Phase 1 upgrade of the CMS forward hadronic calorimeter

The CMS experiment at the Large Hadron Collider at CERN is upgrading the photo- detection and readout system of the forward hadronic calorimeter. The phase 1 upgrade of the CMS forward calorimeter requires the replacement of the current photomultiplier tubes, as well as the installation of a new front-end readout system. The new photomultiplier tubes contain a thinner window as well as multi-anode readout. The front-end electronics will use the QIE10 ASIC which combines signal digitization with timing information. The major components of the upgrade as well as the current status are described in this paper.