The New Zealand Railways Magazine, Volume 3, Issue 9 (January 1, 1929)
The Rimutaka Incline — A Unique Railway
One of the most difficult tasks with which railway engineers have ever been confronted (and one of their greatest triumphs) was the construction of the railway across the Rimutaka Ranges. The story of this remarkable railway is told in the following article.
In the mountain regions between the capital city of New Zealand and the Wairarapa Plains, is a short connecting link of railway which is unique in the railway world. It has the distinction of being the only section of railway in the two hemispheres which is operated on the “Fell” centre rail system, with steam locomotives. This link in New Zealand's railway system is known as the “Rimutaka Incline,” and, because of the special locomotives and vans used to work trains over it, and the interesting features of the permanent way, it presents many points of interest to both the railway engineer and the ordinary traveller.
The length of the Incline is three miles. In that distance, the line rises from Cross Creek (the station at the foot of the Incline), no less than 971 feet to the station at the top, appropriately named the Summit. Curves of five chains radius are a predominating feature. The longest piece of straight track, about a quarter of a mile in length, has been facetiously dubbed “The Long Straight.” Three tunnels have been pierced, the length of the longest (situated at the end of the Summit yard) being 649 yards. The average grade is 1 in 15 (which can also be expressed as a 6½% grade, or 353 feet to the mile), and one or two short stretches have a grade of 1 in 11.
Where Strong Winds Blow.
At times northerly winds sweep with hurricane force down the narrow gullies, and during the early days of operating the Incline, these winds constituted a real menace to the safe running of trains. A mishap caused directly by the wind, occurred in September, 1880, when three carriages were blown completely off the line where it crossed a deep narrow gully named, not inaptly, “Siberia.” On that occasion, even the heavy tool boxes, which were not bolted down, were blown off the engine. Describing the mishap, Mr. J. Hosie, the then fireman (now a retired driver), stated, so great was the force of the wind, that, except by crawling on his hands and knees, and hanging on to the centre rail for support, he was unable to traverse the rest of the way across the gully. Eventually, he reached the Summit and help was forthcoming. Since that mishap massive timber breakwinds have been erected at the more exposed positions on the Incline, and travel over this part of the system is now as safe as anywhere else in the Dominion.
The Adhesion Principle.
The method of traction on mountain railways of other countries is mostly by some system of rack-rail. Herein the Rimutaka Incline differs, in that traffic is operated solely by adhesion. In between the usual parallel rails, at a height of some 6½ inches, is the centre rail. This is a double headed rail mounted on its side, on heavy longitudinal timbers; which, in turn, are securely fastened to brackets bolted to the ordinary transverse sleepers. The centre rail commences at the top end of the Cross Creek yard and has its termination some distance inside the south portal of the Summit tunnel. To assist the drivers in locating the latter end of the rail a gong is placed on the tunnel wall, twenty feet from the end of the centre rail. This gong is operated through treadle motion, by the wheels of passing vehicles.
The Famous “Fell” Locomotives.
The “Fell” locomotives, known to railway-men as class “H,” are used exclusively for this section of railway, These engines have a total weight of 39 tons. Their construction and operation are most interesting. In passing, it may be news to many, to learn that four of the “H” class engines had names painted on their tanks, viz., “Mt. Cook,” Mt. Tongariro,” “Mt. Egmont,” and “Mt. Conis.” It is a pity that the old custom of naming our locomotives has fallen into disuse.) These engines are carried on six wheels of a diameter of 32ins. The two leading pair of wheels are coupled, and the trailing wheels constitute a radial bogie, situated under the cab. The coupled wheels, which have outside bearings, are driven by cylinders 14in. diameter × 16in. stroke. The steam pressure is 1601bs. per sq. inch. Four of the locomotives have Stephenson valve gear, and two are fitted with Joy's patent valve gear, all of which are outside the frames.
