At present, all T4 Illawarra Line (Suburban) and South Coast (Intercity) services terminate at Bondi Junction.  There are 14tph T4 services from Hurstville, Cronulla and Waterfall and 4tph South Coast (Intercity).  

Following the ATP/ATO upgrade, the overall frequency will be increased from 18 to 24tph.  3 of the current 4 SCO Intercity services, plus an additional service, will be diverted to Sydney Terminal.  The other SCO service from Thirroul to Bondi Junction will be retained.  That frees up an additional 9 paths for T4 services from Hurstville, Cronulla and Waterfall, the apportionment of which is still to be revealed.

As I said before, I doubt if 10 car D sets will operate via the North Shore Line or to Bondi Junction.  They are likely to be operated by the shorter 6 or 8 car sets.  There are no plans to extend platforms on the Suburban network that I'm aware of other than Waterfall.


My understanding is that there will be no eight car D sets.
At present, only 4, 6 and 10 car trains are authorised to operate.
The present contract delivers 55 ten car sets and one four car set.

Marshalling four car sets into eight car rakes means that there will be twice as many sets limited to six cars which will have relatively few seats for peak hour traffic compared to a six car V set or eight car H set.

As I've said, there is no good reason not to use ten car sets on the underground or at short suburban platforms. The train will detect from a balise on the track which doors on which side should be opened. It might be necessary to improve passenger information as to which cars will be in the platform in advance of the stop but this is no different to H sets on the North now.

The last two cars could display which stations they will be able to unload passengers. However, those cars provide seats for other passengers as long as they are aware that they have to move forward at many intermediate stations.

Peter

It's impractical to use the 10 car D sets on the North Shore Line or the Eastern Suburbs Railway and I'll demonstrate why.

If the last 2 cars are unable to allow access to the CBD stations, then no one is going to board them even when they are able to at the outer stations with longer platforms.  Conversely, no one will be able to board them in the CBD, regardless of their destination.  They will largely be empty, so what's the point in having them?  In the absence of any 8 car sets, they will have to be 6 cars in the peak if they continue on the North Shore Line or the limited SCO service on the ESR to Bondi Junction.

It's still not clear whether the Gosford/Wyong Intercity services will continue on the North Shore Line.  They may all continue to Sydney Terminal via Strathfield which would require interchange at Hornsby for those wanting access to North Shore Line destinations.

I agree that St James is a natural fit for a mid-city Airport Line terminus.  It would provide a seamless cross platform interchange with the City Circle and there would also be the option of continuing through the CC in the off-peak when more paths would be available.

Regrettably, the unused underground platforms 26 & 27 at Central are unlikely to be available, as part of the platform space will be used for equipment to service the new metro platforms via a tunnel link, which is short sighted IMO.

I have previously suggested an alternative link to St James from the surface platforms 22 & 23 at Central via a new viaduct on a steeper alignment between the existing viaduct and Elizabeth St, where there appears to be enough space.  However, it would have to be much steeper to pass under Hay St because of the encroachment by the Goulburn St carpark beyond the Campbell St overpass.  It would avoid any disruption to existing Airport Line services with only a weekend shutdown to connect the new link with the the existing line. The existing gradient from Eddy Ave to the Hay St overpass is 1 in 75, so a new line would have to be at least 1 in 30 to pass under Hay St and the existing CC line.  I don't know whether or not it's feasible, but it's worth further investigation.

Extension of the quad from Revesby to East Hills and preferably Glenfield would allow for compatible SD trains to operate an all stations service via the Airport Line in tandem with SD express trains from Badgerys Creek, merging at Wolli Creek.  Increased T8 Campbelltown/Macarthur DD services could then run express from Glenfield via Sydenham to the City Circle.  There would be no need for the T8 services to stop between Wolli Creek Junction and Central, other than Sydenham and Redfern, as T4 will service the intermediate stations with an increased all stations pattern.

Butting the "Metro" equipment on the unused platforms I wouldn't think precludes the platforms from potential future use as intended. They are putting that equipment there because its an unused space with no immediate plans for alternative use. I assume this "equipment" is either computer or electronics of sort all of which is relocatable and likely much cheaper than building a new station.

My preference for using 26/27 over 22/23 is also alot to do with the standard of the station, from personal experience, using 22/23 with suitcases basically sucks, access and platform width is all substandard. While there are some comments that 26/27 is not suited being a bit narrow, it is 1000 x better than 22/23.

