US Patent 9506218 Underwater trenching apparatus

An underwater trenching apparatus comprising a soil cutting arrangement having a forwardly disposed cutting portion and a rearwardly disposed non-cutting portion, a soil removal device configured to remove soil from a location forward of the soil cutting arrangement and barrier device located and configured substantially to prevent passage of soil to the non-cutting portion of the soil cutting arrangement. The soil cutting arrangement is typically a rockwheel or chain cutter. The soil removal device is typically a dredge pump or eductor.