| 摘要 |
<p>A method of deploying a cable or other line (34) in a fluid transportation pipeline (10) whilst in normal operation full of and transporting a fluid (12) under a positive pressure. A collapsible centralising device (62,64) is attached to the leading end of the cable (34) and is then fed in a collapsed state into the pipeline (10) via a first fluid sealing means (30) at the cable entry position (14). That device (62,64) maintains the cable end (34) centralised in the pipeline cross section whilst the cable (34) is fed into the pipeline (10). Magnetic sensing means (68,74,76) disposed near the cable exit position sense the presence of the cable end (34) and control the cable infeed so as to position the cable end (34) in a predetermined cable retrieval position. A tubular lance (54) is fed into the pipeline (10) through a second fluid sealing means (32) disposed at the cable exit position (16), and a grab (56) housed in the nozzle of the lance (54) is ejected to engage and capture part of the centralising device (62,64) and cable end (34), whereafter the grab (56) closes on being drawn back into the lance (54). The lance (54) is then withdrawn through the second fluid sealing means (32) so as to draw with it the grab (56) and the captured centralising device (62,64) and cable end (34).</p> |
