Reeds Vol 5: Ship Construction for Marine Engineers. Paul Anthony Russell, E.A. Stokoe dancindonna.info ISBN. This textbook covers ship construction techniques and methods for all classes of E A Stokoe Media of Reeds Vol 5: Ship Construction for Marine Engineers. See larger image. Published: Format: PDF eBook (Watermarked). 5th ed. Covers the majority of the descriptive work in the syllabus for Naval Architecture in Part B of the Department o.
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Volume 05 - Reed's Ship Construction For Marine Students (5th Edition ).pdf - Download as PDF File .pdf), Text File .txt) or view presentation slides online. Reed's Vol 05 ship construction for marine dancindonna.info - Download as PDF File . pdf), Text File .txt) or view presentation slides online. A division of Reed Educational and Professional Publishing Ltd. A member of Third edition Fourth edition Ship construction/David J. Eyres. – 5th ed.
Affiliations and Expertise Former lecturer in Naval Architecture at Plymouth University, UK Reviews 'This book has to be the ultimate in ship construction, very informative and in reviewing this volume I can say that during my studies I have come across other books on the subject, but in my opinion none as good as this. A must for all students and those of us who need a little refreshing now and again. The subject matter is presented clearly and a great deal of information is contained in the one volume. Those for whom this book is intended will find it very useful for imparting knowledge in a field in which there are few textbooks. It's about how a ship is built rather than how it is designed and starts with the basics on welding methods and steel characteristics and goes on from there. It's interesting to compare this book with Reed's Shipbuilding in Iron and Steel from
It When I ship sags, the bottom shell is in tension while the deck I. In compre ion Fig. Chin In bendin. If the buoyancy amidships exceeds the weight, the ship will hog, and may be likened to a beam supported at the centre and loaded at the ends.
This is particularly true in the case of cargoes such as iron ore which are heavy compared with the volume they occupy. There is a tendency in such ships, when loading heavy cargoes, to leave the deep tank empty.
Unfortunately there is also an excess of buoyancy in way of the engine room, since the machinery is light when compared with the volume it occupies. A ship in such a loaded condition would therefore hog, creating very high stresses in the deck and bottom shell. This may be so dangerous that if owners intend the ships to be loaded in this manner, additional deck material must be provided. The structure resisting longitudinal bending consists of all continuous longitudinal material, the portions farthest from the axis of bending the neutral axis being the most important Fig.
Danger may Occur where a point in the structure is the greatest distance from the neutral axis, such as the top of a sheerstrake, where a high stress point occurs. Such points are to be avoided as far as possible, since a crack in the plate may result.
In many oil tankers the structure is improved by joining the sheerstrake and stringer plate to form a rounded gunwale. When the wave crest is amidships Fig.
This tends to cause the ship to hog. The buoyancy amidships is reduced while at the ends it is increased, causing the vessel to sag Fig. The effect of these waves is to cause fluctuations in stress, or, In extreme cases, complete reversals of stress every few seconds.
Fortunately luch reversals are not sufficiently numerous to oaul. The greatest differences occur when a ship passes through waves whose lengths from crest to crest are equal to the length of the ship.
The transverse structure of a ship is subject to three different types of loading: a forces due to the weights of the ship structure, machinery, fuel, water and cargo. The decks must be designed to Support the weight of accommodation, winches and cargo, while exposed decks may have to withstand a tremendous weight of water shipped in heavy weather. The deck plating is connected to beams which transmit the loads to longitudinal girders and to the side frames. In way of heavy local loads such as winches, additional stiffening is arranged.
The shell plating and frames form pillars which support the weights from the decks. In the machinery space other factors must be taken into account. Forces of pulsating nature are transmitted through the structure due to the general out of balance forces of the machinery parts. The machinery seats must be extremely well supported to prevent any movement of the machinery.
Additional girders are fitted in the double bottom and the thickness of the tank top increased under the engine in an attempt to reduce the possibility of movement which could cause severe vibration in the ship.
For similar reasons the shaft and propeller must be well supported. Dockins A considerable force is exerted on the bottom and side shell by [he water surrounding the ship. The double bottom floors and side frames are designed to withstand these forces, while the shell plating must be thick enough to prevent buckling between the floors and frames.
