Nuclear weapons and the United Kingdom the year. During Operation Hurricane, an atomic bomb was detonated on board the frigate anchored in a lagoon in the Monte Bello Islands in Western Australia on 3 October 1952. Britain thereby became the third country to develop and test nuclear weapons. This led to the development of the first deployed weapon, the Blue Danube free-fall bomb. It had a diameter, 32 explosive lens implosion system with a levitated pit suspended within a natural uranium tamper. The warhead was contained within a bomb casing measuring diameter and long, and it weighed approximately , of which about was high explosive. The
Residual-current device to the appliance. The test button (8) allows the correct operation of the device to be verified by passing a small current through the orange test wire (9). This simulates a fault by creating an imbalance in the sense coil. If the RCD does not trip when this button is pressed, then the device must be replaced. Residual-current and overcurrent protection may be combined in one device for installation into the service panel; this device is known as a GFCI (ground fault circuit interrupter) breaker in the USA and Canada, and as an RCBO (residual-current circuit breaker with overload protection)