Absolute Block Override

You are here: Home > Forum > Simulations > Released > Worksop > Absolute Block Override

Page 1 of 1

Absolute Block Override 15/08/2011 at 18:37 #19453
quickthorn
Avatar
23 posts 		Hi. I've just had my first go on the Worksop area sim. I think it's great, but there's one thing I seem to be constantly falling foul of, and that's handling trains on the absolute block sections between Shirebrook E Jn, Creswell and Woodend Jn.

Most of the time, things go ok, but every now and then I have to override one of the AB panels. This might happen when I've obtained line clear, set a route through the section in front of an oncoming train and then been distracted by something somewhere else. When I've finally remembered, the train's been through the section and gone before I'd pressed Train On Line, and the panel is stuck on line clear. The only thing that clears it is an override.

This has also happened when I have remembered to press TOL, but I've then forgotten to set to normal (Train out of section) until the train has been through the section and away.

I'm wondering whether there's some sort of timeout at work, or whether the panel locks if the train has got a certain distance beyond the end of the block section before the panel is set back to normal. ?

Anyway, I'd appreciate some advice on the best way of handling traffic through these absolute block sections, ie when to set routes in relation to working the block instruments, how far ahead to set the route, etc.

Thanks
Log in to reply
Re: Absolute Block Override 15/08/2011 at 18:52 #19454
jc92
Avatar
3629 posts
Online 		first of all, i guess the only way to avoid using the overide is to pay attention (i dont want to sound patronising if it did). in regards to obtaining a line clear theres no specific time limit but its usual to do it where possible once train on line has been recieved from the box in rear

but try this for a guidline:

elmton and cresswell: offer the train on when train entering section has been recieved from the box in rear. eg a worksop to notts train should be offered to shirebrook when train entering section is recieved from worksop.

worksop: offer the train before the train is due to leave the station or sidings, or for a through train, as it passes mantonwood.
offer to maltby as the train passes brancliffe east jcn

shirebrook- offer the train once it has passed mansfield woodhouse or welbeck

clipstone: offer the train to thoresby as it passes welbeck or mansfield colly.

thoresby- offer as it arrives in the sidings from the branch.

maltby- offer as the train passes firbeck A junction

not a hard and fast guide but can be roughly followed. also if your hacing trouble keeping up with giving train on line then simply send it once you have cleared the signals for the train to proceed. not striclty accurate but you wont be penalised for it

hope this helps
"We don't stop camborne wednesdays"
Log in to reply
The following user said thank you: quickthorn
Re: Absolute Block Override 18/08/2011 at 18:52 #19579
Adrian the Rock
Avatar
111 posts 		Having only finally got round to trying out Worksop this week, the block instruments are a great addition but there is certainly scope for refining how they work.

I had to use the block overrides quite a bit myself, almost always after forgetting to send Train On Line (TOL) until after the train had travelled beyond the far end of the section. Unfortunately, having to use the "block override", which I take to be a simulation of a Welwyn Control release winder, is totally anti-prototypical in this case. In real life, what would happen in this situation is:

  1. when the train occupies the 'berth' track in rear of the home signal at the far end of the section, the block needle would be forced to TOL, and remain there until both (2) and (3) below have been done;

  2. at any time thereafter, the advance box can turn the commutator to TOL; and

  3. subsequently, provided the train has cleared the berth track (and, where provided, any track circuits within the clearing point), the commutator can be replaced to Normal and the block needle will revert to this.

The block 'lock' only comes into play when a line clear is given but, for whatever reason, the train never travels to the far end of the section and occupies and re-clears the berth (and, if provided, clearing point) track circuits. Unless these tracks are actually occupied, the block can be always reset to normal, either directly or via TOL, but unless the tracks were occupied at some stage a further line clear cannot be pegged up until the release has been operated.

Therefore, my suggestion for an improvement to the block instrument simulation would be the following:

  • the advance ('pegging'box can peg up TOL at any time, regardless of anything else;

  • if a train hits the berth TC at the far end while the instrument is still showing LC, the TOL buttons at both ends should flash red (and the green ones revert to black), and remain flashing even if the train then clears all the relevant TC(s);

  • when the above happens, if the rear box clicks the TOL button, the 'train entering section' message should appear, but the button should continue flasing red;

  • if the advance box clicks TOL when the button is flashing because the train has arrived at or passed the home signal, the button changes to steady red and the 'TOL acknowledged' message is logged (even if TOL was never sent by the rear box!)

  • after pegging up TOL as above, the advance box can then send Train Out of Section (TOS) in the normal way provided the train is no longer on the relevant TC(s);

  • an override is only needed if the TC(s) were never occupied and cleared.
Last edited: 18/08/2011 at 18:56 by Adrian the Rock
Reason: removed duplicated bullet
Log in to reply
The following user said thank you: NCC1701
Re: Absolute Block Override 19/08/2011 at 15:39 #19593
NCC1701
Avatar
129 posts 		" said:


This has also happened when I have remembered to press TOL, but I've then forgotten to set to normal (Train out of section) until the train has been through the section and away.

I believe you can peg Line Normal (aka "Blocked"anytime after the train as been through the section and passed the clearing point. I've successfully pegged Line Normal some several minutes later, with the train long gone. I've never needed the override in this situation.


I like the sound of the modifications Adrian The Rock proposes above
Signalman Exeter West & Llangollen
Last edited: 19/08/2011 at 15:41 by NCC1701
Log in to reply
Back