News –

Drives ensure trenchless tunnel construction.

A new sewage tunnel is under construction in the capital of the United Arab Emirates. Drive solutions from NORD ensure safe transport of personnel and materials in the access shafts.

Bargteheide, 2019-04-19

Dubbed the underground project of the century, the new sewer construction in Abu Dhabi is gigantic — 40 kilometers, up to five meters in diameter, and 800,000 m3 waste water. The Strategic Tunnel Enhancement Program (STEP) is intended to meet the increasing demand for sewage disposal in the growing city. In an effort to minimize the inconvenience to residents during project, planners determined the tunnel construction had to be carried out without trenches and instead from tunnel shafts. This approach required lifting equipment with robust drive solutions that could operate almost without maintenance for more than two years and were capable of operating as synchronous pairs in order to lower personnel and materials over considerable distances of up to 90 meters.

The conveyor technology specialist ElectroMech from India utilized NORD expertise for this mammoth task. Over the years, the two partners have implemented several projects together. This time solutions based on heavy duty bevel geared motors were jointly developed for the main and auxiliary lifting equipment, which have an efficiency of more than 95% as well as a very high load capacity. Each crane was equipped with a pair of drums with two separate drive systems, each consisting of a geared motor and frequency inverter.

Automation of the entire system utilizes encoder signals to perfectly synchronize the two drums, so that there is no risk that the supply platform will become dangerously tilted. NORD inverters with field-oriented control work are used to ensure constant speeds and high starting torques even with varying loads. This enables loads to be positioned quickly and precisely.