If your lucky enough to be travelling to Australia’s Gold coast this year you may notice a strange looking vessel working off the coast, it just might be a Dredge. The local government is delivering a major beach nourishment project to increase the sand volume on the local beaches, and has contracted the BALDER R a Danish flagged Hopper dredge for the job. The project is expected to run from June until mid October 2017 and deliver approximately 3 million cubic metres of clean sand to the local beaches, at a cost of approximately 14 million dollars. This will ensure the beaches are wide and healthy for next years Commonwealth games and for many years after that, it also creates great sand banks for the local surfers.
The BALDER R Hopper Dredge is 111 metres long and can hold 6000 cubic metres of sand in its hull. The dredge sucks up sand about 3 kilometres off shore, at a maximum depth of 35 metres and fills it hull with sand. Once full of sand the dredge travels in close to the shore and pumps the sand and water mixture into the shallow areas around the wave break zone. The water sand mixture appears to travel over 100 metres through the air, a process they call Rain Bowing, the Dredge can also dump through its hull but that’s not very exciting to watch. The BALDER R takes approximately one hour to empty it’s 6000 cubic metre load and it also takes approximately one hour to fill up. It is estimated that it will deposit between 200000 to 300000 cubic metres per week depending on the weather conditions.
The dredge doesn’t actually place the sand on the beach, it places the sand in the waves and over time the waves move the sand up towards the shore making the beach wider. So far I haven’t noticed any widening of the beach but I have noticed the surf improving. TheDredge works 24 hours a day and only has to refuel once every 3 weeks, It is also very quiet in operation.