The Thames Ironworks and Shipbuilding Company, Limited was a shipyard and iron works straddling the mouth of Bow Creek at its confluence with the River Thames, at Leamouth Wharf (often referred to as Blackwall) on the west side and at Canning Town on the east side. Its main activity was shipbuilding, but it also diversified into civil engineering, marine engines, cranes, electrical engineering and motor cars.
The company notably produced iron work for Isambard Kingdom Brunel's Royal Albert Bridge over the Tamar in the 1850s, and the world's first all-iron warship, HMS Warrior, launched in 1860.
The company originated in 1837 as the Ditchburn and Mare Shipbuilding Company, founded by shipwright Thomas J. Ditchburn and the engineer and naval architect Charles John Mare. Originally located at Deptford, after a fire destroyed their yard the company moved to Orchard Place in 1838, between the East India Dock Basin and Bow Creek. There they took over the premises of the defunct shipbuilders William and Benjamin Wallis.
The firm did well and within a few years occupied three sites covering an area of over .
Ditchburn and Mare were among the first builders of iron ships in the area; their partnership commenced with the construction of small paddle steamers of between 50 and 100 tons, before progressing to cross-Channel vessels and by 1840 were building ships of more than 300 tons. The company's early customers included the Iron Steamboat Company and the Blackwall Railway Company, several paddle steamers being constructed for the latter, including the Meteor and the Prince of Wales, which operated between Gravesend and the company's station on Brunswick Wharf.
In this period the company was also awarded several contracts by the Admiralty, including HMS Recruit (a 12-gun brig) which was one of the first iron warships built. They also constructed the P & O Company's steamers Ariel and Erin, along with the paddle steamer for Prussia.
Thomas Ditchburn retired in 1847 and the business was carried on by Charles Mare, under the name of C.