Using the railway to Prebbleton

Posted on March 8, 2012 by

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It is generally well-known that Christchurch’s rail “network” consists of three lines which radiate out from the city; the Main North Line which links to Papanui, Northwood, Belfast, Kaiapoi, and Rangiora; the Lyttelton Line, which links to Opawa, Woolston, Heathcote and Lyttelton; and the Main South Line, which links to Sockburn, Hornby, Templeton and Rolleston. Currently, there is a proposal (and penty of counter proposals) to utilise that network for public transport purposes.

However, there is also a fourth line, branching off the Main South Line and heading through the commercial and retail and industrial heart of Hornby, and onwards for a further 3-4km until reaching Prebbleton. It does not appear that this line has featured in any official plans for developing a rail passenger rail network for Greater Christchurch, which I think is a shame. The operating line, known as the Hornby Industrial Line, ends at the Watties factory on the northern side of Marshes Rd, but the track and, more importantly, the intact corridor, continues on to reach Prebbleton – terminating next to Springs Rd as you enter the village, just before the primary school next to the mushroom factory, and down the road from the town centre (see red line in the image below).

 

Previously, the line continued on to Lincoln, and then to Southbridge. At Lincoln there was a line branching to Little River. Both branches were cut back to Lincoln in 1962, and the remainder was cut back to Prebbleton in 1967. The final short section into Prebbleton was last used in the 1980’s. The Prebbleton station and yard was located on the other side of Springs Rd, which crossed the tracks via an overhead bridge. Unfortunately, the bridge was demolished in the late 1990’s and the track cut back to the other side of the Springs Rd. The station and yard area has now largely been developed.

The proposed extension of the Christchurch Southern Motorway, which is due to begin construction about 2016, will cut across the southern portion of the railway line, and there is as yet no indication that any allowance for the line to potentially cross under the motorway is being made. I guess there is a pretty good case for why it shouldn’t. First, it isn’t currently used for any particularly important purpose beyond the Watties factory. Second, it currently isn’t earmarked for any future use beyond the proposed motorway corridor. However, latching on to the second point, I think that it should be earmarked as a future public transport corridor, and should thus be protected with an allowance made for the line to continue under the to-be-built motorway corridor.

So why do I think this should be the case? I think I can sum that up with the following reasons:

  • It is there
  • Prebbleton is a growing urban area, with the village and surrounding lifestyle block areas accounting for about 3000 people at the 2006 census (and it has grown a lot since)
  • Lincoln is within its catchment, via park and ride, cycling, bus connections, and a possible future extension
  • Taking all the above into account, it represents a unique opportunity to provide a superior level of public transport to this region
  • It would have a positive impact on service levels on the Hornby-City section of the proposed rapid transit network

For those reasons, I simply think it would be a waste not to do something with it, and I believe the route should be protected along its current length. Hornby-Lincoln is not included in the draft City Plan’s rapid transit network, but I think it should be given its potential to provide a better connection between key regional centres and the city. In many ways, it would be a branch of the proposed Rolleston route, and would act in a similar function to the Melling branch in Wellington, or the Onehunga branch in Auckland to the rest of the proposed network.

This has got me thinking about two things. First, how would a service operate within the context of the rest of the tentative rapid transit network? Second, with the first question in mind, how might this route be extended to provide a direct connection to Lincoln?

Lets suppose that a basic heavy rail service is reintroduced to Christchurch rail lines. North to Rangiora, south to Rolleston, and south-east to Lyttelton. How would a Prebbleton service fit in? Simple really. A station in Hornby South to serve the commercial and residential areas there, plus a station at the Prebbleton terminus with park and ride, an area to lock up cycles, and space to transfer from bus to rail. From Hornby into the City services would double-up, increasing service frequencies.

The termination point of the line at Prebbleton. The blue line is the track, the cross marks the empty paddock space that could make way for development of station, park and ride etc. The line previously continued across Springs Rd (which was on an overbridge) and through the area being developed on the other side. Prebbletons main shopping area is at the bottom left.

The end of the rail is currently located in a paddock at one end of Prebbleton. It isn’t far from the centre of the village, but still isn’t the ideal location, with the opposite end of the village being a bit of a hike. Park and ride and buses would mitigate this, but it still wouldn’t be the most ideal location (although it isn’t bad). Lincoln residents would rely entirely on connections to link with a Prebbleton rail service. Prospects for extending the line as heavy rail, to better serve Prebbleton and toward Lincoln, are extremely limited. Residential developments have made reusing the former rail corridor problematic, and the former Springs Rd rail overbridge was demolished over a decade ago. Hooray for short-sighted thinking!

