Mounted roadbreaker

The task

Breaking road surfaces

The problem

The most common tool used to break up road and pavement surfaces is the hand-held percussive breaker. These tools typically produce hand-arm vibration magnitudes of between 5 and 20 m/s2 with an average of around 12 m/s2. A full-time breaker operator working on a road excavation job might be exposed to this vibration for an average of 3 hours per day which would give a typical exposure of 7 m/s2 A(8) which is above the exposure limit value. The amount of work that an operator can do with one of these tools in a day varies depending on the depth and hardness of the surface to be broken up.

The solution

In some circumstances it is possible to greatly reduce the vibration exposure by using a larger breaker attachment mounted on the arm of an excavator. This method was used by a utilities contractor for digging telecommunications trenches in the road in a busy urban area. There was already an excavator on site for digging out the trenches once the surface had been broken, and the bucket was replaced with a breaker attachment, which took about 5 minutes, whenever required. The breaker is powered using the excavator hydraulics and is activated by a foot pedal. The arm position is controlled by a pair of levers, passing very little vibration (vibration magnitude is less than 1 m/s2) to the operator's hands. A hand-held breaker, fitted with a sharp cutting tool, was used for about 5 minutes at the beginning of the day to score the edges of the area to be broken up with the mounted breaker.

Mounted breaker being used to break roadway

Mounted breaker being used to break roadway

The result

  • This method reduces the time the operators are exposed to vibration. The exposure for the hand-held breaker operator was reduced to little more than 1 m/s2 A(8).
  • On the type of surface found in this example, the mounted breaker works approximately 10 times as fast as one person with a hand-held tool.
  • The attachments on the excavator can be changed very quickly.
  • Overall there is less disruption and noise.

