Presentation on theme: "Blast Site Edge Protection"— Presentation transcript:
1Blast Site Edge Protection Drilling and BlastingToolbox Talk : 03Blast Site Edge ProtectionInformation on the use of edge protection systems in the blasting areaTarget AudienceAny person likely to be working in the blasting area and those supervising such operations.Quarries Working towards a safe and healthy quarrying industry NationalJoint EmployersAdvisory EmployeesCommittee Health and Safety ExecutiveThis publication may be freely reproduced except for advertising, endorsement or commercial purposes.The information is current at February Please acknowledge ‘QNJAC’ as the source Updated September 2009
2Blast site edge protection 1 : Introduction Lives have been lost in the past through falls from quarry faces.Thankfully this is now very rare mainly due to control measures introduced to prevent it.This toolbox talk is designed to help the industry to reduce further the likelihood of these incidents.In deciding what are the most suitable control measures for any particular circumstance, account needs to be taken of both The Quarries Regulations 1999 and the Work at Height Regulations 2005.
3Blast site edge protection 2 : Managing the Risk The Operator is responsible for Health and Safety on site including all drilling and blasting activitiesThis includes the design, construction and provision of blast site edge protectionBlast site activities includeSurveying, marking out, drilling, loading and firingIt is therefore very important to carry out a site specific risk assessment including all the personnel likely to be involved in the blasting operationFor ExampleDriller, Shotfirer, Explosives Supervisor, Quarry ManagerBulk explosive supplier, Geotechnical Consultant
4Blast site edge protection 2 : Managing the Risk The following topics should be considered as a minimum in a risk assessmentPrevention of personnel and equipment from falling over the edgeThe site geology and stability of the face.Access to the blast site for drill rig, delivery of stemming, explosives delivery vehicles, bulk explosive trucks and emergency vehicles.Blast design parameters Such as spacing, burden, etcProfiling and surveying operationsWeather conditions
5Blast site edge protection 2 : Managing the Risk The Work at Height hierarchy should be followed in selecting the method used:-Collective measures should be given priority over personal protective measures. Physical barriers such as the safety bund and post and strap should be considered firstWhere the use of physical barriers creates an unacceptable risk then other measures such as delineation of the danger zone or harnesses should be consideredThe Quarry operator should be able to show that they have considered how a fall from an open edge will be prevented for that particular shot.
6Blast site edge protection 3 : Protection Methods Safety BundAdvantagesProvides protection for peopleDoes not need removing before blastDisadvantagesCan cover up bad edge conditionsA safe system of work needs to be established detailing how such bunds put in placeRequires the movement of mobile plant close to the crest
7Blast site edge protection 3 : Protection Methods Safety BundHow high do the bunds need to be ?People only on the blast areaNot less than 1mIn this case a second bund will be required behind the blast to prevent vehicles from encroachingVehicles operating on the blast areaA minimum of 1.5m or the radius of the largest vehicle wheel
8Blast site edge protection 3 : Protection Methods (continued) Post and StrapDesigned to prevent personnel from accidentally approaching the edgeAdvantagesActs as a physical barrier to prevent personnel from falling over faceDisadvantagesBarrier will not prevent machinery from falling over faceRequires a drill rig to approach the edge to drill post holesPlacing and removal of system requires personnel to approach the edgeNormally this will require the use of an additional fall prevention systemRemoval of system can result in the initiation system being disturbed with the potential for misfires
9Blast site edge protection 3 : Protection Methods (continued) Post and Strap – Bad PracticeOnly a single straphas been used!Worse than useless as the protection has been placed such that the face edge comes inside the protection
10Blast site edge protection 3 : Protection Methods (continued) Post and Strap – Good PracticeTwo straps have been usedStraps are tensionedLine of protection is positioned just in front of the first row of holes
11Blast site edge protection 3 : Protection Methods (continued) Stand-off DistanceIn this case workers may not approach within a specified distance to an unprotected edgeThe distance needs to be well delineated with some form of barrierGood example is when used with cones and ropeThis system needs to be well supervisedAdvantagesNo need for the drill rig to approach the bench edgeCan easily be removed before the blastDisadvantagesDoes not prevent either people or equipment from falling over face
12Blast site edge protection 3 : Protection Methods (continued) Example of Stand-off DistanceIn the photograph this system is used on a site that employs a stand-off distance of 3m.A cone and rope system has been used to indicate the stand-off distance from the edge of the faceNote also that in this case a bund has been positioned to prevent equipment such as bulk explosive trucks from coming on the blast area
13Blast site edge protection 3 : Protection Methods (continued) Fall Prevention SystemsShould only be used as a last resortShould be installed so as to prevent personnel reaching the crest and falling over the faceRequires that personnel are also trained in emergency recovery procedures.Many sites require the use of such system when removing the post and strap system previously described
14Blast Site Edge Protection 4 : Key Points Edge protection is required for all blast areasEach blast should be separately assessed to determine suitable protection measures for that locationA single edge protection system may not be universally appropriateIf you think the edge protection is inadequate STOP WORK and inform your supervisor