when the
maintenance regime is poor;
 Vibrations which are often caused by a rough road surface or wide
expansion joints; badly inflated tyres will exacerbate this problem;
 Manual handling resulting from manoeuvring the load by hand or
lifting batteries or gas cylinders;
 Ergonomic hazards occurring as musculoskeletal injuries caused by
soft tyres and/or undulating road surface or holes or cracks in the
road surface (e.g., expansion joints).

26. 26
Fork-lift trucks 7/7
Control of hazards
Operating area Every crane should be tested and certificate should be issued;
the safe working load clearly marked, etc.
Lighting Cranes should be inspected regularly with any faults repaired
immediately; records of inspections should be kept
Battery charging
and refuelling
Battery charging and LPG refuelling areas should be well-ventilated
and lit with no smoking and or naked lights permitted
Reversing
movement
Reversing lights and/or sound warnings should always be fitted
where possible
Operator training Training should be provided for operators in the safe operation of
their equipment, followed by certification

27. 27
Conveyors and elevators 1/3
Types of conveyors: belt conveyor

28. 28
Conveyors and elevators 1/3
Types of conveyors: roller conveyor

29. 29
Conveyors and elevators 1/3
Types of conveyors: screw conveyor

30. 30
Conveyors and elevators 2/3
What can go wrong?
 The in-running nip, where a hand is trapped between the rotating
rollers and the belt;
 Provide nip guards and trip devices;
 Entanglement with the power drive;
 Fit fixed guards and restrict loose clothing which can be caught in the
drive;
 Loads falling from the conveyor;
 Provide edge guards and barriers;
 Impact against overhead systems;
 Provide bump caps, use warning signs and restricted access;
 Contact hazards;
 Remove sharp edges, use conveyor edge protection and restricted
access;
 Manual handling hazards & noise and vibration hazards

31. 31
Conveyors and elevators 1/2
Brick & tile elevators

32. 32
Conveyors and elevators 2/2
Hazards and hazard control
 Entanglement with the power drive;
 Fit fixed guards at either end of the elevator and around the power
drive;
 Loads falling from the elevator;
 Use restricted access;
 Manual handling problems at both the feed and discharge ends of the
elevator;
 Use manual handling hazard control measures

33. 33
Hazards in vehicle operation 1/7
Common vehicles found on sites
 Site dumper trucks;
 Fork-lift truck (perhaps the most common);
 Fork lift trucks with telescopic handlers;
 All terrain and rough terrain vehicles;
 Heavy goods vehicles;
 Excavators;
 Tipper lorries;
 Various types of earth moving equipment used on larger construction
sites.

34. 34
Hazards in vehicle operation 2/7
The most common hazards
 Loss of control of the vehicle;
 Overturning; and
 Collision with structures on the site, pedestrians, or other vehicles.

35. 35
Hazards in vehicle operation 3/7
The causes of hazards
 Non-segregation of pedestrians and vehicles
 Uneven road surfaces
 Attempts to drive vehicles up inclines which are too steep
Arising from the site layout
 Presence of excavations
 Scaffolds and falsework sited near a roadway
 Attempts to drive vehicles up inclines which are too steep
 Falling materials, noise, dust, poor maintenance of vehicles
Arising from construction methods

36. 36
Hazards in vehicle operation 4/7
The key control measures
 The provision of safe routes
 The separation of pedestrians and vehicles
 The restriction of the carriage of people on site
 The prevention of falls into excavations by the erection of strong
barriers.
 Introduction of one-way systems
 Introduction of speed limits
 Adequate lighting at road junctions
 Separate entrances and exits to the site with adequate turning room
 The use of clear signs

37. 37
Hazards in vehicle operation 5/7
Safe routes on the site
 Avoidance of sharp bents
 Avoidance of blind corners (unless suitably placed mirrors are located
at the corners)
 Avoidance of narrow gaps
 Avoidance of low head rooms and adverse cambers
 Avoidance of steep gradients
 A regular inspection and repair of road surfaces

38. 38
Hazards in vehicle operation 6/7
Separation of pedestrians and vehicles
Pedestrian/vehicle crossing area
Separation of pedestrians from the work and
traffic

39. 39
Hazards in vehicle operation 7/7
Protective barriers
Barriers to prevent collision with tank surrounds

40. 40
The end of part six
Donkey-engine