discuss these two parts, some of the rules governing makeup and use
of the timetable, and the authorized abbreviations that may appear on
it.     First,   however,   the   following   subparagraphs   explain   some   of   the
important aspects of the application of timetable rules.
a. When   timetables   take   effect.     The   effective   date   of   a
timetable   is   listed   on   it,   and   at   0001   hours   on   that   date   that
timetable supersedes the previous timetable.   All trains operating on
schedules   not   provided   for   in   the   new   timetable   will   secure   valid
authorization   from   the   dispatcher   to   continue   their   runs   and   go   as
extra trains.
b. Schedules.     If   a   train   running   late   will   tie   up   the   railroad
or   create   a   safety   hazard,   a   train   order   is   issued   to   each   train
affected   by   the   running   of   the   late   train,   designating   how   late   it
will be at each station on the line.   The rules of train superiority
will be in effect throughout the run of the late train.  It will keep
its same class unless a train order is issued annulling its schedule.
When a train is running so late that it affects the entire rail line,
its   schedule   may   be   annulled   by   train   order.     After   a   schedule   is
annulled, the train can then move to its destination as an extra.
c. Times.     The   timetable   schedule   lists   all   regular   trains   by
number,  class,  and  direction,  gives  the  leaving  time  for  each  at  the
original   station,   and   gives   the   arrival   time   for   each   at   its   final
destination.     When   a   train   leaves   a   station,   the   schedule   for   that
train is in effect.
d. Train   meeting   and   passing.     On   a   singletrack   division,   most
trains   meet   and   pass   at   designated   stations.     These   stations   are
shown   on   the   timetable   in   fullfaced   type   (darker   and   heavier   type
than that used elsewhere in the body of the timetable).   When one or
more   trains   are   to   meet   or   pass   another   train   at   a   station,   their
numbers are shown in small type beside the meeting or passing time.
e. Timetable   changes.     Changes   to   the   timetable   are   made   by
issuing   a   new   timetable,   by   timetable   bulletin,   or   by   train   order.
When   minor   or   temporary   changes   to   the   timetable   are   necessary,   a
timetable bulletin is issued or a train order is given.  Generally, a
bulletin makes changes in the special instructions; train orders make
changes   in   the   scheduled   movement   of   trains.     If,   for   example,   the
speed   limit   over   a   certain   section   of   the   division   needs   to   be
reduced for safety from 55 kph to 30 kph, this change to the special
instructions   of   the   timetable   is   made   by   a   timetable   bulletin.     On
the   other   hand,   if   the   schedule   of   one   regular   train   needs   to   be
annulled 
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