How many tracks?

“Skyrail” blog coming in a day or two, but first another related issue to cover: How many tracks is best?

Single track can work for very infrequent rail services, but in a suburban setting, with frequent services, causes problems.

Witness the Altona Loop — the single track (with passing loops) severely limits the number of trains that move through — a maximum of three trains per hour in each direction. Even during normal operations, trains have to wait for each other at passing loops (the photo above is at Westona).

Any little delay can quickly escalate, so Metro often have trains bypass this section altogether, leaving 44+ minute gaps in the middle of peak hour. The latest Track Record quarterly report says this happened 393 times in the year to September 2015.

Single track really has no place on a modern suburban train network. Puffing Billy? Sure. But not Metro. Yet it persists on the Altona Loop, and lines to Upfield, Hurstbridge, Lilydale, Belgrave and Cranbourne.

Double track is obviously the default, allowing trains in both directions without causing delays. Express running (including for long distance trains) can be tricky to manage — the Dandenong line manages a bit of this, but at peak times the V/Line expresses are little faster than the stopping trains.

Glenhuntly station in the fog, June 2005

Three tracks was fashionable in Melbourne up until the 1980s, with prominent examples on the Ringwood and Frankston lines. Expresses can overtake slower trains in one direction only.

The catch is that since the 1990s, the amount of inner-city stabling has been reduced markedly, so all those trains need somewhere to go between peak hour runs. This is problematic with three tracks — in the morning the single outbound track gets congested; this can result in delays and clogged level crossings, and may be problematic when aiming to connect outer suburban centres like Dandenong and Ringwood with express trains (in both directions) from the inner city.

Four tracks is now what they’re moving to when building for extensive express running. Separate track pairs can isolate different lines and/or keep stopping and express trains apart.

City to Footscray expanded from two tracks to four in the 1970s. With Regional Rail Link, it expanded again to six.

So when you look at lines like the Dandenong line, remember: it’s two tracks now (and the “Skyrail” will initially also be two tracks). But planning and provision for future expansion will be for four tracks, not three.

By Daniel Bowen

Transport blogger / campaigner and spokesperson for the Public Transport Users Association / professional geek.
Bunurong land, Melbourne, Australia.
Opinions on this blog are all mine.

25 replies on “How many tracks?”

Hi Daniel,

Was it explicitly stated that there would be provision for an extra 4 tracks in the elevated Dandenong design? It wasn’t mentioned anywhere that I could find. I guess it would be simpler than adding those extra tracks in the so-called ‘trench’ option though.

I reckon that (until the duplicate it) the Altona loop should run one-way only in peak hour (obviously going inbound in the morning and outbound in the afternoon), with the reverse journeys running on the express line.

In the morning, anyone wanting to go from the loop to Laverton or south, or to the loop from Newport or north could either double-back, and/or you could have a bus doing the reverse journey. Vice versa for the afternoon. Any inconvenience to those people is significantly outweighed by the number of people who would benefit from a more frequent and more reliable commute to and from the city.

I’m not sure if you’re aware but Kingston City Council Moorabbin Station Precinct plan apparently has provision for a 4th platform with a layout similair to Burnley. Would be good if it happened, 4 tracks from Moorabbin to Caulfield would allow for more reliable express trains in both directions. I believe the grade seperations at Ormond, McKinnon and Bentleigh have passive provision for a 4th track.

Life is confusing enough on the Altona loop currently without adding yet another option. City bound you catch anything that comes along but in the opposite direction you need to know which train you’re looking for. Werribee, Laverton, the Laverton shuttle. Adding a bus at certain times of the day would make it even more abominable. We don’t need to drive patronage lower, the current timetable has already done this. It’s not a huge project to partially duplicate it, just get on with it!

*** Altona loop & Single track sections ***

I do not mind the Altona loop staying as single track. You have trains to service just three stations, so frequency would not need to be great.

As for when they stop all stations into the city, yes, that is a point, but there should also be Williamstown line trains there too.

I would push more towards duplication between Westona and Laverton, and keep the rest single. Mostly because Westona to Laverton is wide and open, and you can have some tolerance in punctuality when you have a long loop rather than a short one.

Same or similar would be with the Alamein line too.

Cranbourne line may need longer loops soon. The Merinder Park railway station was built with duplication in mind. That would provide an opportunity for an additional loop to be put into the line, as well as putting wires above the freight track at Dandenong South. That could be used by Metro during peak hours only?

