In Northern Germany Volvo Construction Equipment’s new concept in pipelaying machinery is helping to build one of Europe’s major gas pipelines.
Surrounded by sand, ten Volvo PL4611 pipelayers stand alongside one another to carefully lower-in a section of the Bunde-Etzel gas pipeline into the freshly excavated trench. As the 12 tonne, 1200mm diameter pipe is lowered, a short, sharp, whistle blow carries above the engine noise and the machines’ booms halt. The whistle belongs to a spread manager standing at the side of the trench, orchestrating the lowering. At his signal the machines move, one by one, along the pipe to lower the next section.
The Bunde-Etzel pipeline in Northern Germany will be 60km long and operable in both directions, between the cavern storage at Etzel and the gas pipeline hub at Bunde – situated on the German- Dutch border. IVG Caverns GmbH, which operates caverns for both crude oil and gas in Etzel, is expanding its storage facilities and the new pipeline is needed to deal with the increasing demand for gas. It is expected to hold 4.5million Nm3/h.
A new concept
Ghizzoni S.p.A is the Italian contractor in charge of the project. Ghizzoni was commissioned by Bunde Etzel Pipeline (BEP) to complete the pipeline by mid 2011, for a contract value of 60 million Euros.
Ghizzoni has been operating in the pipeline industry for 60 years and has extensive experience of constructing and laying cross country pipelines for oil, gas, and water transportation.
Lowering and laying is the sole purpose of the Volvo pipelayers onsite. The machines work tirelessly for eight hours every day, accompanied by 10 Volvo EC290BNLC crawler excavators. The machines are currently inserting the pipeline in four different areas consecutively. Generators pump out ground water before the Volvo excavators dig a trench. Then the pipelayers stand in a row and lower sections of the pipeline into the ground. Water is then pushed through the pipeline to check for leaks, which can be fixed onsite if found, before the trench is covered over. “The lowering and laying by the Volvo pipelayers is excellent,” says Marco Scazzina, Construction Leader at Ghizzoni. “We can lower a1km long pipe in one go using 10 pipelayers at the same time.”
The Volvo pipelayers are different to the conventional side-boom track-type tractor pipelayer and Ghizzoni was keen to try the new concept. “The boom on the PL4611 can turn 360°, unlike the fixed boom on a normal dozer,” explains Marco. “This provides enormous flexibility, precision and better control for the operator in pipe placement.”
The Volvo PL4611 is based on the Volvo EC460C standard hydraulic excavator design, which makes the machine very versatile. “It can be disassembled easily and transported quickly, within the hour, by hydraulically lowering the counterweight and removing the track frames,” continues Marco. “This is important on such a big project because time is very precious,” he says. During the project the PL4611 can be transformed into an excavator, by switching the boom for digging equipment, enabling contractors more flexibility onsite.