Page:Rambles on the Golden Coast of New Zealand.djvu/191

Rh out of the mines to the time when it is put on board. The sidings are made as nearly as possible to be self-acting. When the full waggon is unhooked from the wire rope of the incline, it runs down (the brake being up) to its position on the full siding. When an empty waggon is required to be hooked on, the brake is lifted, and it runs forward to its position at the foot of the lower incline. Of course the empty ones are placed on the empty siding, and the full ones taken from the full siding by the railway locomotive engine. The inclines are worked entirely by gravitation—that is to say, the full waggon in descending draws the empty one to the top. Two separate wire ropes are used on each incline, which wind and unwind on the drum, 9 ft. in diameter, placed horizontally about 200 ft. back from the brow of each incline. The drums are divided into two compartments, and provided with powerful brake machinery, so that should one rope break, through any accident, the waggon on the other rope can be immediately held stationary. The ropes used are of steel, four inches in circumference, and are capable of bearing a strain of forty tons, but are never subjected to a strain of over eight tons. They are carefully attended to, and kept coated with a mixture of tar and anti-friction grease. Each of these ropes lasts about two years. There are two separate inclines, each with its own brake drum and pair of wire ropes, and the height is nearly equally divided, the waggons being lowered a height of 807 ft. on the upper, and 866 ft. on the lower incline. The lower incline is by far the longest, and the average grade therefore much less steep than on the upper one, the horizontal length of the lower incline being 3300 ft., giving an average grade of about one in four, while the horizontal length of the upper incline is 2000 ft., giving an average grade of about one in two and a half. The grades vary on both inclines, following to a certain extent the natural surface of the country; this was rendered necessary by the rough and uneven nature of the country, as the cost of making two planes on a theoretically perfect section would have been prohibitive. The steepest grade number reached on the inclines is one vertical to one and a half horizontal, and a good portion of the top of the upper incline is constructed on this grade, or about the slope of an ordinary staircase. In both inclines, which are counterparts of each other as far as method of working is concerned, there are three rails on the top, branching out into two separate lines in the middle, where the waggons pass each other, and ending below the turnouts in a single line. Line pulleys or rollers are arranged along the inclines wherever the rope touches the ground, about a foot in length and six inches in diameter, while at the brow, or brake head of each incline, the pulleys are much larger and heavier, as the rope presses more heavily there, and has a slight lateral motion, caused by the winding and unwinding of the drums. Each incline is perfectly straight in itself, although there is a slight difference in their direction. The permanent way consists of rails weighing 40 lbs. to the yard, with sleepers and fastenings exactly similar to those used on the railway, except that the sleepers, where crossing any viaduct work, are fastened down by ten-inch coach screws instead of railway dogs. The formation of these inclines is of the most solid and substantial description throughout, and although constructed on an extremely rough and rugged hillside, composed mainly