One of the Royal Navy's opening moves in WWI was to cut a cluster of telegram cables leading from Germany to the rest of the world. A cable steamer, either the Telconia or (more likely) the Alert, hauled up five German telegraph cables running through the English Channel, and cut them. At a stroke, this removed Germany's main transatlantic telegraph route. A number of other cables, running to other European powers, were also cut or redirected into Allied hands. However, none of these cables were used to send the Zimmerman telegram. Instead, the encrypted note was passed to the American embassy in Berlin, which transmitted it overland to the American embassy in Copenhagen. From here, it was transmitted on a trans-Atlantic cable to the USA, and from there to Mexico. However, this trans-Atlantic route passed through a British relay station, at Porthcuno in Cornwall, where signals were boosted for the long journey across the Atlantic. It was trivial for the British to copy these signals, including the Zimmermann telegram, and they were in turn passed to the Admiralty's code-breaking department, Room 40. Here, they were analysed and broken.