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Author Topic: Seven car trains  (Read 1964 times)

Offline OzGamer

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Seven car trains
« on: December 03, 2013, 12:04:15 PM »
Hi, long time lurker, second time poster.

I've been reading these forums with interest for some time and I thought it time to raise/discuss some issues that have arisen recently.

I am interested in a discussion around the possibility of introducing seven car trains into the SEQ commuter network. I note that there are some strong feelings around this and I am interested in hearing arguments on both sides. My feeling is that seven car trains are a good option for the following reasons:

1) It is an incremental increase, which would presumably make many operational matters simpler, such as dead running, movement into and out of stabling etc
2) Many stations, particularly new ones such as on MBRL, are built with 175m platforms which could probably support seven car trains with no alteration.
3) Most stations could have their platforms extended to support seven car trains with a simple bit of concrete in the existing alignment, which may not be the case for an increase to support nine car trains.
4) Existing platforms could support seven car trains through the simple expedient of locking the first and last doors. This would certainly work at stations with light loadings, meaning they may never need upgrading.
5) It appears that the NGR trains are to be built as six car consists, rather than two three car consists joined. That being the case, there is no longer any particular reason to think in terms of 3, 6 or 9 car trains. Any number of carriages can be put together in principle.
6) While I don't know, I think it may be possible that seven car trains could use the same traction as existing six car trains with little decrease in performance, meaning existing IMU/SMU 160/260s could potentially be modified in the future.

If UBAT is buillt to support seven car trains, I would think a staged program of upgrading stations to seven car platform lengths, starting with Gold Coast and MBRL stations and major/busy stations on the lines that will probably use UBAT such as Caboolture, Petrie, Northgate, Beenleigh, Loganholme and progressively moving to less busy stations, possibly never doing minor/lightly used stations, and maintaining the locking of unused doors operation.

Any thoughts? (Please be nice)

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Re: Seven car trains
« Reply #1 on: December 03, 2013, 12:19:50 PM »
The difficulty comes that our trains aren't built to be seven car trains, either 3 car, 6 car, 9 car or 12 car sets (9 car and 12 car sets being only seen when they are being shunted around the yard).  The NGR units will be fixed 6 car sets, so seven car sets is unlikely unless you rebuild them to do that.  And anyway, seven cars aren't really that impressive in increasing capacity on a train, you might as well go 9 cars and take out some of the seats in the cars to get more capacity in the train (among signalling and more infrastructure).

Offline aldonius

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Re: Seven car trains
« Reply #2 on: December 03, 2013, 01:27:21 PM »
There's certainly quite a few knee-jerk reasons not to do 7 cars.

Eg, as with 9 car trains, there are some lines with stations which 7 cars might be too long for, even if you do lock one carriage. I'm thinking of Mitchelton in particular here - level crossings immediately either side. Not entirely sure if Central's platforms are long enough either - they're slightly longer than the train, but not by a whole carriage, surely. Have fun extending that!

Of course, if we restrict them to UBAT lines only, things are slightly better, but also the 'fewer stations to upgrade' argument diminishes...

Offline OzGamer

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Re: Seven car trains
« Reply #3 on: December 03, 2013, 02:10:27 PM »
The difficulty comes that our trains aren't built to be seven car trains, either 3 car, 6 car, 9 car or 12 car sets (9 car and 12 car sets being only seen when they are being shunted around the yard).  The NGR units will be fixed 6 car sets, so seven car sets is unlikely unless you rebuild them to do that.  And anyway, seven cars aren't really that impressive in increasing capacity on a train, you might as well go 9 cars and take out some of the seats in the cars to get more capacity in the train (among signalling and more infrastructure).

I guess my point was that while going from six to seven only gets you a 17% capacity increase and nine gets you 50%, going to nine car sets is probably an order of magnitude more difficult on existing lines for the reasons I stated above. Many more stations would need things like track realignments, property resumptions etc, whereas for most if not all of the required stations, going to seven cars might only mean a bit of concrete at the end of the platform.

Offline OzGamer

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Re: Seven car trains
« Reply #4 on: December 03, 2013, 02:16:08 PM »
There's certainly quite a few knee-jerk reasons not to do 7 cars.

