Circle line oddities

I noticed a couple of unusual things this morning, and I wonder if anyone knows what was happening?

1) At Moorgate, while waiting on platform 1 there was a train standing in platform 3 - not unusual, a few Metropolitan Line services start there. This destination indicators on the side of the train though were showing it as being a Circle line service "via Embankment". I would have thought that a Circle Line service starting there would have just gone straight along the top to Hammersmith - anyone know what was going on there? Maybe doing a lap and a bit of the old Circle Line before heading to Hammersmith?

2) At Aldgate, I heard an announcement of a Circle Line train via Kings Cross from platform 1 - trains via Kings Cross would normally go from platform 4. It sounded odd so I checked the departures board on the concourse which confirmed the announcement. Do Circle Line trains sometimes reverse at Aldgate? It's not something I've seen before. The carto.metro map doesn't show a crossover that would let such a train get to the correct track from platform 1.

Sounds as if some trains are running round the traditional circle rather than doing the "teacup" route from Hammersmith to Edgeware Road. I have heard of this happening before in unusual circumstances, no doubt somebody with inside knowledge will bring us up to date soon.

sprunt said:

The carto.metro map doesn't show a crossover that would let such a train get to the correct track from platform 1.

Click to expand...

It does, there's a sliver of yellow — immediately at the north end of P1 — showing a route onto the section of pink track where Westbound H&C are the only regular services.

Perhaps the Circle "via Embankment" was turned back at Moorgate due to service disruption but hadn't yet changed its destination display. The one at Aldgate sounds like another clockwise Circle becoming an anticlockwise, so both would be consistent with disruption at or beyond Tower Hill.

None of these are particularly unusual. Late running trains from Hammersmith will often be sent to Moorgate to lay over and present at Edgware Road 'right time' for their Inner Rail working if going round the Outer will cause them to miss their path. The same, as alluded, will also happen for trains extended off the Outer Rail to Moorgate if they miss their Inner Rail path at Edgware Road.

In this circumstance I expect there is more to the story as it shouldn't be displaying 'via Embankment' on the train if set up as an Inner Rail Circle at that point. It would likely in this instance have been a short notice diversion off the Outer Rail and the driver did not change the CIS.

Reversing via platform 1 at Aldgate isn't a booked move, but can (and is) regularly used whereby the District becomes unavailable to accept services. Booked C&H Aldgate reversers run out of the middle bays, except for certain engineering timetables. Of note this route can also be used to reverse an S8 in an emergency, but requires certain mitigations in place and is a very tight berth. To my knowledge it has only happened under failure conditions.

As suggested by another poster, there was likely disruption on the District side this morning causing services to diverted, reformed and curtailed as required.

With a handful of exceptions at the start and end of service for stabling purposes, no trains operate the 'traditional' Circular service on the ordinary WTT35, although it does still happen on some engineering timetables (next working being 3/4 March along with H&C services reversing in platform 3 at Edgware Road), but not a day goes by where a Circle isn't diverted to Moorgate for one reason or another.

bluegoblin7 said:

Reversing via platform 1 at Aldgate isn't a booked move, but can (and is) regularly used whereby the District becomes unavailable to accept services. Booked C&H Aldgate reversers run out of the middle bays, except for certain engineering timetables. Of note this route can also be used to reverse an S8 in an emergency, but requires certain mitigations in place and is a very tight berth. To my knowledge it has only happened under failure conditions.

Click to expand...

Presumably this is only when the Moorgate bays have been passed already, or are full? Could an S8 reverse via Aldgate East if necessary (obviously without a passenger call)?

Only if passed already in the case of S7s. King's Cross or reversing off platform 1 at Moorgate would be more likely alternatives if the bays were already full, unless Aldgate was already available. But, bear in mind that as soon as this sort of thing happens Circles will be taken off as far back at Hammersmith, so it is unlikely that we would get to this point (ten minute circle service). S8s would be curtailed at Baker Street and would not run to Aldgate pfm 1, and are not cleared to proceed to Aldgate East during traffic hours.

bluegoblin7 said:

Only if passed already in the case of S7s. King's Cross or reversing off platform 1 at Moorgate would be more likely alternatives if the bays were already full, unless Aldgate was already available. But, bear in mind that as soon as this sort of thing happens Circles will be taken off as far back at Hammersmith, so it is unlikely that we would get to this point (ten minute circle service). S8s would be curtailed at Baker Street and would not run to Aldgate pfm 1, and are not cleared to proceed to Aldgate East during traffic hours.

Click to expand...

