Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!brl-smoke!smoke!Swenson.PA@xerox.ARPA From: Swenson.PA@xerox.ARPA Newsgroups: net.railroad Subject: Re: VIA rail train collides head-on with freight. Message-ID: <1070@brl-smoke.ARPA> Date: Tue, 18-Feb-86 16:26:56 EST Article-I.D.: brl-smok.1070 Posted: Tue Feb 18 16:26:56 1986 Date-Received: Wed, 19-Feb-86 20:36:54 EST Sender: news@brl-smoke.ARPA Lines: 77 >2. Do American freights run on schedules? There are several different methods in common use of controlling the movement of trains on mainline tracks, as contrasted with yards. In very high traffec areas in the east, there are other systems using manual blocks & block operators. I am not familiar with these. Time Table & Train Order. The employees have a timetable, which lists all scheduled trains. The dispatcher can modify the timetable by issuing Train Orders, which are delivered to the trains involved by operators at various stations. Frequently only passenger trains are listed, with all freights running "Extra". On lines with no passenger trains, the timetable may only list the stations, miles to a specifice point, signal systmes in use, facilities at each station, number of tracks, etc. Timetable, Train Order & Automatic Block. The Timetable & Train Order system is supplimented with Automatic Block Signals. The signals provide added safety, but do NOT authorize train movements. Traffic Control Systems. TCS systems, such as CTC, Centralized Traffic Control, provide for operation by signal indicatiion which superseeds the timetable. The timetable is still used for passenger trains and also contains the other information listed above. Here the dispatcher has a track diagram in front of him which displays current train position, and has control of certain signals, usually the signals at each end of each siding, and usually also control of the siding switches. The dispatcher operates the signals & switches directly. TCS is useful on multiple track as well as signal track, since it enables the DS to easilly run trains in the same direction around each other, enabling a faster train to pass a slower one. Allowable speed. I think that the ICC rule is still in force which limits freight trains to 49 mph and passenger trains to 59 mph unless some form of block signaling is in use, and all trains are limited to 79 mph unless cab signals or some form of train stop system are in use. >3. Are there shut off levers (as on many (ALL?) subway systems) which throw > the break on immediately if a train runs a red light? (Otherwise, with > should the engineer have a heart attack, for instance, > the train would just keep rolling). The press is not yet indicating > whether such a system was in place on the freight, but it appears the > engineer was alone at the time of the accident. Cab signals provode the engineer with a current look at ths signals governing the block he/she is in. Cab signals are usually supplimented with speed limit control, which will prevent the train from exceeding the appropriate speed limit for the signal indication. Typical speed limits are 30 mph when running under "approach" signals (yellow) and 15 mph running under "stop & proceed" signals (red). Intermittent train stop usually sounds an alarm when the train passes a restricting signal, and unless the engineer acknowleges it, will stop the train. Many cab signal & train stop systems have been removed over the last 2 decades, since they are expensive to mantain and limit flexibility of locomotive assignment. (One time when I was riding the California Zephyr, the Western Pacific, D&RGW, Burlington streamliner, and a tunnel fire closed the WP Feather River Canyon line so the CZ was running over SP between Alazon (Winnemuca, Nevada) and Sacramento, Calif, the CZ had it's own 3 unit engine but the lead engine was a SP engine because the SP engine had train stop and the WP engines did not, and the lead engine was required to be equiped with train stop equipment.) Except for cab signals, none of the signaling equipment would do much to prevent a collision when one train improperly, presumably in violation of the rules, goes from a siding onto the main line, or fouls the main line, or goes from multiple track to single track, in front of a train moving in the other direction. About the only thing I know of that would help in these situations would be a derail operated by the signal system which would derail the improper move. The general opinion appears to be that derails on high speed lines would cause more dammage than the accident. Bob Swenson Former student of Railroading