Christchurch - cut & cover tunnel could bring commuter rail into city centre

A diesel hybrid train in Japan - but under Christchurch city? There IS an option....

This essay © David Welch 2018  Updated April 2018

The Christchurch Railway Station is too far from the centre of the business and commercial area.  This has been a complaint since 1863 !! Complaints were expressed even before the city's first station opened on "South Belt" (Moorhouse Avenue). Calls were made for horses to pull the detached railway carriages (arriving from Heathcote) up into the central business area. As researching old newspapers will reveal, the distance of the station from the centre of the city it has been constant Canterbury grievance for 155 years. In 1993, and the then privatisation of rail, the city's “central” passenger station was moved to an even more distant location, at Addington.

Any suggestion of re-instating a regional commuter rail network falls at this, the first huge hurdle: -  If most of the passengers have to transfer from the train service to buses to access the city centre, it negates any time saving efficiency and renders the whole system too clumsy and expensive to be attractive. Car usage in the modern age has created a cultural expectation of door to door travel with immediately adjacent parking – this has becoming increasingly difficult to achieve in a congested city, but it is still the gold standard.

However, subject to further investigation, there appears to exist an unique opportunity for Christchurch to bring commuter rail services right into the heart of the city and to do so at a relatively low cost by world standards. Such a move seems likely to  boost central city revival and increase investment in new businesses and employment  significantly.

Auckland's cut and cover tunnel project

Inspiration is offered by the construction of the circa $2.8 - $3.5 billion City Rail Link in Auckland, a 3.5 km underground loop line from the city's main station, Britomart,up to Mt Eden and the western rail corridor. The first kilometre of of the Auckland underground system, from Britomart is a "cut and cover" tunnel just below the surface. Most of the remaining underground will be bored at a deeper level - this is a necessity because the Mount Eden  part of Auckland is situated on hills too steep in their incline to allow the railways to follow exactly below surface slopes.

Of particular interest, is the way the City Rail Link follows the alignment of Albert Street through central Auckland, a huge trench being dug out (one side of the road at a time) and then lined with reinforced concrete walls, creating two parallel tunnels. When a concrete ceiling is placed on these, and the various underground services are reconstructed, the road above will be restored as it is now. This concreted trench tunnel will allow commuter trains to run in both directions some metres below the street.

At a quick glance it seems surprising that such a massive excavation can occur right in the midst of large tower buildings, but it is of course common to excavate large holes for the foundations of high buildings, with one high rise excavated right beside another. An added requirement, and an often huge cost of tunnelling under established streets, is the construction of new alignments for other underground services, such as water pipes, sewerage, electrical cabling, stormwater drains, etc., along or across the streets.

A cut and cover railway tunnel into the Christchurch central area

I believe, if the political will was there  it would be possible to build a similar cut and cover tunnel, offering two railway lines (possibly more at station points) and three simple underground stations, starting from a point near the current Christchurch railway station at Addington, into the commercial and business heart of of central Christchurch.

The suggested cut and cover tunnel could be built across - that is to say well under - Hagley Park, under hospital corner (and an underground station there) and  under Tuam Street to an underground station complex near the Bus Exchange and Colombo Street. This cut and cover tunnel could then continue on to an underground terminus at the planned new sports stadium and exhibition centre between Madras and Barbadoes Street.

This scenario would require the purchase of part of the former stock sale-yards site, in Deans Avenue, now demolished and currently in temporary use as a one level car-park for the hospital, served by shuttle buses. All other land required I believe is in the public domain, requiring no land purchase costs or legal disputes.

I have included here some ballpark figures for likely costs. Noted; these are not minimised to be appear more palatable to potential opponents, but realistic in terms of similar projects in other cities. Large "game changing" and city building infrastructure of this nature, designed for long term benefits into the billions, can not be built by enfeebled suggestions of reusing third-hand cast off rail units ex Auckland, or (most bizarrely) creating a "temporary commuter rail system".  Rather costs are broadly calculated in reference to similar projects in Auckland and Wellington, obviously this can only offer a very rough guide, but not one I hope completely amiss.

