Tuesday, December 20, 2011

Christchurch - Sure to Rise? A hill here, an embankment there??


A couple of months back I was walking the section of the Little River Rail Trail with a friend.

This former railway corridor skirts Lake Wairewa on an embankment. At times, I'd guess, this heavy shingle embankment built over 125 years ago is up to 6-8 metres high in places.

"Isn't it amazing," I said at one point, "that all this shingle had to brought by horse and cart. Such an incredible amount of work".

We walked another couple of metres before I exploded in laughter at my own stupidity.

"How ridiculous, " I corrected myself, "Of course they didn't bring it by horse and cart, they brought it by rail as the line advanced and tipped it off rail trucks."

It is a truly sad and tragic way to have gained this,  but one asset Christchurch has gained since the year of horrendous earthquakes is an absolutely humungous pile of broken bricks and masonry rubble.

Most of this is at the Burwood landfill and may just stay there - I am not sure how "clean" this rubble is in terms of things that might leach into the ground, or say PVC cabling and all that sort of stuff. Or how much it can be cleaned if needed. But after World War II the bombed cities of Europe made some very attractive hills and parks by piling huge piles of rubble and covering these with earth and trees.

The photo, sourced from Wikimedia Commons, is one of these, a hill park called  Olympiaberg made from rubble generated in the war-time bombing of Munich.

I have advocated building a freight and commuter rail configuration and includes a spur to planned new housing areas at Highfield and Prestons ....it would not take a great deal, while the land is still in farmland to extend a temporary rail line across the Burwood rubble dump.

This would allow massive amounts of in-fill masonry rubble to be carted long distances (if needed) and used to create new rolling land contours here and there around our mostly very flat or very steep city. In terms of building a new rail link between Redwood and Islington, through or past various existing or planned subdivisions and industrial areas, this would offer ample opportunity to create gentle rising parkland style embankments on approaches to over-bridges. Or to disguise or noise reduce airport facilities or, ditto,a shallow rail trench with a mixture of embankment, trees and shrubs and, if necessary, non-visible security fencing.

Of course this could also effect the view of the Southern Alps (which many people value) for those living too close but then again modest hillocks scientifically positioned could also be engineered to mitigate the effect of certain winds - the colder bite of nor-easters in Sumner for instance, greatly enhancing lifestyle and property values in that area.

The mountain of masonry re-sculpted elsewhere not least could ensure that any new railway line from Redwood to Islington via the airport would never need to have level crossings, greatly increasing speed and safety of rail operations.

A curse of the city's flatness is that grade separated crossings of the triple tracked Hornby-Lyttelton railway corridor tend to be huge,ugly and spiritually and visually divisive of the city. The over bridges at Waltham Road; Colombo Street; Durham Street; Blenheim Road extension; and Sockburn, do little for the felt quality of the city and may have contributed to the decline of Sydenham.

Yet as the city and its economic export engine, the Port in Lyttelton, will continue to grow in size and productivity there can not help but be an inevitable increase in rail traffic competing with cross motor traffic at level crossings such as Wrights Road;  Whiteleigh Avenue/Clarence Road; and Lincoln Road. The lengthy coal trains are already slow to cross and further rail traffic is a guarantee of increased traffic delays or congestion OR MORE over-bridges. Indeed it could probably be argued that the biggest problem with creating commuter rail would be precisely this - add another four trains or more each way per hour - the absolute minimum - and there are going to be a huge number of traffic queues at level crossings, not least at peak hours!

The "just another brick out of the wall theory"  may also have a part to play here too - could a half and half railway trench be built - perhaps dropping nine metres down after heading west from Durham Street with some crossings removed and others carried on over-bridges of much less height than those current? This would create a much less brutal assault on the visual environment, such as a four lane over-bridge, more a graded rise than a sharp ascent, across the railway lines at Lincoln Road one of the city's foremost (and busiest)  arterial roads. Not only could the rubble play a minor packing and embankment role in such a scenario - it could also be used to pack the base of the trench - dug out to five metres, heavy concrete sides but filled with heavily compressed masonry fill to the first two metres or some such to maximise loading bearing and ground consolidation.

Every hour or two another lengthy coal train rumbles through Christchurch bound tofro the export wharf at the Port. How much greater capacity can rail grow - including around 16 coal trains a day, freight trains, local shunts - and then include commuter trains; and how much bigger can Christchurch population and motorist numbers grow -  before  a section of trenching and/or several more grade-separate over-bridges become a necessity?

Another possibility - complementing the easy access of the suggested rail corridors to the new premier sports ground planned for Addington (joining the existing race course and Events centre) - would be the creation of new contoured sports grounds of significant portions, with a doughnut of natural grassed embankments, to enjoy cricket or speedway or cycling whatever.  The combination of rubble transport by rail from Burwood and a future railway station being built immediately close to such a major sporting venue (and able to deliver crowds from every corner of the suggested figure 8 and spurs circuit ) would allow peripheral areas such as Kaiapoi or Rolleston a chance to become host to national events of a sporting codes, just by virtue of the quality of access, size of host arena and attractive relaxed landscaped setting of venue.

Obviously I am not an engineer so some or all of this could be totally uneeded, or unsuitable or absolutely twaddle !! But it does suggest there could be much synergy in a commuter rail line to Prestons being temporarily linked to Burwood forest while rubble is remoulded to enhance multiple greater Christchurch areas!

Rebuilding Christchurch brick by broken brick?  Northern suburbs to get park with a view?Christchurch Sure to Rise?   There certainly seem some interesting possibilities here.

I hope so! I am sure the late Thomas Edmonds (cake products)  would not like his famous slogan being used for half baked ideas!






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