I also don't buy the reported weight of modern trains comments that I've read over the years. I mean seriously, the station was built at the same time as the rest of the ESR which was designed for DD's and as far as I'm aware has not have red rattlers in regular use on the line ever. Meanwhile the 100 year old Townhall and Wynyard stations built using rivets, no issue, hell they even have had freight trains using the stations.

Quadding beyond East Hills is certainly do able and can be left for the future as needed.

Agree, extra services connecting to Airport via Leppington would certainly make sense, as the stopping pattern Glenfield to East Hills is the same as SW so only need quad if capacity issue.

So summary
- T9? - East Hills / BC Airport via Mascot Airport to St James terminating in peak, via Outer CC in off-peak

- T8 SW services would be on the western pair of tracks north of Wolli Creek, stopping only Sydneham into Outer CC

- T4 Cronulla / Waterfall / South Coast via western pair of tracks from Hurtsville to Eskinville

- T4 Hurtsville - Eastern Pair of tracks all to BJ

Longerterm I'd also be completing the 5km Sexupt from Wolli Creek to Eskinville (no need for building new platforms) to enable T8 to operate segregated from T4 and allow growth on both T4 and T8 and their respective interurban services. Potentially the IU services could share the new tracks like the Western corridor.

It's impractical to use the 10 car D sets on the North Shore Line or the Eastern Suburbs Railway and I'll demonstrate why.

If the last 2 cars are unable to allow access to the CBD stations, then no one is going to board them even when they are able to at the outer stations with longer platforms.  Conversely, no one will be able to board them in the CBD, regardless of their destination.  They will largely be empty, so what's the point in having them?  In the absence of any 8 car sets, they will have to be 6 cars in the peak if they continue on the North Shore Line or the limited SCO service on the ESR to Bondi Junction.

It's still not clear whether the Gosford/Wyong Intercity services will continue on the North Shore Line.  They may all continue to Sydney Terminal via Strathfield which would require interchange at Hornsby for those wanting access to North Shore Line destinations.

As a former CC commuter I'll say there will see people use the carriages because they will have empty seats. However what will happen is at the stations there will be a delay in unloading the last door as it will be discharging not 0.5 of a carriage but 1.5 carriages. Dwell times blown out of the water and on a 20-24 t/h frequency, this isn't going to work well.

t's impractical to use the 10 car D sets on the North Shore Line or the Eastern Suburbs Railway and I'll demonstrate why.

If the last 2 cars are unable to allow access to the CBD stations, then no one is going to board them even when they are able to at the outer stations with longer platforms.  Conversely, no one will be able to board them in the CBD, regardless of their destination.  They will largely be empty, so what's the point in having them?  In the absence of any 8 car sets, they will have to be 6 cars in the peak if they continue on the North Shore Line or the limited SCO service on the ESR to Bondi Junction.

It's still not clear whether the Gosford/Wyong Intercity services will continue on the North Shore Line.  They may all continue to Sydney Terminal via Strathfield which would require interchange at Hornsby for those wanting access to North Shore Line destinations.

If nobody can use the additional two cars, the train is effectively an eight car train at the stations can only fit eight cars.

But this is the same as short platforms with eight car trains now...

But assuming the passengers can use the end doors, people will travel in them.
As long as the passenger information system  works and passengers understand it, people will move forward at stations where the doors won't open.

Even with all trains running to Sydney Terminal, people will board the nearest two cars and have to move forward at any station only accommodating eight cars. I think these will have to display messages like "Hornsby, Gosford and Broadmeadow only".

I'm not recommending the use of ten car trains. But they have bought 55 of them and radically changing all the services to suit the new trains won't be popular.

When I have caught H sets on the up North Shore, the majority of passenger leave at St Leonards or North Sydney, with a few at Chatswood. Even if you could arrange a connection at Hornsby on platform 2, it wouldn't be popular and since most North Shore trains depart from platform 1, it would be unpopular with North Shore passengers. Using the steps to get from Platform 3 to platform 1 in the peak hour would be most unpopular.

I think running ten car trains on the North Shore would cause less disruption thanmaking passengers cange trains at Hornsby, particularly on the down in the evening when there will be no seats left.

Peter

t's impractical to use the 10 car D sets on the North Shore Line or the Eastern Suburbs Railway and I'll demonstrate why.

If the last 2 cars are unable to allow access to the CBD stations, then no one is going to board them even when they are able to at the outer stations with longer platforms.  Conversely, no one will be able to board them in the CBD, regardless of their destination.  They will largely be empty, so what's the point in having them?  In the absence of any 8 car sets, they will have to be 6 cars in the peak if they continue on the North Shore Line or the limited SCO service on the ESR to Bondi Junction.