A tunnel under Hagley Park

It is envisioned that from the main trunk line between Addington and Riccarton Road (running parallel with Deans Avenue) two separate lines would branch off heading eastwards in to Hagley Park. One line would offer access to trains tofro Rangiora and north, and the other access to trains tofro Rolleston and south. Both these lines would follow a gentle downward sloping curve that would take trains under Deans Avenue and then under Hagley Park. This might require a slight rise to carry Deans Avenue over the tunnel entrances, or even a slight landscaped hill at the edge of Hagley Park, to allow a sufficiently graduated slope into the two railway tunnels. Once under the park these two curving tunnels would come together and become either a straight double-track tunnel, or two parallel tunnels, and head underground towards "Hospital Corner."

Tunnelling costs around the world, are greatly effected by the surface being cut through but there will be no unexpected hard rock mass under Hagley Park or central Christchurch. Drainage will no doubt be a factor, but building a cut and cover tunnel through shingle or soft ground across the open space of Hagley Park, is likely to be cheap tunnelling by any world standards. Allowing for complex railway junctions and all safety and ventilation aspects, on roughly similar projects, I'd guess cost for this section, probably under $60 million.

After completion of the construction phase of the cut and cover tunnel, the earth and grass would restored over the tunnel ceiling perhaps two or three metres below ground-level. There would be no obvious change in the appearance of Hagley Park, other than a possible removal of a few large trees whose roots would otherwise interfere with the tunnel. There has been public resistance to past proposals to build car park facilities under Hagley Park – but that concept by its very nature feels a violation. I would imagine this option, intrinsically fostering a “greener” more pedestrian friendly Christchurch, would encounter a much smaller rump of opposition.

A station at hospital corner

At Hospital Corner, the tunnel would pass under Hagley Avenue and into - and of course under - Tuam Street, with obvious potential for station at this point. The existing under-road pedestrian tunnel for hospital staff and a separate public pedestrian tunnel could link to the hospital and outside areas to platforms on both sides of an underground station, as well as to the bus stops above.  Modern underground stations typically have glassed off tracks, these platform length doors only opening when trains are actually stopped, preventing accidents, suicides, graffiti etc.

The "Hospital Corner" station would offer easy walking distance access not only to the hospital and medical school, but also to the planned Metro Sports Facility, Hagley Learning Centre, Hagley Park and the cricket oval, the Botanic Gardens and boatsheds, Museum, Arts Centre, Christs College, City Council buildings and to the office blocks and apartments west of the Avon.

A tunnel under Tuam Street to city centre near Bus Exchange

Passing under the alignment of existing streets will be considerably more expensive than tunnelling under open park land. This said, the length of track suggested here, from hospital corner to the suggested terminus is not much over one kilometre. Based on the one kilometre of cut and cover tunnel being cut under Auckland's far more intensely developed lower Queen Street and Albert Street (where large storm water works also had to be shifted) I suspect that such distance in Christchurch might be constructed for about $200 million.

The two simple underground through-stations with above ground entrance foyers, at the Hospital, and a City Central station, near Colombo Street/ and linked to the Bus Exchange might add another $60 million. These stations are fairly close together, the trains between them would virtually just slide along at under 20km, but link directly to the different mass catchments, including direct access to all Colombo Street and Cathedral Square. 
A third station and terminus, only three blocks further east is also suggested and would be need for operational reasons anyway.

Central city rail tunnel continues to new Sports Stadium and Exhibition Centre

The terminus could be about 400 metres further along under Tuam Street between Madras Street and Barbadoes and directly beside or under the proposed new giant sports stadium and exhibition centre. This might also sensibly include an underground stabling area, four to six tracks wide, or similar. This could create significant operational economies as overnight night, or during the off peak period during the middle of working days, some of the trains could be parked and cleaned here. 
Constructing a couple of island type platforms could also allow various units, and longer locomotive pulled trains, to load simultaneously (including those for Dunedin and South Canterbury etc.) following major sporting events, or during large exhibitions and festive events held at the stadium. 

This station might cost another $60 million, although possibly it might instead be built and leased back by the stadium builders or operators. Potential savings in terms of excavation, pile driving, stadium/station pillars etc. might also be achieved by simultaneous construction.

Both the Central City station and a Madras/Barbados Terminus, in the scenarios here would offer easy walking access to the Justice Precinct, the new Hoyts 7 Cinema complex, the Bus Exchange, Ara (Polytech), Catholic Cathedral College, High Street and Cashel Street Malls and Laneways and only slightly longer walking distance, Cathedral Square and other parts of the central city. 
The area of the central city south of Cathedral Square has always had more capacity to form the busiest shopping, commercial and business part of central Christchurch - the suggested railway line conveniently intersects this primary activity zone.