I prefer to see more railway lines, suprs and branches constructed than have duplication done.

**** Re 4th track ***

I want to push the LevelCrossing Removal authority to include funding and inclusion of the third and fourth tracks to be laid with the skyrail project. We are well overdue for those extra tracks.

On those busy sections, I would rather a fourth track than just three, especially the longer inner sections such as those expressed above.

Newport to Footscray could do with a third track. A middle track that is express only and bidirectional. should V/line trains need to be directed via Newport, and the short length of this route should still enable most Werribee line trains to make use of it too.

Daniel, I’m looking forward to your article and analysis of the Skyrail project, I live adjacent to the line and as with most other affected residents, we’re only learning about the development through the press. Can you comment on the various “artists impressions” of the road crossings from Koornang road to Poath road on the level crossing authority website, to my mind the clearance depicted from the road to the base of the concrete only appear to be about 4m at most, which I would have thought would lead to problems with truck clearances.

Box Hill to Richmond manages to have counter-peak expresses in the afternoon without any overtaking. Around 5-6pm there are two express and one all stations services every 15 minutes. How well this works in practice I’m not sure as I don’t travel on this line very often, but I wonder if you could use a similar system for other lines.

Otoh, I don’t know why they bother to have a whopping 3 Richmond-Darling express services per day on the Glen Waverley line to save a paltry 3 minutes.

@ Daniel – well written.

@ Dgusten – you’re the second person I’ve seen in favour of the concept, and it could work because Newport South to Werribee, both tracks are signalled in both directions. Newport South junction at Champion Rd would end up congested especially in the morning peak, so it really needs a proper analysis to prove it could work, but my gut feel is that timetable slots ‘wasted’ there might be a good opportunity to add the Williamstown trains at Newport.
@Jen – with this pattern, it would probably be a 20min service outside of peaks. AMP 5min-or-so service stops all to city but nothing outbound, change at Newport for Werribee or bus/drive to Laverton. PMP opposite – 5min-or-so service stops all from city, nothing inbound, change at Laverton for city services or bus/drive to North Williamstown or Newport, whichever is more convenient.

@ Michael – can you provide any further details? Also, four tracks doesn’t have to mean four platforms – it would make more sense to have four tracks with a single island platform in the middle for stopping trains, and expresses running on the outside. That saves width and costs associated with things like lifts and escalators, and the curve speeds for the express trains to go around the stopping tracks are not particularly significant. In any case, the stopping tracks would be used only for Metro (not necessarily MTM) stopping trains, up to a train every 4min because of the merging required at Caulfield; the outside express tracks could be used for express, empty movements for workshops, V/Line, freight and anything else as required, probably in the range of 6-10 trains per hour in normal circumstances due to merging Caulfield, and allowing for different power/weight ratios, maximum speeds etc.

@Jim – linking Westona to Laverton Loop makes sense; but with the level crossing being grade separated anyway, we might as well use the opportunity to duplicate from Altona Junction to but excluding the Cherry Lake runoff. Those together would be sufficient for a 15min service comfortably; it doesn’t fit the standard 10/20 headways so the extra capacity is really futureproofing plus a bit of breathing room.

Re Merinda Park, I have to wonder if the works on the South Morang line act as a precedent for duplicating the Cranbourne line – will the level crossings between Dandenong and Cranbourne all need to be grade separated, or not?

@Nick – Using 3rd track Burnley to Box Hill can allow for expresses overtaking stoppers in both directions, but the maximum service is around 10min in each direction with little to no breathing room. Depending on City Loop direction, it can work with both 3-track sections pointing towards Camberwell (outbound trains overtake around Hawthorn, inbound overtake around Cantebury, Loop clockwise), or both tracks pointing away from Camberwell (reverse). But there are limits on stopping patterns, and reliability penalties because it only works if the whole schedule is on time. One late train can cause problems for hours. Lilydale, Moorolbark, Box Hill and Alamein would run every 20 minutes, and Belgrave every 10 minutes. Box Hill and Alamein would stop all, with the other three running express Box Hill – Camberwell – Burnley.

