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Wonders of World Engineering

Part 23


Part 23 of Wonders of World Engineering was published on Tuesday 3rd August 1937, price 7d.


Part 23 includes a colour plate showing a Pelton Wheel. It formed part of the article on The Pelton Wheel. The colour plate was also used as the cover design for this part.




The Cover


This week’s cover shows a Pelton Wheel, one of the several types of turbine now used for converting the energy of falling water into electrical energy. The photograph shows the jet and the buckets into which it directs the water, and a short description of the wheel appears on page 662.


The cover design was also used for the colour plate in this issue.

A Pelton Wheel


Contents of Part 23


Oil Refining in Iran (Part 2)

The Pelton Wheel

The Pelton Wheel (colour plate)

Making Giant Propellers

Lifts and Escalators

London’s Riverside Highways

British Empire’s Longest Tunnel (Part 1)







Oil Refining in Iran (Part 2)


The story of the largest and most modern oil refinery in the Eastern Hemisphere, by Howard Barry. The chapter is concluded from part 22.

(Pages 657-661)



Near Masjid-i-Sulaiman

ACROSS A DEEP RAVINE near Masjid-i-Sulaiman the pipe line is carried on a suspension bridge. In this illustration men are seen assembling the lengths of pipe line after the completion of the bridge.

(Page 661)


London’s Riverside Highways


One of the most famous thoroughfares in the world is built on land reclaimed from the River Thames. Known to Londoners as the Embankment, this thoroughfare includes the Victoria Embankment on the north, and the shorter Albert Embankment on the south bank of the Thames. Engineers have made enormous strides in providing solutions to various modern traffic problems. One of the largest works of this nature was opened to the public as long ago as 1870. This was the Victoria Embankment, which created an invaluable new highway in the heart of London. This outstanding work and the companion Albert Embankment is described in this chapter by Sidney Howard.

(Pages 677-682)


Building a Mould for a Propeller Casting

BUILDING UP A MOULD for a propeller casting. The mould is a large structure built up of bricks on an iron foundation plate. In the preparation of the sand mould the striker board (top right) plays an important part. One end of this board moves up and down a central steel shaft and the level is determined by the sloping timber guide. Notches in the striking board raise marks on the sand for fixing the zinc templets.

(Page 664)


Lifts and Escalators


Tall buildings and underground railways have brought about the rapid development of two highly efficient systems of vertical transport, the safety and reliability of which are accepted without question by millions of people every day. In Part 17 Lieut.-Com. R T Gould described the construction of such skyscrapers as the Empire State Building, New York, with a height of 1,250 feet above the street. One essential to a building such as this is the elevator. In this chapter, F E Dean describes the operation of various types of elevator, electric and hydraulic. He will deal also with the escalators, which are such a feature of underground railway stations and of many large stores in London. London is famous for its escalators and New York for its elevators, although there are many examples of both in either city. The speed of the elevators in modern buildings is remarkable. Fifty-eight of the passenger elevators in the Empire State Building run at speeds ranging between 1,000 and 1,200 feet a minute.

(Pages 669-676)


You can read more on escalators in Railway Wonders of the World.


A Section Through the Victoria Embankment

A SECTION OF THE VICTORIA EMBANKMENT, showing the position of the tunnel for the Metropolitan District Railway, now part of the London Passenger Transport Board’s Underground railway system. The subway on the left carries gas and water pipes and, with the sewer, forms a buttress to the wall. Subway, sewer, and river wall are tied to one another by cross-walls.

(Page 679)


Entrance to the Otira Tunnel

THE OTIRA ENTRANCE to the tunnel, photographed while constructional work was in progress. This end of the tunnel is in the gorge of the Rolleston River, about three and a half miles from Otira Station, and at this point is 1,586 feet above sea level.

(Page 683)



Making Giant Propellers


Fifty tons of molten metal may have to be poured into one mould for the casting of a huge propeller for a transatlantic liner. Precision and accuracy are essential in every operation of casting, fettling, boring or milling, and amazing machines have been devised for these purposes. This chapter is by Rolt Hammond and describes the making of huge propellers for such great ocean liners at the Queen Mary and the Normandie. Propellers for ships such as these may weigh as much as 35 tons each, yet their manufacture calls for the most extreme degrees of accuracy and precision. Special machines have been invented to carry out the finishing processes and in this chapter a unique machine used in a foundry in Charlton, Kent, for the operation of machining the working face of the propeller is described. This is the sixth article in the series on the Romance of Industry.

