| 摘要 |
<p>To facilitate the inspection and repair of the interior of ships' hulls or of large fuel storage tanks, a permanent pylon is fitted inside the hull or tank. The pylon has a stub shaft at each end which runs in bearings. The pylon supports a horizontal platform which can be moved up or down to any desired position. The platform carries a horizontal girder which can be assembled from sections to any required length. In addition, the girder can be moved horizontally and also the end section can be swung to the upright position.</p> |
