$27.2M facelift has put Chch-Picton line on right side of track

Press, 2 June 1982, Page 25

$27.2M facelift has put Chch-Picton line on right side of track

Story:

JOHN BURNING

Pictures:

DAVID CHARTERIS

Tell anyone you are going to Picton by rail and the usual reply is: ‘‘How many days have you set aside for the trip?” In the past there may have been an element of truth to this type of off-hand remark, as the rail link between Christchurch and Picton was beset by industrial stoppages and slips. But now Railways is determined to negate these remarks with positive achievements . . . achievements which have not come cheaply. In an attempt to return Railways to the mantle it held during the great era of steam, the corporation has spent $27.2 million over the last five years upgrading the Picton line and making it an efficient alternative to other transport modes. ■ ‘‘There is no denying that we had problems in the past, but last year the line was closed only for 65 hours, which is less than one per cent of the year," says the Christchurch assistant district engineer, Mr Murray Kennedy. Mr Kennedy admits that it will take a lot to convince people of the improvement Railways has made. “They will still point the finger at us. no matter how impressive our recent record has been." Upgrading the route has been a headache that not

even $27 million can completely overcome. Railways engineers have encountered many problems over the last five years, among them: • Culverts too small to handle heavy rainfall. • Cuttings so steep they are prone to slips. • A tunnel too low to allow large containers through. • Slopes susceptible to erosion that caused large shingle deposits during floods. • Cuttings so narrow that machinery could not operate efficiently when clearing slips. • A major rail bridge with snallow foundations. • Unstable geology with beds of clay on top of gravel. • A bridge so low that flood waters flowed down an adjacent tunnel. Originally, the line north from Christchurch was designed as a secondary route and not geared to handle the traffic that passes north and south today. , However, the introduction of the Picton ferry in 1962, and the abolition of the Lyt-telton-Wellington service in 1976, meant that Picton became the main depot for rail transport leaving or arriving in the South Island. In 20 years the number of trains using the track jumped from two to 16, while the freight carried in the last 10 years has doubled. Work began on upgrading the line in 1977 when $3.5 million were spent. Although

the work carried out did not meet everyone's approval, changes were soon apparent. Some inefficient and seldom used sidings were closed and others were upgraded. Several groups objected to sidings in tneir areas being closed . but. by rationalising their numbers’ freight could be loaded and unloaded much more quickly. Small, low-cost shelters have been built where old goods sheds once stood. Freight carried on the line now amounts to 30,000 tonnes a week and the capacity has

not been reached. Trains are becoming more frequent and pulling greater tonnages. Bigger locomotives have been bought. Concrete sleepers are being used to replace the treated pine units, and heavier gauge rails are being laid to carry the bigger trains. Treated pine has an expected life of about 30 years; concrete is expected to last 50 years. Concrete sleepers and fastenings are also cheaper. Originally, 50 pounds per yard rail was laid, but this has been doubled in many

places to carry the” larger trains. Larger trains have also meant that bigger loops have to be made. (A loop is a section of track where two trains can pass.) The loops could hold only 50 waggons and a large train had to be split to be accommodated off the main line. This was time consuming. Now, at places like Scargill, trains with 120 waggons can be placed in one loop and can be back running again in 20 minutes. The cost of upgrading a loop can be as high as $lOO,OOO. At pre-

sent there are 12 loops on the Picton-Christchurch line and Railways hopes to have 27 built by the year 2000. Building loops, pulling down goods sheds, laying concrete sleepers, and installing heavier gauge rail was only an entree compared to the main course that was ahead — a course which gave engineers and workmen ample opportunity to appease their appetites for work.

The section of track between Parnassus and north of Kaikoura (75km), notorious for its slips, floods, narrow cuttings, tunnels, and tempestuous weather, was where the bulk of the money was

channelled. At the Hawkswood Cutting (144 km north of Christchurch) slips had closed the line on an average of once a year for the last 40 years. The steep-sided, 20-metre-high cutting was so narrow at the bottom that there was no room for machinery to work when a slip occurred, thereby compounding the problem.

Over the last three years $400,000 has been spent widening the cutting by four metres on either side and removing 250,000 cubic metres of soil.

