silniční reportáž v originálu 2/2
What lies beneath Down Under
The third and final construction stage on Sydney’s WestConnex project has begun, including the underground Rozelle Interchange – with a lot of help from Komatsu
M8 air quality monitoring
The M8 motorway, part of stage 2 of the three-stage project, opened in June this year. The 9km twin-tube underground tunnel runs from the end of the M5 Motorway at Kingsgrove to St Peters Interchange in Sydney’s south region. A network of ACOEM air quality monitoring systems is providing environmental management.
Under stringent government regulations, all underground motorway tunnels require the inclusion, operation and maintenance of three specific air quality monitoring functions: sensors inside the tunnel, ventilation outlets and ambient locations around the tunnel.
The WestConnex M8 is the first tunnel project in Australia that incorporates ACOEM air quality monitoring hardware for all three regulatory components. In-tunnel air quality sensors are supplied by Tunnel Sensors. Ecotech has supplied ambient and ventilation outlet monitoring stations. Both companies are members of the AECOM group.
In addition, Ecotech has also been contracted to provide ongoing maintenance and data validation for air quality monitoring on behalf of WestConnex | Transurban which is responsible for owning and operating the asset during its concession.
- Motorists can breathe easy as they glide through the twin tunnels of the recently opened M8 (image WestConnex | Transurban)
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ACOEM has supported the tunnel delivery contractor, CPB Contractors Dragados Samsung Joint Venture since the project’s inception in 2014. Michael Preston, strategic business development manager with ACOEM, has noted that by using equipment from AECOM companies, there has been a “seamless solution for all aspects of air quality monitoring from initial planning, through construction phase and testing all the way to operations and maintenance contracts”.
Tunnel sensors, formed in 2005 as a subsidiary of Dynoptic Systems, is based in the UK. It designs and manufactures a range of air pollution monitoring equipment specifically for tunnels in the areas of visibility and dust, toxic gas emissions, air speed and direction as well as tunnel luminance and illuminance. Tunnel Sensors became part of ACOEM in 2019.
Ecotech, based in Melbourne, was set up 40 years ago to provide environmental monitoring for air, water, gas, noise, vibration, blast, meteorology, fine particulate and dust. It operates in more than 80 countries and became part of the AECOM group in 2017.
Last year Ecotech was commissioned to undertake continuous emissions monitoring and data reporting for the M4 East tunnel ventilation facilities, part of the stage 1 construction that was completed in July 2019. The M4 East tunnel ventilation facilities consist of two stacks, the Underwood Road Ventilation Facility (URVF1 and URVF2) and the Parramatta Road Ventilation Facility.
Komatsu goes underground
Komatsu has supplied 58 machines to the joint venture between September last year and August this year for stage 3 work, including the underground M4-M5 Link and the Rozelle Interchange. They are now removing a total of 2.65 million m3 of material from the site over the three-year construction period, ending in 2023.
The M4-M5 Link Tunnels run between the M4 at Haberfield and the M8 at St Peters and work includes stub tunnels to the Rozelle Interchange. The contractor for this work is an Acciona Samsung Bouygues Joint Venture (ASBJV) along with management by WestConnex | Transurban.
The contractor on the Rozelle Interchange and Iron Cove Link is John Holland and CPB Contractors Joint Venture, with management by Transport for NSW.
As well as the Komatsu equipment on the Rozelle site, the project has shotcrete rigs, rock bolters and face drills. Up to 22 roadheaders are carrying out the primary tunnel excavation. These machines - also called boom-type roadheaders or simply header machines - consist of a boom-mounted cutting head, a loading device usually involving a conveyor and a crawler travelling track to move the entire machine forward into the rock face to allow for continual cutting.
Komatsu’s site support includes what is called a pop-up workshop and parts store where three qualified Komatsu diesel technicians are on call 24 hours a day. Also, there is always one HM300-2 articulated dump truck on standby.
John Bostock, project plant manager for the Rozelle Interchange Project, says there were a number of reasons why Komatsu was chosen as the primary earthmoving equipment supplier for the project. “To start with, their service, support and equipment package was pretty good.”
