 So I'm construction manager for our joint venture for the Sydney Metro Tunnels and Station Excavation Project. So we're constructing twin tunnels between Chatswood at the north and Merrickville at the south for the next section of the Sydney Metro. So twin 15.5 kilometre tunnels stretching as we said from Chatswood to Sydney or Merrickville in the south there passing beneath Sydney Harbour and the CBD. We excavate dive structures at Chatswood and Merrickville to join into the existing network. We have six underground stations or six stations, three of those underground at Fick Cross Martin Place at Pit Street and open stations at Beringaroo, Waterloo and Crow's Nest with a crossover cabin at Beringaroo. We're also setting up the precast facility at Merrickville for the fabrication of 99,000 precast segments and we also renovated the demolition contract for all the buildings on the station along the alignment. So our board tunnels on the Sydney Metro project, we're utilising tunnel boring machines for those mainline tunnels. We launched two TBMs from Chatswood, they'll excavate 6.2 kilometres through to Blues Point where we have a temporary retrieval shaft, they're a hard rock double shield TBM and they'll be passing through about 90% sandstone and about 10% shale just at the commencement of their drive. We have a slurry TBM for the under harbour drives so that passes from Beringaroo through to that temporary retrieval shaft at Blues Point. It'll do that crossing twice, recovered from Blues Point and taken back. It's about 80% sandstone and with about 140 metres in soft grounds made up of clays and sediments and our remaining two TBMs come from Merrickville in the south through to Beringaroo. Again double shield hard rock machines, they've got just over 8 kilometres to do each and again a similar amount of 90% sandstone, a little bit of shale down at the Merrickville end. I guess we're conscious of the different rock types and the different silica contents that those different rock types have. I guess the key sources of silica that we see in tunnelling and in this project are firstly in the host rock disturbance, two real sources of that in the works that we're doing, tunnel boring excavation and also in our cross passage mine tunnel excavation. Our other significant source of silica is from other operations occurring behind the face. So all of our spoil is transported out of the tunnel using conveyor belts so that's a dust generating operation and also our vehicle movements within those tunnels. I mentioned also that we're doing the precast yard so all of our tunnels are lined with a precast concrete element so we do have repairs to those segments so the exposure during the drilling and grinding for those repair operations is another key source of silica. I've worked in tunnelling in Sydney for coming up to my 20th year this year so a fair bit of exposure to silica. I do go to the dust board for my regular checkups and fortunately unlike some of my colleagues I am clear but I guess we're continuing to work off of what we've done in the past and our statement is staying ahead of the game and I guess that's really testament of what we're trying to do and learning off what we've done in the past. At Northwest Metro we had pretty good levels of compliance but we know there's always areas for improvement and I guess today I just wanted to focus on three key, four key areas that we've identified. There's always many, many more but the four key areas we saw and I wanted to share with you of how we're trying to up that game. So those four areas, TBM ventilation, cross-spassage ventilation, some of the modifications we've made to plant and some of our concrete dust extraction ideas. So this is a schematic of a tunnel boring machine. At the left hand end of the screen there is the front of the machine so that's the cut ahead. That first 12 or 13 metres is what we call the shields. Within that section there is where we do the excavation and we also build that precast lining. Trailing along behind that we have the backup there, January around 150 metres long and that's where we house all the logistics of the machine and it's also where most of our workforce are stationed and I'll point out some of the stations there because you'll see some of the significance in the next couple of slides. At the front we have the ring builders. We have an operator in a cabin. Next behind that is our grouters. Other people on the machine. Segment handers unloading those segments. We have service extensions towards the rear of the machine and we have deliveries in and out of that TBM. At Northwest Rail the ventilation is set up there. Barely typical fresh air supply from the surface into the rear of the machine. We used a flexible vent bag to do that. So we were blowing fresh air from the surface that would then force under pressure and flow back out of the tunnel. Within the TBM itself we allowed that air to flow through the machine. So direction of air flow was from the rear of the machine with some additional fan assistance but essentially the air flow forward through the machine to a dust extraction point at the front of the machine. We collected the dust from the cut ahead and any other dust that was created during the operations of the machine at the front of the machine there. So this graph here I guess is the exposure results. So we did a lot of, like most people these days we're doing a lot of monitoring of our work groups and you can see here this really again lines up from the rear of the machine on the right hand side to the front of the machine on the left hand side of the page there. The red dotted line is that exposure standard. So you can see towards the rear of the machine we're generally pretty good. As we get into that ring builder we're just exceeding our operator being in the cab begins in a pretty good place and our ring builders at the front there are exceeding that limit. Those levels I guess compared to historically very good levels of compliance. But obviously we were still very reliant upon our personal respiratory protection to ensure that those workers were their exposures at safe levels. For Sydney Metro we're fortunate enough to buy five new tunnel boring machines and have