Soil Machine Dynamics was founded in 1971 and is a privately owned engineering company based in the North East of England specialising in the design and manufacture of vehicles and support equipment for operation on the seabed.

Founded by Dr Alan Reece, SMD's origins were in agricultural engineering related to earthmoving activities. In the early 1970's, the North Sea oil industry required the development of seabed geotechnical knowledge, together with theoretical analysis of the particular problems encountered in earthmoving activities underwater.

This led SMD to develop a range of ploughs for trenching oil and gas pipelines, and subsequently backfilling the trench with the ploughed soil to cover and stabilise the pipeline and provide thermal insulation. Currently these machines weigh up to to 140t, requiring tow forces up to 300t. The complete plough and all support systems are designed and manufactured by SMD.