When it comes to better and safer drilling and blasting either at quarries or at construction sites, effective communication is essential between quarry management or contractor, the drilling crew and the blasting team. That is according to James Buchanan and Allan Greene, presenters at this year’s Mine Blasting Safety and Application Seminar at the National Mine Health and Safety Academy near Beckley, WV. Buchanan, who serves as Technical Services Manager for KEMEK, LLC., and Greene, a 35-year industry veteran and Mine Safety and Health Representative for the North Carolina Department of Labor, emphasized the importance of taking responsibility for thorough communication between drillers, blasters and site management. They offered proven guidelines and current MSHA regulations as ways for crews to implement this on a daily basis.
Blast plan and layout
Buchanan’s overview included what he called his “Best Practices” for drillers and blasters. These consisted of blast planning and layout, blaster to driller and driller to blaster communication, effective use of the drill log and shot day communication all working together to help ensure a safe blast. He said there is often an illusion that there has been effective communication between people, when in fact there hasn’t. He reminded attendees that it is each person’s responsibility to assure that the others have actually heard and/or understood what was being communicated.
Buchanan said that quarry or site managers should conduct what he calls a Blast Optimization Team (BOT) meeting each day. This gives everyone an opportunity to share information pertaining to the blast. This would be the time to discuss areas of improvement, fragmentation needs, blast timing and other important details.
He noted that this is where everyone’s expectations can be outlined. “Blasting parameters are covered here,” he said. “Is the site ready to be laid out? Can the drill move around safely? Can the face burdens be properly assessed? Is there good access for explosive delivery?”
Other items to be covered at the planning and layout stage include blast size, expected breakage, results of previous blast designs and any environmental constraints either inside or outside the quarry or construction site.
“What are the customer expectations? What are his scheduling needs? What results are they looking for when the job is done?” he asked. These all need to be addressed at this time.
Likewise, what are the blaster’s expectations? “The quarry needs to know what the drillers need. Is the site prepared? Does the driller need assistance? Do they need someone to bring stemming for the shot? Are there any other obvious needs?” he asked.
Buchanan recommended that blasters confirm with the driller what the layout pattern is and what the shot parameters are. He said the plan drawing should match the layout on the ground. Ground markings should be numbered in accordance with the drawing. The diagrams must be clear so the driller can prepare the site appropriately.
The driller needs to know shot parameters as well. These include hole depth, hole angle and direction, design burden and spacing and hole diameter. Most importantly, the blaster needs to make sure that the driller actually gets this information accurately. Buchanan said he prefers using a hard copy of the information rather than relying upon an electronic version. That way everyone has the correct information to do the job.
He said there is always the possibility that the driller might call in sick and a replacement person does the drilling. That replacement needs to be fully informed. The method for making this happen needs to be consistent at a particular jobsite.
Driller – blaster communication
“The driller is the Blaster’s ‘eyes’ below the surface of the ground,” said Buchanan. “What the driller tells the blaster helps to lead to a safe, successful blast. What the driller doesn’t tell the blaster could result in a number of problems. They include exceeding the blast limits, fatalities, litigation, [thousands of dollars] of damage and potential license revocation.”
He said an inadequately prepared drill log is a prime example of how the driller could misinform the blaster. Some of the information that is needed on the drill log, in addition to the driller’s name and contact information, includes hole depth and angle drilled, amount of overburden, any anomalies in the rock including seams or cracks, changes in rock competency and clay or mud seams.
With this information, a blaster can make good use of a detailed drill log as a way to plan for a properly prepared blast. Incomplete or inaccurate drill logs can lead to problems later, especially when there are flyrock problems following a blast. The drill log needs to be completed at the time the drilling takes place. The driller should be alert and in attendance when the drilling is being done.
Accordingly, the blaster needs to read and act on the information in the drill log. Any missing or unclear information should be discussed with the driller. If possible, the blaster should spot check the information for accuracy. The blaster needs to convey any issues to the site manager. The drill log can be used to change the blast design or loading to help keep the blast safe. By knowing the geology, the blaster can load the shot properly.
Shot day communication
On shot day, the blaster needs to be in touch with the site manager, the workers on the site, any contractors or visitors to the site, any neighbors or off-site businesses and the public. Blasters need to communicate any changes in blast design, the demarcation of the blast site and the blasting area, the expected throw of the blast and any issues that might arise from that, the posting of sentries and how they would communicate, the expected firing time and firing signals. “Don’t take any shortcuts,” he concluded.
Allan Greene’s presentation focused on contractor-to-contractor and contractor-to-owner communication. Greene used regulations from the Mine Act and the Program Policy Manual (PPM) as the basis for his discussion. Using personal stories from his experiences as a North Carolina mine inspector to demonstrate the importance of why these regulations are in place, he emphasized that workers who go onto mining operations need to be familiar with these regulations.
“The mine operator is responsible for anyone on mine property,” he said. Greene reminded attendees that part 45 of the PPM specifies that production-operators are subject to all provisions of the Act. “This overall compliance responsibility includes assuring compliance by independent contractors with the Act and with applicable standards and regulations.” This is especially true when contractors and not company personnel are doing drilling and blasting.
He said mine operators need to make sure that the contractor provides a Contractor Register because MSHA needs the information to issue citations to the contractor and not the operator, when necessary. Additionally, the mine operator needs to have a contractor register whether or not the mine is employing contractors on any given day. He added that regulation 30 CFR § 45.4 outlines the requirements for the independent contractor register.
Additionally, Greene said contractors and vendors are required to have site-specific hazard awareness training according to 30 CFR § 46.11. Those needing training include office or staff personnel, delivery workers, scientific workers, customers including over-the-road truck drivers, construction workers or employees of contractors, visitors, vendors and miners, drillers and blasters who move from one mine to another. Each site has its own site-specific hazards.
Greene said that both drillers and blasters need to understand a number of safety procedures. These include proper parking procedures, drill site inspections, pre-shift inspections for self-propelled mobile equipment and tools, other machinery and equipment. They also need to know what the tool and equipment manufacturer’s recommendations are on specific items. This includes inspecting fire extinguishers for proper operation.
“Do they have a HAZCOM program and follow it? Do they know not to work between machinery and the highwall?” he asked. “This is all part of effective communication.”
Focusing on drillers, Greene emphasized that drillers must attend drills when the equipment is in operation. Quoting regulations: (.7012) While in operation, drills shall be attended at all times and (.7052) Persons shall not drill from positions which hinder their access to the control levers, Greene said that surprisingly, drillers have been known to leave their machines unattended even when the drill rig is drilling. Noting that the equipment must be turned off when not attended, Greene concluded, “Make sure the drillers understand these regulations.”