It's still not clear whether the Gosford/Wyong Intercity services will continue on the North Shore Line.  They may all continue to Sydney Terminal via Strathfield which would require interchange at Hornsby for those wanting access to North Shore Line destinations.

If nobody can use the additional two cars, the train is effectively an eight car train at the stations can only fit eight cars.

But this is the same as short platforms with eight car trains now...

But assuming the passengers can use the end doors, people will travel in them.
As long as the passenger information system  works and passengers understand it, people will move forward at stations where the doors won't open.

Even with all trains running to Sydney Terminal, people will board the nearest two cars and have to move forward at any station only accommodating eight cars. I think these will have to display messages like "Hornsby, Gosford and Broadmeadow only".

I'm not recommending the use of ten car trains. But they have bought 55 of them and radically changing all the services to suit the new trains won't be popular.

When I have caught H sets on the up North Shore, the majority of passenger leave at St Leonards or North Sydney, with a few at Chatswood. Even if you could arrange a connection at Hornsby on platform 2, it wouldn't be popular and since most North Shore trains depart from platform 1, it would be unpopular with North Shore passengers. Using the steps to get from Platform 3 to platform 1 in the peak hour would be most unpopular.

I think running ten car trains on the North Shore would cause less disruption thanmaking passengers cange trains at Hornsby, particularly on the down in the evening when there will be no seats left.

Peter

Surprisingly in the 1980's before CC trains used the NSL, we got off Platform 3 and walked across to Plat 2, seemed to work quite well and I personally did it from 1982 to 1986 daily to go to school and I'm sure it will again if reintroduced. If the PM, you had to cross the bridge in peak and again seemed to work fairly well and humanity as we know it didn't come to an end.

Ironically the outrage that occurred back then when the Suburban sets were to travel from Gosford via the NSL so people could travel direct via the shore line was no toilets, no high backs, no arm rests, the govt forcing such low standards on longer haul users, oh the humanity.

The D sets will not operate on the NSL in 10 car format as it will delay services through the tunnels, it would be madness to do so and likewise 6 car if capacity through the city tunnels is an issue.

Personally I could the H -sets remaining for a few services (2t/h) during peak from Gosford only, but I thought the Govt has said the H-sets will be used for Suburban use only.

Surprisingly in the 1980's before CC trains used the NSL, we got off Platform 3 and walked across to Plat 2, seemed to work quite well and I personally did it from 1982 to 1986 daily to go to school and I'm sure it will again if reintroduced. If the PM, you had to cross the bridge in peak and again seemed to work fairly well and humanity as we know it didn't come to an end.

Ironically the outrage that occurred back then when the Suburban sets were to travel from Gosford via the NSL so people could travel direct via the shore line was no toilets, no high backs, no arm rests, the govt forcing such low standards on longer haul users, oh the humanity.

The D sets will not operate on the NSL in 10 car format as it will delay services through the tunnels, it would be madness to do so and likewise 6 car if capacity through the city tunnels is an issue.

Personally I could the H -sets remaining for a few services (2t/h) during peak from Gosford only, but I thought the Govt has said the H-sets will be used for Suburban use only.

I'm not sure how easy it would be to repeat the practice of the 1980s in present day, with the complete rebuilding of Hornsby yard and the removal of the ladder of single(?) slips at the north end of the platforms. Platform 2 seems to be mainly used for the increased number of Berowra trains. The much greater crowds in recent years make using the steps more of a challenge.

I can only recall Tangara sets on Gosford services, which of course had high back seats and in some cases toilets.

I'm pretty sure that all the H sets will be needed on suburban services. The Tangaras have a very limited future since their chopper equipment is no longer supported by the manufacturer. The C sets were withdrawn before the K sets (whose camshaft controls are still supportable) partly to provide spares for the Tangaras. The Chopper V sets will provide further spares for the Tangaras, and will probably be withdrawn before the camshaft control sets. But even with all this cannibalisation, Tangaras have a limited life unless they are rebuilt with AC traction equipment. And more suburban trains will still need to be purchased to replace the Tangaras.

It might be possible to convert some D sets from six cars to four cars by removing the DT and DNL vehicles to produce eight car sets. Otherwise, a new batch of "outer suburban" Waratahs with toilets might solve the problem.

The D set numbers listed on Sydney Trains TOC waivers suggest a further 136 D set cars will be purchased. These would be 12 further ten car sets and four further four car sets. That would allow two eight car sets for North Shore trains, and a third could be formed using the other separate four car set and one more from the main fleet.

