Introduction
------------
The South Devon simulation encompasses the controlled area of Exeter Panel Signalbox 'A' & 'B' panels from Crediton and Stoke Canon southwestwards to Ivybridge, as well as that of three neighbouring smaller boxes at Exmouth Jn, Feniton and Paignton. The area was extensively MAS resignalled in the late 1980s, and the resignalled layout is the one reflected.

There are fringes with the older Plymouth Panel Signalbox in the west, Honiton Signal box in the east, Crediton Signal box in the north & with the Exeter 'C' panel (which controls from Tiverton Jn eastwards) to the northeast.

Interfaces also exist with two preserved lines, the South Devon Railway (Totnes- Buckfastleigh) and the Paignton & Dartmouth Railway (Paignton- Kingswear), as well as several freight or stabling yards.

The area covered extends to approx 105 route or 160 track miles, with approx 200 signals and 105 points & should therefore challenge even the most seasoned of operators.

Famous for I.K.Brunel's fabulous sea-wall along the Dawlish Coast, steep gradients west of Newton Abbot that challenge most trains, fabulous scenery, a short but very steep bank between Exeter St Davids & Central stations for which special operating methods apply, as well as a lengthy & very visible high-speed stretch of main-line alongside the M5 motorway, Devon's railways have much to offer both rail-enthusiasts and tourists alike.

The opening photograph taken from Red Rock is a GNER HST on hire to Virgin Trains traversing the Up Main line between Dawlish & Dawlish Warren (also known as Ladies Mile) with a summer Saturday cross-country service in August 2007.
 
Bi-directional & permissive working
-----------------------------------
Bi-directional working is available on the single line sections plus the Down Waterloo line between Exeter SD and Exeter Ctl and the Up Main between Dawlish Warren & Teignmouth (the latter not being scheduled for timetabled trains- as it exists as a contingency facility for weather related problems which occasionally close the outer Down Main line along the Sea Wall). All the platforms at Exeter SD and Newton Abbot are bi-drectional, and bi-directional working (some for reversing or shunting movements only) exists in certain platforms at Exeter Ctl, Dawlish Warren, Paignton & Totnes.

Permissive working is available for all platforms at Exeter SD (with the exception of trains from Exeter Central which can only be signalled into a clear platform at Exeter SD). Also it is available for non-passenger trains only at Newton Abbot.

Platform capacities at principal stations
-----------------------------------------
Figures in brackets indicate maximum number of vehicles, inclusive of loco(s):

Exeter St Davids
Pl.1  283m		(14)
Pl.2  102m		(5)
Pl.3  276m		(13)
Pl.4  277m		(13)
Pl.5  322m		(16)
Pl.6  323m		(16)

Exeter Central
Pl.1  184m		(8)
Pl.2  287m		(14)
Pl.3  276m		(13) 

Exmouth
Plat  119m		(6)

Newton Abbot
Pl.1  327m		(16)
Pl.2  326m		(16)
Pl.3  327m		(16)

Paignton
Pl.1  251m		(12)
Pl.2  209m		(10)

Totnes
Pl.1  193m      (9)
Pl.2  178m      (8)

Usual train reporting numbers (TRNo) in the area
-----------------------------------------------
FORMAT  USUAL DESTINATION

Express passenger
1Axx   London Paddington
1Cxx   Exeter, Paignton, Plymouth & Cornwall
1Exx   Former Eastern Region (Leeds, York, Newcastle etc)
1Lxx   South West Trains services from Waterloo (where xx is an odd number)
1Lyy   SWT services towards Waterloo (where yy is an even number)
1Mxx   Former Midland Region (Birmingham, Midlands & the North-west)
1Sxx   Scotland
1Vxx   Exeter, Paignton, Plymouth & Cornwall (CrossCountry services from North)
1Zxx   Special trains (Shown as 1Yxx, see ++ below)

Local passenger
2Axx   Newton Abbot
2Bxx   Barnstaple
2Cxx   Bristol, Exeter, Penzance
2Exx   Exeter SD
2Fxx   Exmouth
2Gxx   Gloucester, Cheltenham, Worcester & Gt Malvern (or Gunnislake)
2Kxx   Okehampton
2Mxx   Bristol
2Nxx   Newquay
2Pxx   Plymouth
2Rxx   Exeter Ctl
2Txx   Paignton (Torbay)

Freight/Engineering
6Xxx   Freight or engineering trains or machines (various detinations, X = any letter)

Supporting movements
5Xxx   Empty stock trains (Xxx normally reflects the previous or next train's TRNo)
0Xxx   Light locomotives (various destinations, X = any letter)

++ See 'Design Compromises' below

Routing for trains from Exeter St Davids to Exeter Central
----------------------------------------------------------
The route must be set all the way to either E215 or E315 signal in one setting to achieve the main aspect signal from St Davids. Ignore signals E213 or E313, which are only routed to for shunt movements that will return to Exeter St Davids.

