Cornwall shunt between Par Up Siding and St. Blazey on Bang Road

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Cornwall shunt between Par Up Siding and St. Blazey on Bang Road 14/04/2024 at 21:30 #156058
rfw
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When you try to run a train from Par to St. Blazey via the Up siding and bang road of the block section the sim reports wrong / no route at PR15.
However if you get a train into the Up Siding you can route the train through to St. Blazey as demonstrated in the attached timetable

My question is: Is this movement legal?

From what I can see in the below videos of this curve there isn't a limit of shunt.
https://www.youtube.com/watch?v=TZhg5y5gbXg&pp=ygUUY2FiIHJpZGUgbmV3cXVheSBwYXI%3D
https://www.youtube.com/watch?v=0khyQb5QYpY&ab_channel=WorldOfTransit

So I guess it comes down to the rule book and local operating instructions, which I don't have access to.

If it isn't a legal move, the Sim could report wrong / no route to St. Blazey at PR40?
And route from the US to St. Blazey in the timetable editor not validate?

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The train now standing on platform 2, should be on the rails
Last edited: 14/04/2024 at 21:33 by rfw
Reason: formatting

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Cornwall shunt between Par Up Siding and St. Blazey on Bang Road 15/04/2024 at 18:20 #156064
Steamer
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The manual describes it as 'blocking back', this is a 'wrong line' shunt movement into a block section, which then reverses and returns in the direction it came from. At Par, this allows a shunt to reverse behind PR53. The relevant bell code is 3-3, requested by the sending box and acknowledged (if safe to do so) by the far end box. When the train has exited the section again, train out of section (2-1) is sent in the usual manner. LOS signals weren't usually provided for these moves as far as I know.

This is distinct from 'Wrong direction working', in which the train travels through the section against the normal direction of travel for the line. This would be signalled as 2-3-3, once the train has passed through the section the receiving box sends 5-2 (train clear of section) which is the 'wrong line' equivalent of 2-1.

Someone with local knowledge may correct me, but from reading the manual and looking at what validates in the timetable, I'd assume that blocking back is authorised here but not wrong line working.

Shunting into forward section (i.e. a shunt move having to draw past the section signal in order to reverse) can also be done, offered as 3-3-2. When the shunt has drawn back inside the section signal, 'shunt withdrawn' (8 bells) is sent.

"Don't stress/ relax/ let life roll off your backs./ Except for death and paying taxes/ everything in life.../ is only for now." (Avenue Q)
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Cornwall shunt between Par Up Siding and St. Blazey on Bang Road 15/04/2024 at 18:36 #156065
TUT
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Steamer in post 156064 said:
The manual describes it as 'blocking back', this is a 'wrong line' shunt movement into a block section, which then reverses and returns in the direction it came from. At Par, this allows a shunt to reverse behind PR53. The relevant bell code is 3-3, requested by the sending box and acknowledged (if safe to do so) by the far end box. When the train has exited the section again, train out of section (2-1) is sent in the usual manner. LOS signals weren't usually provided for these moves as far as I know.
This was absolutely the case for many years, although now obstruction removed (2-1-2) is required to be sent instead of 2-1. (Strictly speaking, well, depending on which Rule Book you're using, obstruction removed was always what you sent, it's just that 2-1 used to mean train out of section, or obstruction removed.) Limits of shunt are provided for these movements on the Worcester patch, but that doesn't mean they were everywhere. In Cornwall they appear to have instead been provided in advance of the outermost home signal to stop anything before it gets as far as the home signal.

Steamer in post 156064 said:
Someone with local knowledge may correct me, but from reading the manual and looking at what validates in the timetable, I'd assume that blocking back is authorised here but not wrong line working.
I had a quick look through a relevant sectional appendix and couldn't find a reference to working in the wrong direction being authorised, which I would expect to see if it was authorised, but I wouldn't take that as the last word on the subject.

Last edited: 15/04/2024 at 18:37 by TUT
Reason: None given

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Cornwall shunt between Par Up Siding and St. Blazey on Bang Road 15/04/2024 at 21:47 #156068
Stephen Fulcher
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It was not permitted to transit the section in the wrong direction.

The wrong route call is correct as from the Up Loop Siding there is no legitimate way to get to St Blazey.

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The following users said thank you: rfw, TUT, Steamer
Cornwall shunt between Par Up Siding and St. Blazey on Bang Road 16/04/2024 at 07:46 #156071
kbarber
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TUT in post 156065 said:
Steamer in post 156064 said:
The manual describes it as 'blocking back', this is a 'wrong line' shunt movement into a block section, which then reverses and returns in the direction it came from. At Par, this allows a shunt to reverse behind PR53. The relevant bell code is 3-3, requested by the sending box and acknowledged (if safe to do so) by the far end box. When the train has exited the section again, train out of section (2-1) is sent in the usual manner. LOS signals weren't usually provided for these moves as far as I know.
This was absolutely the case for many years, although now obstruction removed (2-1-2) is required to be sent instead of 2-1. (Strictly speaking, well, depending on which Rule Book you're using, obstruction removed was always what you sent, it's just that 2-1 used to mean train out of section, or obstruction removed.) Limits of shunt are provided for these movements on the Worcester patch, but that doesn't mean they were everywhere. In Cornwall they appear to have instead been provided in advance of the outermost home signal to stop anything before it gets as far as the home signal.

Steamer in post 156064 said:
Someone with local knowledge may correct me, but from reading the manual and looking at what validates in the timetable, I'd assume that blocking back is authorised here but not wrong line working.
I had a quick look through a relevant sectional appendix and couldn't find a reference to working in the wrong direction being authorised, which I would expect to see if it was authorised, but I wouldn't take that as the last word on the subject.
I think it's inconceivable that working in wrong direction would be authorised but not shown in the SA. (Possible exception: a new authority that would be shown in Section D of the WON and subsequently the PON until a new SA is issued.)

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Cornwall shunt between Par Up Siding and St. Blazey on Bang Road 16/04/2024 at 23:49 #156077
rfw
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Stephen Fulcher in post 156068 said:
The wrong route call is correct as from the Up Loop Siding there is no legitimate way to get to St Blazey.
As a suggestion, could it be investigated to remove route validation from Par US to St. Blazey, as it isn't a legal route and therefore any timetables that may have used it shouldn't have.
OR
To add a wrong route call at PR40 when trying to run a train wrong line to St. Blazey, that won't get triggered when blocking back

The train now standing on platform 2, should be on the rails
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