No-Block Line definition

[Birmingham1066]

Hi all,

I have always used the phrase "A line on which the signaller does not monitor the condition of the block section" as the definition for a No-Block line.

However someone I was discussing it with was unsure whether there is a more succinct way of putting it.

Are they any particular ways people describe a No-Block line method of working?

 

[Railsigns]

However someone I was discussing it with was unsure whether there is a more succinct way of putting it.

Are they any particular ways people describe a No-Block line method of working?

The phrase that comes to mind is: "worked as a siding".

 

[AndrewE]

The phrase that comes to mind is: "worked as a siding".

is that effectively "1 engine in steam?"

 

[Railsigns]

is that effectively "1 engine in steam?"

No; OEIS enforces one train in the section at a time, whereas "no block" does not.

 

[Tomnick]

is that effectively "1 engine in steam?"

Quite the opposite. You can keep putting trains into a "no block" line until there isn't room for any more. I used to work with one, a mile or so long between boxes (it's still there) and it was common to have two in there at a time, and I've had three in each (full length intermodals in one case – I was a little worried that the third wouldn't fit!).

 

[AndrewE]

Quite the opposite. You can keep putting trains into a "no block" line until there isn't room for any more. I used to work with one, a mile or so long between boxes (it's still there) and it was common to have two in there at a time, and I've had three in each (full length intermodals in one case – I was a little worried that the third wouldn't fit!).

how is that diifferent from permissive block?

 

[Tomnick]

how is that diifferent from permissive block?

In permissive block, the section is worked co-operatively and trains are offered and accepted (or refused) in a similar way to Absolute Block (and there's a distinction between accepting a train into an empty section and into an occupied section).

No-block is pretty much what it says on the tin – there's no form of block working. It is, as @Railsigns suggests, as good as working it as a siding, but for the fact that's it not technically a siding. You can just pull off for them to go in, the same way whether it's clear or occupied, and just tell the other signaller for information. No need for them to then tell you when it's clear again, although we usually did as a courtesy, to make it easier for them to make regulating decisions.

 

[Starmill]

how is that diifferent from permissive block?

Not that different from a tramway that runs on line of sight. You'd likely be going very slowly regardless.

 

[ComUtoR]

What about "time interval working" ? Is that still a form of 'Block' ?

No-block is pretty much what it says on the tin – there's no form of block working. It is, as @Railsigns suggests, as good as working it as a siding, but for the fact that's it not technically a siding. You can just pull off for them to go in, the same way whether it's clear or occupied, and just tell the other signaller for information.

I used to work a 40mph Goods Loop that was permissibly worked. It was 'sorta' in a sidings but technically considered 'mainline'. Would that count ?

No; OEIS enforces one train in the section at a time, whereas "no block" does not.

OEIS ?

With 'no block'. What do you consider as a 'Block' ? would 'Moving block' still be a block of sorts ?

Cheers in advance.

 

[edwin_m]

With 'no block'. What do you consider as a 'Block' ? would 'Moving block' still be a block of sorts ?

One Engine in Steam.

With "moving block" the train has knowledge of the occupancy and speed of the line ahead and slows down if it gets within braking distance of any reason to. There is effectively a section of track reserved for the train that moves along in front of it, and varies in length depending on speed, braking performance and gradient.

 

[Railsigns]

What about "time interval working" ? Is that still a form of 'Block' ?

No; it's a method of working, but one that doesn't involve blocks to ensure the safe separation of trains.

I used to work a 40mph Goods Loop that was permissibly worked. It was 'sorta' in a sidings but technically considered 'mainline'. Would that count ?

It's hard to say without knowing all the details, but the speed would suggest not.

OEIS ?

One Engine In Steam, per the message I was quoting. Nowadays referred to as "One Train Working".

With 'no block'. What do you consider as a 'Block' ? would 'Moving block' still be a block of sorts ?

In both cases, the clue's in the name.
No block: There's no block.
Moving block: Blocks are enforced that move behind each train, as opposed to each block equating to a fixed portion of track.

 

[ComUtoR]

So what is 'One engine in steam' ?!

If 'no block' literally means 'no block' and I can understand 'worked as a siding' Where does that put permissive working in general ?

Oooh. Just a random thought. Would temp block or single line working be considered a form of 'no block' ? Would the tickets be considered as a form of 'block'

Ta

 

[snowball]

What about "time interval working" ? Is that still a form of 'Block' ?

As far as I know, time interval working is what was used in the earliest days of railways, and was replaced by block working because it led to crashes. It means what it says on the tin - a certain number of minutes after a train has passed, you allow the next one to pass, without knowing for certain how far the first train has got.

== Doublepost prevention - post automatically merged: 20 Feb 2024 ==

So what is 'One engine in steam' ?!

Usually used for short single-track branch lines such as the Windermere branch. It means that an identified train is allowed on the branch and can go up and down it to its heart's content, but no other train is allowed on. No signals required except at the junction with the main line. In steam days it meant what the name literally says.

 

[Annetts key]

If not supervised or controlled by a signaller, a single line for freight may be a C2 line:
"LINES WORKED UNDER THE CONTROL OF A PERSON IN CHARGE (THE C2 SYSTEM)"

 

[Lucy1501]

To the best of my knowledge no block is still in use between:

• Langham Junction and Oakham on the Down and Up Goods Lines
• Peak Forest South and Great Rocks Junction on the Down & Up Through Siding
• Potentially Worcester Shrub Hill and Tunnel Junction on the station avoiding lines.

Everyone else has summed up the definition quite well.

I believe the general procedure is to phone (or bell) the other signal box as required nowadays.

I was able to find the following in the LNE Sectional Appendix:

The Down and Up Goods lines between Langham and Oakham boxes are worked in accordance with the Regulations for working trains over goods lines not worked on any block system (No Block). Stop signals will normally be maintained at Danger but when cleared, the Driver must understand that the line ahead may be occupied, even if the signal is cleared without the train being stopped or nearly stopped at the signal.