[ station symbol near Moorhouse Ave is intended as sample  - not return to former station  site!!]

Hybrid diesel or hybrid electric trains, an obvious option

Obviously it is not suitable to use diesel power in busy underground tunnels. Electrification of Auckland railway cost $1.3 billion, not counting the new trains. The huge cost of electrifying all the Canterbury lines could be postponed for many years, or even permanently avoided by using hybrid passenger rail units and locomotives. These systems can operate with batteries linked to either standard diesel, or with overhead powered electric trains. When running only on the batteries these locomotives or units are capable of pulling surprisingly large loads (over a thousand tonnes) over reasonably long distances, typically 60-100km. Several international railway vehicle builders now offer hybrid options. Indeed, Auckland Transport had planned to purchase 17 hybrid such hybrid electric units, until both the main political parties announced they would fund overhead electrification of the line between Papakura and Pukekohe.

The added chance to recharge batteries from an overhead power supply, every time, whilst running through the central city tunnels, or while parked at mid-day or overnight in the underground terminus, would clearly support such a system and ensure smoke and exhaust free operation in the tunnels, as well quiet running trains as far afield as Rolleston and Rangiora, perhaps using diesel only beyond these points. A fleet of, say 20 hybrid 140 seat passenger units, and several separate hybrid locomotives to shunt or pull conventional coaches (including dedicated cycle coaches on the main peak hour trains) - the minimum rolling stock needed to operate a sufficiently frequent service (given population and regional distances) - would probably cost about another $250 million.  

For those who need to cycle at both ends of their rail journey, peak hours trains (rather than units) could probably include dedicated multi-cycle carriages as used in the New York area.

The general upgrade of railway across the city to allow for commuter rail and (and no doubt a chance to improve freight movement) would also be needed, this might absorb another $200 million, and might include over-bridging of rail tracks on some arterial roads and the building extensive car parks for commuters in outer suburbs and towns. Wellington railway has over 4000 such car parking spaces across the region, Auckland is struggling to create more. The old equation “public transport versus private car” still occurs in local newsmedia or politician speeches; - it does no justice to “park and ride” character of public transport  in many modern systems serving sprawling built-up metropolitan areas. (Boston for example has over 46,000 park and ride spaces – in other words 46,000 cars that don't get driven into the city or on congested roads). Secure bicycle day-storage systems would also be necessary at most suburban stations.

I am only an amateur "train (and bus) spotter" but I believe it is possible that this core system could be created for around $600 million, spread over several years., and a $250 million loan for the purchase of trains. These actual amounts could be more accurately determined by professional engineer or a proper feasibility study.

If Christchurch is going to catch up, it needs to face realities and lift its game and its vision, study comparable systems in New Zealand and overseas and seek intelligent levels of funding. The city has wasted over two decades investigating piecemeal and underfunded proposals utilising third hand rolling stock and inadequate stations, including such professional absurdities as a “temporary” commuter rail system! It has also completely ignored bus-way corridors, by-passing congestion, and taken an absurd 20 years merely to establish bus lanes on short lengths of congested roads!

Local and Regional authorities to meet only half the cost of construction?

This $850 million seems (and is) a huge amount of money, BUT on the precedent of Auckland and Wellington it might be expected that central Government would provide a $250 million loan for purchasing modern rolling stock. This is then repaid as an annual operating cost by the regional authority overseeing railway operations. By similar precedent, central Government would also fund about half of the construction costs, these met directly by central government and its agencies, and in some aspects as part of KiwiRail.

Despite such a large sum, it is well below large tax-payer amounts spent (and to be spent) in Auckland and Wellington.

That greater Christchurch should seek about $300 million in direct Government support seems nothing but a bit of "transport equality" and “balancing of the books”, given the huge investment by Governments (both Labour and then National) in commuter rail in Auckland and Wellington. Since 2003 Auckland has received at least $3,300 million in government support for rail and busway infrastructure with $1,400 million (and more if needed) promised for the underground City Rail Link loop, previously mentioned. 

Since 2007 greater Wellington – like Christchurch only quarter the population of Auckland - has only received $500,000 in Government grants and loans towards upgrading railways infrastructure. Just before Christmas the Greater Wellington Regional Council announced it was seeking another $200 million from Government for a further rail upgrade. Further pressure is on for Government funding of light rail to the airport, which on similar costs to the Gold Coast light rail, will require well over a $1000,000,000 dollars and make little difference to journey time.

