High voltage power lines to nowhere

On the outer eastern edge of Melbourne there is a curious piece of infrastructure – a high voltage power line to nowhere. So why was it built, and why is it currently sitting idle?

Dead end transmission line at Coldstream, Victoria

Running south-west from Coldstream to Templestowe, via Chirnside Park, Wonga Park and Warrandyte, I was first tipped off to the existence of the transmission line by someone who lives in the area.

Transmission lines at Coldstream, Victoria

The path taken was quite easy to see on the Melway – the eastern end is located at tower T293 in Coldstream.

While the western end terminates at tower T342 in Templestowe.

Eventually I paid a visit in person, and the dead-end nature of the transmission line was easy to see.

The northern end at Coldstream is located alongside two 500 kV transmission lines.

Dead end transmission line at Coldstream, Victoria

While the Templestowe end is located among the transmission lines that serve the Templestowe Terminal Station.

Dead end transmission line at Templestowe, Victoria

But unfortunately I was no closer to finding the reasons for the lines laying abandoned, until my recent post on transmission line crossovers. What started with an exploration of power lines in Sydney, expanded to Rowville Terminal Station in Melbourne, and then down a rabbit hole of State Electricity Commission of Victoria reports.

I eventually landed on a 1983 report on transmission lines serving Melbourne by the Natural Resources and Environment Committee. The purpose of the report was as follows:

This report specifically addresses the SEC’s proposal for a 500 000 volt transmission line from Coldstream to South Morang and in particular:

(i) The need for reinforcing transmission to the 500 000 volt terminal stations in the outer metropolitan area;
(ii) The feasible route to be subjected to detailed examination of environmental issues; and
(iii) The recommended process for assessment and approval of the route in this instance.

The report detailed the current state of the high voltage transmission lines linking the power stations of the Latrobe Valley to Melbourne.

The existing transmission system from the Latrobe Valley to the Melbourne metropolitan areas consists of three 220 kV double circuit lines and three 500 kV single circuit lines.

Two of the 500 kV lines were established in the late 1960s on a northern easement in conjunction with the Hazelwood Power Station and supply the western metropolitan area from the Keilor Terminal Station (KTS). The lines were routed via Coldstream and South Morang with one line being on a direct Coldstream to South Morang easement and the other routed via Templestowe to provide for later development of supply for the north-eastern metropolitan area. The easements from Coldstream to South Morang were each approved with capacity for a second circuit, thereby providing for the four incoming 500 kV lines to South Morang.

The third 500 kV line was established in late 1982 on a southern easement via Cranbourne, Narre Warren and Templestowe, in conjunction with commercial service of the completed Yallourn W Power Station and in preparation for service of the initial Loy Yang A units. The planning permission for the section of this line between Hazelwood and Cranbourne included easement provision for two further 500 kV lines. The section between Cranbourne and South Morang was established on an existing easement.

As well as how the SEC planned to add a fourth 500 kV transmission line into the system:

The further 500 kV line from Hazelwood to Melbourne is planned to be established on the southern 500 kV easement adjacent to the existing 500 kV line from Hazelwood to Templestowe. The section of the line between Narre Warren and Templestowe has already been constructed and the Rowville to Templestowe part of this section is temporarily in service at 220 kV.

And the interesting bit – the abandonment of the transmission line between Coldstream and Templestowe.

To achieve connection of the fourth 500 kV transmission line into South Morang, the SEC propose to take the existing second 500 kV line (the southern circuit on the northern easement) directly into South Morang from Coldstream, so as to free up the section between Templestowe and South Morang for inclusion as part of the fourth 500 000 volt line.

The short section on the northern easement between Templestowe and Coldstream would then be left out-of-service until the future establishment of new 500 kV switching stations at Templestowe and Coldstream.

If that wasn’t clear as mud, this diagram depicted the current state, as well as three proposals for adding a fourth 500 kV circuit between Hazelwood and Melbourne.

Abandoning a section of high voltage transmission line sounds like an odd thing to do – something which Mr. R.F. English, resident of the Bend of Islands Environmental Living Zone immediately adjacent to the proposed transmission line easement, pointed out in his submission to the Natural Resources and Environment Committee.

The decision to take the Coldstream to Templestowe 500 kV line out of service until at least the fifth 500 kV line is constructed and required – this would probably be in at least 25 years or more.

As the Coldstream to Templestowe line is approximately 20 kilometres long, and based on $470,000 per km, this would mean a $9 million asset would remain idle and depreciating for 25 years.

This appears to me to reflect a gross planning error in the SEC’s long term plans “to scar the landscape with 500 kV power lines”.

So what ended up happening?