Since water pressure increases with the depth of immersion, the load on the bottom shell exceeds that the side shell. When the ship passes through waves, these forces are of a pulsating nature and may vary considerably in high waves, while in bad weather conditions the shell plating above the waterline will receive severe hammering.
When a ship rolls there is a tendency for the ship to distort transversely in a similar way to that in which a picture frame may collapse. This is known as racking and is reduced or prevented by the beam knee and tank side bracket connections, A Ihip usually enters dry dock with a slight trim aft.
Thus as th. As Iftor. At the Inatlnt bltor. If this thrult II excelsive it may be necessary to strengthen the after block. Such a problem arises if it is necessary to dock a ship when fUlly loaded or when trimming. The ship structure in way of the keel must be atron nou,h to withstand this load.
In most ships the normal Irrln m. If a duct keel Is fitted, however, care must be taken to ensure that the width of the duct does not exceed the width of the. The keel structure of an oil tanker is strengthened by fitting docking brackets, tying the centre girder to the adjacent longitudinal frames at intervals of about 1.
Bilge blocks or shores are fitted to support the sides of the. These shores are known as breast shores and have some slight effect in preventing the side shell bulging. They should preferably be placed in way of transverse bulkheads or side frames.
Pounding When a ship meets heavy weather and commences heaving and pitching, the rise of the fore end of the ship occasionally. The fore end then. Iamming effect, known as pounding. While this does not occur with Ireat regularity, it may nevertheless cause damage to the bottom of the ship forward.
The shell plating must be stiffened to cr. Pounding also occurs aft in way of the aru r. In some cases they are fitted after the water is out of the dock, while some docks have blocks which may be slid into place while the water is still in the dock. The latter arrangement is preferable since the sides are completely supported. At the ends of the ship, the curvature of the shell does not permit blocks to be fitted and so bilge shores are used. The structure at the bilge must prevent these shores and blocks buckling the shell.
As soon as the after end touches the blocks, shores are inserted between the stern and the dock side, to centralise the ship in the dock and to prevent the ship slipping off the blocks. When the ship grounds along its whole length additional shores A. The effect of this is found to be greatest at the ends of the ship, particularly at the fore end, where the shell is relatively flat.
Such movements are termed panting and, if unrt. Th tructur. These forms were termed sections and were produced by passing the material through suitably shaped rolls. The development of these bars continued with the introduction of steel until many different sections were produced. These sections are used in the building of modern ships and are known as rolled steel sections. Ordinary angles These sections may be used to join together two plates meeting at right angles or to form light stiffeners in riveted ships.
Two types are employed, those having equal flanges Fig. Bulb plates In welded construction the flange of the bulb angles is IUptrnuoul, Inereuina the weight of the structure without any appreclabl. Inereale in strength, since it is not required for connection purposes. A bulb plate Fig.
A plate having a bulb on both sides has been available for many years but its use has been severely limited due to the difficulty of attaching brackets to the web in way of the bulb. The modern section rtlolves this problem since the brackets may be either overlapped or butt welded to the flat portion of the bulb. Bulb angles vary in depth between mm and mm and are used throughout the ship for frames, beams, bulkhead stiffeners and hatch stiffeners.
They are used for general stiffening purposes in the same way as bulb angles. Channels Channel bars Fig. Channels are used for panting beams, struts, pillars and girders and heavy frames. In insulated ships it is necessary to provide the required strength of bulkheads, decks and shell with a minimum depth of stiffener and at the same time provide a flat inner surface for connecting the facing material in order to reduce the depth of insulation required and to provide maximum cargo space.
In many cases, therefore, channel bars with reverse bars are used for such stiffening Fig. Both the weight and the cost of this method of construction are high. Many ships have bilge keels incorporating T-bars in the connection to the shell. Large flat bars are used in oil tankers and bulk carriers for longitudinal stiffening where the material tends to be in tension or compression rather than subject to high bending moments.