(Pages 663-668)


You can read more on ship’s propellers in Shipping Wonders of the World.


The Pelton Wheel


THE PELTON WHEEL is one of the several types of turbine that convert the energy of falling water into electrical energy. A powerful jet of water is directed through a circular nozzle by a needle valve into the buckets of the wheel. The wheel is shown here without its casing and the nozzle casing is cut away to show its construction. This turbine, designed for a power station in India, works at a speed of 375 revolutions a minute with a head of 1,630 feet of water.

  

(Facing page 662)

Near Masjid-i-SulaimanThe Abadan refinery


The Abadan Refinery





BENCH 55 AT ABADAN, which is still in use, is part of the earlier plant used in the refinery. Bench 65, which is illustrated below, is a further development which incorporates the most modern improvements in refinery technique.

 






THREE FRACTIONATING COLUMNS are incorporated in Bench 65, the most recent installation at the Abadan refinery. The fractionating columns are used to separate the crude oil into different groups of “fractions” for the distillation of the numerous by-products. The largest column, which operates at atmospheric pressure, is 122 feet high and has a diameter of 22 feet.


(Page 658)



The Pelton Wheel


OF the several types of turbine now converting the energy of falling water into electrical energy all over the world, the Pelton wheel, so called after its inventor, most nearly resembles the old-fashioned water wheel in that it consists of a number of buckets arranged in a circle round the shaft which is to be driven. Here, however, the resemblance ends. In the commonest type of waterwheel, the overshot wheel, the shaft was really turned by the weight of the water as bucket after bucket at the top of one side of the wheel was filled, to be emptied again as it neared the bottom.


The Pelton wheel, on the other hand, is driven round by the impact of a powerful jet of water striking the buckets which come successively into line with it as the wheel turns. The illustration shows four Pelton wheels supplied by Boving and Co, Ltd, for a generating station in the Punjab, India. The old type of waterwheel developed perhaps 7 or 8 horse-power. Each of the turbines here shown can develop 17,000 horse-power at a speed of 428·5 revolutions a minute. A steel pipe line conveys the water from the intake canal, 1,668 feet above the turbine, to the turbine nozzle, from which the jet issues. The pressure in the turbine inlet is, roughly, 720 lb per square inch.


The photograph was taken in the erecting shop and does not show the buckets, as they are cased in, but they resemble deep oval basins (see colour plate below), with ridges across the centre. The jet of water is directed to the inside of the buckets and, striking the ridge, is deflected to both sides, thus obtaining a greater area on which to exert its force. The jet is directed through a circular nozzle by what is termed a needle valve. This is a conical streamlined valve tapering to a fine point, and projecting through the nozzle. In front of the nozzle is a hinged flap called the deflector, and this, as well as the valve-moving gear, is controlled by a governor. The valve is connected to a piston on one side of which is a spring which tends to close the valve, and on the other side there is oil pressure tending to open it.


When the load on the turbine is reduced, that is, when less current is required from the generators, the governor affects a mechanism which turns down the deflector in front of the jet and bends it away from the buckets to a greater or less extent as required. At the same time the needle begins to close slowly under the action of the springs and the size of the jet is decreased, the deflector being then moved back sufficiently to clear the smaller jet. Increase of load is followed by the simultaneous opening of the needle and the raising of the deflector, a regulating device preventing shock in the pipe line.


The curved pipes in the photograph are the water inlet pipes, and the needle-actuating oil cylinder is seen at the bend. The vertical cylinders seen near two of the turbines contain the governor and control gear. There are various safety devices fitted which act automatically in such circumstances as failure of the oil supply, overspeed should the governor gear fail, and so forth.


This is the fourteenth article in the series on Modern Engineering Practice.

(Page 662)


Pelton wheels supplied by Boving and Co Ltd






















Building a Mould for a Propeller CastingHow a propeller is cast

THIS SECTIONAL DIAGRAM shows how a propeller is cast. Metal is poured from the ladle B into the runner box A, equipped with a controlling gear comprising a ball D whose vertical movement is actuated by a screw and wheel E. Metal flows through the runners F to the casting.

