Earlier in the year, the team at Tutt Bryant Heavy Lift & Shift (TBHL&S) managed a complex bridge demolition project in the Hunter Valley region of New South Wales. With extremely limited access and a tight time frame, the lifts had to be meticulously planned.
Over the past 24 months, the Australian Rail Track Corporation (ARTC) has replaced three bridges in the Hunter Valley region of New South Wales. These include the Hunter River bridge, Muscle Creek bridge and Bridge Street bridge with two new bridges within and next to the rail corridor, in Muswellbrook, NSW. The lifts involved the onsite bridge demolition of the bridge over Muscle Creek and Hunter River. The Bridge Street site involved the demolition of the existing bridge superstructure and central pier.
Kyle Greenwood is the New South Wales Supervisor for Tutt Bryant Heavy Lift & Shift (TBHL&S). He explains more about the complexities of the project
“The project involved lifting a couple of different bridges out from the one setup. The only way to execute the project was to use the 600t capacity Demag CC 2800-1 which was set up on a natural jetty between the two rivers, the Hunter River and Muscle Creek.
“We were literally set up on the 18m long jetty that we had engineered and had earthworks completed for the lift so we knew it could sustain the combined crane and lifts being undertaken. manage the crane. We had to access to the jetty through a caravan park, so setting the crane up was tight with very little tolerance for error.
“We had the whole site aerially scanned as part of the lift planning. They scanned it with a drone and then put it all into a CAD system with which we calculated that we would just be able to manage the lifts. We could only use 66 meters of boom, I would’ve liked to use more, but we literally could not build more in the area we had,” said Kyle.
Building the Demag CC 2800-1 was a very complex process in itself, due to the lack of space. To lift the heavy parts of the crawler, like the track frames and counterweight, TBHL&S used a Grove 300t all terrain, GMK6300L says Kyle.
“There was just enough room for us to get our Grove GMK6300L onto the site and assist with the build. We actually set the Grove up on the Superlift counterweights pad. We had the outriggers fully out on the lifting side, and then we had the half jacket on the non-lifting side.
“We had to bring the two track frames in on a 7 line steerable Drake platform trailer due to the narrow roads in the caravan park, we then had to unload them, sit them on the ground, and then bring the car body in and install the track frames. If we delivered the car body first, we wouldn’t be able to get the trucks close enough to the 300t Crane to unload as they weight 45t each.
“We couldn’t use the Grove any further because we couldn’t slew it around. So, we brought in a Sennebogen 683 HD 80t capacity tele-crawler for the rest of the build. We walked it up and down the track and walked in the boom sections and Superlift mast and everything else,” said Kyle.
The Hunter River Bridge was an old riveted steel structure with a calculated weight of 120t to 130t, so using that weight TBHL&S examined assets which would suit the application and all options for the location of the lifts. Three possible locations were identified to complete the lift but the team at TBHL&S had to use a natural jetty in the caravan park as it was the only location to build the boom long enough to get the head height at the required radius. The site also had several large and protected river gum that eliminated the other two possible crane locations. The next problem was clearing out 7 cabins and constructing a crane pad to support the crane and super lift counterweight. After engineering a pad design and surveying the site TBHL&S’s 600t Terex Demag CC2800-1 was the largest capacity crane that could fit on the jetty, and it had a SWL of 129t at the required radius.
“Ideally, we would’ve liked to have used a 700t capacity crane or even our 800 tonner, but there wasn’t enough room to set up a larger capacity crane on the site, so we had to work out how to reduce the bridges weight to maximum tare weight of 108t (this is due to hook block, rigging and wire rope weight adding 18t. This meant a total lift weight of 126t which would be 98% utilization of the cranes’ charts.
“Without compromising the structural integrity of the span, once we knew we could achieve a 108t tare we then organized a company to jack the bridge up so we had a known weight which eliminated the 50 per cent demolition allowance. The company came to site and weighed the bridge which come in at 132t, we then removed two 12t pieces from the span and confirmed the weights with the jacks.
The first lift was the Hunter River Bridge, which weighed 108t. Because TBHL&S had to use a H-pattern spreader, a 250t capacity spreader connected to two 80t spreaders below meaning the total weight of the lift was 126t.
“We were basically sitting right on the crane’s limits at 98 or 99% of its capacity. Ideally, we would’ve liked to have used a 700t capacity crane or even our 800 tonner, but there wasn’t enough room to set up a larger capacity crane on the site.
“Slope stability of the jetty was assessed, and where we had our Grove GMK6300L on the Superlift counterweight, we were only allowed to load that area of the ground for 20 hours. So we could only stack the Superlift counterweight and have it sitting on the ground for 20 hours. The lift had to be completed inside that window and then the tray de-stacked, because of how close it was to the slope,” said Kyle.
The old bridge was lifted and placed over to the other side of the new bridge, which was planned as it had the same lifting radius of 46m of the new bridge which meant no time was wasted de-stacking the Superlift counterweight trays.
“Once the old bridge was safely on the ground, the demolition crew came in and cut it all up on site and then removed it in small trucks over a temporary bridge they had built over the Muscle Creek River to access the spot,” said Kyle.
The second lift was the Muscle Creek Bridge which weighed a total of 69.6t
“We lifted the Muscle Creek Bridge out and put it over behind the Hunter River Bridge which was a 56m pick. Once again, we were able to put it down within the same radius. We then had a series of smaller bridges to lift out. These were only around a 30t each. There were eight bridge sections lifted in total in a three day outage.
“The TBHL& S team worked 24 hours a day for three days. We utilized our New South Wales heavy lift team during the day and our Queensland heavy lift team at night. I was running the night shift. It was hectic, but it all went according to plan which was as a result of the detailed planning and the careful implementation of the methodology,” said Kyle.
“TBHL&S was initially contacted about the job two years ago and we started to scope out a plan. When the project came into focus, it took eight to 10 weeks of full-time planning and liaising with geotechnical engineers, structural engineers to obtain approval for the lift plans to be signed off.
“Complex projects like this take meticulous planning and time to get everything signed off and over the line. We were not able to use soft slings except for above the top spreader. That’s because they could have been caught, nicked or damaged on the steel of the bridge. We used 32mm chains and doubled them up. There were a number of factors to consider which included the D/d ratios and different specifications to consider and to ensure we were within Australian Standards,” said Kyle.