Background Organised European settlement of Canterbury began in December 1850 with the arrival of the first
Canterbury Association settlers. The settlers had two options for transporting themselves and their goods between the harbour at Lyttelton and the Canterbury plains: the
Bridle Path over the
Port Hills, or by
ship over the
Sumner Bar then up either the
Ōpāwaho / Heathcote or
Avon / Ōtākaro Rivers. Captain
Joseph Thomas had considered a tunnel between the deep-water port at Lyttelton and the
Canterbury Plains in 1849 but rejected the idea because he had neither the money nor the workforce to consider such a project and he wanted nothing to distract from building the road he had planned between Lyttelton and Sumner. They presented Tullock with plan and section drawings, which Jollie believed were sent to London. The Committee's report was released on 1 November 1851, but took over a month to be printed and published. Rev. O. Mathias felt a tunnel was "
too visionary and chimerical" and the colony could not afford to throw away money. The inability of the commission in its final report to make an unequivocal recommendation as to the best option for connecting the port to the plains resulted in plans for the railway to be temporarily suspended. This only exacerbated the problem to the point where, in 1858, Superintendent
William Sefton Moorhouse prevailed upon the Provincial Council to consider the matter again. In response, the council set aside £4,000 to engage the services of an
engineer and to seek tenders from reputable engineering firms that may be interested in the project. The that had been established to implement the recommendations of the council, chaired by W. B. Bray, set about investigating the two railway proposals that had earlier been considered, west and east of
Mount Pleasant. Provincial Engineer
Edward Dobson favoured the latter route as it meant that Gollans Bay could be used to berth ships at a deepwater
jetty without having to dredge the area. However, there were several factors against the Gollans Bay route that had to be considered, not least that it bypassed Lyttelton, a growing commercial centre of some importance; its exposure to the wind; and the lack of suitable land at the bay for
port facilities. Though the commission considered it to be the best route to the harbour, they discounted the route and decided against a detailed survey of it, as their terms of reference had tasked them with finding a route to Lyttelton. The report from
George Robert Stephenson, a consulting engineer to the Provincial Commission, was largely in favour of the "Bray" route, and made the following points: it was the shortest route providing access to all necessary points; construction costs would be 32% less than the alternative; it would be cheaper to work; and less expensive to maintain. The only point he noted in favour of the route via Gollans Bay was that it would take three years to construct as opposed to five years for the direct route. Having considered the available data, the commission adopted the report from Stephenson and requested that he obtain a tender from a suitable English
contractor.
Construction Stephenson retained the services of English contractors John Smith and George Knight, who had agreed to complete the project within five years. They dispatched an agent, chief
miner and a party of 12 miners to New Zealand near the end of 1859. On arrival in Canterbury, Smith & Knight's miners drove trial shafts at each end of the tunnel. Nine chains from the Lyttelton end they encountered rock much more difficult to bore through than what they had been led to believe they would encounter from samples that had been sent back to England. Given this new information, they concluded that it would not be possible to complete the contract for the original amount, and they sought an additional £30,000 to complete the work. After consulting with the provincial engineers, the Canterbury Government decided not to proceed with the services of Smith & Knight. It was later discovered that Smith & Knight were in severe financial difficulty at the time, a fact which may possibly explain their request for the £30,000 extension on the contract. Work began on the tunnel on 17 July 1861. Work proceeded at both ends of the tunnel, with the rate of progress determined by the difficulty encountered in drilling through the rock. By the time work started on the Canterbury Southern Railway, 91.66 chains of the 130.66 chains total length had been bored. Hole-through was achieved on the morning of 28 May 1867 from the Lyttelton heading to the Heathcote side. Temporary rails had been laid through the tunnel by mid-November, enabling the passage of the first locomotive, No. 3, on the night of 18 November. The first goods train through the tunnel was headed by No. 3 and driven by Abraham Beverley a week later, to be followed by passenger services on 9 December. The tunnel was not considered complete until June 1874, by which time the government had outlaid a further £20,710 on "maintenance". In 1923 duplication or electrification of the
bottleneck tunnel was again proposed.
Operations At the time the colonial government decided to implement a national railway gauge, they made exceptions for some existing railway systems that had already been laid using different gauges, generally on the proviso that any new track was to the national gauge. One such system was the railways of the Canterbury Province, which were brought under the jurisdiction of a special act of parliament, the Canterbury Gauge Act. This act made provision for the regauging of existing lines by laying a third rail between the two existing rails to allow for the use of narrow gauge rolling stock on the same track. Rather than incur the inconvenience of this approach, the provincial government decided to lay a new narrow gauge line beside the existing broad gauge line from Addington to Lyttelton. The narrow-gauge line reached Christchurch on 7 March 1876 and Lyttelton 34 days later. The nuisance of smoke in the tunnel created by steam locomotives prompted attempts by the Railways Department to alleviate the problem. In August 1909, they had locomotive
WF 433 converted to oil burning to reduce the amount of smoke produced. The locomotive was used for a trial period to haul 450-ton goods trains through the tunnel. Though the modification proved to be efficacious, the benefit did not outweigh the cost involved and the idea was abandoned. The second attempt was to electrify the line from Christchurch to Lyttelton. Following the successful electrification of the
Otira Tunnel in 1923, and a report recommending electrification of the suburban networks of New Zealand's four main cities, it was decided to electrify the Christchurch – Lyttelton route using the same system as had been used at Otira. Fortunately, because the tunnel had originally been built to accommodate the provincial railways' larger broad gauge rolling stock, the tunnel was already large enough to accommodate the overhead catenary without modification. The first electric train ran from Christchurch to Lyttelton on 14 February 1929. Electrification lasted until 1970, by which time the
EC class electric locomotives had reached the end of their working lives. With the decline in rail services after the opening of the
Lyttelton road tunnel in 1964, and with dieselisation almost complete and only a few steam locomotives left in revenue service, the electrification system was scrapped in favour of diesel haulage. ==Today==