In February of 2018, Birdon commenced dredging works on the renourishment of Hampton Beach for the Victorian Department of Environment, Land, Water and Planning.
To perform the works, Birdon supplied and installed a submerged pipeline of approximately 1 kilometre in length to pump 20,000 m3 of sand from designated areas of Port Phillip Bay just outside of the Sandringham Yacht Club Marina. Birdon then used an excavator to spread and profile the sand along a 1.5km section of Hampton Beach to achieve the appropriate design levels.
Birdon was responsible for the supply and establishment of all equipment, including construction of temporary pipelines. This project was completed with the operation of Birdon’s cutter suction dredge “BALLINA”.
The “before and after” photo below shows the improvement to the Beach after Birdon had completed the renourishment.
Birdon undertook maintenance dredging works within the Newport Canals for Moreton Bay Regional Council.The work included the removal of sediment within the canal system using a long reach excavator mounted on a hopper barge.
Sediment was excavated from the seabed and loaded directly into the hopperbarge before being transferred to a larger barge approximately 1km offshore. Once the larger barge reached capacity (500 cubic metres) it was then towed to Mud Island for disposal.
South Australian Common User Facility
This project included maintenance and capital dredging around the common user facility (CUF) and ASC ship building facility within South Australia’s maritime precinct, Techport Australia.
The CUF is a State-owned facility and consists of a ship-lift, wharf, ship transfer system and dry berth for shipbuilding and ship maintenance activities. Its primary purpose is to support the construction of the Air Warfare Destroyers for the Royal Australian Navy.
The scope of work included:
Capital dredging of 54,000m3 of predominantly hard material to allow for the extension of the CUF wharf
Maintenance dredging to remove infill sediment from both the CUF and ASC ship lifts
Maintenance dredging of infill sediment from under the ASC wharf area.
Birdon pumped the removed sediment, via a temporary pipeline, more than 2.5 km to designated settling ponds. Due to the distance, Birdon deployed booster pumps to ensure efficiency. The water was allowed to settle and monitored for quality before being returned to the river. Key to securing this bid was Birdon’s innovative solution which involved using a low pontoon to manoeuvre the pump under the ship lift. This allowed for dredging under the ship lifts without the need to remove the deck timbers of the structures. This resulted in minimal docking restrictions during the work.
Rosslyn Bay is situated just east of Rockhampton, adjacent to Yeppoon, in Northern Queensland. The central feature of the town is its busy harbour, used by both commercial and recreational vessels. The harbour is within Keppel Bay and close to the Mackay/Capricorn management area of the Great Barrier Reef Marine Park.
The harbour requires maintenance dredging about every 3-4 years to maintain accessibility and internal public channels.
Birdon was awarded a maintenance dredging contract to improve navigational access to the Boat Harbour in 2012 and again in 2016.
In excess of 85,000m3 of material was dredged in 2012 followed by another 75,000m3 in 2016. The material consisted of a combination of silt and sand. Dredged materials were transported via a submerged underwater pipeline to an offshore disposal area approximately 1.1km from the Harbour entrance.
The work was carried out using Birdon’s cutter suction dredge “DARWIN” on both occasions.
Great Lakes Dredging
Birdon delivered maintenance dredging of Lower Myall River entrance to aid navigation and replenish beach sand in eroded areas within Port Stephens. This project involved dredging approximately 110,000m3 of sand from the eastern channel of the Lower Myall River, near Jimmy’s Beach, and relocating it to the badly eroded Winda Woppa sand spit.
Work was undertaken in three phases:
Sand was excavated from the area of the channel above mean water level using a 30-tonne excavator and loaded into articulated dump trucks. This was then transported and placed to form a perimeter bund for the sand stockpile.
Birdon used a 10” cutter suction dredge for removal of the remaining material from the river channel. This material was then pumped up to 2km via a temporary pipeline to be stockpiled or for beach renourishment.
Birdon placed the dredged sand along a 600m section of Jimmy’s Beach to provide protection from erosion and restore the beach. The remaining material was deposited in a nearby stockpile for future beach renourishment.
