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Axle counters: reset procedure

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Axle counters: reset procedure 17/10/2021 at 18:23 #141902
TUT
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I've got a few questions about the process for resetting axle counters.

I found a very good old thread here:

https://www.simsig.co.uk/Forum/ThreadView/39409?postId=70561

Which gives some nice details, but it's still a little bit unclear to me what the full process entails, would anyone be able to talk us through it in full? I gather there's such a thing as a reset/restoration failure list but I don't really know what one of those looks like or what it's for.

I'm also a little bit confused by some of the instructions in the National Operating Instructions. The NOIs tell us what to do when an axle counter section fails to clear or shows occupied for some other reason and we are told:

Quote:
Once you have made sure that the last train has passed clear of the affected section, the process to reset the axle counter section can start without initially performing a line examination.
I notice the word initially is used but what if the reset is successful? Do you have to examine the line or not? I know that if you have conditional axle counters and the reset is successful then aspect restriction will be indicated, but are we then examining the line or just cautioning? Because in section 3.5 (Actions subsequent to an axle counter failure and successful reset) we have this:

Quote:
After a successful reset, the first train must always be cautioned through the affected area and the driver instructed to report back the state of the line. This ensures that the axle counter section(s) is clear of any other train.
But it doesn't tell you to get the line examined after a successful reset.

However, sections 3.2 and 3.3 tell you how to deal with the first train to pass on an adjacent line and the first train to pass over the affected line and they both make very explicit reference to the affected line being examined. But if we attempt to reset the axle counter and it succeeds, do we need to carry out 3.3 and get the line examined or not?

My instinct would be to conclude that 3.3 always applies: you always examine the line. Now if you attempt a reset and it's successful, then you examine the line anyway (per 3.3) and that kind of covers 3.5. However, if you couldn't be sure the line was clear and so had already examined the line before attempting to reset, or the reset was initially unsuccessful and you've had to get S&T out or whatever it is, then 3.5 becomes its own separate requirement and when the section is finally reset you have to caution the next train through. Is that about the sense of it?

Because there are some very confusing instructions in the NOI, such as:

Quote:
3.1.8
Unless you are sure that the line is clear, you must arrange for the line to be examined as well as carrying out the instructions in 3.2 and 3.3.
(But 3.3 deals almost exclusively with getting the line examined and 3.2 tells you what to do if you haven't got the line examined yet so I really don't understand what that's supposed to mean).

And:

Quote:
4.1.1
Aspect restriction is a control that restricts the aspect of a signal after the reset of an axle counter section. After a successful axle counter reset, where aspect restriction is indicated instruction 3.1.1 must be applied.
(This is especially confusing because it takes you back to what you do before the passage of the first train when an axle counter section fails to clear or shows occupied for some other reason, which is to attempt to reset the axle counter)

Also if you read instruction 4.6 Aspect restriction & Engineer’s possessions it seems to roll examination of the line in with removing aspect restriction (e.g. 'where possible, a train or road rail vehicle should be used as this will release the aspect restriction' ) but then aspect restriction should only be indicated after a successful reset which shouldn't be attempted unless you're sure the line is clear, but section 3 makes it seem like if you are sure the line is clear, you don't have to examine it.

Help!

Last edited: 17/10/2021 at 18:28 by TUT
Reason: None given

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Axle counters: reset procedure 17/10/2021 at 19:31 #141903
Stephen Fulcher
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I do not know much about the rules and regulations side, but do understand the technical side of things.

Assuming AzLM with EPRs there are two ways you can reset a section that is disturbed, conditionally and unconditionally.

Unconditionally is where an EPR has been applied and as long as the equipment on the ground is working there is nothing to stop the reset, and no aspect restrictions will be in place once the section has reset.

Conditional resets are where the equipment has failed in service. Assuming all the equipment on the ground is working correctly, the last count must be an axle leaving the section (if it is not the reset will be rejected by the system and a train will need to “sweep” the section to set the last count to out), the axle counter section will then reset but the protecting signal will be held at danger by the interlocking (termed Aspect Restriction) until a train has been over that route and the section operated correctly for that train, which will need to be talked past the signal. If this works then the signalling will then work normally.

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Axle counters: reset procedure 17/10/2021 at 19:36 #141904
TUT
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Thanks Stephen

Stephen Fulcher in post 141903 said:
Conditional resets are where the equipment has failed in service. Assuming all the equipment on the ground is working correctly, the last count must be an axle leaving the section (if it is not the reset will be rejected by the system and a train will need to “sweep” the section to set the last count to out), the axle counter section will then reset but the protecting signal will be held at danger by the interlocking (termed Aspect Restriction) until a train has been over that route and the section operated correctly for that train, which will need to be talked past the signal. If this works then the signalling will then work normally.
Which suggests that, in the latter case, you have to send a train through at caution twice? Once examining the line and 'sweeping' the section and then, regardless of the fact that you've just had the line examined, a second time to remove aspect restriction?

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Axle counters: reset procedure 17/10/2021 at 21:37 #141905
Ron_J
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Quite frankly the NOI section on axle counters contains some of the most badly drafted and confusing instructions I’ve ever seen written in any railway operating document. When I emailed Tony Raine about them I got no reply, unsurprisingly.
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The following user said thank you: TUT
Axle counters: reset procedure 17/10/2021 at 21:55 #141906
TUT
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392 posts
Ron_J in post 141905 said:
Quite frankly the NOI section on axle counters contains some of the most badly drafted and confusing instructions I’ve ever seen written in any railway operating document. When I emailed Tony Raine about them I got no reply, unsurprisingly.
Well I didn't wanna be the one to say it, but this is my second attempt at getting my head around these, just cause I thought, y'know, it's something to do ain't it?

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