But there was also Komatsu’s knowledge gained from working on other Sydney tunnelling projects, he notes. Komatsu equipment has been extensively used on the WestConnex 1b project (Homebush to Haberfield), WestConnex 3a (Haberfield to St Peters) and NorthConnex (Wahroonga to West Pennant Hills).
“The performance of the equipment since we started here in September last year has proven to be pretty good; there were a couple of issues with accumulators, which they replaced, but overall reliability and availability have been very good, in line with what we expected.”
Bostock and his plant management team recognise that skilled and careful operators are critical to successful equipment operations. To facilitate this the team has put additional effort into ensuring that operators look after their equipment and – importantly - are recognised for doing so.
“Tunnelling is a very harsh environment and we’re running a 24-hour-per-day operation,” he explains. “If you add up the number of plant items onsite, it’s around 130 to 140, plus forklifts, underground vehicles and so on. We need to be able to crew up to 22 roadheaders working three shifts. It’s also a challenge to get really good operators and it’s important to find people who want to look after the gear.”
To achieve this, Bostock’s team is running a Take Pride in your Plant campaign. Posters are up throughout the site reminding operators of the importance of caring for their equipment and working safely.
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“We want the cabins to be pleasant places in which to work, not filled up with dried mud and dust. So we ask the operators to clean their cabins at the end of their shift. And with COVID-19, in the pre-starts we communicate to operators the importance of wiping down their cabins, steering wheels and controls as an additional measure to sanitise the machines,” he says.
If a machine is scratched, even incidentally or there is very minor damage, Bostock says he wants to know about it, no matter how minor the incident. If it gets reported, then actions can be taken to mitigate a similar incident in future.
To encourage operators to report such incidents, Bostock’s team has implemented a plant award following a random inspection of four pieces of equipment per team. “We mark against various criteria, including safety, cleanliness, if the machines are in good order and so on.”
It is recognition for the extra effort the operators and teams put into their work. “The reward is a monthly barbecue for the winning site team and a trophy to keep at reception until the next inspection. For us, the benefits are safety, cost control, fleet efficiency and taking pride in their work and their fleet. And we are seeing some great results,” he says.
KOMTRAX, Komatsu’s remote machine monitoring technology, has proven to be an essential part of managing the Komatsu fleet at Rozelle. An in-tunnel WIFI system connects each machine to a surface transmitter and from there to the company’s remote monitoring satellites.
Bostock has also been applying feedback from KOMTRAX to ensure optimum operation of machines. “It allows us to intervene to eliminate poor operating habits. By having all of this information available to us quickly, we can talk to operators about any incorrect operating procedures,” he says.
“This added technology from Komatsu is a good tool in helping us reach our goals of the safe and correct operation of equipment at all times and ensuring maintenance is kept up to date.”
The WIFI also includes a tracking system giving the location of each piece of equipment, vehicle and person. The project team always knows the location of each machine and person in relation to each other.
Bostock is also using this tracking system to optimise the use of equipment onsite – particularly the movement of trucks which is a complex process across the three tunnelling sites.
“We have quite an advantage here in that all three tunnel access points are located on the one site, which allows us to maximise the use of our fleet across the tunnels,” he says.
“The rule of thumb is that you need two trucks per roadheader. So if you have 22 roadheaders in operation at any one time, you’d need 44 trucks. But we know our utilisation factor is about 60%, which means we need only 28 trucks onsite full time. So we’re running it here like an Uber operation. The trucks are all on call and using our tracking technology we put them where they’re needed, when they’re needed.”
The bulk of the Komatsu equipment onsite – all but 11 machines – are fitted with ultra-low emission Komatsu Tier 4 Final engines which contribute to significantly cleaner air quality underground.
Emissions testing is carried out on all the underground equipment every month to check for compliance and safety. In the past, with Tier 1, 2 and 3 engines, catalytic converters have had to be added to meet requirements for underground use. “But what we are finding with these Tier 4 engines, the emissions are much lower, conditions are much cleaner,” says Bostock. “In fact, the emissions levels are significantly better than putting a catalytic converter on a Tier 3 machine.”
AECOM, KOMATSU
Zdroj: portál WH