A custom pump station for the Port of Hamburg
Few ports can have as much experience as that of the City of Hamburg when it comes to dredging. It is positioned 110 kilometre inland on the River Elbe, one of central Europe’s largest waterways draining nearly 150,00 km2 of landmass into the North Sea. The resulting sediment coming off the land has meant that dredging has long been a necessity, and indeed mechanical dredging has been going on in Hamburg since 1834.
Today, that responsibility lies with the Hamburg Port Authority (HPA), an organisation that prides itself on delivering future-orientated management from a single source. In the modern harbour, about 90 percent of the dredging is undertaken by hopper dredgers, supported by a unique floating pump station that plays an important role in the never-ending battle against sediment and its disposal. Jens Bald, project manager at HPA, takes up the story.
Building on a long history
“The HPA has had a floating pump platform operating in the port since 1905. Its role; to receive sediment from both HPA and privately-operated barges and pump it ashore for treatment and disposal. In recent years the Sauger III, built in 1905, began to show its age so the decision to replace it was made. The contract was put out to a European tender, with interest shown by 10 shipyards. That was reduced down to a short list of four and the order was finally awarded to Damen in December 2014. What makes the pump station so special is that it the only facility in the port of Hamburg that is able to pump dredged sediment ashore.
“The station is essentially a pontoon fitted with sophisticated pumping equipment capable of managing very large volumes of sediment, plus crew accommodation. The core equipment consists of two pumps each connected to an arm on deck. One of these extracts the silt from the barges that come alongside to offload and then pumps it ashore via a 1000-metre floating line. The second pump/arm combination adds water to the mud to keep it in a liquefied state. The sediment is cleaned as it passes through the pumping apparatus.”
The HPA is very conscious of its environmental responsibilities, and has been a pioneer in the management of dredged material. Once ashore, additional treatment takes place at the HPA-owned METHA plant. METHA was the first major sediment-processing plant in the world to mechanically process dredged harbour sediments. It separates and drains polluted silt from sand. The sand can then be used as a building material while the silt is processed and either used as packing material or deposited in an environmentally safe manner.
Building for the future with an eye on the past
“Our specifications for the new platforms, also named the Sauger III, were very precise,” continues Mr Bald. “We wanted to ensure that the newbuild would draw on all the experience gained from the previous platforms going back over 100 years, and so a number of key components were designed using the plans of the original Sauger III. In particular, the feed pump has been built to the same plans as before to make it easier to maintain. The new platform is also the same size as its predecessor so that it can fit in the existing berth.
“One of the reasons we chose Damen was its extensive experience in building hopper and cutter suction dredgers such as CSD Amoras,” concludes Mr Bald.
“This is a sector that they really understand.” With the platform expected to have an operating life of at least 40 years, quality was another key factor.
“The entire project was scheduled to take 24 months from November 2014. The actual build took 15 months at Damen Shipyards Hardinxveld, following by commissioning, so the Sauger III has only recently begun operations on the Elbe. We are now evaluating its performance, and have every confidence that it will perform as expected.”