Underground coal bolter miners have a tough life in harsh conditions. After just four to five years of life underground, they can look almost worn out – but in the case of Sandvik’s MB series of bolter miners, the company says “these machines have the inherent durability and strength that allows them to be completely rebuilt to as-new condition.” “Sandvik’s MB series of bolter miners are the leading machines in underground coal mine longwall development applications – with more than 50 of these machines operating in mines in NSW and Queensland,” said Troy Robertson, Sandvik’s Project Manager Overhauls – Mechanical Cutting, Underground Coal.“An important element of the economics of running bolter miners is their ability to be completely rebuilt from the ground up a number of times during their working lives,” he explained. “A key part of Sandivk’s service and support offerings for our MB series machines is our capability of carrying out these rebuilds to OEM standards, and with full factory warranty.”Manufactured by Sandvik in Austria, its original ABM series dates back to the early 1990s, and the range has undergone continuous upgrading and improvements since introduction.“The main models we sell in Australia are our MB650 and MB670 bolter miners – these fit with the seam heights for most longwall mines looking for bolter miners in their operations,” said Robertson. “It’s a market segment that’s unique to Sandvik; as a result of our ongoing engineering design, performance, safety and ergonomics, no other supplier has been able to deliver the required combination of production, safety and ease of operation. “The rule of thumb is that after three rebuilds – with four to six years between rebuilds – the technology in our MB series has developed to the extent that the price to upgrade to the latest specifications ceases to become economical,” he said. “In addition, compliance requirements are ever-changing – and bolter miners have to comply with all the latest safety standards before they can go back underground.”Today, all MB series bolter miner rebuilds in Australia take place in Sandvik’s Heatherbrae facility, north of Newcastle, NSW.“We have a dedicated MB series rebuild facility at Heatherbrae, with the ability to take a tired bolter miner and restore it to as-new factory-warranted condition,” Robertson said.The great bulk of the rebuild work is done by trained Sandvik technicians, including the initial mechanical stripdown, engineering, electrical systems, gearboxes, components, bolting systems, and upgrades, followed by re-assembly, function testing, commissioning, painting and detailing.Also included in the rebuild process are updated Link1 parts manuals, revised and updated documentation, operator and maintenance crew training, and plant safety files.“We have sufficient capacity to carry out six full machine rebuilds a year – and if we need to do more, we have the facilities, space and people on call internally to meet additional demands.”Robertson said that Sandvik offered MB series machine owners the only option to ensure fully compliant, factory-certified rebuilds.“Only with Sandvik certified rebuilds can customers be assured of upgrading their bolter miners to the latest standards and safety innovations, to full OEM specs.“In addition, the only way to access the latest technology upgrades is through our OEM upgrades, which are then backed by full six-month factory warranties,” said Robertson.“Before we start a bolter miner upgrade, we carry out a full engineering feasibility study, so the customer knows what is legally required, as well as what additional options are available – and the benefits that those options will bring.“We do a lot of work up front to ensure our customers get the best end-product they possibly can out of our rebuilds, so they know exactly what they will get, with no surprises.” he said.Robertson said that feedback from customers who have had rebuilds carried out – which includes the major mining houses – has been universally positive.“Following every rebuild, we ask customers to fill out a feedback form on how well we have performed across a range of critical areas.“The feedback we receive rates us very highly in the quality of our service and workmanship, the degree to which we keep customers informed of progress, developments and issues, our flexibility once rebuild work commences, and our ability to upgrade machines to incorporate latest technology and innovations,” he said.Sandvik bolter miners are electrically powered, track-mounted continuous mining machines designed to excavate longwall development roadways and install roof bolts simultaneously in underground coal mines.Their ability to carry out simultaneous cutting and bolting greatly speeds up production, resulting in substantial economic and safety benefits.Sandvik’s MB series bolter miners are high-capacity solutions for both rapid entry development in longwall mining and full-scale production in room-and-pillar mining.The cutter drum is mounted on a hydraulically actuated sliding frame, giving it the ability to sump into the face independently of the mainframe and tracks. And since the roof and rib bolters are mounted on the stationary mainframe, they can be operated throughout the cutting cycle.