For what it’s worth, if 10min services is all we want, then four tracks Caulfield to Southland, three tracks Edithvale to Carrum (two outbound, one inbound) and four tracks Carrum to Frankston should be sufficient to allow for freight and Stony Point extended to Southern Cross. But that doesn’t allow for peaks, and has reliability issues. It can be made to work with three tracks Caulfield to Southland, with great difficulty and crossovers either side of McKinnon, requiring overtakes at Glenhuntly and Patterson-Moorabbin with a ridiculous degree of precision. Basically, if one of four trains is late by as little as 90 seconds, you’ll end up with four trains trying to get through McKinnon station with only three tracks. One will have to wait, and that causes cascading delays through the rest of the timetable, like skipping pebbles across a lake.

Below is an analysis I put together of 2/3/4 tracks between Caulfield and Frankston, with respect to express and freight provision and infrastructure required. Gives an idea of the difficulties of providing a mixture of stopping/express trains with only three tracks.

Concept: 10min Cheltenham-Loop plus 10min Frankston express-direct service. No freight whatsoever.

If the down express departs Richmond at 10:23, then the down stoppers either side must depart 10:15/16/17 and 10:25/26/27 to allow for overtakes at Bentleigh, McKinnon, Glenhuntly respectively.
If the up express arrives Richmond at 10:48, then the up stoppers either side must arrive 10:44/45/46 and 10:54/55/56 to allow for overtakes at Patterson, McKinnon, Ormond respectively.
Obviously for both of these to occur, additional pointwork must be added in the section McKinnon-Bentleigh, with down overtakes at Glenhuntly and up overtakes at Patterson.

In all cases the restriction is catchups between South Yarra and Richmond, plus the length of the overtaking track. Extending the third track from Moorabbin makes Patterson overtakes more reliable, but otherwise has no bearing.

This does NOT take into account faster speeds post-removal of Glenhuntly tram square, or changes in section times due to new gradient profiles. Also, there is no capacity for freight trains – they would need to be under curfew, effectively banned from running through daylight hours. Also assumes current Caulfield operation, with no interaction between Dandenong and Frankston lines. V/Line Traralgon trains would need to cross from Richmond 5/6 to Flinders Street 8/9/10, rather than anything near Caulfield.

Headways are currently 1.5min behind express or 2.5min behind stopping, Richmond-Caulfield; then 3min Caulfield-Frankston, except centre track Caulfield-Moorabbin which is 3min behind an express or 5min behind a stopping train. If that was changed to a flat 2min, then it might be possible to fit two stoppers for each express, i.e. 10:13e, 10:15, 10:17, 10:23e, 10:25, 10:27, 10:33e etc on the down through Richmond. The key would be terminating capacity.

If the stopping train is extended to Mordialloc, then the express train can be changed to Mordialloc-Southland-Caulfield-South Yarra. A third platform at Mordialloc would be ideal but perhaps not critical; trains would terminate in Platform 2, wait 2min to make sure all passengers are clear, then run into the yard. During that 2min, the next citybound stopper will have made its way into Platform 1. At the three-minute mark the down express will need Platform 2, and at minute 5 the up express will need Platform 1. Worst-case scenario, the down express may have to run along the centre track and skip Mordialloc. That might make enough difference in headways. The level crossing down end Mordialloc station would be closed for six of every 10 minutes, conservatively. This also requires down overtake at Glenhuntly, up overtake at Patterson. The other two paths outlined above with resignalling could be used as Moorabbin/Southland/Cheltenham/Mordialloc, for a three-tier solution.

If the stopping train is extended to Carrum, then the express train can be changed to Carrum-Mordialloc-Southland-Caulfield-South Yarra. This also works perfectly fine with two tracks Moorabbin (or Highett) to Carrum, except that the down express will have caught up and there’s no easy terminating facility at Carrum, clear of the mainline. To solve this problem, you will need two down tracks Chelsea-Carrum, plus a centre turnback per Watergardens/Wyndham. One up track is sufficient.

If the stopping train is extended to Frankston, then the express train can be changed to Frankston-Carrum-Mordialloc-Southland-Caulfield-South Yarra. This needs two down / one up track from Chelsea to Carrum, then four tracks (two each way) Carrum all the way to Frankston. The express and stopping trains in both directions end up running practically parallel for this length, because of the higher track speed limit south of Mordialloc and the further station spacing.

To allow any freight whatsoever, four tracks to Moorabbin, preferably further will be absolutely necessary. This allows the freight trains to be included in the overtake moves between Caulfield-Moorabbin, either on the express or slow lines. The cost cannot be justified by the existing freight traffic, but Port of Hastings, Frankston Activity District and Express trains from Stony Point together will be more than enough.

