Blockjoint location

[Deleted]

At some signals with short overlaps I've noticed that the blockjoint is often positioned right next to the trainstop head. At other signals it is sometimes positioned slightly ahead of the trainstop head, but still next to the casing for the trainstop machinery. Are there any rules on where blockjoint installations of this type should be made?

[Tom]

Not really, as long as the trainstop head is before the replacing blockjoint. It's more critical with trainstops that have a wrong road release, where they must be level with the joint.

[Deleted]

look at the e/b starter at st james's park and you will see the blockjoint is inline with the head of the trainstop

[Deleted]

theonekea said:

At some signals with short overlaps I've noticed that the blockjoint is often positioned right next to the trainstop head. At other signals it is sometimes positioned slightly ahead of the trainstop head, but still next to the casing for the trainstop machinery. Are there any rules on where blockjoint installations of this type should be made?

Most places have RBJs, which simply tell the signal to show a red aspect again, and they have nothing to do with the actual signalling section.

The reason this is the case is because unlike NR LUL do not like showing a green signal behind a train, this would be the cae if an RBJ wasnt there, as the signal would only got back to red once the train had gone over the blockjoint.

[Chris M]

Is the difference between LU and NR primarily an intensity of service thing? i.e. on LU the train behind will be a lot closer than on an average NR line.

[russe]

awkward42 said:

Is the difference between LU and NR primarily an intensity of service thing? i.e. on LU the train behind will be a lot closer than on an average NR line.

Yep. NR does revert its signals to red when the train passes, but LUL likes to do it in a shorter distance.

Russ

[Deleted]

metapprentice said:

Most places have RBJs, which simply tell the signal to show a red aspect again, and they have nothing to do with the actual signalling section.

The reason this is the case is because unlike NR LUL do not like showing a green signal behind a train, this would be the cae if an RBJ wasnt there, as the signal would only got back to red once the train had gone over the blockjoint.

Ah. So I wasn't actually seeing the blockjoint between the signal overlap and the next block, but the replacing blockjoint for that signal.

Thanks for the info MetApp

[Tom]

metapprentice said:

theonekea said:

At some signals with short overlaps I've noticed that the blockjoint is often positioned right next to the trainstop head. At other signals it is sometimes positioned slightly ahead of the trainstop head, but still next to the casing for the trainstop machinery. Are there any rules on where blockjoint installations of this type should be made?

Most places have RBJs, which simply tell the signal to show a red aspect again, and they have nothing to do with the actual signalling section.

That scenario is more the exception than the rule these days; in most cases that track circuit does form part of the signal's selection.

[Deleted]

russe said:

awkward42 said:

Is the difference between LU and NR primarily an intensity of service thing? i.e. on LU the train behind will be a lot closer than on an average NR line.

Yep. NR does revert its signals to red when the train passes, but LUL likes to do it in a shorter distance.

Russ

On the c2c, the back of a four car train can be a fair way past the signal before it goes to red.

It's always struck me as a bit dodgy; if the train stops for some reason just after the signal and the signal stays green then presumably AWS/TWPS etc is going to let the train behind clout it at full speed if the driver isn't looking where he's going.

Presumably the previous signal would still be red, but if the next driver passes that at danger under rule and then forgets what he's doing... It would have to be an unfortunate combination of events, but then that's how accidents happen.

[piccadillypilot]

adw said:

On the c2c, the back of a four car train can be a fair way past the signal before it goes to red.

It's always struck me as a bit dodgy; if the train stops for some reason just after the signal and the signal stays green then presumably AWS/TWPS etc is going to let the train behind clout it at full speed if the driver isn't looking where he's going.

However, the signal behind the one you can see is still at Danger.

[Deleted]

Oops! Piccadilly Pilot made his post whilst I was modifying mine by adding the last paragraph.

[trainopd78]

When training, I always use Southfields Westbound "station starter" as an example, as the train travels a fair distance before the signal returns to danger.

[Christopher J]

GB13 (Kew Gardens WB Station Starter) has quite a distance between the Signal and Blockjoint too, as these Photo's I took (on Seths Camera ) on Monday show:

[russe]

Well spotted and photted, Chris, but Richmond is a bit, err, 'branchline' innit?

Russ

[Deleted]

In the days of semaphore signals and manual signalling, it was a rule that a signal should not be returned to danger until all the train had passed it. This was because the signal at clear locked other levers in the signalbox and prevented conflicting moves. There was a nasty head-on collision at Hull in the 1920s that was partly caused by a signalman neglecting this rule.