In principle, there are two kinds of landfills, the dump-type and the pit-type. In the pit the seeping water must be piped to the shafts which are also placed in the waste. The effects on the shafts which are caused by the settings in the waste of up to 40%, destroy every normal shaft construction. Therefore the TNS developed the so-called telescopic shaft about 20 years ago. Here the individual shaft elements are stored flexibly and can move with the waste object.
Usually the shafts have a diameter of 2000 mm or more because the maintenance must be carried out in the shafts. On the bottom of the shaft there are pumps for the transport of the seeping water as well as the entrances to the lechate pipes which have to be cleaned in regular distances. The telescopic shafts allow construction heights of up to 100 m in the waste object. The landfill site Mechernich at Cologne is a reference in this extremely difficult installation case.
Nowadays our PROFILEEN® telescopic shafts are found in all pit-type disposals of the Federal Repuplic Germany and with the adaption of the European norms and quality standards more and more neighbouring countries also consider this innnovative product by planning the landfill sites. Telescopic shafts can also be integrated into the existing dumps later so that the quality of old landfill sites can be improved considerably. Such projects were carried out by us on a large scale in England in the last few years.