Transmission lines at Coldstream, Victoria

And you guessed it – State Electricity Commission of Victoria got their way, with the fourth 500 kV transmission line being pushed through the Bay of Islands bushland along the “LV1: second Coldstream to South Morang line” route, and the transmission line from Coldstream to Templestowe abandoned.

But will it be used in the future?

Back in the 1980s the SECV believed that a fifth 500 kV transmission line would be required by 1990 to serve the increasing energy demand of Melbourne.

Transmission lines beside the Maribyrnong River at Footscray

But this prediction was overly optimistic – development of the massive 4,00 MW Driffield Project west of Morwell was abandoned follwing a change of government, and the Loy Yang power station petered out at 3,250 MW of the 4,400 MW capacity originally planned.

In 2009 Victorian energy network operator VENCorp dusted off the old SEC plans, in their ‘Vision 2030’ document:

Development of eastern corridor distribution

A new (fifth) 500 kV power line from the Latrobe Valley to Melbourne via the Northern easement terminating at Templestowe via Coldstream, and establishment of new 500 kV switching stations at Coldstream and Templestowe (140 km). This line would incorporate the currently unused 500 kV line between Coldstream and Templestowe.

Cost: $460 million

But with the decommissioning Hazelwood power station, no new coal fired power stations on the horizon, and the rapid growth of distributed rooftop solar and battery storage, the need for additional capacity between Melbourne and the Latrobe Valley seems redundant.

And another example

Sent in by a reader – a dead end transmission line outside the Geelong Terminal Station.

The transmission line runs north towards the Moorabool Terminal Station, but terminates a short distance to the south.

My guess – the original 220 kV circuit to Geelong was replaced by parallel 220 kV circuits on a new set of pylons, with a 220 KV circuit to Terang taking over the northern-most part of the easement.

Photos from ten years ago: January 2008

Another instalment in my photos from ten years ago series – this time it is January 2008.

We start in the Geelong suburb of North Shore, where I found a Y class locomotive shunting a rake of loaded log wagons into the Midway wood chipping plant.

Y171 shunting the Midway siding

The logs were sourced from native forests in East Gippsland, loaded onto trains in Bairnsdale, transported to Geelong by rail, fed through a massive wood chipper, then sent to Japan to be turned into paper. The export of wood chips continues today, but the transport of logs by rail ceased in 2009, following the destruction of the forests in the 2009 Black Saturday bush fires.

Down the road at Corio I found another freight train – this time a load of export grain being hauled by a company called El Zorro.

GM36, T386 and GM43 on the up outside Corio

The company had been running trains for some time, but hit the big time in 2008 after winning a grain haulage contract from AWB Limited. For the next few years they were a railfan favourite, operating trains across Victoria using a hired fleet of locomotives, many of them ancient museum pieces, until the company struck financial difficulties and was wound up in 2013.

The return of grain traffic to the Victorian rail network also saw some much overdue investment on the railway line to Mildura, when $73 million was provided by the State and Federal governments to bring the line speed back up to 80 km/h – a task that required replacing two in every five timber sleepers along the 525 kilometre line.

Trackwork between Gheringhap and Bannockburn

Work started at Geelong then continued north, reaching Mildura by the second half of 2009. In the end this was only a patch up job – a decade later the $440 million Murray Basin Rail Project is rebuilding the line a second time, but this time with longer lasting concrete sleepers, and converted to standard gauge so that trains from anywhere in Australia can travel on it.

Meanwhile at Southern Cross Station, I was catching the last train of the night to Geelong.

Last train at Southern Cross

Operated by a single Sprinter railcar, a practice banned since 2014 due to level crossing activation issues.

Speaking of level crossings, this one west of Geelong at Gheringhap will never have any activation issues.

Level crossing at Gheringhap

Nor will this one on a freight siding – protected by a traffic controller holding a stop/go paddle!

Level crossing protection on the Grain Loop

But a decade ago the biggest concern regarding level crossings was trucks failing to stop at them – the 11 V/Line passengers killed following a collision at Kerang in 2007 still fresh in the public’s mind.

The solution – Active Advanced Warning Signs (AAWS) located on the approach to level crossings on major highways.

New Active Advanced Warning Sign (AAWS) at the Hamilton Highway, Inverleigh level crossing

These effectiveness of these additional warning devices in improving level crossing compliance was evaluated in 2009 – the verdict being ‘inconclusive’ due to limited data, but the rollout has continued.

Footnote

Here you can find the rest of my ‘photos from ten years ago

When high voltage transmission line cross over

Out on the western edge of Sydney I came across a curious sight – not one, but two sets of high voltage transmission lines crossing over each other.

They were located either side of Luddenham Road in the semi-rural suburb of Orchard Hills. One set to the east, the other to the west.

This is what they looked like from overhead.

