The number and efficiency of the submarines rose rapidly in the course of the war; in considering numbers, however, one must always remember that in wartime, U-boats are to be reckoned as follows: One third of the total in active service, one third on the outward or return journey, one third undergoing repairs. The achievements of the U-boats aroused the admiration of the entire world and won the ardent gratitude of the fatherland. Admiral von Tirpitz's tremendous success in creating the commercial colony of Tsing-tao must never be forgotten. Here he gave proof once more of his brilliant talent for administration and organization in all directions. Those talents of his created, out of a place that was previously almost unknown and entirely without importance, a commercial center which, within a few years, showed a turnover of between fifty and sixty millions. The dealings with Reichstag members, the press, and big industrial and world-commercial elements gradually increased the Admiral's interest in political matters, particularly in foreign affairs, which were always bound up with the utilization of ships. The clear world-vision acquired by him as a traveled sailor, well acquainted with foreign parts, qualified Tirpitz to make quick decisions, which his fiery temperament wished to see translated promptly into action. The opposition and slowness of officialdom irritated him greatly. A certain tendency to distrust, perhaps strengthened by many an experience, often misled him to harbor suspicion--sometimes justified, sometimes not--against individuals. This caused a strong tinge of reserve in Tirpitz's character and "hampered the joyful workings of the heart" in others. He was also capable of bringing to bear new views on a matter with great decision, when, after renewed reflection or study of new facts, he had altered his previous view. This made working with him not always exactly agreeable or easy. The tremendous results of his achievements, of which he was justly proud, gave him a consciousness of the power of his personality, which sometimes made itself apparent even to his friends. During the war Tirpitz's tendency to mix in politics got the upper hand with him so much that it eventually led to differences of opinion which finally caused his retirement, since von Bethmann, the Imperial Chancellor, demanded the dismissal of the Admiral-in-chief with the observation that the Imperial Secretaries of State were his subordinates and that the political policy must be conducted by himself alone.