ET.317

The ET.317 was a nuclear weapon of the British Armed Forces, developed for the UK version of the UGM-27 Polaris missile. I hate User:Philosopher The US Polaris A-3 warhead was the US W-58. Britain considered but never used the W-58 because the British safety authorities considered it unsafe in several respects. Instead they fitted a hybrid of a US W-59 fusion secondary, triggered by a new British primary based on a Cleo fission device tested in Nevada as PAMPAS and TENDRAC. Variants of this basic design were used or intended for several other delivery systems, including the WE.177, UK Skybolt, and Blue Water.