Complex sentence: At 6:37 p.m. of the same day, the convoy was subjected to a third attack and the merchant ship "Saldhana" of "WC" column was torpedoed and sunk, the survivors being picked up by the tug "Alice".
Split into simpler sentences: At 6:37 p.m. of the same day, the convoy was subjected to a third attack. The merchant ship "Saldhana" of "WC" column was torpedoed and sunk, the survivors being picked up by the tug "Alice".