This allows for greater continuity in the vicinity of watertight or oiltight bulkheads. Several other sections are used in ships for various reasons. Solid round bars Fig. Half-round bars Fig. Joist or H-bars These sections have been used for many years for such items as crane rails but have relatively small flanges. They are used for crane rails, struts and pillars, being relatively strong in all directions. In deep tanks and engine rooms where tubular pillars are of little practical use, the broad flanged beam may be used to advantage.
Tee bars The use of the T-bar Fig. Occasionally they are toe-welded to bulkheads Fig. This becomes an advantage since the dies are relatively cheap to produce, allowing numerous shapes of section to be made. Thus there are few standard sections but the aluminium companies are prepared to extrude any feasible forms of section which the shipbuilders require in reasonable quantities.
Metal particles from the electrode then bombard the workpiece, forming the weld. The arc and the molten metal must be protected to prevent oxidation. In the welding of steel a coated electrode is used, the coating being in the form of a silicone. This coatins melts at a slightly slower rate than the metal and is carried with the particles to form a slag over the molten metal, whil.
It exists in many different forms from the forging carried out by blacksmiths to the modem electric welding. There are two basic types of welding, resistance or pressure welding in which the portions of metal are brought to a welding temperature and an applied force is used to form the joint, and fusion welding where the two parts forming the joint are raised to a melting temperature and either drawn together or joined by means of a filler wire of the same material as the adjacent members.
The application of welding tQ.. Metallic arc welding. A metal electrode, of the same material as the workpiece, is clamped into a holder which is connected to one terminal of a welding unit, the opposing terminal being connected to the workpiece. An arc is formed between the electrode and the workpiece in way of the joint, creating an extreme temperature Ire PI 3.
The coatings cause the aluminium to corrode and, being heavier than the aluminium, remain trapped in the weld. It is nevertheless necessary to protect the arc and an inert gas such as argon may be used for this purpose. In argon arc welding, argon is passed through a tube, down the centre of which is a tungsten electrode. An arc is formed between the workpiece and the electrode while the argon forms a shield around the arc.
A separate filler wire of suitable material is used to form the joint.
The tungsten electrode must be water cooled. This system of welding may be used for most metals and alloys, although care must be taken when welding aluminium to use a.
Types of joint and edge preparation The most efficient method of joining two plates which lie in the same plane is by means of a butt weld, since the two plates then become one continuous member. A square-edge butt Fig. Above this thickness, however, it is difficult to obtain sufficient penetration and it becomes necessary to use single vee Fig.
The latter are more economical as far as the volume of weld metal is concerned, but may require more overhead welding and are therefore used only for large thicknesses of plating. The edge preparations for all these joints may be obtained by means of profile burners having three burning heads which may be adjusted to suit the required angle of the joint Fig.
Overlap joints Fig. Such joints are used in practice, particularly when connecting brackets to adjacent members. Fillet welds Fig. The welds may be continuous on one or both sides of the member or may be intermittent. Continuous welds are used when the joint must be watertight and for other strength members. Stiffeners, frames and beams may be connected to the plating by intermittent welding Fig.
This means that a welded ship may carry more cargo on the same load draught. Welding, if properly carried out, is always watertight without necessitating caulking, while in service riveted joints may readily leak. With the reduction in overlaps, the structure of the ship is much smoother. This leads to reduction in hull resistance and hence the fuel consumption, particularly in the first few years of the ship's life. The smoother surface is easier to clean and less susceptible to corrosion.
This is of primary importance in the case of oil tankers where the change from riveting to welding was very rapid. A welded joint is stronger than the equivalent riveted joint, leading to a stronger ship. Unfortunately a faulty weld may prove much more dangerous than poor riveting, and at the same time is more difficult to detect.
The methods of testing welded joints given below, are, while quite successful, nevertheless expensive. If a crack starts in a plate it will, under stress, pass through the plate until it reaches the edge. In riveted construction the edges are common and hence the crack does not have serious results. In welded construction, however, the plates are continuous and hence such a crack may prove very dangerous.
It is therefore necessary in welded ships to provide a number of longitudinal crack arrestors in the main hull structure to reduce the effects of transverse cracks. These crack arrestors may be in the form of riveted seams or strakes of extra notch tough steel through which a crack will not pass. At the same time, great care must be taken in the design of the structure to reduce the possibility of such cracks, by rounding the corners of openings in the structure and by avoiding concentrations of weld metal.
