In 1810, specialised shipbuilding on the River Clyde began when the brig "Janet Dunlop" entered the water from the shipyard of William Simons in Greenock. Although he temporarily suspended work on the Clyde in1812 when he moved to Montreal, where his firm built 12 vessels, he returned to Greenock 6 years later. In 1826, he relocated to Whiteinch and thence to the Renfrew East Yard in 1860.
Eventually, after 150 years of experience and over 100 years of competitive rivalry, William Simons and Lobnitz & Company combined to form one of the world's leading organisations in the building of ships, dredges, and specialised marine and offshore equipment, creating a name synonymous with the industry, Simons-Lobnitz Limited, out of which emerged Seadrec.
Henry Lobnitz was born in Denmark and came to Britain to work as an engineer, initially at Greenwich and then later on the Clyde where he joined the staff of James Henderson & Son at their Renfrew West Yard in 1857. He was steadily promoted and eventually became a partner in the firm which became known as Lobnitz, Coulborn & Company and later Lobnitz & Company Ltd. Like the Simons shipyard, Lobnitz also specialized in building dredgers but with more of an emphasis on rock breaking and cutting capabilities.
In the later part of the 19th century, both companies produced increasing numbers of dredges, hopper barges, tugs and other specialised craft and by 1960 a total of over 1260 specialised vessels had been built.
The Weir Group took over Simons in 1957 followed 2 years later by the adjacent Lobnitz yard resulting in the two yards combining to form Simons-Lobnitz. Although the Renfrew yard closed in 1964, the shipbuilder, Alexander Stephens & Sons, acquired the name and continued to build further dredges under the name of Simons-Lobnitz at their Linthouse Yard.
Ultimately, Alexander Stephens with Simons-Lobnitz were absorbed into Upper Clyde Shipbuilders, but in 1969, due to their declared marketing policy to concentrate exclusively on the design and building of standard vessels, it was decided to safeguard the considerable knowledge gained in the field of dredging by forming an independent company, Seadrec Limited.
Seadrec is therefore founded on more than150 years of Clyde shipbuilding and commenced its life with the Executive Directors and the Technical Staff, expertise and background of their former companies, Simons-Lobnitz Limited and Alexander Stephens. Seadrec is considered the modern-day successor to the renowned Clydeside dredge building companies of Simons and Lobnitz.
Since its inception, Seadrec Limited has rapidly expanded its range of marine activities. In addition to undertaking major dredge and shipbuilding projects, it designs, builds and supplies an extensive range of dredges and associated craft from the International Class Suction Hopper Dredges carrying 14,000 tonnes of spoil through Bucket, Dipper and Grab Dredges to powerful Contractor Class Cutter Suction Dredges. In addition Seadrec supplies a range of dredging equipment, including their established range of dredge pumps.
In recent years, successful contracts have been implemented in Finland, Sweden, USA, Canada, Mexico, Cuba, India, Norway, Singapore and U.K.