Peter

Butting the "Metro" equipment on the unused platforms I wouldn't think precludes the platforms from potential future use as intended. They are putting that equipment there because its an unused space with no immediate plans for alternative use. I assume this "equipment" is either computer or electronics of sort all of which is relocatable and likely much cheaper than building a new station.

My preference for using 26/27 over 22/23 is also alot to do with the standard of the station, from personal experience, using 22/23 with suitcases basically sucks, access and platform width is all substandard. While there are some comments that 26/27 is not suited being a bit narrow, it is 1000 x better than 22/23.

I also don't buy the reported weight of modern trains comments that I've read over the years. I mean seriously, the station was built at the same time as the rest of the ESR which was designed for DD's and as far as I'm aware has not have red rattlers in regular use on the line ever. Meanwhile the 100 year old Townhall and Wynyard stations built using rivets, no issue, hell they even have had freight trains using the stations.

I'd like to think you're right, but a separate services tunnel was bored through from the metro station box under Central Walk, so I don't know how feasible it would be to relocate the equipment now being installed on platforms 26/27.  I don't think it's just for computers or electronic equipment.  Still, it's a short sighted decision IMO, which may cut off possible future options such as diverting the Airport Line.

All of the current Central Suburban platforms (16-23) are being connected by twin sets of escalators and lifts with Central Walk, so I don't think the access for those with suitcases will be an issue.  The overall accessibility for the suburban platforms will be greatly enhanced.

The main issue with using platforms 26/27 seems to be for fire and safety reasons, but that's a bit of a furphy considering that platforms 24/25 on the lower level on the ESR would be more of a risk.  This could largely be overcome by installing more escalators.  I agree that the weight of the trains is a non-issue.  All sorts of reasons have been thrown up about how 26/27 can't be used, rather than how they could be adapted for possible future extensions.

Quadding beyond East Hills is certainly do able and can be left for the future as needed.

Agree, extra services connecting to Airport via Leppington would certainly make sense, as the stopping pattern Glenfield to East Hills is the same as SW so only need quad if capacity issue.

So summary
- T9? - East Hills / BC Airport via Mascot Airport to St James terminating in peak, via Outer CC in off-peak

- T8 SW services would be on the western pair of tracks north of Wolli Creek, stopping only Sydneham into Outer CC

- T4 Cronulla / Waterfall / South Coast via western pair of tracks from Hurtsville to Eskinville

- T4 Hurtsville - Eastern Pair of tracks all to BJ

Longerterm I'd also be completing the 5km Sexupt from Wolli Creek to Eskinville (no need for building new platforms) to enable T8 to operate segregated from T4 and allow growth on both T4 and T8 and their respective interurban services. Potentially the IU services could share the new tracks like the Western corridor.

I agree with your summary, except that it is proposed T4 Cronulla/Waterfall services will cross to the eastern track pair (Main) at Wolli Creek, merging with the T4 Hurstville all stoppers to Bondi Junction.  South Coast Intercity services, except for the Thirroul service for the time being, will continue on the western track pair (Local) to Erskineville, crossing to the Dive to Sydney Terminal.  The T8 and South Coast services will share the western track pair from Wolli Creek Junction to the Illawarra Dive stopping only at Sydenham.  There would be spare capacity for future direct Southern Highlands Intercity services to ST once electrification is extended.  T4 and T8 suburban services would be totally segregated.

In view of the government's recently released proposal to run all T8 services via the Airport Line up to 18tph (prior to the signalling upgrade) it's still unclear what will happen after the upgrade (ATP/ATO) is completed as far as any T8 services continuing via Sydenham to the City Circle.  It will depend on whether the Airport Line can be upgraded further to increase frequencies to 24tph, in which case the Illawarra Local from the Illawarra Dive to Central will virtually become redundant.

I don't think there's any need to complete the sextup from Wolli Creek to Erskineville. Aside from the fact that the Local would potentially only be handling T8 and the limited number of SCO/SHL Intercity services (T4 crossing from the Local to the Main at Wolli Creek), there would need to be a tunnel constructed under the XPT maintenance centre and the former Bankstown Line platforms which have been taken over by the metro.  T4 and T8 would already be separated between Wolli Creek and Erskineville on the Main and Local respectively.

The future operation of direct Central Coast Intercity services via the North Shore Line is still to be confirmed.  I would be extremely surprised if any 10 car D sets were used, for reasons already expressed.  The only options I can visualise are either 6 or 8 car sets or all CCN Intercity run to Sydney Terminal via Strathfield.  I don't think it's intended that all peak hour D sets will be 10 cars.  There may be some 6 car sets in the peak and 4 and 6 car D sets will most likely run in the off-peak.

