“The cover this week shows the Transporter Bridge over the Old Harbour of Marseilles. This structure, which is described in the chapter entitled Transporter Bridges, is one of the biggest landmarks in the famous French seaport.”
The marvellous improvements which are now used to aid the miner in his work and to minimize the danger in which he toils. This chapter is by David Masters and is concluded from part 12.
The Marseilles Transporter Bridge
“THE ENTRANCE TO THE OLD HARBOUR of Marseilles, France, is spanned by a transporter bridge designed by Arnodin, the man who was responsible for building many such bridges. The bridge at Marseilles has a span of 540 feet, and was built in 1905. The towers reach to a height of 282 feet and the girders carrying the traverser are 164 feet above the water.”
This bridge is also illustrated on the cover of this issue.
Underground Electric Railways
“UNDERGROUND ELECTRIC RAILWAYS are used extensively in coal mines. Above is shown a train of this type, with overhead conductors, in a mine in Virginia, USA. Similar types of locomotive haul the tubs from the coal face to the cages which bring them to the surface.”
ONE OF THE BIGGEST FEATS of engineering in Africa in recent years was the building of the Benguela Railway, from the port of Lobito across Angola to the Belgian Congo and Northern Rhodesia. The railway was built with British material and British capital. At Nova Lisboa are huge railway repair shops, for which power is derived from the hydro-electric plant at the Cuando River Falls a few miles away.
Upstream Face of the Burrinjuck Dam
“UPSTREAM FACE of the Burrinjuck Dam in the course of construction. The dam has a height of 236 feet and is 168 feet wide at the foot, tapering to a width of 18 feet at the top. The dam measures about 780 feet along the crest.”
The principle of control by the photoelectric cell has unlimited applications in the field of engineering. In an amazing variety of ways the cell is a safeguard in industry and an invaluable part of the engineer’s equipment. One of the most important things in the development of engineering is the way in which the scientist and the engineer so often work together. This is particularly noticeable in recent times when science has made such remarkable progress. Among the many discoveries of science is the photoelectric cell which has now been applied to so many things in our everyday life - as, for instance, in traffic-actuated signals. Many remarkable adaptations of the photoelectric cell principle have been made by the engineer and in this chapter, T J Fielding explains how the photoelectric cell has affected various forms of engineering.
The Photoelectric Cell as a Mechanical Counter
“AS A MECHANICAL COUNTER the photoelectric cell is virtually infallible. In a newspaper office, for instance, parcels of newspapers pass along a conveyor for dispatch. A light source is mounted on one side of the conveyor and a cell on the other. As the parcels pass they interrupt the ray of light and each interruption is duly recorded by the photoelectric cell.”
The many processes involved in the production of millions of copies of a periodical - such as typesetting, printing, folding, binding and trimming - are carried out by machines which work at remarkable speeds and with extreme precision. When you open your copy of Wonders of World Engineering you do so only because industrial engineers have perfected over scores of years huge machines which cast the metal type, set it, and make it possible for hundreds of copies an hour to be made. The story of a great printing works is full of interest, not only to the engineer but also to the layman. This chapter is by F E Dean and is the second article in the series on the Romance of Industry.
Electricity in the Heart of Africa
“WORKMEN are shown (bottom) preparing a trench for the pipe line which carries the water to the electric generators. The men are drilling holes to take charges of gelignite which will blast the rock and earth. In the trench a concrete bed was prepared (top) to take the pipe line. Sections of the pipe line are lowered into the trench and riveted together, as shown on the left-hand side.
To combat drought, the Australian farmer’s greatest enemy, mighty barrages have been built and thousands of miles of canals dug. Work has entailed stern battles against the forces of Nature in mountainous country far from civilization. This chapter is by Harold Shepstone and deals with many of the irrigation schemes in Australia, and describes the building of the huge Burrinjuck Dam in a remote district of New South Wales. The article is concluded in part 14. It is the fifth part in the series on Triumphs of Irrigation.
Building the Burrinjuck Dam
“THE CYCLOPEAN PRINCIPLE was used in building the Burrinjuck Dam. A number of cruciform units of concrete, measuring 9 feet, 12 feet and 15 feet in height, were made and placed so that adjoining units broke joint horizontally and vertically. The units were built up of heavy timber and concrete was run in to make a bed. In the concrete were embedded boulders or “plums” each of them averaging about 15 tons in weight. More than 50,000 tons of cement were used.”
The Burrinjuck Dam
“BURRINJUCK DAM (above) was built across a gorge of the Murrumbidgee River, New South Wales, just below its confluence with the Goodradigbee River. The dam is 236 feet high, with a width of 168 feet at the base, tapering to 18 feet at the top. The crest of the dam is 780 feet long. There is a spillway on either side of the dam to carry off overflow water, in addition to four 4½ feet valve openings in the base of the dam. The dam, which was completed in 1914, has formed a reservoir with a water surface area of 12,780 acres, with a maximum depth of 200 feet.” This article is concluded in part 14.