My long term concept is for four tracks from the city to both Dandenong and Frankston – two tracks down the centre for stopping trains, approx. every 4 minutes merging to two minutes at Caulfield and running via the loop; and the outside tracks for express trains (inc. V/Line) plus freight, empty car transfers and everything else under the sun, adding to a total of perhaps 20tph. This would start with Caulfield-Moorabbin, then stage 2 would be Moorabbin to Cheltenham plus Chelsea to Frankston, then work towards the middle.

Restrictions on current infrastructure as of 2008:
Cheltenham – prefer terminate Platform 1 except during occupations for access, but 40 km/h diverge limit.
Mordialloc – All down trains departing Mordialloc are restricted to 40 km/h because of the placement of Platform 2. Could be resolved by removing current track through Platform 2 and extending the platform surface to meet the current middle track.
Chelsea – signalbox still active, but has been running on automatic for nearly 30 years. Extra point of failure.
Carrum – easy to depart sidings, difficult to enter due to track layout. Cannot depart west-edge siding after 7am because it (somehow?) causes loss of overhead power on Up line – worth checking if still true.
Frankston – maintain clear track for freight; Siding B (northwest of station) – trains not to enter or depart 0000 to 0600hrs; possible restriction/conflict

Mordialloc – 4 trains
Carrum – 6 trains
Frankston – 6 trains

Can I ask why was three tracks fashionable also doesn’t that also cause more things to go wrong since one track requires bi-directional signalling. Also it requires trains to slow down to cross-over points to access the third track. Three tracks are not at all ideal. Wasn’t more simple to have four tracks.

It also kind of matters with the four tracks in terms of layout for example up main, down main, up local, down local or up main, up local, down local, down main. Operation wise it kind makes a difference.

As someone who live near Laverton station, the Altona Loop issues doesn’t affect me as much as most other Altona Loop commuters. However, as a regular weekend user of the Werribee Line, I noticed a few issues with the single tracked Altona Loop. Trains are often forced to wait near the Altona junction, at Westona station or at the Laverton junction when there is an extended delay in the train coming the other way.

I know there is a lack of political motivation seeing that this involves a safe seat belonging to the government, who is also occupied with the removal of 49 other level crossings. However, I would like to see future planning put into alleviating this issue in stages. Another passing loop at Seaholme would be ideal (with a second platform of course), plus the duplication of tracks at either end of the loop.

Making the Altona loop one-way during the peak hours sound like a workable idea and I think it might improve the service we have there today, however, I have 2 issues with it:
1) Passengers who have to commute the other way will instead jump into their cars (if they can afford to) since traffic is in their favour the other way), or take the bus to Laverton station (not that that’s a bad thing) and take a longer commute.
2) I think the true bottleneck is actually at the Newport – Footscray portion. In the peak hours, technically 3 lines run this route – the Werribee (express Laverton to Newport), the Altona Loop (Laverton via Altona to Flinders St) and the Williamstown line. There used to be a fourth – the V/Line plied along this route prior to the Regional Rail Link realignment.

@Tranzit Jim

On my journeys through Newport to Yarraville, I’ve noticed that there must be some provisions for a future expansion but it looks quite unlikely now with the current developments. It looks like if they’re willing to shut the line for a couple of months, they could put retaining walls, realign the tracks and put in a third and maybe even a fourth track. However, if you want to put a middle express track, you’ll need to tear down some stations to do this.

@Ilham, three tracks is cheaper than four. That’s why it was popular.

The best outcome Caulfield-Dandenong is two stopping tracks with an island platform, and express tracks on the outside. That means it’s easy to provide turnbacks on the stopping lines, avoiding conflicts with the express trains from further out (which are far less likely to need any such facility).

A Seaholme loop might help, but I think the point of Daniel’s previous post was that building temporary infrastructure is probably a waste. We need to decide at what point we’re going to duplicate/elevate the entire line, and if so, will it still be heavy rail, or is light rail more suited due to easier construction and the ability to, say, extend above Point Cook road?

@Arfman, the capacity limitation isn’t Newport-Footscray, but Newport and Altona Junctions. Without those, and with additional signals between Newport and Werribee, 20 trains each way each hour to Werribee would be viable depending on turnback/terminating facilities (especially since Werribee’s three platforms are now always available). Aside from the junctions, secondary limits are the single track on the Westona Loop, and the single platform at Williamstown.

