Control of automatic signals on LUL

[Future]

Observing LUL signalling diagrams on the wonderful ‘Harsig’ page, there are obviously long gaps between controlled areas filled with automatic signals. Is there a way to tell what box would supervise these automatic signals or are they outside any box’s control? Many thanks for any help in advance.

 

[Dstock7080]

Automatic signals are purely operated by the passage of trains, they are not controlled by signal boxes/control rooms.
Usually diagrams in these rooms do not show the aspect of the automatic signals.

 

[Future]

Automatic signals are purely operated by the passage of trains, they are not controlled by signal boxes/control rooms.
Usually diagrams in these rooms do not show the aspect of the automatic signals.

Were an auto to fail, however, how would the T/Op know what box to contact?

 

[Dstock7080]

In traditional terms, the signal would not have a telephone, train radio didn’t exist, the driver had their own authority to apply the appropriate Rule to pass the signal and report it at the next appropriate place.

 

[bramling]

Observing LUL signalling diagrams on the wonderful ‘Harsig’ page, there are obviously long gaps between controlled areas filled with automatic signals. Is there a way to tell what box would supervise these automatic signals or are they outside any box’s control? Many thanks for any help in advance.

Traditionally such signals were not supervised by anyone as such. Indeed the Metropolitan Line between Wembley Park and Harrow-on-the-Hill is still something of a signalling nomansland.

However over time it has tended to become the case that automatic signals have come to appear on signal box diagrams, generally as signal boxes have tended to control multiple areas and therefore it has made sense for areas in between to be included. However the Rule Book gives drivers authority to “apply the rule” during failures, a signaller doesn’t have to be involved.

 

[ThameslinkUser]

There are, however, a very select number of automatic signals that can actually be held at danger by signallers. Three that I know of are on the Uxbridge branch.

 

[Mojo]

There are, however, a very select number of automatic signals that can actually be held at danger by signallers. Three that I know of are on the Uxbridge branch.

There’s some on the Bakerloo too.

On the other side of the coin the there’s also the semi-automatic signal which can have an illuminated ‘A’ set; allowing it to be treated as an automatic signal.

Were an auto to fail, however, how would the T/Op know what box to contact?

In this circumstance, the train operator wouldn’t contact the signaller, they would attempt to contact the controller.

 

[Daniel]

Whilst when at an auto remaining at danger most drivers would contact the controller not the signaller, it’s relevant to note that on LU drivers don’t choose which signaller to call. They push the ‘signaller’ button on the radio head and it sends a call request to any dispatcher logged in as a signaller which is monitoring that radio cell.

 

[1Q18]

With a Chiltern train on the Metropolitan line, whether or not they’re at a controlled signal they would talk to the line controller and not to any of the three relevant signal cabins (Amersham, Rickmansworth, Harrow-on-the-Hill), because none of the signal cabins have a GSM-R base station, only the line controller at Hammersmith.

 

[Dstock7080]

With a Chiltern train on the Metropolitan line, whether or not they’re at a controlled signal they would talk to the line controller and not to any of the three relevant signal cabins (Amersham, Rickmansworth, Harrow-on-the-Hill), because none of the signal cabins have a GSM-R base station, only the line controller at Baker Street.

The Metropolitan Controllers are at Hammersmith

 

[1Q18]

The Metropolitan Controllers are at Hammersmith

Corrected

 

[Daniel]

With a Chiltern train on the Metropolitan line, whether or not they’re at a controlled signal they would talk to the line controller and not to any of the three relevant signal cabins (Amersham, Rickmansworth, Harrow-on-the-Hill), because none of the signal cabins have a GSM-R base station, only the line controller at Hammersmith.

Whilst it is correct that only the Controller has GSM-R, I found the reality was that the Chilterns tended to use SPTs and contacted the signaller directly for signalling related issues.

 

[bluegoblin7]

Whilst it is correct that only the Controller has GSM-R, I found the reality was that the Chilterns tended to use SPTs and contacted the signaller directly for signalling related issues.

Can’t remember the last time I’ve used one of the SPTs! Pretty much all of it goes through GSM-R and the controller now. It makes sense even if it does make the process a little more convoluted.

 

[trainJam]

Just curious, how is the GSM-R used (in terms of functionality e.g. standing at signal) on the Metropolitan line?
How does an emergency call work if the LU trains use a different radio system?

 

[bluegoblin7]

Functions the same as the national network for all intents and purposes, but it is a separate system.

SG would go through to the service controller who would call the signaller if required (thus why some Chiltern drivers will use an SPT instead), as would GSM-R REC. The service controller would then make a separate code red call via Connect if necessary. If a mayday call came via LU Connect first, a code red would follow for Chiltern services via GSM-R shortly afterwards, or the signaller would intervene in other ways.

Similar is true for plenty of other areas where multiple radio networks are used, including the Richmond, Wimbledon and Harrow branches, and on other non-LU networks.

 

[D7666]

Just to add a bit here, from the technical view, the LU train radio system ("Connect") technology does adhere to an international standard but is not GSM-R or GSM at all but TETRA (Terrestrial Trunked Radio).

Just thought I'd mention this as there is a certain urban myth floating among the uninformed masses that Connect is unique and bespoke - but in reality is not with TETRA is widely recognised and used, in UK, and elsewhere.

Not going here into all the pros and cons on details of why LU use TETRA and not GSM-R, save saying there are a number of specific functions advantageous to the application and environment. Of course there are disadvantages too, but outweighed. Early days of Overground projects such ELL route upgrade did consider TETRA for the then planned routes for 378s, but here the opposite applied GSM-R advantages outweighing TETRA.