Devon Fire Brigade was formed in 1973, by the amalgamation of Exeter City Brigade, Plymouth City Brigade and Devon County Brigade. It became Devon Fire and Rescue Service in 1987. The Service's main headquarters is located at Clyst St George near Exeter. Its main training centre is the Service Training Centre (STC) at Plympton fire station. The Service employs approximately 1,850 staff, including 578 whole time firefighters and 36 control room staff, 930 retained firefighters and 300 non-uniformed staff. Each county operated its own control room until 2012 but they now have a single control room at Service Headquarters, Exeter. The fire service operates 85 fire stations, which is the second most in an English fire service after those of the London Fire Brigade. Pods:   Trailers  Urban search & rescue (USAR):   Modules:   CBRN response:   Devon and Somerset Fire and Rescue Service works in partnership with South Western Ambulance Service to provide emergency medical cover to areas of Devon and Somerset. These are areas that have been identified as having a greater need for ambulance cover. The aim of a co-responder team is to preserve life until the arrival of either a rapid response vehicle (RRV) or an ambulance. Co-responder vehicles are equipped with oxygen and automatic external defibrillation (AED) equipment. Co-responder stations have a dedicated vehicle for co-responder calls. The vehicle, known as the emergency response unit (EMS), attends in place of the fire appliance (providing there are enough crew members still on duty), allowing the fire appliance to remain available. Nineteen stations operate as co-responders:  The M5 motorway is the arterial route through Devon and Somerset. It is the main link road to the south west from the Midlands and the North. Devon and Somerset Fire and Rescue Service divide the M5 into sections so that the nearest appliances attend. The station grounds are:  HMNB Devonport Dockyard, in Plymouth, is home to twenty one of the Royal Navy's fleet of ships and submarines. The dockyard falls into the station ground of 48 Camels Head, and is backed up by 49 Crownhill. Each part of the dockyard is divided into risk areas; this then reflects in the level of attendance by the Fire Service. Some parts of the dockyard are considered a very high risk and therefore attract a high attendance, sometimes as many as four pumping appliances and the aerial ladder platform are mobilised to a fire alarm actuating, in contrast to one pumping appliance to a town dwelling.