As for the third track concept, there is also a plan available on Peter Vincent’s website (though I’m having trouble finding the URL at the moment), showing a third track proposed on the south side of what was then Footscray platform 4, now platform 6. Reference BJ883. If the 3rd track were added today-
Footscray – a platform 7 could be added on the south face of current platform 6, though it would mean another extension of the bridge for access.
Seddon – Shift station building citybound southwest about 45m to plot 31-41 Pentland Pde, demolish footbridge and outbound platform building. Then shift both tracks, both platforms west about 6m, which frees room to add a third facing east side of current platform 2, clear of Bellairs Ave.
Yarraville – Convert the current outbound platform into an island, though modern regulations require a straight platform and that would affect about 36 carpark spots.
Spotswood – reduce width either Hope St or Hall St, use to convert one of the two platforms to an island.
Newport – shift gas lines, abolish footpath between Melbourne Rd and Newport station, replace underpass with footbridge. Gives room to separate standard gauge alignment to be flush with Melbourne Rd ramp, then convert Platform 1 to an island.

Overnight we saw in Germany what can happen if there’s only one track.
Daniel, your piece yesterday was quite prophetic.

@David Stosser

A passing loop at Seaholme need not be temporary. You can build a side platform (and there’s plenty of space there), and like Westona, will easily allow duplication down the road.

@Arfman, depends on whether or not the entire length of the Altona line is due to be grade separated anytime in the forseeable future.

The Hurstbride line is single track from Greensborough, less than 18km from the City. It is certainly a lot like Puffing Billy past Eltham in particular!

Frequency at Diamobd Creek is:
. 20-25 min AM and PM peak
. 40 min during the day and weekends
. 60 min after 7pm

This is not comparable to other lines 20km from city and is NOT a modern metro service!

Common problems include:
. Outbound trains waiting 200m before Greensborough for over 5 mins regularly waiting for the inbound service
. Train cancellations off peak meaning up to a 120 min gap between services (this happened to me at 10pm one Friday night in the City)

I think the realistic solution is:
. Duplication Greensborough yo Eltham (not historic trestle bridge though) improving reliability and allowing a 10 min frequency like Ringwood, Frankston, Ringwood,etc
. Use the recently upgraded signals to allow a 20 min service Eltham to Hurtstbridge or maybe a frequent bus for every second train at least!

@David Stosser

I don’t see the Altona Loop being grade separated anytime soon. There has been no plans to grade separate any lines in the last few decades (other than at level crossings) and the only future plan is the “Sky Rail” which is itself motivated by level crossing grade separations.

There is also the issue of the water table at Altona. The traffic at level crossings in Altona aren’t among the most congested.

In short, express trains are expensive as they require extra track to untangle them from stopping-all-stations service. There needs to be more consideration of whether the travel time and environmental, from mode shift, benefits are worth these costs.

@Arfman, high water table is irrelevant if you’re elevating the line. You could have two parallel single track bridges, with the current rail alignment between Railway St north and south converted to a roughly 3-hectare linear park.

@Diamo, I did an analysis of the Hurstbridge line a while back. Short version: pending analysis of single track at Heidelberg, and conflicts at Clifton Hill junction:
-30min to Hurstbridge could be done tomorrow.
-20min to Diamond Creek with 40min or 60min to Hurstbridge could be done tomorrow. Buses could meet trains at Diamond Creek for the run to Hurstbridge, perhaps as an extension of Route 580 (which could well be faster than the train).

Addition of an Eltham North station changes the schedules slightly, but not enough to matter. Duplication has limited benefit other than for reliability (until you need 10min services past Greensborough), and the priority would be from Eltham station southbound to bridge.

@Sam, well said. Of course sections of line like Caulfield-Dandenong the result is pretty obvious.


I’m doubting that there is a political will to grade separate the Altona Loop. I live in the area but I don’t think I’ll see it in the next 30-50 years nor am I demanding for it.

Unlike the “skyrail”, there are only about 4 or 5 level crossings and only about 2 of them (Millers Rd and Maidstone St) have a decent amount of traffic on them. They pale in comparison to other lines. I’d rather see some level of duplication along the Altona Loop.

Now with the windfall from the sale of Melbourne Ports. The State Gov should run 4 tracks Caulfield to Dandenong along the Skyrail and extend it to go over Warrigal and North Roads. A new interchange station at South Yarra is also no brainer.

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