She was 30.48 meters (100 ft 0 in) long and displaced 229.7 metric tons (226 long tons; 253 short tons) while surfaced and 248.9 metric tons (245 long tons; 274 short tons) while submerged. An experimental design, U-1 included unique features such as a diving chamber and wheels for traveling along the seabed. Originally powered by gasoline engines for surface running, sea trials throughout 1909 and 1910 showed these engines to be incapable of reaching the submarine's contracted speed and to pose a risk of poisoning the crew.