The problems with cables breaking were largely due to difficulty controlling the tension of the cable with the braking mechanism as the cable was payed out. A new mechanism was designed and successfully trialed in the Bay of Biscay with "Agamemnon" in May 1858. On June 10, "Agamemnon" and "Niagara" set sail to try again. Ten days out they found themselves in a severe storm and the enterprise was nearly brought to a premature end. The ships were top heavy with cable that could not all fit in the hold and struggled not to capsize. Ten sailors were hurt and Thomson's electrical cabin was flooded. The vessels arrived at the middle of the Atlantic on June 25 and spliced cable from the two ships together. "Agamemnon" paid out eastwards towards Valentia Island, "Niagara" payed out westward towards Newfoundland. Again the cable repeatedly broke. The first time after less than 5.5 km (three nautical miles), again after some 100 km (54 nautical miles) and for a third time when about 370 km (200 nautical miles) of cable had run out of each vessel.