Complex sentence: The Ottomans began a reconstruction program, but the four "Osmaniye"-class ships were found to be not worth rebuilding a second time, and so all were ultimately decommissioned in 1909.
Split into simpler sentences: The Ottomans began a reconstruction program, which was to have included the four "Osmaniye"-class ships. But the ships were found to be not worth rebuilding a second time, and so all were ultimately decommissioned in 1909.