'Longshanks' was the British raid, otherwise known as 'Boarding Party', against a German merchant ship moored, as a neutral, in the Portuguese enclave of Goa in western India (9 March 1943).
The operation was undertaken by members of the Calcutta Light Horse, a reserve unit of the Indian army and inactive since the Boer War (1899/1902), and the Calcutta Scottish Regiment, against the 7,752-ton Ehrenfels. The operation was organised by the India Mission of the Special Operations Executive (Force 136), and was long kept concealed to avoid the political ramifications of contravening Portuguese neutrality.
It was believed that Ehrenfels, lying at a berth in Mormugao harbour, was transmitting information on Allied ship movements to Axis submarines operating in the Indian Ocean. The British attempted to bribe the captain of the German ship to take his vessel outside Portuguese waters, where it could then be legally boarded by British forces, but this proved impossible as the vessel was no longer able to make way under her own power.
The definitive British operation was therefore based on the idea of 'cutting out' Ehrenfels and towing her into international waters. The raiding party embarked on the powered barge Phoebe at Calcutta and sailed round India to Goa, where some of Ehrenfels's men fired on the approaching British, and then set off demolition charges and opened the sea cocks as the British boarded the German vessel.
After Ehrenfels had erupted in a fireball and sank, British intelligence dispatched an open message over the wire falsely warning that the British were planning to seize Goa. This persuaded the crews of the other two German ships in Goa, the 6,342-ton Drachenfels and 7,847-ton Braunfels, already troubled by the destruction of Ehrenfels, to scuttle their own ships in Goa’s harbour to prevent their capture in the supposed invasion of Goa. The single Italian ship in the harbour was also scuttled.
The real need for the operation is suggested by the fact that Axis submarines sank 12 Allied ships in the Indian Ocean during the first 11 days of March 1943, and only one in the rest of the month.