The future operation of direct Central Coast Intercity services via the North Shore Line is still to be confirmed.  I would be extremely surprised if any 10 car D sets were used, for reasons already expressed.  The only options I can visualise are either 6 or 8 car sets or all CCN Intercity run to Sydney Terminal via Strathfield.  I don't think it's intended that all peak hour D sets will be 10 cars.  There may be some 6 car sets in the peak and 4 and 6 car D sets will most likely run in the off-peak.

While having the H sets helps, what proportion of V sets run as eight car trains during peak hours. and what proportion of V sets run as six or four car sets during peak hours?

Clearly part of the problem is that they are attempting to replace two distinct fleets inter-city and outer suburban with a single fleet of inter-city vehicles.

Trying to run V sets on the North Shore as they had run G sets and H sets would have been impractical.

But the D sets can theoretically run on any line with the ability to only operate the appropriate doors for a given station.

London Transport ran nine car tube trains during the late 1930s on lines where all underground stations had seven car platforms. This required two guards per train. I understand that alternate stations were served by either the first seven cars or the last seven cars. This practice was abandoned during WWII largely due to manpower shortages, the inability to supply two guards per train.

In NSW, the decision has been taken that the leading car will stop in the platform, although stopping with one car forward of the platform would allow for a better distribution of passengers into the end cars, and allow better for passengers travelling in cars not in the platform to exit through an adjacent car.

So Adamstown, with a level crossing at the North end of the platform was SP4, but now the southbound platform has been extended to ten D set cars, to avoid blocking the level crossing while the northbound remains at four cars.

This stopping with the leading cars in the platform is a reversal of practice with V sets, where (according to a list I saw recently) V sets usually stopped with the trailing cars in a short platform. So if D sets will run with V sets, presumably V sets will have to stop with the leading cars in the platform.

Of course, the improved passenger information systems and clear digital voice announcements will help passengers find the right cars to exit at their stop. But even for trains stopping at few suburban stations, the last two cars in a 10 car D set should carry indication externally that passengers can exit at only around five or six specific stations.

I have often used the 0755 to Newcastle from Hornsby on Saturdays, and this was often a four car V set. This was the first Northern line service available to early international air arrivals, and the lack of luggage space became obvious. I found that I could catch the preceding (then) Wyong service which was an eight car H set that was virtually empty, and because of the longer running time with anall stations service, I had a short wait at Wyong for the now nearly empty V set to arrive. But I was surprised that all 8 H cars fitted into stations marked SP6 on the PID.....

Peter

I'm not sure how easy it would be to repeat the practice of the 1980s in present day, with the complete rebuilding of Hornsby yard and the removal of the ladder of single(?) slips at the north end of the platforms. Platform 2 seems to be mainly used for the increased number of Berowra trains. The much greater crowds in recent years make using the steps more of a challenge.

I can only recall Tangara sets on Gosford services, which of course had high back seats and in some cases toilets.

I'm pretty sure that all the H sets will be needed on suburban services. The Tangaras have a very limited future since their chopper equipment is no longer supported by the manufacturer. The C sets were withdrawn before the K sets (whose camshaft controls are still supportable) partly to provide spares for the Tangaras. The Chopper V sets will provide further spares for the Tangaras, and will probably be withdrawn before the camshaft control sets. But even with all this cannibalisation, Tangaras have a limited life unless they are rebuilt with AC traction equipment. And more suburban trains will still need to be purchased to replace the Tangaras.

It might be possible to convert some D sets from six cars to four cars by removing the DT and DNL vehicles to produce eight car sets. Otherwise, a new batch of "outer suburban" Waratahs with toilets might solve the problem.

The D set numbers listed on Sydney Trains TOC waivers suggest a further 136 D set cars will be purchased. These would be 12 further ten car sets and four further four car sets. That would allow two eight car sets for North Shore trains, and a third could be formed using the other separate four car set and one more from the main fleet.

Peter-

- They were mostly double slips

- A full C set in 1988 holds the same number as a full A set in 2021

- Plat 2 was also the home of Berowa trains, nothing has changed

- K sets ran to Gosford, lots of photos in google

- I doubt very much the Govt has any interest in "chopping" The D-sets before they even enter service

- The govt won't order more B sets to replace the H sets when they could just as well left some H sets and order more B sets.

