Line Blockage Guidance for Signallers, COSS, IWA, PC & Planners

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Line Blockage Guidance for Signallers, COSS, IWA, PC & Planners
Line Blockage Guidance for Planners
Operational Close Call Line Blockage Group
24-Mar-14 /
Rule Book and Standards Guidance
Guidance to Signallers Rule Book TS1
Guidance to IWA/COSS/PC Handbook 8
Guidance to Planners NR/L2/OHS/019
Following a number of issues of interpretation that of have resulted in
confusion between Signallers, Track workers and Planners regarding
the “correct” signals to be agreed during the process of taking a line
blockage . This subject has been discussed at the National Operational
Close Call Line Blockage group.
The intention is to produce further guidance for all groups that is
acceptable across the three disciplines.
Attached are three briefings, one for each group giving guidance on
what is expected when planning a line blockage, requesting a line
blockage and granting a line blockage
Above all, the underlying principle is making sure that the correct
protection is given to the track workers and that signallers and planners
are supported in the decisions they are making.
24-Mar-14 /
Principle of a Line Blockage
What does the Planner, Signaller, IWA, COSS or PC need to understand when planning,
requesting or granting a line blockage?
Where is the work activity taking place?
•This should include the access to the site of work and any protection requirements.
•Which lines will be affected during the work activity?
How will the activity be protected?
•What signals will be used to protect the activity? (a protecting signal must be identified for each
line that will be affected by the work) e.g. Diagram 1 – Up Main L6 Diagram 2 AB4-AB19
•What other signals will be kept at danger to protect any route that leads towards the line
blockage? e.g. Diagram 1 – Up Branch L8 Diagram 2 AB6-AB8-AB21
•What points need to be set so that trains can be signalled normally on unaffected routes?
(away from the line blockage) e.g. Diagram 2 – Up Main AB15
Will the safety of the line be affected and what additional protection would be required?
•Agreement by all parties what additional protection is going to be used.
24-Mar-14 /
Guidance – the Rule Book states:
If a request for a line blockage is received by the signaller
you must agree with the IWA, COSS or PC:
the line to be blocked
the nature of the work
the locations between which
the work will take place
the amount of time needed to
do the work
the time after which permission
can be given for the line
blockage to start
 which signals will be kept at danger to
protect the activity
 any additional protection needed if
the work will affect the safety of the
 the arrangements if single line
working is taking place
 the arrangements at any level
crossings affected by the line
What does this mean to a planner when they receive a request for a
line blockage?
24-Mar-14 /
Planner Guidance
The Planner must prepare a plan that clearly identifies;
which running lines are affected by the work
► the precise location of the work to be undertaken
► The protecting signals for the work
The Planner must make sure that the submitted plan is approved through
publication in the WON, Signal Box Instructions or Signallers GZAC Daily List
(Status of Accepted or With Changes in SSOWPS2)
The Planner must issue the safe system documentation pack to the
IWA/COSS/PC at least a shift in advance
The Planner must make appropriate amendments to plans in response to valid
feedback being received
The Planner should refer to other submitted plans for Line Blockages so they
avoid independently applying for blockages where others have already applied
(consider PC option if appropriate).
20-Mar-14 /
GZAC Guidance
The GZAC (current title Possession Support Assistant) shall receive and
process all line blockage applications received into Green Zone Planner (via
SSOWPS2 or Directly input) to check that they;
Clearly identify the location of work
► Clearly identify a valid protecting signal for each line affected by the work
► Do not clash with WON published items, agreed Signal Box Instructions or
other applications in the system
► Do not cause Signaller work load limits to be exceeded
The GZAC should try to facilitate different work groups sharing line blockages
under a PC by directing different Planners towards each other
20-Mar-14 /
Diagram 1 Simple Line Blockage
The COSS rings the signaller and requests a line
blockage of the Up Line from signal L 6 to L4, the
COSS will then request a line blockage of the Down
line from signal L 3 to L5.
SSOW plan will show Signals L 6 to L4 & L3 to L5
Up Branch
Down Branch
Up Main
Site of
Down Main
The Signaller and COSS will have a safety
communication and agree that Signals L8 and L1
will also be held at danger for the protection of the
work group
Up Branch
Down Branch
20-Mar-14 /
IWA/COSS/PC Guidance
The IWA/COSS/PC shall receive a safe system of work pack including an
RT9909 and RT3181 that;
Clearly identifies the location of work
► Clearly identifies a protecting signal(s) for each line affected by the work
The IWA/COSS/PC should receive the pack for Verification at least a shift in
The IWA/COSS/PC must check that the protecting signals stated on the pack
actually provide protection for the work to be undertaken on the running line (s)
During the safety conversation with the Signaller record on the RT3181 &
repeat back the details of all/any other signals maintained at danger by the
20-Mar-14 /
Diagram 2: Bi-directional lines & working clear of points
AB 6
AB 8
Location of COSS
AB 21
AB 4
AB 19
Up Main
Site of Work
Signals the COSS will quote that protect the site of work Reversible
Down Main
AB 11
Following safety conversation, agreed signals held at red
AB 15
AB 17
Points are set and maintained for the down main signal
used as normal for that route.
Signaller will expect the IWA/COSS/PC to identify where they are working and what signals on that
line are required as protection. (Signals highlighted in Red)
The Signaller and IWA/COSS/PC will have a safety conversation that will agree which signals will be
kept at danger to protect the activity (Signals highlighted in Blue)
Also what Signals can be used as normal, this may include maintaining a set of points in a specific
position, for routes that do not affect the site of work. (Signals highlighted in Green)
20-Mar-14 /
Guidance - IWA/COSS/PC RT3181 contents
The IWA/COSS/PC, have an RT3181 form where the columns in Section 2 – Blocking the Line
are currently headed as shown below…
It is completed to the convention illustrated
(Uni directional line)
Running Line A
Running Line B
From Controlled Signal
From C/O Points
To defined Exit location
From Controlled Signal
To defined Exit location
From Controlled Signal
To defined Exit location
From Controlled+BiDi Sig
To defined Exit location
From Controlled+BiDi Sig
(BI directional line)
Running Line C
Running Line D
From Controlled Signal
From C/O Points
Provided that the actual work mileage area is totally within the limits shown on the RT3181 – the
arrangements can be implemented during the safety conversation.
The Signaller will determine any other signals to be maintained at danger or routes to be set with
appropriate reminder devices fitted during the safety conversation.
20-Mar-14 /
Closing Slide
20-Mar-14 /
Fly UP