SS Shieldhall is a preserved steamship that operates from Southampton. She is the largest operational historic steamship in Europe and one of the last reciprocating steam engined ships built, using technology that dated back to the last quarter of the 19th century and which was obsolete at the time of her construction. She spent her working life as one of the "Clyde sludge boats", making regular trips from Shieldhall in Glasgow, Scotland, down the River Clyde and Firth of Clyde past the Isle of Arran, to dump treated sewage sludge at sea. These steamships had a tradition, dating back to the First World War, of taking organised parties of passengers on their trips during the summer. SS Shieldhall has been preserved and offers cruises to the paying public.