Eg, as with 9 car trains, there are some lines with stations which 7 cars might be too long for, even if you do lock one carriage. I'm thinking of Mitchelton in particular here - level crossings immediately either side. Not entirely sure if Central's platforms are long enough either - they're slightly longer than the train, but not by a whole carriage, surely. Have fun extending that!

Of course, if we restrict them to UBAT lines only, things are slightly better, but also the 'fewer stations to upgrade' argument diminishes...

If the system is strongly sectorized post-UBAT, it's quite conceivable that only the UBAT sector would ever use longer trains. ie it may be that the Ferny Grove stays with six cars for ever, meaning no need to ever upgrade any of those stations. Likewise it's difficult to imagine needing the capacity on Doomben or Shorncliffe trains.

Generally speaking you want to increase frequency first. I would only advocate longer trains on lines which were already operating at 6-8 minutes in peak and were still experiencing overcrowding, which is none yet.

Offline Derwan

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Re: Seven car trains
« Reply #5 on: December 03, 2013, 02:29:39 PM »
Before you consider any increase in train length, you have to consider things such as signal locations and block lengths.  Some signals are located at the end of the platform meaning that a 7-car train (with front door closed) cannot stop at the platform unless that signal is clear.  6-car trains can stop at the platform even if the signal is red.

There are a number of blocks that are just long enough for 6-car trains.

If you're looking at making major modifications to allow for longer trains - including signalling and allowing the larger trains to take up 2 blocks - wouldn't you go the extra mile and make them 9-car trains?  Why spend all that money for (as OzGamer points out) a 17% capacity increase?

As OzGamer mentioned, you could possibly identify certain corridors (using UBAT) where 7-car trains could be used exclusively.  But what happens during system-wide issues where trains need to be swapped around?  It would be difficult to have some 6-car and some 7-car trains.  (Granted it wouldn't be that easy to split 9-car trains while in service - but at least it would provide SOME flexibility.)
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Offline mufreight

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Re: Seven car trains
« Reply #6 on: December 03, 2013, 04:39:39 PM »
obviously not a lot of practical thought from some of these posts, at present 6 car sets are made up of 2 x 3 car sets, the NGR sets are to be fixed 6 car sets which in all probability will not be MU compatible with the existing 160 / 260 series sets so where are the additional cars to come from to form these 9 car sets and still maintain operational flexibility.
The logical option is that instead of the foam 7 and 9 car sets improved frequencies and given the nature of the services operated by QR three doors per carriage is less than practical, dwell times can be reduced by some 20% by having platforms at carriage floor height making them fully DDA compliant as well, something that can readily be achieved at minimal cost when stations are refurbished.
It will be interesting to see what eventuates at Graceville and Dimnore

Offline SurfRail

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Re: Seven car trains
« Reply #7 on: December 03, 2013, 05:14:18 PM »
^ Fixing Central platforms 1-4 alone would probably create a noticeable improvement in dwell time.

3 doors would also allow for significantly better passenger circulation, but if the NGR stock will be mainly configured effectively as IMUs it seems unlikely that will be happening.

Perhaps something for the order following the NGR stock post-UBAT, when there will be 2 surface sectors and only limited amounts of express or longer range running on either one.
« Last Edit: December 03, 2013, 10:45:23 PM by SurfRail »
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Offline HappyTrainGuy

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Re: Seven car trains
« Reply #8 on: December 03, 2013, 08:14:24 PM »
obviously not a lot of practical thought from some of these posts, at present 6 car sets are made up of 2 x 3 car sets, the NGR sets are to be fixed 6 car sets which in all probability will not be MU compatible with the existing 160 / 260 series sets so where are the additional cars to come from to form these 9 car sets and still maintain operational flexibility.
The logical option is that instead of the foam 7 and 9 car sets improved frequencies and given the nature of the services operated by QR three doors per carriage is less than practical, dwell times can be reduced by some 20% by having platforms at carriage floor height making them fully DDA compliant as well, something that can readily be achieved at minimal cost when stations are refurbished.
It will be interesting to see what eventuates at Graceville and Dimnore

It's way down the line before we start seeing 9 car sets. Depending on the electronics etc onboard the NGR rollingstock they might be in a position to modify the then old NGR rollingstock by adding an additional 3 carriages to the middle with the middle car being the power unit - similar to the existing ICE power pairs (P-T-T-T-P-T-T-T-P) or just build fixed 9 car sets to run on selected lines.