The cannibalization program is interesting, thanks.

While having the H sets helps, what proportion of V sets run as eight car trains during peak hours. and what proportion of V sets run as six or four car sets during peak hours?

Clearly part of the problem is that they are attempting to replace two distinct fleets inter-city and outer suburban with a single fleet of inter-city vehicles.

Trying to run V sets on the North Shore as they had run G sets and H sets would have been impractical.

But the D sets can theoretically run on any line with the ability to only operate the appropriate doors for a given station.

London Transport ran nine car tube trains during the late 1930s on lines where all underground stations had seven car platforms. This required two guards per train. I understand that alternate stations were served by either the first seven cars or the last seven cars. This practice was abandoned during WWII largely due to manpower shortages, the inability to supply two guards per train.

In NSW, the decision has been taken that the leading car will stop in the platform, although stopping with one car forward of the platform would allow for a better distribution of passengers into the end cars, and allow better for passengers travelling in cars not in the platform to exit through an adjacent car.

So Adamstown, with a level crossing at the North end of the platform was SP4, but now the southbound platform has been extended to ten D set cars, to avoid blocking the level crossing while the northbound remains at four cars.

This stopping with the leading cars in the platform is a reversal of practice with V sets, where (according to a list I saw recently) V sets usually stopped with the trailing cars in a short platform. So if D sets will run with V sets, presumably V sets will have to stop with the leading cars in the platform.

Of course, the improved passenger information systems and clear digital voice announcements will help passengers find the right cars to exit at their stop. But even for trains stopping at few suburban stations, the last two cars in a 10 car D set should carry indication externally that passengers can exit at only around five or six specific stations.

I have often used the 0755 to Newcastle from Hornsby on Saturdays, and this was often a four car V set. This was the first Northern line service available to early international air arrivals, and the lack of luggage space became obvious. I found that I could catch the preceding (then) Wyong service which was an eight car H set that was virtually empty, and because of the longer running time with anall stations service, I had a short wait at Wyong for the now nearly empty V set to arrive. But I was surprised that all 8 H cars fitted into stations marked SP6 on the PID.....

Peter

The reason for the leading car stopping on short platforms was to get rid of the guard, by retaining this practical the govt clearly intends to leave this door open. Also it may be driven by the fact the drivers should be able to see the station prior to closing the door from a safety point of view, which makes sense. By the looks of the D -sets are following the QR example where the driver actually closes the door, not the guard. Stations like Koolewong, Tascot, Cowan and Wondabyne, the driver is down the road, often in a cutting and completely out of view.

The platform lengths are often under quoted. For example one side of Koolewong is 2 cars, the other 4, but everyone was always told to ride in rear 2 cars. Likewise Tascot was 1.5 cars, but told to ride in rear. Often guards used to simply state Koolewong, Tascot and Point Claire, ride in the rear car. Figuring the regulars know the requirement, the announcement is for the nubes and keeps it simple rather that rattling off each station with its own requirements.

SP6 may also mean for V-sets so 24 x 6 = 144 m, 8 car H set is 160 m. So if the station had a bit of fat or a Vset 6 car, then yep could happen.

Clearly part of the problem is that they are attempting to replace two distinct fleets inter-city and outer suburban with a single fleet of inter-city vehicles.

The irony here is, the new trains are built much more like the H sets, but have the operational limitations of an all V set fleet.

Considering most or all T8 line services will travel via the airport and the Bankstown line will no longer travel between Redfern and Sydenham, would the T4 all-stoppers make extra stops at Erskineville and St Peters? If so would that slow down express services from Cronulla/Waterfall beyond Wolli Creek?

Also, I am pretty sure that part of the reason for the Tangara Technology Upgrades was to replace systems and parts that are becoming harder to find. The C-Set parts are mostly for the chopper V-Sets, maybe for the K-Sets as well where possible. The upgrade is still happening but has been severely delayed as the works are now being done in-house by Sydney Trains at Hornsby Maintenance Centre. T72 and T106 are being utilised as templates for two other 8-car sets. Replacements for the T-Sets won’t be required for a while to come.

Considering most or all T8 line services will travel via the airport and the Bankstown line will no longer travel between Redfern and Sydenham, would the T4 all-stoppers make extra stops at Erskineville and St Peters? If so would that slow down express services from Cronulla/Waterfall beyond Wolli Creek?

