The Gelugor transportation system is a 24'' gas pipeline from the Tenaga Nasional Berhad (TNB) Prai Power Station, Mainland Peninsular Malaysia across the Strait of Pinang to the TNB Gelugor Meter Station on Pinang island. The pipeline has a length of 6.4 km and was put into use in the beginning of 2000. Boskalis Offshore has constructed the protection of the pipeline with rock material. The function of the protection differs along the chainage of the pipeline. A shipping channel is situated between the island and the peninsular. The pipeline in the shipping channel has been covered for to protect against ship anchors (drop and drag).
Outside the shipping channel, the pipeline is partially protected to secure the stability of the pipeline. Furthermore, the protection serves to limit the length of the possible freespan to an acceptable length. Spanning of a pipe can be caused by morphological changes of the seabed. The preparations of constructing the protection started in the beginning of January 2001; the rock dumping started in the beginning of February. The environmental conditions, limited time span and life pipeline made the project more complicated.
Caused by tidal variations, the occurring current velocities reached levels of upto 2.0m/s. The water depth along the chainages varied from 0 to 16 meters. A high voltage cable (132kV) was already constructed along the gas pipeline and in use. Precautions were required that the anchors did not damage the high voltage cable. The limited time span of the project was set by the Client to diminish the risk of damaging the pipe. Furthermore, damage of the life pipeline would have heavy impact on the ecological environment. These conditions required accurate rock dumping and tailored working methods.