Temperature-stable protective pipes of the high-performance class LHT^®
Efficient cable entry with the WATUCAB method

The Serbian transmission system operator Elektromreza Srbije (EMS) needs to an aging high-voltage underground cable that supplies electricity to the government district in Belgrade. For this complex and future-oriented project, the renowned Serbian special construction company Kodar Energomontaža Ltd. and the European pipe manufacturer Gerodur were already involved in the planning phase. The planned cable route with a total length of 4 km leads from the substation in the south-east of Belgrade to the city centre and will be divided into individual subsections due to the infrastructural complexity of this city of over a million inhabitants. In order to meet the high thermal requirements during the subsequent operation of the power supply, high-temperature resistant protective tubes of the E-POWER system from Gerodur were used. These were laid in parallel as a triple bundle in the open trench. The high-voltage cables are then installed using the innovative WATUCAB method.
With this method, a pulling pig is attached to the cable, which is pushed through the pipe by water pressure, pulling the attached cable behind it. Due to the water filling of the protective pipe, the cable to be pulled in is driven up and thus causes significantly less friction on the pipe wall.
For this effective cable entry, pressure- and temperature-resistant EMDS protection tubes of the high-performance class LHT^® were therefore used and joined by means of heat element butt welding or electrofusion. Further project-specific E-POWER system components were used for the specific production of the protective pipe routes:
- E-POWER heating coil coupler made of temperature-stable PE-RT
- E-POWER pipe bends with bending radii 5 m to ensure continuous pig intake
The installation, joining and laying work was also supported by the provision of various machines and aids from the extensive GEROtool range (HS machines, HM automatic machines, etc.).