“The consistent results achieved on the panel advance at United are fundamental to the overall results for the development process. The available cutting hours are increased and the work is carried out safely and to a high standard,” Richardson said.

United, located in the Hunter Valley 20km west of Singleton, develops about 13km of roadways per year.

Typically the panel advance takes 10.5 hours from last coal to first coal in the belt road with the travel road typically taking it out to 12.5-13 hours. However, according to Richardson, “it has not always been this way”

“In the beginning, it was assumed that the best result would be achieved by commencing the panel advance as soon as the pillar was completed. It was considered that to be fair to all, the shifts should share in the panel advance.

“A common outcome was for a crew that had been averaging 15-20m per shift and needing to cut 10m to hit the trigger to begin the advance would experience all sorts of bad luck and only make the trigger at the end of their shift,” he said.

It was also found that it was difficult to predict when advance would start and therefore predict how many resources, such as load-haul-dumps, were required and when.

So what changed? A series of workshops with crew members showed that the day crew were more motivated towards continuing to improve on the time taken to complete the panel advance.

Trials were undertaken using more people and machinery to tackle more tasks in parallel, including the transformer move as part of the advance every second pillar without any increase in the time taken.

“Instead of trying to get a good result with whatever number of people happened to be available, the attitude became: we are doing a panel advance – how do we find enough people to make it happen.”

Contractors, overtime or non-essential work around the mine were rescheduled to free up labour and according to Richardson, “take the excuses away”. Manning levels were increased to 10 mine workers, a fitter, an electrician, a deputy and two others for four hours.

The decision was also made to have the dayshift crew do the belt move every time – a “clear case of whipping the willing horse”, Richardson said.

“The intent is on every panel advance that the dayshift crew are able to hit the ground running – breaking up into their teams without having to be involved in parking up machines, cleaning roadways, servicing LHDs and more.”

The set-up work – or “park-up” – is achieved efficiently by the night crew stopping production before shift-end to ensure the boot end is cleaned, both continuous miners are parked in the overdrives with the CM cable recovered and the shuttle cars behind the miners.

Two LHDs and the multi-purpose vehicles are in the panel ready to go and dayshift crew isolate the conveyor at the drivehead on their way into the panel.

By committing a great deal of resources to the panel advance, mine management showed they were serious about supporting crews to achieve the best possible outcome.

A combination of leadership, “can do” attitudes, task specialisation and confidence has enabled United’s crews to achieve rapid panel advance.

Question & Answers selection taken from sessions with Richardson at ACARP’s Roadway Development Workshops in Mackay, Pokolbin and Penrith last month.

Q: Is there a specific development maintenance window, and does maintenance get done during development time?

A: Maintenance to the belt road equipment is linked to a full shift (usually Thursday) each week when “stop belt” maintenance is carried out. The travel road equipment is carried out when services are being advanced after the travel road miner has mined to 130m chainage.

Q: Why does the mine work a 5 day roster, why not a 7 day roster?

A: Five days are enough to maintain longwall continuity; rosters are simple; management are not burnt out; and we are not paying penalty rates.

Q: What is the pillar cycle time?

A: Typically 4 days in the middle 20 pillars of gateroad development, extending out to 5 days at the start and finish of panel due to mining conditions.

Q: Can you go through the road clean up and cut through holing process?

A: The travel road CM is advanced to 132m to complete overdrive before being pulled back to clean up the travel road from outbye cut through to face. Following clean up of the travel road the vent ducting is recovered and the extension of services is commenced.

The belt road CM completes 20m overdrive in the belt road before commencing cut through. When belt road CM holes it takes about 2 hours to complete bolt up, during which time a loader is used to doze up belt road into overdrive. The belt road CM is then trammed into the belt road and an LHD cleans-up the cut through into belt road overdrive, before the CM is trammed to the face and loads out stowage at face into shuttle car.

Q: When are the belt hanging bolts installed?

A: On the “stop belt” shift although we may have to do it during the panel advance is there is no “belt stop” shift between panel advances.

Q: Why not pre-hang the belt hanging chains rather than hang them at the start of the belt move?

A: One has fallen down and hit an operator, and there have also been reports of them falling down and catching equipment. It also doesn’t add too much time. We fully encapsulate 2100mm belt hanging bolts which are part of our roadway support system.

A workshop participant reported that they pre-hung the chains and marked the grade line on the chains to expedite levelling of the conveyor structure.

Q: How long are the longwall blocks, and do you have any problems pulling the belt out of the LTU over that distance?

A: 3.2km long. Problems are experienced at times due to soft floor conditions in inbye section of the panel, however, we utilise a second LHD to assist.

Q: Do you have any views regarding roof and floor mounted structure?

A: 1200mm belt operates at 5.2m/s and needs to be high standard, and we utilise roof mounted structure to provide a high standard “longwall ready” conveyor. Minimal works are undertaken on completion of gateroad development to get conveyor “longwall ready”

Q: What improvements could be made to panel advances at United?

A: Considering use of monorail services management system in both headings to take the extension and relocation of panel services off the critical path. Expect panel advances could then be completed in 4.5 hours.