As far as I know 9 car sets were planned to only be used on certain lines where frequency would take a hit in favor of the longer higher capacity rollingstock. An easy example would be instead of running every 5 mins with 6 cars run it every 7 or 8 minutes with 9 cars. It could be applied to MBRL taking over Albion-Petrie with Petrie-beyond merged into 1 new route running Strathpine-City via NWTC to the City. As I said earlier its still a long way down the line and I doubt they'll go to the extent of modifying stations, signaling, crossovers etc to accept 1 car more for the short run when they could spend the same amount on just applying it to a handful of stations.
« Last Edit: December 03, 2013, 08:32:18 PM by HappyTrainGuy »
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Offline OzGamer

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Re: Seven car trains
« Reply #9 on: December 04, 2013, 08:47:15 AM »
obviously not a lot of practical thought from some of these posts, at present 6 car sets are made up of 2 x 3 car sets, the NGR sets are to be fixed 6 car sets which in all probability will not be MU compatible with the existing 160 / 260 series sets so where are the additional cars to come from to form these 9 car sets and still maintain operational flexibility.
The logical option is that instead of the foam 7 and 9 car sets improved frequencies and given the nature of the services operated by QR three doors per carriage is less than practical, dwell times can be reduced by some 20% by having platforms at carriage floor height making them fully DDA compliant as well, something that can readily be achieved at minimal cost when stations are refurbished.
It will be interesting to see what eventuates at Graceville and Dimnore

Well, with respect, I don't think considering seven car trains is foam, as that is what the government seems to be foreshadowing in the discussions around UBAT. My point is that it seems as though seven car trains could in fact be quite practical on some lines given designs built into UBAT and the nature of existing Gold Coast and future MBRL stations, for example. I was, in fact, drawing a distinction between what I see as a potentially achievable move to seven car operation on some lines in the medium term and the far less practical move to nine car trains that some people seem to advocate.

I don't see why the NGR contract couldn't be varied to enable some of the later deliveries to be built as seven car trains new or designed to have an extra carriage inserted after a few years. I believe these are due to be around 2017/2018 at the earliest, only a couple of years before UBAT is due to open, so some planning now could see infrastructure and operations ready for them to be used effectively within 5-10 years.

Obviously things like level platform heights, more doors per carriage, internal layout changes and station design changes can all be done in parallel. The benefit of increasing the total capacity of the vehicles themselves is that it would be much cheaper to operate six seven car trains than seven six car trains, and once you're at about 6tph in peak, increasing frequency doesn't really change the usability of the service that much. Who really cares if there's a seven car train every ten minutes rather than a six car train every eight?

Offline HappyTrainGuy

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Re: Seven car trains
« Reply #10 on: December 04, 2013, 12:38:45 PM »
It actually sort of is. Because it's just not practical to have 7 car trains running. 15 stations would have to be modified before Petrie could run 7 car trains on to the MBRL. 12 station modifications of which become redundant if a NWTC happens to be constructed. The expense to modify the existing network for signaling/station modifications and extensions, rollingstock and rollingstock facilities such as stabling and mtce facilities, downtime for these modifications and the general cost far outweighs the benefit. As I said in my post the thing with 9 car trains is that they would only be applied to lines where frequency gets cut in favor of capacity (typically the longer distance lines between cities) utilising new railway corridors - many of which are set for upgrades in the future where additional capacity would be needed rather than the frequency which already has rollingstock running at 100kph or faster.

One big and very huge factor you are forgetting about on the MBRL is that the stations might be getting built a little longer but the signaling and station corridor design is to be based on a future provision of a full 9 car set running via NWTC.

NGR is to be up and pumping out rollingstock in a couple years. NGR would keep pumping out sets to keep up with expansion, frequency boosts etc but as soon as it got to a fixed number when the reliability of the NGR has been sorted out for across the network the EMU phase out phase would begin while the remaining NGR sets continue to come online. You have to remember the order is only for a few extra trains. It's not a very big order in the grand scheme of things.

9 car trains are still well off. The network just isn't set up for it and either is the current patronage. 9 car sets would come into its own when the network can fully take advantage of future expansion.
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