Also, I am pretty sure that part of the reason for the Tangara Technology Upgrades was to replace systems and parts that are becoming harder to find. The C-Set parts are mostly for the chopper V-Sets, maybe for the K-Sets as well where possible. The upgrade is still happening but has been severely delayed as the works are now being done in-house by Sydney Trains at Hornsby Maintenance Centre. T72 and T106 are being utilised as templates for two other 8-car sets. Replacements for the T-Sets won’t be required for a while to come.

To achieve the proposed increase in frequency to 24tph with the ATP/ATO upgrade from Wolli Creek to Bondi Junction on the Illawarra Main and ESR, it would have to be a single all stops pattern.  The current T3 Bankstown Line provides this service now to Erskineville and St Peters, so there isn't a need for T4 to also stop there, particularly as the SCO Intercity services also run semi-express to Bondi Junction.

When the Bankstown Line is removed from the Sydney Trains network and with the apparent diversion of all T8 services for the time being via the Airport Line, it's logical that these stations will be served by T4, as the SCO services, with the exception of the single Thirroul service, will be diverted to Sydney Terminal on the Local.  Even with the current signalling, the time saved by skipping a couple of stations is minimal and is hardly worth it.  I expect that with the upgraded signalling, the journey times for an all stops pattern will actually be faster than the current semi-express service.  Erskineville and St Peters will receive a greatly enhanced service of 24tph compared with the current 12tph (10xT3 + 4xT8 alternating between Erskineville and St Peters).

The downside to diverting all T8 services to the Airport Line, if in fact that's the longer term intention, is that T8 passengers won't have the opportunity to interchange to the metro line earlier at Sydenham and will have to wait until Central, with a longer walk to the metro platforms.  

Good to hear that the Tangara Technology upgrade is still proceeding, albeit at a slower pace.

Erskineville and St Peters will receive a greatly enhanced service of 24tph compared with the current 12tph (10xT3 + 4xT8 alternating between Erskineville and St Peters).

The downside to diverting all T8 services to the Airport Line, if in fact that's the longer term intention, is that T8 passengers won't have the opportunity to interchange to the metro line earlier at Sydenham and will have to wait until Central, with a longer walk to the metro platforms.  

Not all T3 services actually stop at those 2 stations in peak hour and the T8 services certainly do not either.

Also I wonder if some all stops or all all stops services from say ashfield or homebush could terminate at Central platform 20.

Also I wonder if some all stops or all all stops services from say ashfield or homebush could terminate at Central platform 20.

No, that move is not allowed as far as I can tell. You need to go around the Circle. I’ll reference the documents and get back to you, but I am sure you can’t terminate and go back.

Not all T3 services actually stop at those 2 stations in peak hour and the T8 services certainly do not either.

Also I wonder if some all stops or all all stops services from say ashfield or homebush could terminate at Central platform 20.

As it's currently configured, obviously no.  Only the road through platform 23 has BiDi signalling, allowing the airport line to operate stand alone.

But re-signalling (which in theory is happening anyway), a trailing crossover from the Illawarra Local UP to the Western Local DOWN somewhere between Redfern and the Flying Junctions would implement that.  IMHO it's a very reasonable suggestion.  As for fitting it in to the rest of the network ... good luck!

As an aside, if the reconfig of Central ever gets any public input/ EIS, I'm going to submit they extend platforms 21 and 23, and incorporate Bi-Di signalling on those, along with double crossovers over the Illawarra Main (or perhaps just the locals - or both track pairs even) between the flying junctions and Redfern, allowing those two redundant platforms to terminate SCO services (and maybe even Highlands trains) without choking - or requiring major modifications to - the yard throat to Sydney Terminal.

No, that move is not allowed as far as I can tell. You need to go around the Circle. I’ll reference the documents and get back to you, but I am sure you can’t terminate and go back.

Checked the docs and asked some people. 22 and 23, you can apparently terminate and reverse on. You can do so from 16/17 to 18/19 with a shunt movement.

Erskineville and St Peters will receive a greatly enhanced service of 24tph compared with the current 12tph (10xT3 + 4xT8 alternating between Erskineville and St Peters).

The downside to diverting all T8 services to the Airport Line, if in fact that's the longer term intention, is that T8 passengers won't have the opportunity to interchange to the metro line earlier at Sydenham and will have to wait until Central, with a longer walk to the metro platforms.  

Not all T3 services actually stop at those 2 stations in peak hour and the T8 services certainly do not either.

Also I wonder if some all stops or all all stops services from say ashfield or homebush could terminate at Central platform 20.