Birdon was contracted to dredge 1.4 million cubic metres of consolidated ash from two primary settling ponds at Loy Yang power station. The material was pumped 1 km to a newly constructed void for dewatering and long term storage.
AGL Pty Ltd operates Victoria’s largest coal mine and power station –Loy Yang – responsible for the supply of one third of the state’s electricity.
During the production process on site, fly ash and bottom ash had built up in the main settlement ponds. This required regular removal and transfer to a storage area.
The work was undertaken using a 10-inch cutter suction dredge with the material pumped via a temporary pipeline to the elevated storage void.
All work was undertaken while the power plant and settling ponds remained in operation. This required careful planning to achieve settling requirements while still leaving enough water for dredging operations.
Birdon worked closely with AGL to amend the working area and adjust the scope of work which allowed the ponds to remain operational throughout the project.
Broadwater Channels Dredging
This project consisted of maintenance dredging of navigation channels in the Broadwater on Queensland’s Gold Coast. The scope included removal of 110,000m3 of sand from the north and south channels as well as South Wave Break Island channel.
Birdon used a cutter suction dredge to remove sand from the North Channel and pump it, via a temporary pipeline, across the southern tip of South Stradbroke Island. It was then discharged into the ocean-side tidal zone.
The sand from the South Channel and South Wave Break Island Channel was pumped to the stockpile on the spit for storage and future beach renourishment. Birdon delivered the project without disrupting existing waterway users.
Lakes Entrance Dredging
Lakes Entrance is home to the largest commercial fishing fleet in Victoria and increasingly is used by local and visiting recreational vessels. Regular dredging at the entrance to the Gippsland Lakes has occurred for more than 120 years and has been essential for maintaining access between the Gippsland Lakes and Bass Strait since the permanent entrance was constructed in 1889.
Gippsland Ports awarded Birdon the contract for the hire and operation of a cutter suction dredge for 18 months while they sourced their own dredge.
Birdon undertook the following scope of work:
Supply, establishment and operation of cutter suction dredge discharging to fixed slurry pumping station at Lakes Entrance
Dredging of boat harbour with discharge to beach for re-nourishment at Port Welshpool
Maintenance of dredge and pipeline
Development of preferred dredging practices
Birdon subsequently won the tender to build and supply a purpose-built cutter suction dredge for Gippsland Ports.
Garden Island Dredging
Birdon was responsible for maintenance dredging activities at Fleet Base East and Garden Island Naval Base wharves to maintain operational and functional capabilities for the Department of Defence.
Garden Island Naval Base is located within Sydney Harbour, approximately two kilometres east of the Sydney CBD. The work involved the mechanical excavation, dewatering, treatment and disposal of approximately 10,000m3 of contaminated material to an onshore registered waste facility. Due to the limited available land area at Garden Island, the contaminated sediments were solidified by addition of polymer in the on-water hoppers and loaded directly onto trucks for transport to landfill.
Another 10,000m3 of clean material was also excavated and disposed of using bottom dump barges to an offshore spoil site.
The work included site establishment and the supply of all materials, plant, equipment and labour required for the completion of the dredging and disposal activities. Birdon also completed all survey activities associated with the works, including calibration, pre-dredging survey and post-dredging surveys.
Murray Mouth Dredging
Birdon was awarded a three-year contract by South Australia Water Corporation for the dredging of the Murray mouth entrance and adjacent channels which was extended by another three years.The project involved two cutter suction dredges plus a booster pump operating on a 24 hour day, seven days per week basis.
The Murray Mouth, near Goolwa in South Australia, is a dynamic system influenced by the flow of Murray River water through the barrages and tidal movement from the Southern Ocean.
Periods of low flow, such as the Millennium Drought in 2002, have led to the mouth threatening to close. The mouth was dredged for eight years from 2002 to 2010, during the Millennium Drought, to keep it open.
Birdon began work in 2007 and continued to 2010. Birdon was then awarded a further three-year contract which was suspended in 2011 when flood waters negated the need for continual dredging.
The contract was a turn key solution involving provision of all plant, equipment labour and services including construction of pipeline, operation of cutter suction dredge, booster, work boats plant machinery and associated equipment and vessels.