Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.PCS 1/10/84; site mtgzz.UUCP
Path: utzoo!watmath!clyde!cbosgd!ihnp4!houxm!mtuxo!mtgzz!jis1
From: jis1@mtgzz.UUCP (j.mukerji)
Newsgroups: net.railroad
Subject: Re: Signals and Safety
Message-ID: <1680@mtgzz.UUCP>
Date: Wed, 19-Feb-86 08:59:52 EST
Article-I.D.: mtgzz.1680
Posted: Wed Feb 19 08:59:52 1986
Date-Received: Thu, 20-Feb-86 07:34:55 EST
References: <6389@utzoo.UUCP> <3236@umcp-cs.UUCP>
Organization: AT&T Information Systems Labs, Middletown NJ
Lines: 42

> Richard Snell asks:
> 
> >1. Does Amtrak share tracks with freights?
> 
> Outside of the NE Corridor, yes.  The electrified section of the Corridor
> has parallel freight trackage.
> 

Actually, on most of the New York - Washington DC section, Amtrak does share
its own track with freight trains. For example Conrail runs upto 6 freight
trains a day between Oak Island NJ and Enola PA (OIENs) over Amtrak tracks
between Harrison NJ and Trenton NJ. Similarly, Conrail freight uses Amtrak
tracks between Havre-de-Grace MD and Landover MD (just outside Washington
DC). There also is some freight traffic on Amtrak between Philadelphia PA
and Wilmington Del.

> >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.
> 
> Such devices exist, but I'm not sure about how widespread is their usage.

On the North-East Corridor, where cab signalling is extensively used, if a
train enters a section that is more restrictive and the driver does not take
adequate corrective measure within a short time (few seconds) the train
comes to a dead stop on its own. The driver cannot intervene once the
auoto-stop mechanism has been triggered. S/He can reset the mechanism only
after the train has come to a standstill and then proceed. 

There is a dramatic illustration of this feature in one of the Metroliner
Videos that I saw sometime back. Apparently the train passed into a section
where it was supposed to slow down to 50mph from the 120mph that it was
doing, and the driver failed to do so fast enough, and indeed, the train
came to a complete standstill, the controller immediately called up the
driver over radio and asked him what had happened, and the driver explained
that he had tripped the governer (speed governer?) and that he wuould be out
of the way very soon.

Jishnu Mukerji