What I mean is, if an S8 has left Liverpool Street eastbound, and then a fault develops which takes Aldgate out of service. Reading between the lines on your answer, it would reverse back to Liverpool Street?

Interesting stuff - thanks all.

rebmcr said:

What I mean is, if an S8 has left Liverpool Street eastbound, and then a fault develops which takes Aldgate out of service. Reading between the lines on your answer, it would reverse back to Liverpool Street?

Click to expand...

In all likelihood, yes. Taking an S8 to Aldgate East introduces two immediate problems - firstly the driver will be a Met Line driver and therefore isn’t trained on the route, and secondly the train will possibly (?) be too long for the platform. There’s ways round all of this, but only as a last resort.

In reality they would either wrong-road the train back to Liverpool Street, work the train into Aldgate under failure conditions, or sit still until the failure was resolved. Naturally the last option would be time bound.

bramling said:

In reality they would either wrong-road the train back to Liverpool Street, work the train into Aldgate under failure conditions, or sit still until the failure was resolved. Naturally the last option would be time bound.

Click to expand...

If an S8 has left Liverpool Street and is standing at OB1 (my favourite signal on the whole network incidentally...) or OB2, and the bays aren't available, the prefered course of action is always a wrong directional move to Liverpool Street and thence (nominally) east to west over the crossover. This would only not happen if a train was blocking the platforn.

Reversing an S8 at Aldgate East would be option of absolute last resort; as mentioned, it introduces a lot of issues. It will "fit" from a signalling point of view (S8s have been as far as Bromley-by-Bow) but would require end door cutout (emergency open) at Aldgate East, as well as the aforementioned piloting problems. I understand also that it would be required to trip past the Aldgate East starter and then change ends to allow a reversal back to the Met. Ultimately it's a similar situation to reversing an S8 at Edgware Road - if all other options are not possible.

bluegoblin7 said:

If an S8 has left Liverpool Street and is standing at OB1 (my favourite signal on the whole network incidentally...) or OB2, and the bays aren't available, the prefered course of action is always a wrong directional move to Liverpool Street and thence (nominally) east to west over the crossover. This would only not happen if a train was blocking the platforn.

Reversing an S8 at Aldgate East would be option of absolute last resort; as mentioned, it introduces a lot of issues. It will "fit" from a signalling point of view (S8s have been as far as Bromley-by-Bow) but would require end door cutout (emergency open) at Aldgate East, as well as the aforementioned piloting problems. I understand also that it would be required to trip past the Aldgate East starter and then change ends to allow a reversal back to the Met. Ultimately it's a similar situation to reversing an S8 at Edgware Road - if all other options are not possible.

Click to expand...

All correct, one additional point though, Met drivers are trained, (on paper) to reverse from platform 1 at Aldgate but things would have to be desperate or, more likely, a wrong route have been offered and accepted.

philthetube said:

All correct, one additional point though, Met drivers are trained, (on paper) to reverse from platform 1 at Aldgate but things would have to be desperate or, more likely, a wrong route have been offered and accepted.

Click to expand...

Covered already.

bluegoblin7 said:

Reversing via platform 1 at Aldgate isn't a booked move, but can (and is) regularly used whereby the District becomes unavailable to accept services. Booked C&H Aldgate reversers run out of the middle bays, except for certain engineering timetables. Of note this route can also be used to reverse an S8 in an emergency, but requires certain mitigations in place and is a very tight berth. To my knowledge it has only happened under failure conditions.

Click to expand...

Last time it happened (due to a failure) I think we lost the City for about two hours as the route to reverse an S8 itself then failed.

What looks like more service recovery fun at Aldgate this morning - as I was coming out of the station a train pulled into platform 4 showing District Line to Barking and everyone got off - I'm guessing this would be related to the currently ongoing signal failure at Tower Hill?

A significant points failure occurred at Tower Hill, which is likely to cause disruption until the end of the day.

What you saw was less 'service recovery' and more 'get trains out of section'! District train 021, on the eastbound, was the first train to be affected by the failure at 0825. The only route available was to Aldgate, so T021 was diverted to Aldgate by 0850 and detrained. The train remained there until a spare C&H driver was available to move it (a stock and crew took place with C&H 211), District drivers not having route knowledge via Aldgate.

We've been recovering the service (at least on the C&H) ever since, involving short trips and diversions to get trains as close to timetable as possible. Circle line services remain suspended, with an 'old-style' Circular service now running on the Outer Rail only (yay, emergency timetable). This has included a number of trains reversing Outer to Inner at Aldgate platform 1.