The sides of the cutting have been stabilised by hydro-seeding — a mixture of grass, fertiliser, and paper mache or latex, sprayed on to the hillside -r- and small bushy willows which will grow to about three metres tall have been planted. Plastic mesh was pegged in place over the slopes to consolidate the earth while the grass and legumes grew underneath. There have been no slips in the area in the last two years and any further slumps will be cleared much quicker because of the greater access for bulldozers and trucks. Farmers adjacent to these areas often receive the spoils of Railway labours. One farmer near such a site got an extra four hectares of flat land by filling in a large gully with some of the soil removed from a cutting. For work to be given the go-ahead it must be proved that there will be a 10 per cent return oh expenditure. “Expenditure can be justified on these jobs by outlining the cost of continual maintenance, the damage if a train crashes into the slip and waggons are derailed, and expenses incurred while the line is closed," Mr Kennedy says. “On this particular project we were able to show a 12 per cent rate of return.”

An innovation has been the installation of two-way radios on each locomotive. In the past, trains had to be stopped to use the track-side telephones. Repeater stations have been built at Beltana and Ward and give excellent reception. By being able to contact train control direct, workers and machinery further along the track can be left on the line longer; in the past much time was wasted as work groups were conservative in their estimates of when to get off the track. Work is not restricted to weather proofing the line, but also to making it a faster and safer route. Between Claverley and Hundalee private contractors have been employed by the corporation to turn a sharp bend into a gentle curve, allowing trains to travel over the section of track at a faster speed. “This bend is at the end of a long straight section and if trains had not slowed sufficiently before negotiating the bend they were in danger of being derailed. By changing the radius of the curve it also makes it safer,” Mr Kennedy says. This section of the track is plagued by “mud pumping,” which occurs when the sleepers have gone' through the foundation or ballast and do not have a solid base .to stand on. The effect is similar to jumping up and down on a stretch of pavement which has a broken drain underneath. North of this project is a section of line that it is not practical to upgrade. Near the Haumuri tunnel, about 20km south of Kaikoura, there have been severe runoff problems since Cyclone Allison ripped away all the vegetation in 1975. The tunnel is about 50 metres above the sea and a third of the way up the

mountain. To repair and upgrade this section would cost $l5 million. “This is just one area we are never going to fix properly, but we would only expect the line to be closed for two days during a severe storm,” Mr Kennedy says. The areas around Kaikoura, characterised by steep-sided cliffs, . sparse vegetation, and numerous shingle slides, are prone to flash floods and severe erosion. Culverts are generally too small — some only an eighth the required size. During heavy rainfall these quickly reach capacity, and water and shingle pours over the railway and the road. It costs about $40,000 to repair one culvert. Just north of Kaikoura, at both Hapuku and the Moririmu Stream, the costs of solving the problems are too great. At Hapuku, a tunnel would have to be extended to stop water flowing back into the tunnel during a flood, whereas $700,000 would have to be spent to raise the Moririmu bridge four metres and lift it above the level of the river’s flood peak. Two years ago this bridge was lost under a mountain of shingle as flood, waters piled debris and rocks over the structure.. ” North ( of Moririmu Stream the railway line moves away from the hills slightly (in contrast to the previous 70km where it ran at the foot of steep rocky cliffs) and the problems are not as acute. The major work in this area was strengthening the foundations on the Clarence River rail bridge. “The foundations were rather shallow and to protect our investment we strengthened them. A washout on a bridge this size would be catastrophic and the money spent on repairs astronomical,” Mr Kennedy says. " - . ' ; To help control run-off along this area the Depart-, ment of Lands and Survey bought a farm that had - major erosion problems and retired large parts of it.

A tunnel in the Dashwoods, which was too small to allow out-sized containers to pass, was removed for $300,000. To accommodate the extra tonnage being carried on the track, nearly $1 million has been spent upgrading the Spring Creek depot, now effectively the railhead for Nelson, and another $2 .million on a locomotive workshop and track at Picton. All this work on the line , a could mean a drop in the workforce required, and with labour taking up 60 per cent of all costs this could lead to a substantial saving for the corporation. Repairmen and inspection gangers will still be required. Each day an ; inspection ganger travels his length of track looking for minor defects, broken rails, broken fastenings, and obstructions on the track. “We still have another five years of upgrading work to be done, but the major work has been completed,” Mr Kennedy says. “We would like to be open for 100 per (cent, of the time, and last year we nearly succeeded. I would say we compare favourably with Christchurch and Wellington airports.”