In my travels around Victoria, I’ve never seen overhead line crossovers – the only examples I can think of place the lower voltage line underground, such as the Geelong-Portland 500kV line outside Bannockburn.

So what’s the story up in Sydney?

Wikipedia has something to say on everything, including overhead line crossings:

At crossings of overhead lines by other overhead lines, the two lines must be kept at the necessary safety distances between the lines and the ground. As a rule, the line with the lower voltage passes under the line with higher voltage.

Construction workers try to plan these crossings in such a way that their construction is as economical as possible. This is usually done by leaving unchanged the line that is crossed, if possible.

Undercrossings of existing lines are often constructed in proximity to the line’s pylons, since this can often be accomplished without raising the existing pylons and while keeping the necessary safety distances between the ground and the other line.

Luckily the Australian Energy Market Operator (AEMO) has plenty of information on their website, including a handy dandy map of overhead transmission lines, as well as a network diagram showing the individual circuits that make up the national grid.

That allowed me to identify the three transmission lines I had found outside Sydney:

  • Line 38 and 32: double 330kV circuits between Sydney West and Regentville,
  • Line 39: single 330kV circuit between Sydney West and Bannaby, and
  • Line 5A1 and 5A2: double 500kV circuits between Kemps Creek and Eraring.

So the explanation from Wikipedia seems to hold here as well – the 500kV transmission line is on the top, with the lower voltage 330kV lines sneaking below: one via a non-standard pair of pylons, the other thanks to the extra clearance from a higher than normal pylon.

And a Victorian example

One of my Twitter followers pointed out this interesting setup at the Rowville Terminal Station in Melbourne’s eastern suburbs – what looks to be a two three phase bus bars running at ground level, while aerial transmission lines pass over the top.

But they aren’t conventional air insulated bus bars, but ducts filled with sulfur hexafluoride (SF6) gas.

500kV power lines in SF6 ducts at Rowville Terminal Station, Australia [2592×1944][OC]

Such technology is usually used for underground high voltage transmission lines, but at Rowville it was for a different reason – this whitepaper by CGIT Westboro has the details:

Rowville is a 550 kV above ground installation located in Melbourne, Australia.
The sole purpose of the gas insulated bus was to safely transmit two, three phase circuits of 550 kV power across an existing 230 kV overhead transmission corridor.

The customer’s main concern in this project was the possible mechanical failure of either the 230 kV or 550 kV (if overhead lines were used) transmission towers or lines. Failure of one or the other could result in damage to the lower feeder such that outages would be much more inclusive and costly.

The grounded enclosure sheath of the CGIT, however, would protect the ground level 550 kV line from breakdown and prevent further outages to result from 230 kV line failure.

A spare phase was installed at the request of the customer as a further precaution should a single phase of CGIT experience a breakdown. In the event of single-phase failure, this would reduce the outage time to a matter of hours by simply adjusting the line feeder leads accordingly.

The tech specs are as follows:

Commissioned 1979 (first circuit)
Additional circuit commissioned 1984

Voltage Rating: 550 kV
Current Rating: 3000 A
BIL rating: 1800A
2 circuits, including spare phase of GIL
Length: 235m

An expensive, though very ingenious solution!

You have to ‘train’ them young

My son is only just over two years old, but he’s already an experienced trainspotter.

Always ready for a few hours out lineside with Dad to see what trains are due next.

I wonder how long until he’ll be asking for his own camera – so far he just scrolls through the photos on my camera, making train noises the entire time.

Footnote

Train sets – I’ve lost count of the number that my son as received so far, but our house is overflowing with them: wooden, plastic and Duplo!

Connecting Melbourne Central and Flinders Street Station to Melbourne Metro

A few weeks ago the final station names for the Melbourne Metro project was announced – with ‘CBD North’ now ‘State Library’ and ‘CBD South’ now ‘Town Hall’. So how are these two new stations going to be tied into the existing rail network at Melbourne Central and Flinders Street Station?

Site clearance works continue at City Square

Flinders Street Station and Town Hall

The ‘Draft CBD South Precinct Development Plan‘ details the access to the new station:

The design has carefully considered the multiple passenger destinations by incorporating three separate entries into the CBD South Station. These are located at Federation Square, City Square and at the corner of Flinders Street and Swanston Street.

  • At City Square, there are five interchangeable escalators that descend several levels before reaching the ticketed barriers and train platform. Each level leading up to the ticketed barrier will provide for unpaid plaza and concourse areas. Lifts are located adjacent the escalators providing additional access to the platforms.
  • The entrance on the corner of Swanston Street and Flinders Lane (i.e. proposed over-site development area) has four interchangeable escalators which also provide unpaid areas before descending to the paid ticketed barrier on the
    second level. Again, lifts will be providing access to platforms and easy access for the mobility impaired users.
    Provision for over-site development and retail spaces will be provided as part of the Day 1 look of the precinct.
  • Federation Square entrance leads straight to the ticketed barriers, down escalators and along a gradually declining walkway which connects in with the other stations underneath Flinders Street.

