"I'll go back to the engine and see what's going on ..."

I stumbled over the railroadradio.net Web site a while ago. This is a collection of various radio receivers across the country and Canada providing audio streams of the communication between locomotive engineers and their respective dispatchers. The link above goes directly to the Caltrain page, which is a very busy railroad, so there are a lot of conversations going on. The sound quality of the radio transmissions varies a lot, some are extremely clear, others are choppy and very hard to understand.

On a late Tuesday evening one can hear three active trains: southbound 194 and 196, as well as northbound 197. One hears the engineers announcing arrival at stations, asking and getting track authority, as well as more unusual stuff like setting blue flag protection at San Jose Diridon, people walking on the tracks, or an engine failure of train 197 in Redwood City. "I'll go back to the engine and see what's going on there". 10 minutes later he comes back on, reports that "HEP is down, but the main engine is running again" and then asks for authority to proceed to San Francisco with the engine doors open. The HEP (head-end power generator) provides power for the cars. I.e. 197 is currently running dark with no lights, or air conditioning in the cars.