Brunel, who prior to commencement of service had substituted a six-bladed "windmill" design of his own for Smith's proven four-bladed propeller design, now decided to try to improve the speed by riveting an extra two inches of iron to each propeller blade. On her next crossing to New York, carrying 104 passengers, the ship ran into heavy weather, losing a mast and three propeller blades. On 13 October, she ran aground on the Massachusetts Shoals. She was refloated and after obtaining a supply of coal from the American schooner "David Coffin" resumed her voyage. After repairs in New York, she set out for Liverpool with only 28 passengers, and lost four propeller blades during the crossing. By this time, another design flaw had become evident. The ship rolled heavily, especially in calm weather without the steadying influence of sail, causing discomfort to passengers.