The Saint Paul globe., 1897-09-28

signals is at stations and grade cross
iEgs.. In operating the system certain
stations are designated as staff sta-
tions, and one staff is furnished for
each section or block The staff is Of
metal about twenty inches long and
has the names of the two stations be-
tween which it authorizes the train
holding it to move engraved on its end.
On the other end is key. Each STAFF
station is furnished with staff instru
nent, containing ten or. more staffs. III
one instrument there is one permis-
! sive staff and six permissive tablets.
If the operator at Ravenna wishes
to send train across the bridge, he
asks permission of his colleague at
Sabula to withdraw a staff, using a
code of telegraph and bell signals. IT,
Sabula thinks it is all right for the
current to Savanna and unlocks the
instrument there. This enables the
Savanna man to withdraw staff,
which is handed to the conductor OF
the waiting train and by him to the
engineer, who places it in bracket on
the side of the cab and in full view
When the train reaches Savanna the
staff is handed to the conductor and
by him to the operator, who places it
IN his staff instrument. Until this: is
Gone 1t is not possible for a second
staff to be withdrawn from the instru-
ment, either at Savanna or SabuTa.
The mechanical arrangements are con-
trolled by electricity and it is absolute
ly impossible for any operator to tam
per with the instrument.
With this system the bridge dis
patcher has no responsibility except to
give the proper train the preference.
He may delay traffic, but he cannot
create condition of danger. There
are no train orders to be sent and
n n
cannot move as expected. The dis
patcher simply signals for staff, and
in five seconds the engineer has his
authority to proceed. If by any chance
the train should not be able to go for
ward, the staff. can be returned and
replaced in the instrument, enabling
the man at the other end to withdraw
one. When work train is to occupy
the block the delivery of a staff pro-
tects it in both directions, and no flag
man need be sent out
In working the instruments for per-
missive blocking the permissive staff is
withdrawn from the instrument in the
same manner as in the case of the
other staff, and used to unlock a block
containing six permissive tablets.
Each train to be sent forward permiS
sively is given a permissive tablet, the
last train taking the staff and the re-
remaining tablets. Until all the tab
lets have been locked in the tablet box
of one instrument or the other it is
impossible to place the pern1isSive staff
in either instrument.
If there are switches in the block
they are locked with staff lock, and
can only be opened with a staff. I'm
less the switch is set for the main
track and locked in that position the
staff cannot be Withdrawn from the
switch lock. If trainmen leave the
switch wrong they must do 50 by leav
ing the staff in the lock. Failure to
deliver the staff means that no other
staff can be taken from either instru-
ment = n engineer therefore knows
when he has a staff in his possession
that no switch can be wrong.
While the ordinary system of train
dispatching is admitted to be economi-
cal and satisfactory under ordinary
conditions, it has objections re.ating to
safety as well as facility which the ad-
vocates of the staff system claim are
overcome by their plan OF operation.