ROPEWAYS AND CABLEWAYS. The aerial ropeway is essentially an intermittent handling device and may be defined as that method of handling materials which consist of drawing receptacles—such as buckets or skips—suspended from ropes and by means of ropes, from place to place, such receptacles being manually or automatically filled and discharged. There is no limit to the length of a ropeway installation, since it may consist of any number of units, while the length of a single unit may be as much as 42 miles.
At what period of history ropeways were first used it is impossible to say, but the fact that ropes and pulley blocks—which are the essential parts of a ropeway—were known to the ancients, seems to render a pedigree of at least 2,000 years possible. An old engraving shows a ropeway in use in the City of Danzig in 1644. This was the work of Adam Wybe, a Dutch engineer, and is a single ropeway in its simplest form, consisting of an endless rope passing over pulleys suspended on posts ; to the rope were attached a number of small buckets which carried earth from a hill outside the city to the rampart inside the moat. The rope was probably of hemp.
In modern ropeways wire ropes are exclusively used, which date back from about 186o, when a ropeway was erected in the Harz mountains. Since then several systems have been evolved, but space does not permit of entering into details of all the possi ble applications of a ropeway; it must suffice, therefore, to mention the two principal types, which are known as single and double ropeways. In the former, one endless travelling rope both supports and conveys the load, while in the latter the load carriers are supported by a stationary rail rope on which they are hauled along by an independent endless hauling rope. The systems are also termed, respectively, mono-cableway and bi-cableway, but since a cableway is generally understood to be a different type of aerial transport altogether the names single and double rope way are preferable.
Such aerial transport resembles in substance vehicular rail transport ; in this case, however, the rolling stock is suspended from a rope which serves as a rail, instead of running on the permanent way of a light railway. It is obvious that a single overhead rope as a track, has enormous advantages over a pair of rails laid on the ground, as in the orthodox rail-track with its sleepers, the cost of preparation of the ground has to be con sidered, which may involve the construction of embankments, bridges, etc. When building a ropeway the overhead rope should run in a bee-line from place to place—say from an undeveloped area to the nearest available point where main transport is avail able, whereas in the case of a light railway, owing to limitations of grade, usually about 3%, the permanent way has to traverse a tortuous route, three or four times as long possibly, as the bee line of the rope-track, which, moreover, may be negotiated with safety on a grade of 4o%. For example, a ropeway may be cited,
which has a total length of 5,400 ft. with a total difference in altitude of 2,000 ft., the ground which it covers could not have been negotiated by a rail track of less than 15 m. in length, graded at 1 in 42. It is essential to take as straight a line as possible when laying out a ropeway because curves generally necessitate angle-stations, which entail expenditure of more capital and in crease in working cost. On the other hand, ground that would be difficult for the railway engineer, such as steep hills, deep valleys and turbulent streams, has no terrors for the ropeway erector.
The single ropeway consists essen tially of an endless running rope from which the carriers are sus pended and with which they move in the following
receptacles are fitted with simple curved hangers pivoted from a A-shaped saddle, which holds sufficiently tight by frictional con tact to the rope and therefore travels with the same. The sus pended frame of the load carrier is also fitted by the side of the A-shaped saddle with the small grooved pulley which engages at the terminals with shunt rails and thus disengages itself from the running rope; the frame of the load carrier becomes stationary on these shunt rails for filling or emptying, after which it is pushed on to the returning rope again. Or the carriers may be perma nently fixed to this rope and move with it. The ropeway itself consists of an endless rope running between two terminal drums, one of 6 to 1 o ft. diameter, known as the driving drum, being provided with power receiving and transmitting gear, while the drum at the opposite terminal is fitted with tightening gear. The endless rope is supported on suitable pulleys which are, in turn, supported on standards or trestles spaced at intervals, varying with the nature of the ground. The rope runs at an average speed of 4 m. per hour, at which speed the bucket or skip can be ar ranged to load and unload itself automatically. Generally speak ing, the single ropeway is not so suitable for heavy loads and long distances as the double. The work of Ropeways Ltd. favours the single-rope system. The founder of that firm, J. Pearce Roe, intro duced multiple sheaves for supporting the rope at each standard. The maximum load carried on such a ropeway is 150 tons per hour. Another installation on the same system serves an iron mine in Spain and spans 6,500 yd. of very rough country so steep that in many places even the sure-footed mule cannot keep on the track. This ropeway can deal with 85 tons per hour. The greatest distance covered on any one section of the single rope way is 7,100 yd., or about 4 miles. The Dorada ropeway which is the longest in the world-47 m. in length—is built on the single rope system. It has 15 units and a capacity of 20 tons per hour. In addition to the conveyance of merchandise, principally coffee, it is also occasionally used for passenger traffic.