| 摘要 |
<p>The broad suction head has a narrow slotted aperture. Pressurised water nozzle jets bring the soil bottom to be worked into a fluidised state. This enables the suction head which is slowly longitudinally moved, to provide a smooth soil surface, free from ridges. The anchored vessel has a winch arrangement so that the cable can be paid out slowly to give controlled working of the surface. The pontoon has two stem propellers, rudder, and bow-fitted propeller to provide better steering control at slow speed.</p> |
