摘要 |
A flexible mattress-like element usable as ballast or a load for immobilizing and protecting underwater pipelines, includes an outer flexible envelope, preferably made from a non-woven fabric, covering at least one gabion which is made from double-twist, hexagonal-mesh wire netting in the form of a somewhat-flattened parallelepiped and is filled with a mixture of stones or pebbles with a sand-, filler-, and bitumen-based mastic. The composition of the mastic is such that it is fluid at 150 DEG C. to 180 DEG C., semi-fluid at 100 DEG to 140 DEG C., plastic at 10 DEG to 50 DEG C., semi-plastic at temperatures of from 0 DEG C. to -10 DEG C., and tends to become rigid at temperatures below -10 DEG C. Each gabion is made from panels of netting in which the portions of wires which are twisted together are preferably arranged transverse the length of the gabion, that is, parallel to the axis of the pipeline to be immobilized and protected. |