Mayflower is a steam tug built in Bristol in 1861 and now preserved by Bristol Museums Galleries & Archives. She is based in Bristol Harbour at M Shed (formerly Bristol Industrial Museum). She is the oldest Bristol-built ship afloat, and is believed to be the oldest surviving tug in the world. Building Mayflower was built by GK Stothert & Co, who were connected with the Bath-based engineering company Stothert & Pitt. A branch of the family came to Bristol to build railway locomotives (later to become the Avonside Engine Company). After 1852, a separate shipbuilding company was established which survived in business until the 1930s. The tug has an iron hull. She is long, her beam is , her depth is and her tonnage is . Her United Kingdom official number is 105412. Service Mayflower was built to work on the Gloucester and Sharpness Canal and in the River Severn, one of three tugs ordered after trials had shown they were much more efficient than horse-drawn boats. Altogether they cost £3,000. Mayflower started work between Sharpness and Gloucester Docks, towing trains of small sailing vessels such as trows and ketches, and, after the new docks at Sharpness were completed in 1874, larger steamers one at a time. By the late 1890s she was the most seaworthy tug in the fleet, and she was altered to make her suitable for work in the Bristol Channel. Her original single-cylinder engine was replaced in 1899 with a vertical two-cylinder compound condensing engine supplied, along with a new boiler, funnel, propeller and shafting by W Sisson & Co of Gloucester for £940. The steering position, which had previously been abaft the funnel, was moved forward, and a waist high iron steering shelter added to give the skipper some comfort. She went back to work outside Sharpness, towing sailing vessels through the dangerous stretches of the Severn Estuary to the mouth of the river Wye and back again. Around 1907, the Canal Company decided to compete on the River Severn upstream of Gloucester to Worcester. In 1909 Mayflower was again altered when the funnel was arranged to hinge down (counterbalanced with large weights which can still be seen) to enable her to pass under the fixed bridges on this stretch of water. She was now capable of working on every part of the navigation from Worcester to Chepstow, and because of this, became regarded as