PLANING MACHINE for machining the surface of propeller blades. This machine at Charlton, Kent, is the only machine of its type in the world. By an ingenious arrangement of gears the cutting tool is moved backwards and forwards across the blades at a predetermined rate, while the table on which the propeller rests is slowly rotated. The rate of rotation is calculated exactly to give the required curve on the blade. The speed of the cutting tool is about 80 feet a minute, and the maximum depth of cut about ¼-in. The propeller is not rotated continuously, but in a series of steps of exceedingly small dimensions. Thus a remarkably high degree of finish is obtainable on this machine. The vertical feed on the cutting toll is from 1/16 in to 3/32 in for each stroke of the tool. When the propeller has an accurately machined working face the blades are finished by hand in the fettling shop. In the final stages the whole surface of the propeller is ground with abrasive disks rotated by small electric motors.

THE BORING MILL for propellers at the Charlton foundry of J Stone and Company Limited, its the largest boring mill of its kind in Great Britain. The machine weighs more than 165 tons, and is built on massive concrete foundations weighing 200 tons. Before boring is done the riser of the newly cast propeller is cut off by a steel saw with a diameter of 6 feet. Arrangements are made to support the riser as the saw cuts through it, to prevent the saw from being nipped during the cutting process. A tapered bore is then accurately machined, and a groove is made in the propeller to take the key which locks it onto the propeller shaft. This boring mill is capable of accommodating propellers which have a diameter of as much as 25 feet, yet all the operations are carried out with the highest degree of precision. An ordinary type of machine lathe would be unsuitable for the work because of the unwieldy shape of the propellers.  (Page 666)

Click on the small icon to see a short British Pathé newsreel clip of the Clifton Foundry operated by J Stone and Company Ltd in Kent (1948).

Hydraulic Lift for Naval Aircraft


Hydraulic Lift for Naval Aircraft


IN A LARGE HYDRAULIC LIFT for transporting naval aircraft between the flight deck and the hangar of HMS Courageous. Some of the aircraft carriers of the British Navy were originally built as cruisers, and the hydraulic equipment installed for the working of heavy guns was retained for operating lifts.

  

(Page 670)

Electric Passenger Lift


Electric Passenger Lift


AN ELECTRIC PASSENGER LIFT of the geared unit multi-voltage type. The power unit (top) is an electric motor which drives the winding drum through the medium of suitable gearing. The ropes, of which there are several to ensure safety, pass round the drum and are directly connected to the lift at one end and to the balance weight at the other. The first electric lift was installed in 1887.


(Page 671)

SECTIONAL VIEW OF AN ESCALATOR, showing the way in which the treads are arranged as a continuous chain, the formation of which is changed by the guide rails running beneath the stairway. The riving apparatus is housed in a machine room below the floor near the top of the escalator.

Building the Victoria Embankment


Building the Victoria Embankment


SUPPORTING THE COFFERDAM used in the building of the Victoria Embankment. When the iron caissons were in position, timbers were fixed against the inner side of the dam to brace the caissons against the pressure of the water as the tide rose. On the right are the piles which were driven into the clay; their tops were timbered and rails were bolted to the timbers to allow the dredger to be moved along as work progressed.


(Page 678)

A Section Through the Victoria EmbankmentBuilding the Albert Embankment


Building the Albert Embankment

BUILDING THE ALBERT EMBANKMENT, on the south side of the Thames, above Westminster Bridge. This old woodcut shows the scene from the present site of Lambeth Bridge. St Thomas’s Hospital now stands between Lambeth Bridge and Westminster Bridge.

(Page 681)







British Empire’s Longest Tunnel (Part 1)


The east and west coasts of South Island, New Zealand, are linked by the Otira Tunnel, which took fifteen years to build through the Southern Alps, and cost £1,500,000. The tunnel is more than five miles long and its summit is 2,435 feet above sea level. This chapter is by Harold Shepstone and is concluded in part 24. It is the sixth article in the series Below the Surface.

(Pages 683-684)


You can read more on the Otira Tunnel in Railway Wonders of the World.

Entrance to the Otira Tunnel