The Rimutaka Incline was a , gauge railway line on an average grade of 1-in-15 using the Fell system between Summit and Cross Creek stations on the Wairarapa side of the original Wairarapa Line in the Wairarapa district of New Zealand. The term "Rimutaka Incline" is sometimes used incorrectly to refer to other parts or all of the closed and deviated section of the Wairarapa Line between Upper Hutt and Speedy's Crossing, near Featherston. The incline formation is now part of the Remutaka Rail Trail.
History
Background The construction of a railway from Wellington to Masterton was authorised in the Railways Act passed on 13 September 1871. Julius Vogel, Colonial Treasurer, travelled to England to raise finance for a major public works programme for railway construction. Vogel returned via the United States, where he studied rail systems.
After the act of parliament was passed, a survey party set out to make preliminary investigations of possible routes for a railway over the Rimutaka Range (now spelled "Remutaka Range"). These were complete by December 1870, the party having investigated four routes. A commonality between all the proposals was the section from Upper Hutt to Kaitoki (later Kaitoke). Between Kaitoke and the Wairarapa, the four proposals were the Tauwharenikau Route, Mr Sinclair's Route, a coastal route and the Pakuratahi Route.
While the government was conducting its surveys, Wellington Province Superintendent William Fitzherbert instructed his Provincial Engineer, Charles O’Neill, to investigate the possibility of a railway through the Rimutaka Valley (the route of the road between Featherston and Upper Hutt), with a tunnel through the dividing range. The survey was carried out between May and 21 July 1871, and O’Neill reported that a tunnel 130 chains (2.6 km) long would be required, with the line rising at 1 in 60 from the Pakuratahi to the tunnel then descending at 1 in 40 to Featherston. This survey was forwarded to the Minister for Public Works.
In mid-1873 the route to Featherston was chosen after a final survey for the route from Upper Hutt to Summit.
For the line between Summit and the Wairarapa, several proposals were considered. The first, with gradients up to 1 in 30, was dismissed. It was found that to keep the gradient to no steeper than 1 in 40, curves of three chains (60 m) radius would be required. This would have required special rolling stock and heavy earthworks and was thus abandoned.
Another proposal was known as the Birch Spur Incline. This would have involved the line continuing from Summit to Birch Spur from where a rope-worked incline would convey traffic to the valley floor where the railway would continue through a narrow valley to the Wairarapa plains. The Public Works Department engineers investigating this proposal were unable to locate a suitable incline, so this proposal was also abandoned.
The last option was a three-mile (4.8 km) incline with gradients averaging 1 in 15 "to be worked by locomotives of an unusual nature". This line was the most favourable from an engineer's point of view, and required not unreasonable earthworks. The final decision was made by the head of the Public Works Department, John Carruthers. He determined that an incline worked by the Fell system would be suitable, and cited the Mont Cenis Pass Railway as an example. Though special locomotives would be required, factors in its favour were that ordinary rolling stock could be used and it was a proven system. It was to be the third and last Fell system employing the centre rail for both tractive power and braking, and the longest surviving. Though it was considered to be a "temporary" measure, it outlasted the second such system in Brazil by 72 years.
Construction Construction of the Rimutaka Incline was included in two contracts that were let for the building of the original Wairarapa Line. These contracts were known as the Summit contract and the Incline contract.
Summit contract This contract included the excavation of Summit station yard and related drainage, Summit tunnel, and formation work to a point 26 chains (523 m) beyond the tunnel. It was the shortest contract of those let for the line, it was finished by the original contractor, and it had the fewest alterations. Work was to start on 12 July 1874 and to be completed by 22 July 1876, at which time the Pakuratahi contract was due to be completed.
Summit yard was a large cut into the hillside, wide and long initially. Excavations removed material to a depth of 15–20 feet, with this fill being dumped on the opposite side of the yard to form level ground. On the hillside above the yard, further ground was levelled and houses erected thereon.
After the yard had taken shape, the next job was the tunnel. The approach to the tunnel was about 6 chains long and up to deep. The line entered the tunnel on a downward grade of 1 in 1,000, steepening to a grade of 1 in 15 at the eastern portal. At that end a small drainage tunnel had to be built to divert a stream that had flowed down a steep gully where the tunnel mouth was to be. The maximum height of the tunnel was above the floor: once rails were laid the maximum clearance was The width of the tunnel varied from at the floor to at above the floor. Despite castigation from various parties, it was not until March 1877 that work on both ends of the tunnel met at the middle, having taken three and a half years to complete.
The Public Works Department lined the tunnel after the rails had reached the site, enabling them to use work trains to bring materials and other supplies in. It was during this phase that the only fatality on this contract occurred: on 3 May 1878, a sizeable portion of the lining collapsed on two men. One was killed outright, the other lost his eyesight due to severe head injuries.