The most practicable and economical way to carry road traffic across a waterway is often by a transporter bridge. No approach viaducts are necessary, although the permanent span is at such a height as to give plenty of headway for shipping. River traffic is interrupted only by the crossing of the suspended transporter car. This type of bridge is most interesting. There are not a great many examples, because the design is for particular conditions which do not apply everywhere there is a need for a bridge. One of the best known of transporter bridges is the one at Runcorn, Cheshire, and there are some famous examples in France, at Marseilles and at Rouen, for instance. This chapter is by C Hamilton Ellis.
THE manufacture of machine tools for use in engineering workshops forms an industry within an industry. A firm making locomotives or turbines, for instance, does not make its own tools, but buys them from firms which make nothing else. The machine-tool industry is highly-specialized, and a number of British firms with world-wide reputations have spent enormous sums in research and experiment to meet the demands of the manufacturing engineer for powerful machine tools capable of high rates of production.
The number of different kinds of machine tools in daily use and the huge dimensions that some of them have now attained are surprising. An example is here shown of a large plano-milling machine at work on the machining of part of a diesel engine bedplate. The machine is an
ingenious combination of two older forms of tool, the planing machine and the milling machine.
The machine illustrated, made by Kendall and Gent (1920), Ltd, of Manchester, can machine parts as large as 20 feet long, 12 feet wide and 8 feet high. Of the two cutting heads on the cross slide, one is shown fitted with a side cutter, a rotating tool with a number of spiral cutting
edges. This is being used to machine the main bearing recess of the bedplate, the head being automatically traversed along the slides as the cutter rotates. The bedplate does not move. The other cross slide head and the two heads on the side columns are each shown fitted with a
face cutter, that is, with a rotating disk from the face of which project a number of tools arranged in a circle.
The face cutters have finished their work, which was the machining of flat surfaces on the top and sides of the bedplate. When this was being done a face cutter was also fitted to the right-hand cross slide head and the bedplate, which is firmly bolted to the table, was carried back-
wards and forwards by the table as all the four cutters revolved. The top cutters were traversed inwards and the side cutters upwards as the cut progressed. The cross slide can be moved up or down on the columns. The side heads can also be moved up or down. All four spindles can be moved longitudinally in the heads to suit the dimensions of the work. All the cutters are driven by separate electric motors. One great advantage of such a machine is the large number of surfaces that can be machined in different planes without the work having to be reset.
“THE SUSPENDED STIFFENING SPAN that carries the trolley from which the transporter bridge at Runcorn is hung is formed by two great girders, 18 feet deep and 35 feet apart. The undersides of these girders are 82 feet above the level of high water. A trolley driven by two electric motors, each of 35 horse-power, is mounted on the rails laid along the girders. The trolley is 77 feet long and has ten wheels on either rail.”
The Press Room at the Park Royal Works
“THE PRESS ROOM at the Park Royal Works covers an area of 31,200 square feet. The roof, 30 feet above the floor, is carried on immense lattice girders 156 feet long. Powerful mercury lamps illuminate the press room at night and the ducts of the great ventilating system can be seen running along under the roof girders.”
An Intertype Machine
“AN INTERTYPE MACHINE having three main and three side magazines. The term magazines used in this sense is a technical expression meaning store, and must not be confused with the printed magazine or periodical. The magazines hold the matrices from which type is cast on selection by pressing the required key on the keyboard.
At the top of the machine is the distributing gear which returns the matrices, after they have been cast, to their correct positions in the magazines. The Intertype automatically casts type in lines of predetermined length and the lines of type (slugs) are delivered to the table on the left.”
One of the Printing Units at the Park Royal Works
“TWO PAIRS OF TYPE CYLINDERS form one of the five printing units in each press at Park Royal Works. Each cylinder carries twelve semi-cylindrical stereo plates of two pages in duplicate, so that with each revolution of the press two complete copies of the periodical are printed. The press is 64 feet long and more than 20 feet high, covering a floor space of 2,984 square feet.”
Burrinjuck Dam - 2
“ONE OF THE CABLEWAYS across the gorge by which debris was removed from the cofferdam and material was handled for building the Burrinjuck Dam. The gorge was spanned by three cableways, each 1,200 feet long, and supported by towers 33 feet high. The cables had a sag of 60 feet and at their lowest point were 320 feet above the river. They took a maximum load of 15 tons.”
“PASSAGE FOR THE RIVER was provided for, when the retaining wall had risen above the level of the diverting channel, by a tunnel 28 feet in diameter through the base of the dam. This tunnel was later closed up. In addition, a valve house with four 4½ feet valves was provided.”