LOCO LINK
Loco
link is an arrangement of locomotive for working a set of trains from one station
to other station for Mail/Express/Passenger trains. Loco link gives the requirement
of locomotive required to run the given number of trains. Loco link is prepared
by HQ office in consultation with COM.
Factors to be considered while preparing a loco link:
1)
Availability of the Loco.
2)
Trip Inspection:
Mail/Express
or Passenger locomotives are required to be given trip inspection
as under as per AC traction manual:-
Therefore,
loco link has to be prepared in such a way that the trip inspection is done as
per the yardstick and no loco runs overdue trip inspection in the link. Loco
link should
have the provision of the trip inspection at suitable interval.
3) Lie over period at destination station:
When
a loco completes its journey after working a train, this loco is sent to yard,
trip shed etc. This loco is again attached to the train as per the link. The period
for which it remains idle at destination station (i.e. the time period when loco
isdetached
and again attached to train) is known as lie over period of the locomotive.
given
to locomotive. Therefore, lie over period of locomotive is a loco link will depend
on the following:-
A) Lay out of yard and location of trip shed :
If
the locomotive is to be given trip inspection during the lie over period, the time
(T) to be available during the lie over period should be as under:-
T = Time
taken for trip inspection (Tt) + Time
required for movement of loco from
station to trip shed and back (Tm)
Generally,
the time required for trip inspection is 2 hours to 2 hour 30 minutes. However,
time is also taken to attend the drivers booking regarding loco defects.
On an
average, it is seen that one hour time will be required to attend to various
types of defects
booked by drivers. Therefore, for trip inspection, time to be given is about 3’30”
to hours considering the practical working in trip shed. Sometime, when loco arrives
in trip shed, staff may be busy in dealing with the problem of other loco. In that
case, loco has to wait. Therefore, allotting a time of 4 hours for trip shed in case
of
trip inspection to be done is quite reasonable and practical.
Similarly,
some time will be taken for movement of electric locomotive from station
to trip shed. Again this time will vary from one destination to other.
Generally,
trip sheds are located in the yard in such a way that loco can be moved from
station to trip shed within 30” time. However, due to variation in yard lay out and
other operating condition trip sheds are to be located far away from station where
engine is detached. In such situation, the time taken to move the loco from station
to trip shed may be as high as two hours.
B) Whether destination in a terminus :
Moreover,
if the destination of the train is CSTM or HWH or Madras etc. where
the railway track terminates, the locomotive at such station cannot be immediately
detached and sent to trip shed. Therefore, loco has to remain on station platform
till the rake is backed to washing siding in the yard after about 45” from the arrival
of the train. This aspect should also be taken into account while planning the loco
link.
Practical
example
Central
Railway locomotives are reaching HWH after working the train like 12151 Samrasta
Exp. As HWH is a terminus station and also the trip shed is located away from
station at Santaragachi S.E. Railway requires a lie over period of 10 to 12 hours for
trip inspection for the reason explained in above paras.
4) Consultation with other Railways/Divisions :
While
planning the loco link, other Railway or division (where the loco will be detached
and attention will be given) should be consulted for requirement of time for lie
over period. Similarly, trip inspection schedule should also be planned and place should
be nominated in the link.
5) Provision of Schedule Inspection (IA, IB or IC of loco) :
Loco
link should include the withdrawal of loco for monthly schedule after it has
worked for 35 to 40 days in the link. Withdrawal of the loco at Homing Shed station
should be planned in such a way that it suits the homing shed by way of working
hours for carrying out the schedule.
In
electric loco sheds, normally locos are placed for schedule inspection at about
2 to
3
hours in (0-8) shift of working. This helps the homing shed in carrying out complete
testing of locomotives by 8 hours. The staff in (0-8) shift will give complete detail
of unscheduled work to be carried out along with schedule work.
This
will enable the staff in day shift to carry out the work properly. Therefore, withdrawal
of loco to be planned by such trains which reaches homing station at about
0 to 1 hour so that loco reaches the homing shed just in time. Therefore, withdrawal
of loco to be planned while considering following points:
i.
When to withdraw the loco – By suitable train so that it reached homing shed station
at about 0 to 2 hours.
ii.
From which train to withdraw the loco - This
should also be decided judiciously after studying the working time table. there
are some trains where time allowance and running time is sufficient, such
trains can make up the loss of time which takes place while changing the engine
for withdrawing the same for such inspection. Generally, for changing the
engine 10” extra is taken for loco movement and vacuum creation. From
this link in fig. (shown Next page) , we find that for running trains between Igatpuri-Nasik,
Igatpuri-
Calculation of the requirement of engines:
The
loco link gives the bare minimum requirement of engines. Therefore, the actual
engine requirement will be as under:-
The
requirement of loco = Bare minimum requirement +
repair allowance.
The
repair allowance for Mail/Express locomotives is 9.2 statistical. Therefore, requirements
of locomotive will be :-
Bare
minimum requirement as per loco link 0.92
CONCLUSION
In
this subject, we have learned to draw loco link and also factors to be considered
for drawing a loco link. More practical should be done to draw loco links from
the Railway time table for better understanding.
Some example
