Glorious in the June sunshine, Grange Sidings in Stoke-on-Trent was the location for a recent demonstration, staged by Network Rail, of two of the industry’s latest plant powerhouses.
The Komatsu PC210LCi-10 excavator and the newly rail-modified Bomag Variomatic Roller took centre stage in front of 50 ‘movers and shakers’ (or should that be high rollers?) from across the industry, as part of a live trial, showcasing innovation in the plant sector.
However, before the trial could commence, the first job of the day was the removal of two 30ft concrete track panels. The task was undertaken by plant supplier AP Webb. A pair of RA400RR Rail-Max tracked excavators, fitted with panel grab attachments, performed a tandem lift on each panel. The short jibs on the rail-wheeled 45-tonne excavators helped make easy work of moving the panels and they soon had the site clear and ready for excavation.
Digging for victory
Site clear, the Komatsu excavator was moved into position. Experienced operator Mark Fletcher of Quattro Plant, who received two additional days training from Komatsu on the market’s most technically advanced excavator, had a 45-minute window to dig a trench 40 metres long by 3.5 metres wide to a depth of 300mm. With the eyes of the industry upon his and the excavator’s performance, the result was highly anticipated.
Mark needn’t have been concerned though. The Komatsu’s traditional global navigation satellite system (GNSS), combined with stroke measuring sensors, inertial measuring capacity and bespoke electronics and control systems, help create a machine that not only creates an accurate dig but is also a very user friendly experience.
Previously, in order to achieve an accurate dig grade, a level of trust must be put in the operator’s ability, and any additional systems for guidance are after-market ‘bolt-ons’, often subject to damage or theft. The Komatsu changes that, with fully integrated machine control helping prevent over-digging and maintaining grade automatically using only ‘arm in lever’ – the boom raises automatically keeping the bucket edge perfectly on grade.
The excavator’s system was set in a semi-automatic mode, so any movement of the arm from within the cab resulted in automatic boom height adjustment and tracing of the target surface, thus minimising the risk of over-digging.
“I was responsible for the majority of the dig, but used the laser to check when there was about 100mm to go,” Mark explained. “This worked brilliantly and the machine came into its own, taking over just at the right time and providing a ‘safety net’ to prevent over- digging.”
With working tolerances of between 20-30mm (depending on the surface material), there was no need for a banksman on hand to be continually checking that the dig depth was still within the correct boundaries. From a safety point of view, there was therefore one fewer person within the danger zone of the working machine, and less time was lost by stopping digging for checks. Using the machine’s built-in technologies, the team was able to complete the dig quickly, safely and effectively, allowing the next stage of works to commence.
Rolling out the new technology
With a successful track bed dug to exacting measurements, the next vehicle up in front of the crowds was the newly converted Bomag Variomatic Roller. The single drum roller has been successful in the civils market for many years but, following a conversion by RRV specialist Rexquote, the vehicle was ready for its debut into the rail market.
The roller uses intelligent control (IC) technology to measure the status of the ballast it is travelling over, and optimises the force required to ensure a uniform stiffness across the entire bed. The driver was able to set the ‘compaction value’ and the highly sophisticated system took care of the rest. Measurements were taken many times each second to ensure that the roller displaced a correct amount of force at any given time, with the compaction energy adjusted by a bespoke system designed to change the vibrating direction of the drum.
There were no concerns about missing a bit either – GPS signals taken from transmitters located inside the roller itself provided the driver with an on-board, comprehensive, real-time digital map, tracking his route to a distance of two inches, and showing when complete compaction had been achieved, helping ensure that he knew when no further passes needed to be carried out.
Topcon made checks of the levels, which proved to be exactly as they should be, leaving an end result of a perfectly compacted, smooth bed that was ready to receive new ballast.
Top grades for innovation
Spectators having been suitably impressed by the Bomag’s rail capabilities, it was time for the new Komatsu machine to take centre stage again, this time to cover the track bed with a fresh layer of ballast.
The restoning and grading of the bed utilised many of the same technologies as the dig. Topcon GNSS helped ensure that ballast was delivered in precisely the right position whilst the cutting-edge Komatsu sensor technologies helped make short work of grading the delivered ballast, keeping the bucket accurate to profile.
“From an operator’s point of view, the machine does its job, and it does it really well,” said Quattro Plant’s Mark Fletcher who was once again demonstrating the excavator. “Every operator will use the technology differently, but I would suggest that it is especially good both for maintaining quality across a work site and for perfect finishing touches.”
The same technology that was controlling the dig was also helping keep the team safe, providing a failsafe ALO (adjacent line open) system. The machine, including the boom and bucket, know where they are at any given time to ±10mm. The testing site was a perfect location to showcase this – with spectators from across the industry watching the action, as well as an active line just metres away from the worksite.
Did they ‘pass’…?
With fresh ballast down, to exact requirements, the Bomag roller made its final appearance to ensure that the scene was set for the replacement of the track panels. Using the same IC quality control technology demonstrated earlier, the driver was able to make short work of the final pass. A compaction test was carried out to ensure that all levels were as they should be before the work was considered complete.
The demonstration finished an hour early, with all works completed and tested. Both vehicles performed perfectly, working speedily and efficiently, as well as ticking all the required boxes with regards to safety – both promoted less people on track, with less scope for accidents and injury.
“The overall aim for Network Rail at the event was to check whether traditional plant, such as a dozer, could be eliminated to save costs and avoid a longer line closure,” commented Malcolm McCoy, senior product manager at Komatsu. “The testing that took place during the event has proved the PC210Lci-10 to be exceptionally accurate, as well as being a versatile, intuitive rail vehicle designed to tackle the demanding requirements of today’s busy rail industry.”
So, with safety and efficiency the buzzwords for CP5, could Komatsu’s PC210LCi-10 excavator and Bomag’s Variomatic Roller be plant’s new superstars, set to break new ground in rail?
Written by Polly Rivers