Another option I have thought of for developing the line is to develop it as a separate light rail line. There are several sub-options for this, but all would involve the conversion of the line into a light-rail right of way (and, presumably, standard gauge). Once reaching Prebbleton, it could run down the Median of Springs Rd through the heart of the Village itself, before continuing on to Lincoln, either within the Birches Rd corridor, within a new corridor, or partly in the old rail corridor (if that is still possible). On reaching Lincoln, it would again revert to on-street running, perhaps continuing on to terminate at, or near, the university.

At the other end, upon reaching Hornby (where you would have separate light rail platforms) the light rail line could do one of a number of things. It could run adjacent to the railway line toward Sockburn (the corridor is pretty wide through there, so should theoretically be possible) whereupon it might either continue down the railway line toward the city (where it would then revert to on-street running into the CBD at some point) or would leave the railway corridor to run down the median of Main South Rd, through Church Corner, and on to Riccarton. The obvious point to make would be that it could link up with a potential UC/Airport light rail line.

I think that there is much merit to such a concept. However, it isn’t perfect. It would require freight movements on the existing rail line to be dropped, which would require the agreement of Kiwirail and local industry and, were an agreement to be reached, it could cost a lot of money (purchase of the right of way for a start). It would also mean keeping light rail and heavy rail separate down the Main South Line corridor, which would require a lot of room, and even though the corridor is quite wide, Kiwirail may not agree.

Of course, the idea of tram-trains has been mooted from time to time for Christchurch. The line to Prebbleton is a good example of how the tram-tram concept can be taken advantage of. Like light rail, tram trains can operate on-street, but unlike light rail they are designed to operate on the mainline railway network, which brings obvious advantages. Any such service could be easily and cheaply extended to Lincoln, as in the light rail example, but would also have no issues integrating with other rail services, as in the heavy rail example.

The tram-train concept is not as simple as purchasing the equipment and putting it into service, however. Tram-trains would require customisation to our Cape gauge rails which, while not necessarily impossible or cost prohibitive, could nevertheless have the potential to add to costs and make the process complex. Unlike simple light rail or commuter rail, it might be harder to obtain off-the-shelf rolling stock. There are also issues around crash worthiness that need to be taken into consideration with a vehicle intended to operate within the rail corridor as a train, and in the road corridor as a light rail vehicle. It would be quite a commitment, and I don’t think it would be a suitable option in isolation –  an entire network would need to be developed that a Prebbleton/Lincoln line was a part of. However, I do think the Prebbleton/Lincoln line is a really good example of the advantages of developing such a network. The image below shows the railway (blue) and potential light rail/tram-train routes from Prebbleton to Lincoln (red).

There is another option, I guess, for utilising the corridor. Converting it to a busway. This would have the same negative aspects as the light rail option, but would likely be cheaper to implement (and could be a precursor to eventual light rail). A trade-off would be a lesser capacity, which may or may not be that much of an issue. Given that the corridor only runs to Hornby, the advantages of turning the corridor into a bus right-of-way, may not be that far-reaching. The corridor may not be wide enough for buses either (in fact, I doubt it would be)requiring further work to be carried out, or operations to be compromised to a degree. Nevertheless, it is an option that should be stacked up against the others.

So overall I think the line and corridor should be protected, and there are lots of interesting ways it could be developed in the mid to long-term. Heavy rail would provide a useful service along the line and into the Prebbleton/Lincoln area. However, it could be constrained by the extreme costs of extending it to more useful location within the local area. This can be mitigated to some degree through greater investment in park and ride, as well as good bus connections. Eventually converting it to light rail would be a suitable fit, although that would curtail freight services on the line (the prospect of which may mean it is not an option) and there would be integration issues along the rest of the rail corridor. Tram-trains would combine the advantages of both the heavy rail and light rail, but would likely only be viable if it rode in on the back of a much wider implementation of the concept. Nevertheless, the Prebbleton/Lincoln line serves as a good example of the advantages of the concept. Finally, conversion to busway would be a cheaper alternative, but a bus probably wouldn’t be able to take advantage of the right of way to anywhere near the same degree as rail.

Like I mentioned earlier, it is there to be used, and I think I have shown that there are many ways we can do that in future. The area has grown quite considerably in recent years, and while not a Rolleston, should continue to grow in future. Further, services on such a line would have a positive effect on services on a Hornby-City rail-based rapid transit line. So why don’t we ensure the corridor remains intact for future development? Once it is gone, it’s gone.

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