At the base of the smokebox are placed the inside cylinders, 12in. diameter by 14in stroke, which actuate the centre engine. This portion of the engine's anatomy presents much out of the common. The inside cylinders drive on to two vertical axles, and these, in turn, are coupled to two other axles, by suitable rods and pinion wheels. These vertical axles work in axleboxes placed in the cross frames. Keyed to the lower ends are cast steel gripping wheels, having page 38 a flat tread. Sufficient play is allowed in the axleboxes to permit of the gripping wheels being brought into compression against the centre rail for the “up” trip, or being swung clear for the “down” trip. This is accomplished by means of powerful compression springs, operated from the engine cab. In addition to the ordinary Westinghouse brake, the engines are equipped with four cast iron shoes on suitable levers, which can be compressed against the centre rail, pressure being applied by means of rods and screw in the usual manner.
It is, of course, very necessary that the speeds of the inside and outside engines should synchronise when hauling trains up the grade. The drivers are very expert at this.
The Braking Apparatus.
Special four-wheeled brake vans are attached at the rear of all trains ascending the Incline, the number of vans to be attached varying according to the load. When trains descend the Incline the vans are placed at the front end of the trains, next to the engines. The special brake gear consists of four massive upright cantilever arms, pivoted on the floor of the van.
The lower ends, to which are bolted cast iron brake shoes, reach low enough to engage against the centre rail. The upper ends are forked, and work in guides on the sides of gun metal nuts, which, in turn, move in or out from the centre of horizontal shafts (screwed with right and left hand threads), running in suitable bearings. A large hand wheel is keyed to the centre of these screwed shafts, and, according to the direction in which the wheels are revolved, so the cantilever arms press the brake shoes against the centre rail, or move them away from it. So severe is the service demanded of this braking system that a set of blocks rarely lasts more than one trip down the Incline.
How Trains Are Operated.
Let us watch the operation of a train about to negotiate the trip up the “hill.” The practice is for each “Fell” locomotive to be placed at the head of its respective load. When a train arrives at Cross Creek the train engine is detached and the leading “Fell” engine couples on and draws its load up to the commencement of the centre rail, against which the centre engine grip wheels are compressed. The page 39 second engine next couples on to its load and then draws ahead to couple up with the first portion. In like manner a third, or fourth “Fell” engine will be attached to their loads, the requisite number of “Fell” vans placed on the rear of the train, the whole coupled up, the Westinghouse brake tested throughout the train and then the train starts off on its three-mile climb. As the second and successive engines reach the centre rail, the inside engine is put into operation. The speed of trains on the “up” journey is necessarily slow, being five miles per hour. The speed on the downward trip is also, for obvious reasons, curtailed to about ten miles per hour. Close fitting doors and windows are provided on all engines to minimise the discomforts of smoke and exhaust steam when passing through the tunnels. The carriage lamps are lighted during the same period.
At the sound of the gong in the Summit tunnel, the pressure of the gripping wheels is released, the wheels are swung clear and the inside engine ceases operation. After arrival in the Summit yard the “Fell” engines and vans come off the train, which is then made up into one portion, and is ready to continue the journey to Wellington.
“Safety First” is rigidly enforced in the working of this part of the railway system. Immediately after the departure of a train up the Incline the points of a runaway siding at the bottom of the grade are opened and not again set for the main line until the whistle of a descending train is heard. Telephones are situated at a number of points on the Incline, so that in case of a breakdown to a vehicle, prompt notice can be given to the stations at the top or bottom of the Incline. Considering the natural difficulties encountered and the arduous nature of the work of operation, it is a tribute to the efficiency of the officials and men of this section that no serious mishaps have occurred on the Incline since 1880.
When a plumber makes a mistake he charges twice for it.
When a lawyer makes a mistake it's just what he wanted, because he has a chance to try the case all over again.
When a carpenter makes a mistake it's just what he expected, because chances are ten to one he never learned the trade.
When a doctor makes a mistake he buries it.
When a judge makes a mistake it becomes a law of the land.
When an electrician makes a mistake, he blames it on induction—nobody knows what that is.
When a preacher makes a mistake, nobody knows the difference.
But when an editor makes a mistake, Good Night!