As well as the link to Flinders Street Station:

An underground connection through the paid concourse will be provided between CBD South and Flinders Street Station, via the existing Degraves Street underpass. This will provide an effortless connection between various train lines, providing access to additional destinations throughout Melbourne City.

‘B1 – Landing Level Plan’ found in ‘Appendix B: Architectural Plans‘ shows the connection in greater detail.

Located at the same level as the existing Degraves Street subway, the new underground passageway will be carved out beneath Flinders Street itself, connecting into the new Town Hall station box, located at the site of the Port Phillip Arcade.

These modifications hit the news in December 2017, when it was revealed that the eastern sections of the heritage listed arcade would need to be demolished.

Eastern exit from the Degraves Street subway up towards Flinders Street

Also of note is the proposed modifications to the subway beneath the platforms at Flinders Street Station – the western set of stairs to each platform are intended to be replaced by lifts, in order to provide a DDA compliant access route between the two levels.

Missing tiles: Centre Subway to platform 2/3

Melbourne Central and State Library

The ‘Draft CBD North Precinct Development Plan‘ details access to the new station:

CBD North Station will be located directly below Swanston Street providing direct transport interchange with the existing tram network and City Loop. Passengers can enter and exit the station via the main entry on La Trobe and Swanston Streets, at the corner of Franklin and Swanston Street or via Melbourne Central Station concourse.

Diagram ‘B2 – Melbourne Central Concourse & Service Level Plan’ found in ”Appendix B: Architectural Plans‘ shows how this connection will be made – by bashing a hole into the existing concourse.

Right about where this advertising screen is currently located, next door to McDonalds.

JCDecaux advertising screen installed on the Swanston Street concourse at Melbourne Central

Diagram ‘North – South long section – A’beckett Street & Little Latrobe Street shafts’ shows where the escalators will run down to the platforms at State Library.

Pretty simple and uncontroversial, compared to the changes at Flinders Street Station!

What about the names

There was been a lot of debate about naming the new stations – not just the names themselves, but whether ‘CBD North’ and ‘CBD South’ stations should have their own identity, or piggy back off their neighbouring stations – Melbourne Central and Flinders Streets.

There are pros and cons on both sides:

  • separate names means passengers won’t enter one station, only to discover that they have a long walk via the interchange passageway to reach the platform they need,
  • but separate names might also lead to passengers needlessly changing trains at Caulfield and Footscray stations, just so they are on a train to the ‘right’ station in the CBD.

So how do other rail systems name their interchanges?

On the Hong Kong MTR interchange stations usually have the same name, with the exception of two station complexes that have double barrelled names – one being an interchange that requires exiting the paid area then re-entering, the other requiring a long walk via an underground passageway.

Meanwhile on metro systems of the the former Soviet Union, the opposite is the rule – the platforms for each line at an interchange station are usually given their own name.

Over in London they mix and match naming practices at interchange stations – Bank and Monument is has double barrelled name, while ‘Paddington’ is applied to two independent London Underground stations plus the mainline station.

Meanwhile the Paris Metro favours double named stations – a practice born when independently stations on separate lines became associated as interchange stations.

The New York Subway takes confusion to another level – passengers change between different lines at ‘station complexes‘ with double barrelled names, but have to pay attention to identically named stations that are located nowhere near each other!

But the Chicago ‘L’ really takes the cake – with five stations called ‘Western’!

So what to make of naming interchanges?

My take on the situation: if the platforms at an interchange are close enough together that choosing an entrance doesn’t matter – give it the station a single name. If it looks like two stations tied together via an interchange passageway – give the two halves different names, and make sure your network maps point out that the two are linked.

Sources

The Metro Tunnel draft development plans have the full detail – they’re currently up for public display on the Metro Tunnel website.

Daniel Bowen also weighs in on the station name debate in his post The metro tunnel stations will be called….

Footnote: an abandoned plan

The original plan to link CBD South with Flinders Street Station was via a bank of escalators on the Swanson Street concourse.

Figure 5-10 in the 2011 Melbourne Metro business case

Figure 5-10 Concept for CBD South Station Interchange with Flinders Street Station

Further detail of the interchange passageway was found in the 2012 Flinders Street Station Design Competition Design Brief document. From the side:

CBD South station, profile view of linkage to Flinders Street Station

And from the top:

CBD South station, plan view of linkage to Flinders Street Station

These plans now appear to have been abandoned for a simpler link via the Degraves Street subway.