The New Zealand Railways Magazine, Volume 1, Issue 2 (June, 1926)
A Remarkable Railway
In a remote part of the North Island of New Zealand is to be found an outstanding example of the skill and audacity of the Railway Engineer; an achievement that is reminiscent of the spirit shown by the pioneerś when they built the railway across Chat Moss in the North of England. It is history now, but the same courage and doggedness that overcame almost insurmountable obstacles in those earlier days, prevails to-day. It has a smaller opportunity of demonstrating itself, but it is there all the same, as the following short account of the Rimutaka Incline will testify.
When the Railway was constructed between Napier and Wellington (the Capital City), the engineers were confronted with a difficult task. Running across the path of the new line was a range of mountains known as the Rimutakas, and the only way of getting the line through, after many futile surveys, was found to be a tunnel several miles in length. Perhaps, had the line been built in later years the tunnel would have been made, but at the time, when the population along the whole route of the railway only amounted to 30 or 40 thousand, the heavy capital expenditure incurred in such an undertaking was altogether quite out of the question. So the engineers turned to an alternative means of overcoming the obstacle that stood in their way. Instead of tunnelling, they took the line over the ranges; and to-day this section stands as, perhaps, one the most remarkable railways to be found anywhere in the world.
The length of the “Incline” is three miles; grade 1 in 15; curves 5 chains radius; and altitude of Summit Tunnel 1141 feet. In the three miles the line rises well over a thousand feet. Not a record, but still a very wonderful thing when we remember that the railway, with a grade of 1 in 15 is worked by adhesion locomotives, although admittedly of a special type (the “Fell” system), the locomotives having horizontal gripping wheels, besides the normal outside steam cylinder mechanism and driving wheels. These gripping wheels work on a centre rail, giving added adhesion, and enabling ordinary trains to be worked over the incline.
As the grade on which the centre rail is fixed commences in a tunnel, a signal gong operated by the wheels of passing vehicles is situated in the Summit Tunnel at a point 20 feet from the beginning of the “Incline” centre rail, to warn enginedrivers that they are approaching the commencement of the steep down grade. Guards’ vans have special brakes to grip the centre rail and keep trains under control when making the descent.page 8
In ascending the incline each “Fell” engine must be placed in front of its respective load, except that when four engines are run on passenger trains the fourth engine may be placed behind the Guard's van. The “Fell” brake vans are always placed the last vehicles on the train except that in emergencies (at busy race times, etc.) when ascending passenger trains are too heavy for four “Fell” engines to handle, a fifth may be used as a pusher behind the rear “Fell” van.
In descending the grade the “Fell” brake vans are placed next behind the engines; both the Westinghouse brakes and the gripper brakes on the vans must be used, and the speed is never allowed to exceed 10 miles per hour. Should a train get beyond control of brakes the engine driver has to give the “whistle for brakes” (three short pops on the whistle). In such cases the train would be diverted into a safety runaway siding, providing gravity resistance.
It is recorded that on one occasion a violent windstorm struck a mixed train in an exposed quarter of the gully, with the result that one passenger carriage was blown completely off the rails and into a ravine.
After the accident break-winds were erected alongside exposed portions of the railway. These were largely constructed out of old sleepers placed vertically; and, in addition, other precautions were taken against a recurrence. Passenger trains in certain parts are not run down the gradients, either way, by gravitation; but the couplings of all vehicles are kept in tension by the engines steaming, and the application of brakes.
When a gale of wind is blowing, empty horse-boxes, vans or cattle waggons are not allowed to be run on passenger trains between certain stations on more exposed portions of the line.
In conclusion it is interesting to note that a proposal is on foot to do away with the “Incline” which is both expensive and slow in getting trains over the grade. Trains occupy an hour to cover the three miles, much of this time being occupied in shunting the “Fell” engines into the various portions of the train, in order to ease the strain on the couplings that would result if the engines were all concentrated at the head of the train. The maximum load allowed to be taken down the Rimutaka Incline is 250 tons. Traffic over the line is worked with Tyers’ Electric Tablet.