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 During the 1860s, the flintlock pistols that had been purchased in 1829 were decommissioned from service, being superseded by 622 Beaumont–Adams revolvers firing the .450 cartridge which were loaned from the army stores at the Tower of London following the Clerkenwell bombing.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 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 Force, was England's first recognised preventive police unit. The MPU is headquartered on Wapping High Street, in the east of the city, from where it operates a fleet of vessels responsible for policing the River Thames within Greater London. Thames Division was formed in 1839 when the Marine Police Force was absorbed into the Metropolitan Police Force. The original marine force is considered the first preventive police unit in