The backfill blade is used for grading, leveling, backfilling, trenching, and general dozer work. Deeper placer deposits may be sampled by trenching or drilling. Alternatively, the soil excavated from the seabed during trenching can be used as backfill. A tractor-mount trencher is a trenching device which needs a creeping gear tractor to operate. These ROVs can also be used for dredging, trenching, and jetting tools. A trenching excavator bucket is normally wide and with protruding teeth. The tractor should be able to go as slowly as the trencher's trenching speed. As an alternative to trenching, loops may be laid by mini horizontal directional drilling (mini-HDD). The vessel can also be equipped with a 120-ton A-frame for trenching machines and ploughs. It will be laid by using Capjet trenching system and the cable-laying vessel "Skagerrak". He recommends trenching to investigate veins beneath the surface. Another technique that is useful is contour trenching. Some of surface trenching was also completed during the year. The instrument performed 16 bearing tests, seven trenching tests, and two impact tests. The short handled Manvetti is widely used in wet lands for trenching, bunding etc.