Sorry, I got that wrong. In the peak hour, 4xT3 stop at St Peters and 6xT3 at Erskineville. The 4xT8 via Sydenham services all stop at St Peters, but not Erskineville.  To summarise - St Peters has 8tph in the morning peak and Erskineville has 6tph.  That doesn't change the likely increase to 24tph for both on T4 after the Bankstown Line metro conversion and signalling upgrade, unless they decide to maintain a skip/stop pattern, which is hardly worth it for very little gain.  Just keep it simple with a single pattern.

I don't see the point in terminating some T2 services from Ashfield or Homebush at Central as they might as well continue around the City Circle.  Terminating at Central isn't going to add any increase to T2.  It appears from the recently announced changes after the Bankstown Line conversion (based on current signalling), that the 18tph on T2 via the CC Outer (Town Hall) will balance the 18tph on T8 via the CC Inner (Museum).

No, that move is not allowed as far as I can tell. You need to go around the Circle. I’ll reference the documents and get back to you, but I am sure you can’t terminate and go back.

Checked the docs and asked some people. 22 and 23, you can apparently terminate and reverse on. You can do so from 16/17 to 18/19 with a shunt movement.

I remember vaguely the signals on the 16 - 19 many years back. The track work still looks like its set up for it. I can only assume thats its there in case of a major screw up with the tunnels in that all incoming lines can terminate at Central and return.

I remember vaguely the signals on the 16 - 19 many years back. The track work still looks like its set up for it. I can only assume thats its there in case of a major screw up with the tunnels in that all incoming lines can terminate at Central and return.

It is, from P16 you shunt past SY 364, from P17 you shunt past SY 366, then you can come back via 617 and 618 points to P18, and 619 points to P19.

No, that move is not allowed as far as I can tell. You need to go around the Circle. I’ll reference the documents and get back to you, but I am sure you can’t terminate and go back.

Checked the docs and asked some people. 22 and 23, you can apparently terminate and reverse on. You can do so from 16/17 to 18/19 with a shunt movement.

Thanx for that.  I just checked the DRKD - and indeed the old one from 2011 I use because it's all in one indexed PDF, and didn't realise platform 22 is also BiDi.  The arrow on the diagram is only in the DOWN direction (which is what fooled me), but clearly crossover 636 (Illawarra Local Down to Airport Down) is BiDi.

If the Airport Line can be upgraded to 24tph with the resignalling, then that pretty much spells the end of T8 via Sydenham services except for track maintenance and emergency diversions.  The Illawarra Local from Wolli Creek Junction to the Dive to Sydney Terminal at Erskineville would then only be used for SCO and possible future direct SHL Intercity and South Regional services, which would be way below its potential capacity, possibly as much as half, which seems such a waste.  

I get the feeling that they want to eliminate merging from the Illawarra Local via the flying junctions at Central altogether, so that there's a simple continuous through pattern from the Inner West Local to the Airport Line via the City Circle.  It's not a bad idea when you think about it, subject to the feasibility of upgrading the Airport Line further to what is currently proposed (18tph).

It still leaves open the option of running dedicated express trains, possibly SD, from the new airport to Sydney Terminal via Sydenham.

As an aside, if the reconfig of Central ever gets any public input/ EIS, I'm going to submit they extend platforms 21 and 23, and incorporate Bi-Di signalling on those, along with double crossovers over the Illawarra Main (or perhaps just the locals - or both track pairs even) between the flying junctions and Redfern, allowing those two redundant platforms to terminate SCO services (and maybe even Highlands trains) without choking - or requiring major modifications to - the yard throat to Sydney Terminal.

Why would you want to do that?  It just complicates things more than they already are.  I honestly don't know what the future plans are for platforms 20 and 22 serviced by the Ill Local, but they could still have limited use when the Airport Line is shut down for maintenance.

There's next to no chance that they could be used to terminate SCO or SHL Intercity services, as the whole point in constructing the crossovers from the Local to the Main and Dive at Erskineville is to allow them to have a direct run into Sydney Terminal.  

As explained earlier, the yard throat to Sydney Terminal is likely to have 2 track pairs from the Western Main, which includes the Illawarra Dive, and the Suburban tracks.  All other tracks between Redfern and the Central flying junctions would be slewed across in parallel.  It could be done progressively, particularly when the Illawarra Local and the Main will effectively be out of use.  The Ill Local would be slewed to the Main through platforms 9 & 10 at Redfern; the Inner West Local through platforms 7 & 8; the Suburban through platforms 5 & 6 and platforms 3 & 4 linked directly to the second track pair at the Sydney Terminal yard throat.  I can't see it creating any major disruption to existing services once the Bankstown Line is taken out of the equation.