been able to incorporate some of the lessons from the last project into the specification of those machines. So I guess some of the key changes we've made in those new TBMs still rely on our fresh air supply from the surface via vent bag. But the changes we've made on the TBMs, dust extraction, we're actually doing that at two locations. So we've got dust extraction at the cut ahead with a dedicated dust extractor and we also have a second dust extractor at the conveyor transfer point. There are the two key areas that we identified for generating dust and we're able to more efficiently extract from those two points with two standalone dust extractors rather than ducting between them. We've also reversed the airflow through the TBM. So we now will have forced ventilation from that incoming supply from the surface and force that ventilation through the machine and our airflow will now flow back through the TBM. We do believe these changes will reduce our exposure levels. Between the two tunnels we construct cross passages. There's 57 cross passages across this project, 49 standard and 8 with sumps. Those cross passages form the permanent foreign life safety egress cross passages in operational mode. Those cross passages we will construct in parallel with our tunneling operations. So behind the TBM and they'll involve what we can see a little bit in the picture there. So we'll open up the segment lining ring, excavate the host rock and construct it in situ lining. Our method at Northwest Rail, a fairly common use method. Small hydraulic rock breaker on an excavator. We had a mobile platform there to give us access to do the works and we have a dust extractor to collect that dust from those works. This photo here you can see is just the commencement of one of those headings. And as many of you will know, commencement of headings always forms the challenges for us to control our ventilation. Once that headings is established and we get in a little bit, we can get that vent can right to the face and our dust collection works a whole lot better. So that was a challenge for us at Northwest Rail. We did use different methods to try and contain that initial heading. Small brattances put in place. Again, a reliance on the P2 masks and a key awareness of who was out by. Obviously the airflow is coming back from the TBM running up the tunnel so any dust we're not able to control is flows back up the tunnel. I'll just point out in that photo, the yellow vent bag at the top there is all squeezed up in this photo. This photo was taken in a tunnel where we'd actually broken through to the next station box so we were just blowing fresh air through the tunnel and no longer reliant on that vent bag. So what we've been investigating for Sydney Metro is the use of something called a vortex air curtain. So our challenge, as I mentioned, we're trying to excavate these cross passages while we have tunneling operations in front of us so we need to be able to drive past on a very regular basis that cross passage excavation. So trying to build a permanent braddis or some sort of wall in there to control that dust is always a challenge. So what we're investigating here is the use of that compressed air to create a curtain that will essentially shroud that dust generation to allow the dust extractor to remove it rather than getting blown back out of the tunnel and still allow vehicles and others to pass by that work location. So it's a system yet to be proven, but we've looked at it in similar applications and we have a fairly high level of confidence that that will work for us. Getting into some of the more simpler controls for the control of dust. Tunnel vehicle movements in the tunnel are definitely dust creators. We do try and maximize our housekeeping, try and keep that material on the belt, but invariably from time to time, material does fall off as those vehicles travel up and down the tunnel, just like on the surface, they can stir the dust up. So I guess some of the things we put in place there, we do have our housekeeping. We do have wetting down of the floors, but quite a simple but effective one is just the direction of the exhaust from the tunnel vehicles. On the right hand side, there you can see one of our segment carriers. On the left is the backup of a TBM as it's passing through underground cavern. It's a castle crossover cavern. So just by pointing the exhaust up of those vehicles, the dust isn't created from the movement of the vehicles. They're travelling fairly slow, sort of 10 kilometres an hour, but that airflow coming out of the exhaust, pointing down to the ground, we found created a lot of dust. So quite a simple thing to do, but in a bespoke vehicle there, we need to do that back with the manufacturer and best done prior to fabrication. And then finally, into the precast production, as I said, we've got 99,000 segments to make for this project, all down a bespoke plant at Merrickville that we've just set up and started production last week. During that production, we will get some damage to segments, some defects to segments that do require repairs. And likewise, when we install those segments in the tunnel, we will have damage to those segments requiring repairs. Generally, the repair of that segment is done through drilling and grinding. So we do create dust during those operations. And I guess we're looking at two ways of controlling that exposure. In the factory, we're looking at a segregated area with a dressed extraction device. So really trying to do that separately from the rest of our activities and also extraction of source. So a lot of our drills and the like these days, you can get with the dust extraction. So trying to extract that at source rather than letting that become part of the larger atmosphere. Likewise, in the internal repairs, that extraction of source is what we're striving to achieve. So which I guess all comes down to that if we can reduce those exposure levels, we reduce that reliance on the personal respiratory protection, which is a higher level of control. And as always, trying to administer and get people to buy into that controls. If we've got the levels at an exposure level we know and we can control, then we eliminate that issue. Thank you.