Routing for trains from Exeter Central to Exeter St Davids
----------------------------------------------------------
The route from signal E312 is to E337 or E437 ONLY. The platform at Exeter St Davids must be CLEAR.

Other operating notes 
---------------------
Having been MAS resignalled approx 2 decades later than most other areas of the Western Region, the Exeter area resignalling incorporated advances in technology which to some extent allowed a less costly infrastructure in terms of maintenance. For example the use of trap-points for loop exits was minimised and their role replaced by restrictive aspects (i.e. one or more signal in rear is automatically held at red or yellow until the train speed was reduced sufficiently to elimate SPAD risks). Flashing yellow signals approaching Totnes & Newton Abbot provided enhanced protection of key diverging routes whilst allowing them to be approached at and taken safely at higher speeds than previously.

Because of the above the same signal to signal route can be observed to behave differently according to other routes that are set in the area. Some routes will also set and lock points beyond the exit signal from the route (i.e. in the 'overlap'), and hence prevent other routes that conflict with the overlap from being set. Key examples of this in the simulation are:

Exeter SD: 
  Arrivals to pl.1 from Exeter Ctl - up deps from or down arrs into pls.2&3 are prevented.
  Up Main arrivals are approach controlled for all routes except pl.5.
  Up Main arrival on main aspect into pl.4 prevents UM departure from pl.3.
  Down Main arrivals are approach controlled for all routes except pl.4.

Exeter Central: 
  Access to/from bay is not permitted if the reversible route on the DW is set from Exeter SD.

Dawlish Warren: 
  Platform loops are not accesible if the main-line starter signal routes are set (& v/v). 
  Loop entries are approach controlled. 
  Approach routes to through (middle) lines are not available until preceding train stops in the loop.

Newton Abbot East: 
  Not able to route E84 to E86 if Up trains are routed into Pls.1&2.
  Nor E11 to E13 if Up trains from E9/109 to Pls.1&2 have the full non-approach-control route.
  E84 to E386 route protected by flashing yellows.
  E88 to E190 route protected by flashing yellows.

Newton Abbot West: 
  Approach control into platforms 2&3 if East end overlap is not free.

Totnes: 
  As Dawlish Warren, plus loop entry protected by flashing yellow 
  (approach controlled if loop route is not set before the train passes E94 or E1R).

Teignmouth: 
  Down trains on Up Main are not allowed past E276 if the Down Main route is set from E78.

Paignton: 
  Moves to/from Goodrington/P&DSR are not allowed at same time as arrivals from East end.

Pinhoe: 
  Up trains are approach Controlled if single line from Honiton is not clear.
  (If the single line is clear then junction points 329 will lock in reverse. This
  will prevent a subsequent down train coming off the single line until either the 
  up train is standing at Pinhoe or the up direction route is cancelled).
  
Topsham: 
  Trains are approach controlled if departure signal is at danger (both directions).

Design compromises 
------------------
++ xZxx trains are shown as xXxx
Worked Level Crossings are depicted only, not worked.
Overlaps only lock the points, overlap track circuit occupation can not be checked.
Notional EJ30 signal at Exmouth - no physical signal exists but the software requires one.

Abbreviations used
------------------
AHB   LC with Automatic Half Barriers 
CCTV  LC operated remotely using a CCTV monitor to confirm clear
CP    Catch-point (un-worked)
Dn    Down
DPL   Down Platform Loop
FD    Fixed Distant
Jn    Junction
L.    Lympstone
LC    Level Crossing
MAS   Multiple Aspect Signalling (colour lights)
MCB   Manually Controlled Barriers (LC)
P&DSR Paignton & Dartmouth Steam Railway
PSB   Panel Signal-box
Pk    Park
Pl    Platform
P'wy  Parkway
R     Repeater Distant signal: Location & potential (not actual) aspects shown
SB    Signal-box
SD    Sand Drag (Trap-point at foot of bank leads to sand drag and buffer stop)
Sdg   Siding
SPAD  Signal Passed At Danger
TMD   Traction Maintenance Depot (Also known operationally as 'Stables')
TMO   Train-Man Operated (LC)
U/D   Up & Down
UPL   Up Platform loop
Yd    Yard
hhXmm An X in 24hr clock times denotes an Empty Stock movement

Acknowledgements
----------------
Thanks are due to some of the signalmen at Exeter who have kindly answered various can you do ... or what happens when ... type questions during the simulation's development. Also thanks go to the small 'army' of PC-Rail testers, including Alan Sugden, Peter Dean, Russ Ashmore, John Dennis, Vagn Poulsen, Rob Roeterdink & Geoff Foster (apologies if I've forgotten any - it wasn't deliberate) who have done their best (in the nicest possible way!) to break the sim during its various testing stages.