The Summit contract was completed on 10 December 1877, 17 months behind schedule.
Incline contract On 5 October 1875, the Incline contract was awarded to Charles McKirdy for the sum of £49,029. The contract covered the formation only, with the Public Works Department responsible for track laying.
The contract began outside Summit tunnel and terminated at Featherston, a distance of 8 miles 76 chains (14.403 km). It included Cross Creek station yard and runaway siding. Several alterations were made to the contract both prior to and during construction, including the replacement of one of three tunnels by a cutting, and three wooden bridges by embankments.
The line descended at a grade of 1 in 15, passing through the long Horseshoe Gully Tunnel (later Siberia Tunnel). On leaving the tunnel, the line crossed the gully on a high earth and rock embankment, the largest on the section, on a five-chain radius curve. The embankment was about 180 to wide at its base, and around high at its centre line.
After the embankment, the line continued at a grade of 1 in 15 down to Cross's Creek (later Cross Creek) station. From Cross Creek the line descended at gradients varying from level to 1 in 40 to Lucena's (later Pigeon Bush), and from there in a straight line to Featherston.
Work on the contract began on 22 October 1875. None of the major earthworks seem to have presented any great difficulties, save the lower tunnel, which was plagued by accidents and materials failures largely because of the unstable nature of the rock through which it passed. The tunnel was named Price's after the manager McKirdy employed for this contract. On 2 March 1876, two men died due to a cave-in of the tunnel roof.
Between October 1877 and March 1878, platelaying was completed up to Summit. This enabled the use of work trains to haul up materials that were used to line Summit Tunnel. Track laying on the incline commenced in April 1878 and reached Cross Creek the following month. During this work, H 199 was stabled at Summit and used to haul work and ballast trains to the railhead.
Initially, only simple arrangements were made for the station yard at Cross's Creek, as it had yet to be decided the nature of operations on the Incline. It consisted of the main line, an engine siding of 10 chains, and the runaway siding.
After formation work continued beyond Cross Creek, McKirdy ran out of time and money, with the remainder of his contract being picked up by his guarantors, T. W. Young and Robert Greenfield. They finished the formation to Featherston on 17 August 1878, with track laying finishing the following month. The contract was completed 13 months late.
Operation Initially, trains on the incline were limited to the weight that could be managed by a single locomotive. After complaints from management of the expense of running too many trains, two locomotives seem to have been used, both at the head of the train. From 1887 trains were worked with multiple locomotives, each at the head of its rated load. As the maximum weight of a train during this period was 150 tons, no more than three locomotives were used per train. Train operations continued to be modified until by 1908 the maximum load allowed per train had increased to 250 tons descending and 260 tons ascending.
When the line opened, there were two Fell brake vans in service, each long and from floor to ceiling, with open platforms at either end. The wear on the brake blocks fitted to these vans was so severe that a set of blocks seldom lasted more than one trip down the incline. Like the positioning and loading of the locomotives, the arrangements for positioning of the Fell vans varied until they were largely standardised by 1897. For ascending trains, Fell vans were placed at the rear of the train. For descending trains, a Fell van was placed between the locomotives and the leading vehicle. If the gross weight of the train exceeded 120 tons or included more than 15 vehicles (excluding the locomotives in both cases) a second Fell van was attached to the rear of the train. These rules applied before the introduction of the Westinghouse continuous air brake. The Fell locomotives were never turned, running cab first on descending trains.
As descending trains departed Summit the "through" guard applied the brakes on the leading vehicle, then moved through the train applying the brakes on the other vehicles until he reached the train van, which also had brakes that had to be applied. Each Fell van had its own guard to operate the two sets of brakes.
After the introduction of the continuous brake system in 1903 it became possible to operate trains with five locomotives, and on descending passenger trains up to five Fell brake vans could be used – two next to the locomotives, one in the middle, and two at the rear. As each brake van had its own guard and the train had a train guard and locomotive crews, a train with five brake vans and four locomotives had a crew of 14, which added to the expense of the operation. Moreover, to reduce the strain on couplings, when several locomotives were used they would be distributed through the train, as can be seen from photos. This necessitated significant remarshalling of the train at either end of the incline.
Instructions issued in 1885 regarding the use of the safety siding required that the points for the incline be set to the safety siding. As descending trains approached the Cross Creek yard, the driver of the leading locomotive sounded a long whistle, which signalled that all was well. On hearing this signal the signalman would set the points for the arrival road. As far as is known no real emergency occurred. Cross Creek had an unusual six-lever partially-interlocked signalling installation and had no "distant" signals so had points indicators which applied to the "main" line (see Heine for station layout), while Summit had a fully interlocked 27-lever frame.