Iii an impact test in which the specimen must absorb at least 47 J at about 20C. Iv any deep penetration electrodes must show the extent of penetration by cutting through a welded section and etching the outline of the weld by means of dilute hydrochloric acid. This test may be carried out on any form of welded joint. Types of electrode, plates and joints may be tested at regular intervals to ensure that they are maintained at the required standard, while new materials may be checked before being issued for general use.
Por Internal inspection of shipyard welds, radiography is used In the form of X-rays or gamma rays, the former being the most common.
Radiographs are taken of important butt welds by passing the rays through the plate onto a photographic plate. Any differences in the density of the plate allow greater exposure of the plate and may be readily seen when developed.
Such dlrrerences are caused by faults which have the effect of rtduclnl the thickness of the plate.
In way of such faults it is neeellary to take X-rays at two angles. The resultant films are Inserted in a stereoscope which gives the illusion of the third dimension. It is not possible to test fillet welds by. It is usual to take to X-rays of welded joints, checking highly stressed members, joints iIt which cracks are common, and work carried out by different welders on the ship.
Other non-destructive tests are available but are not common Testing of welds. There are two basic types of test carried out on welded joints a destructive tests and b non-destructive tests. Surface cracks which are too fine to see even with the aid of a magnifying glass, may be outlined with the aid of a fluorescent penetrant which enters the crack and may be readily seen with the aid of ultra-violet light. Faults at or near the surface of a weld may be revealed by means of magnetic crack detection.
An oil containing particles of iron is poured over the weld. A light electric current is passed through the weld. In way of any surface faults a magnetic field will be set up which will create an accumulation of the iron particles. Since the remainder of the iron remains in the oil which runs off, it is easy to see where such faults Occur. A more modern system which is being steadily established is the use of ultrasonics.
A high frequency electric current causes a quartz crystal to vibrate at a high pitch. The vibrations are transmitted directly through the material being tested. If the material is homogeneous, the vibration is reflected from the opposite surface, converted to an electrical impulse and indicated on an oscilloscope.
Any fault in the material, no matter how small, will cause an intermediate reflection which may be noted on the screen. This method is useful in that it will indicate a lamination in a plate which will not be shown on an Xray plate. Ultrasonics are now being used to determine the thickness of plating in repair work and avoiding the necessity of drilling through the plate. Faults in welded joints Electric welding, using correct technique, suitable materials and conditions, should produce faultless welds.
It's a great success up to now. Reeds Vol 5 Ship Construction for Marine Engineers Todd Navigation Some 2, islanders headed by Mayor Lucien Kimitete saw Reeds ship construction and his seven-man crew limp into local waters 88 days after they set sail from Chile's northern port of Arica on a voyage of study and exploration. The crew had to abandon half the foot meter boat -- made from 13, reeds from Lake Titicaca, the world's highest navigable lake -- on the high seas as molluscs ate away at its structure.
Reed Ship 1m Length 47ft breadth 15ft depth 6ft Its monumental ruins have often been compared to Stonehenge in that no one knows how an ancient civilization could have made them. It is puzzling not only because some of the stones weigh as much as tons, but because there are no quarries nearby, but rather on the other side reeds ship construction Lake Titicaca. Our theory is that these giant andesite stones were transported across Lake Reeds ship construction on reed boats of ancient design to the closest shores to Tiwanaku, then laboriously dragged 10 kilometers to the city.
We wanted to test this theory by recreating the Tiwanaku building process with a multi-national team of volunteers, aided by leading Aymara experts in totora reed boat building.
Reeds Ship Construction VOL 5 This project was to: If we emulated the ancient design successfully, the boat's porous nature would have filtered out water from the waves kicked up by the fierce winds of the Altiplano. If not, we could have been swamped, and lost the 9 ton stone, or worse. Would our reed boat sink under the weight of a 9 ton reeds ship construction, or would it simply fold and collapse around it as some experts had claimed?
Our boat was about 47 feet long, 15 feet wide and 6 feet high. The mast was about 27 feet high. We had sails made of totora as well as a textile sail.