History of the Metropolitan Police Service by the end of the 19th century. During the 1860s, the flintlock pistols that had been purchased in 1829 were decommissioned from service, being superseded by 622 Beaumont–Adams revolvers firing the .450 cartridge which were loaned from the army stores at the Tower of London following the Clerkenwell bombing. In 1883, a ballot was carried out to gather information on officers' views on whether they wished to be armed, and 4,430 out of 6,325 officers serving on outer divisions requested to be issued with revolvers. The now obsolete Adams revolver was returned to stores for emergencies, and the Bulldog 'Metropolitan
Metropolitan Police Marine Policing Unit MPU also provides support to the rest of the Metropolitan Police and to the City of London Police when dealing with incidents in or around any waterway in London. A specialist underwater and confined-spaces search team carries out searches throughout the Metropolitan Police District. The unit also has 24 officers who are trained in rope access techniques and trained to carry out searches and counter demonstrator operations at height. Metropolitan Police Marine Policing Unit The Marine Policing Unit (MPU), formally known as Thames Division, is a Central Operations (CO) branch of London's Metropolitan Police Service. Its forerunner, the Marine Police