When building work began to prepare the ground for the construction of a new highway tunnel in Oslo, excavators were not prepared for what they were about to find buried under the mud. As work progressed, the largest collection of antique shipwrecks ever found in Norway was gradually uncovered.
Once specialist archaeologists from the Norwegian Maritime museum stepped in to take over the dig, they were surprised to discover the remains of at least 14 wooden boats. The wrecks measure up to 17 metres (56 feet) and are believed to date from the late 16th and early 17th centuries.
The boats are all remarkably well-preserved due to the mixture of mud and fresh water found where the rivers run into the sea at Bjoervika, part of Oslo's old port, near the new national opera house.
Lin Hobberstad, an archaeologist onsite to oversee the safe recovery of the shipwrecks, explained that the removal process had to happen as quickly as possible so that the ships could be examined and construction work on the tunnel could start again:
"Oslo Vei, a construction specialist based in Oslo, recommended Tsurumi pumps for the onsite drainage," she said. "Good reliable pumps are an essential part of an archaeological project like this and Tsurumi was an obvious choice."
The pumps in question are 70 Tsurumi LB-480A contractor pumps – single-phase portable pumps with level sensors which start and stop the pump automatically. The 0.48 kW power-rated LB-480A can pump up to 225 litres/minute at maximum capacity. With the automatic shut-off it is therefore very economical and well-suited to this type of application. The pumps will remain onsite until the end of construction in 2012.