Both these cities have had an obvious strong case for public transport infrastructure funding from taxpayers, Auckland because of its larger size and rapid growth, Wellington because pf its geography, its restricted central area and bottleneck approaches. This greater need has been recognised by the estimated billion dollars taken out of road and fuel taxes generated in Canterbury and transferred to projects in northern cities.  And this said, the population of greater Christchurch is actually larger, faster growing than that of Wellington region and the  extended metropolitan area population of Christchurch is expected to surpass that of greater Wellington region over the next 25 years. (NZ Transport Agency Stats - circa 567,000 versus 527,000)   Simplified graph here - [or see "Lies, Damned Lies and Statistics" page in right hand side box; this also determinines the comparable commuter zones, matching apples with apples]. 

Extremely rapid growth of both Rangiora and Rolleston, and adjacent areas, makes it clear tomorrow's “greater Christchurch” will, in effect, be something of a banana shape extending over 25 kilometres northward and over 25 kilometres southwards. 

Greater Christchurch too has its bottleneck too – the crossing points of the Waimakariri River and - not least - the finite capacity of the city's own arterial roads and urban intersections to provide effective peak hour journey times. 

Exactly the sort of profile best met by commuter rail.

Wellington also has it's Wairarapa Line - $25 million was spent on carriages and line upgrades to from Wellington to Masterton (80km), a service which now offers five trains a day. Could we not one day see at least an early morning commuter train from Timaru and Ashburton to Christchurch, to the benefit of all Canterbury areas linked?  

On precedents set in Auckland and Wellington, direct grants from the Government or Government agencies or incorporated in KiwiRail capital works, would meet about half the construction costs, leaving $300 million to be found from local and regional public authority sources or from public-private partnerships.

Creating a central city rail corridor seems so fundamental to making an increasingly vibrant and attractive rebuilt Christchurch a truly dynamic city centre easily fed by the larger catchment of metropolitan sprawl. This includes being able to tie together the main new growth areas in Rolleston and Rangiora, and keeping the cultural, sporting and business heart of the whole Canterbury province accessible to all. It also allows easier access to housing and employment across the whole metropolitan area, including those in inner city apartments. who residents work further afield. In this light central Government assistance to the tune of around $2-300 million is not an absurdly large expectation. In fact $100 million is already promised by the new Labour government for commuter rail in Christchurch, though this would amount would offer far too little make any sort of effective or game changing attractive system in itself.

As is obvious, no railway construction is cheap, but once established, a railway line into the city centre will can create benefits for generations. A good example of such foresight , close to home, is the Lyttelton Railway Tunnel. The decision to build that huge-for-its-era railway tunnel - the first great engineering project in New Zealand - was made in 1858 when Canterbury had less than 5,000 adult residents. These pioneers held a larger vision and the courage to build a far more difficult transport corridor than that is suggested here.

Of course the approximate $900 million doesn't  just buy a 2 kilometre central city railway tunnel - by seizing the central ground, so to speak (and literally) it secures the pivotal point for  whole core commuter railway network for greater Christchurch. 

Even on just existing rail corridors it links almost 60 km of built up area to the city's heart, with obvious room for expanding peripheral lines over the decades ahead.
In contrast to motorways,  this is without adding further to city congestion, without increasing delays and without  parking costs!!  

Also among other things, a commuter rail running right into the heart of the central city is likely to vastly increase construction of central apartment buildings, major administrative headquarters, and  office complexes, major tourist hotels, copious central city dining and nightlife,  potentially even trains operating right through the night on weekends, helping  to attract super large crowds to sporting and festive events. 

I think this concept put forward here is such a game-changing option that the Councils should professional engineers, transport planners and accountants etc. to do a feasibility study of this concept. Used to assist this, the promised $100 million in Canterbury commuter rail funding by the Labour Government might then go far further than anyone ever dreamed.

Extras
For a more detailed info on  historic Wellington expenditure "Take the money and Run"
For the gross imbalance of NZ taxpayers money invested in Auckland (2013) Government asks New Zealand to massively subsidise Auckland transport?
Greater Christchurch to have a potential commuter base 80,000 people more than Wellington region within 25 years, or see [pages, see right hand column] 
For a previous suggestion,  for a further rail corridor in Christchurch Airport to City rail and Orbital rail route in Christchurch suggested

Since the original blog was posted the new Labour (Plus) Government has announced  - Regional Rail for Canterbury 'On the table".