| 摘要 |
<p>Apparatus for producing a trench in an irregular terrain comprising a plough having plough shares (10) and supporting skids (5). Control means control the distance between shares and skids to control the trench depth (D). The terrain is surveyed along the intended trench route and information from the survey is fed to the control means enabling the plough to react to irregularities in terrain in advance to reduce the effect of those irregularities. Thus, for example, the variation in trench profile may be spread over a longer distance (L1) to reduce the impact of a hump of height (H) in the terrain. This in turn reduces the possibility of upheaval buckling of a flowline placed in the trench. <IMAGE></p> |
