A reliable downhole acoustic telemetry system with increased data rate is disclosed. The output signal is a reference voltage. A document search unit of a search machine provided on the server side forms a keyword from the file contents transmitted from the search condition designating unit and searches similar documents from an index in a search database. The blind fastener installation tool also comprises an optional fastener delivery assembly, said optional fastener delivery assembly constituting: a clip-fed fastener delivery system; or a blowline-fed fastener delivery system. If an operations system core IO device bridge fails, an FWD data copy processing unit copies the FWD data to an FWD of a standby system core IO device bridge; and a system is rebooted after an operations bridge switchover processing unit switches OFF the operations system core IO device bridge and switches ON the standby system core IO device bridge. A heat exchanger can draw air from the compartment and cool the air for use in the cabin of the marine vessel.