| 摘要 |
<p>An underwater trenching apparatus 10 comprises at least one trenching tool (14, fig 2); an lif attachment point 48 configured for lifting & lowering the trenching apparatus to, or from, its location of operation; at least two steerable, by actuators 44a (& 44b, fig 2), endless track units 16a-d for transmitting tractive effort to move the underwater trenching apparatus in use; and for each steerable endless track unit, a first mounting arrangement 28 permitting rotation of the track unit about a vertical axis, and a first actuator configured to move the track unit about the vertical axis 36, and control means configured to control the action of the actuator. In alternative forms, in addition to, or alternative to the steerable endless track units, the apparatus includes height adjustment means 26 for adjusting the vertical spacing between the main body portion and the respective endless tracks; and control means configured to control the action of the height adjustment means.</p> |