Link URLs in this page

  1. Vibrationhttps://www.hse.gov.uk/vIBRAtIon/index.htm
  2. Hand arm vibrationhttps://www.hse.gov.uk/vIBRAtIon/hav/index.htm
  3. About this websitehttps://www.hse.gov.uk/vIBRAtIon/hav/about.htm
  4. Key messageshttps://www.hse.gov.uk/vIBRAtIon/hav/keymessages.htm
  5. Worried about your handshttps://www.hse.gov.uk/vIBRAtIon/hav/yourhands.htm
  6. Overview - Advice for employershttps://www.hse.gov.uk/vIBRAtIon/hav/advicetoemployers/index.htm
  7. Employers responsibilitieshttps://www.hse.gov.uk/vIBRAtIon/hav/advicetoemployers/responsibilities.htm
  8. Assess riskhttps://www.hse.gov.uk/vIBRAtIon/hav/advicetoemployers/assessrisks.htm
  9. Overview - How to protect workershttps://www.hse.gov.uk/vIBRAtIon/hav/advicetoemployers/protect.htm
  10. Control riskhttps://www.hse.gov.uk/vIBRAtIon/hav/advicetoemployers/controlrisks.htm
  11. Information and traininghttps://www.hse.gov.uk/vIBRAtIon/hav/advicetoemployers/information.htm
  12. Health surveillancehttps://www.hse.gov.uk/vIBRAtIon/hav/advicetoemployers/healthsurveillance.htm
  13. Overview - Good practicehttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/index.htm
  14. Overview - Foundrieshttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/foundries/index.htm
  15. Eliminate fettling by improving casting qualityhttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/foundries/fettlingelimination.htm
  16. Machining as a substitute for fettlinghttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/foundries/machining.htm
  17. Automatic fettlinghttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/foundries/automaticfettling.htm
  18. Jig-mounting of grindershttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/foundries/jigmounting.htm
  19. Semi-automatic cut off machinehttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/foundries/cutoffmachine.htm
  20. Isolated casting cut offhttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/foundries/isolatedcasting.htm
  21. Installation of hydraulic cropping machinehttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/foundries/hydrauliccropping.htm
  22. Shell knockout 1https://www.hse.gov.uk/vIBRAtIon/hav/campaign/foundries/castingshell.htm
  23. Shell knockout 2https://www.hse.gov.uk/vIBRAtIon/hav/campaign/foundries/contactcastingshell.htm
  24. Hydraulic pushouthttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/foundries/furnaceliningremoval.htm
  25. Ladle slag chippinghttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/foundries/chippingslag.htm
  26. Overview - Constructionhttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/construction/index.htm
  27. Preparing a code of practicehttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/construction/tunnelling.htm
  28. Construction Industry Council guidancehttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/construction/cicguidance.htm
  29. Mounted breakerhttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/construction/mountedroadbreaker.htm
  30. Directional drillinghttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/construction/directionaldrilling.htm
  31. Crushing concretehttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/construction/crushingconcrete.htm
  32. Bursting concretehttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/construction/burstingconcrete.htm
  33. Diamond wire cuttinghttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/construction/diamondwire.htm
  34. Water jettinghttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/construction/waterjetting.htm
  35. Codes of Practice from the Water Jetting Associationhttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/construction/codeofpractice.htm
  36. Grit blastinghttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/construction/gritblasting.htm
  37. Paint-on retarderhttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/construction/paintonmaterial.htm
  38. Special formworkhttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/construction/specialformwork.htm
  39. Overview - Steel fabricationhttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/fabrication/index.htm
  40. Machininghttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/fabrication/cncmachining.htm
  41. Laser cuttinghttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/fabrication/lasercutter.htm
  42. Plasma cuttinghttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/fabrication/plasmacutting.htm
  43. Noise reduction in the ship repair industry – research report 1992https://www.hse.gov.uk/vIBRAtIon/hav/campaign/fabrication/noisereduction.htm
  44. Abrasive blastershttps://www.hse.gov.uk/vIBRAtIon/hav/campaign/fabrication/abrasiveblasters.htm
  45. Overview - Regulationshttps://www.hse.gov.uk/vIBRAtIon/hav/regulations.htm
  46. Inspector briefinghttps://www.hse.gov.uk/vIBRAtIon/hav/inspectorbriefing.htm
  47. Overview - Resourceshttps://www.hse.gov.uk/vIBRAtIon/hav/information.htm
  48. Publicationshttps://www.hse.gov.uk/vIBRAtIon/hav/publications.htm
  49. Researchhttps://www.hse.gov.uk/vIBRAtIon/hav/research.htm
  50. Statisticshttps://www.hse.gov.uk/vIBRAtIon/hav/statistics.htm
  51. Useful linkshttps://www.hse.gov.uk/vIBRAtIon/hav/links.htm
  52. Vibration calculatorhttps://www.hse.gov.uk/vIBRAtIon/hav/calculator-guide.htm
  53. Overview - Case studieshttps://www.hse.gov.uk/vIBRAtIon/hav/casestudies/index.htm
  54. (HAVS) in two motor companieshttps://www.hse.gov.uk/vIBRAtIon/hav/casestudies/enforceex.htm
  55. Monitoring exposure to Hand-Arm Vibrationhttps://www.hse.gov.uk/vIBRAtIon/hav/casestudies/mhav-carlwest.htm
  56. Overview - Supply project eventshttps://www.hse.gov.uk/vIBRAtIon/hav/project-events.htm
  57. Controlling vibrationhttps://www.hse.gov.uk/vIBRAtIon/hav/controlling-vibration.htm
  58. Q & A on hand toolshttps://www.hse.gov.uk/vIBRAtIon/hav/hand-tools-qa.htm
  59. Q & A on using a vibration consultanthttps://www.hse.gov.uk/vIBRAtIon/hav/qa-consultant.htm
  60. Q & A on health surveillancehttps://www.hse.gov.uk/vIBRAtIon/hav/qa-surveillance.htm
  61. Tunnelling and Pipejacking: Guidance for Designers https://www.hse.gov.uk/construction/pdf/pjaguidance.pdf
  62. Pile cropping. A review of current practice https://www.hse.gov.uk/vIBRAtIon/assets/docs/pilecrop.pdf
  63. Hand-arm vibration at work: A brief guide https://www.hse.gov.uk/pubns/indg175.htm
  64. Advice for employershttps://www.hse.gov.uk/vIBRAtIon/hav/advicetoemployers/index.htm
  65. Regulationshttps://www.hse.gov.uk/vIBRAtIon/hav/regulations.htm
  66. How to protect workershttps://www.hse.gov.uk/vIBRAtIon/hav/advicetoemployers/protect.htm
  67. Constructionhttps://www.hse.gov.uk/construction/index.htm
  68. Engineeringhttps://www.hse.gov.uk/engineering/index.htm
  69. Motor vehicle repairhttps://www.hse.gov.uk/mvr/index.htm
  70. Noisehttps://www.hse.gov.uk/noise/index.htm
  71. Quarrieshttps://www.hse.gov.uk/quarries/index.htm
  72. Agriculturehttps://www.hse.gov.uk/agriculture/index.htm

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Updated: 2021-05-20