The LHCb experiment is a single arm spectrometer, designed to study CP violation in B-decays and search for new physics in rare B-decays at the Large Hadron Collider (LHC). In such studies it is crucial to accurately and efficiently track the charged decay products in the high-density environment of the LHC. For this, the Outer Tracker (OT) was constructed, consisting of 55,000 straw tubes and covering an area of 360m2 of module layers. The detector is foreseen to operate under large particle rates, up to 100kHz/cm per straw in the region closest to the beam. Before and during installation the detector modules and Front End (FE) electronics have been extensively tested. The detector has been installed and commissioned with the help of cosmi...