Section 3. Supervision activity

Words and Terms to be Remembered

Read the text and find the answers to the following questions.

1. What is a lines plan?
2. What plans does it consist of?
3. What are buttocks and diagonals?
4. What is a lines plan necessary for?

Hull shape can be completely represented by the lines (sheer lines) plan showing the moulded surface of a ship.

Lines plan is a set of drawings showing the form of the hull projected on three planes perpendicular to each other. It consists of three plans: 1) a side projection known asprofile; 2) a plan showing the form of the hull at several waterlines called half-breadth plan; 3) a plan showing the form of the hull at cross sections called body plan. Lines plan shows the moulded surface formed by outer edges of frames, floors and beams without the thickness of outer shell plating.

The profile plan is a projection of the ship's lines to her center line plane. It shows the general appearance of the ship, giving the contour of the stem and stern, the arrangement of superstructures, position of bulkheads, extent of double bottom and position of decks. The lines which are the result of intersecting the moulded surface of the ship by planes parallel to the centerline are buttocks. They are called bow lines when in the fore body and buttock lines when in the after body. Bow and buttock lines are spaced at convenient equal intervals from the ship's centre-line. Buttocks are shown in the profile drawing of the ship's lines. The half breadth plan is a projection of the vessel's lines on the horizontal plane. It shows the shapes of decks and waterlines. The body plan is a projection of the ship's lines on the midship section plane. It shows the shapes of equidistantly spaced vertical sections of the ship. Straight lines extending from the longitudinal middle-line plane to the frame sections of the body plan are calleddiagonals or diagonal lines on the half-breadth and sheer plans. In the body plan it is not necessary to draw both sides of the ship. The sections in the fore body are drawn on the right-hand side, the sections in the after body are drawn on the left.

The lines plan is necessary for making all calculations and experiments, connected with the determination of ship seaworthiness and for development of other drawings.

Exercises and assignments

Ex. 1. Arrange the given words and word combinations into the pairs of synonyms. Find in the text the sentences in which they are used and translate into Russian.

Ex. 2. Match the definition with a vocabulary item.

Ex. 3. The diagram indicates the planes and projections of lines plan with figures. Match the terms (under capital letters) with the figures on the diagram and with term explanations (under small letters). Complete the table below. Consult the vocabulary items.

Fig. 4.

a - a plane of longitudinal division of the hull into two symmetrical parts;

b - the left-hand part of the body plan;

c - vertical transverse plane which divides the ship hull into fore and after parts;

d - the right-hand side of the body plan;

e - the projection on the midship plane;

f - a horizontal plane parallel to the constructive water line;

g - a plan or top view of half of a ship shown on the water line plane;

h - lateral view or side projection of the ship's lines.

Ex. 4. Do the following task.

1. Give the meanings of the word "section" in relation to the ship hull structure.

2. Make the difference between two terms: "hull" (корпус) and "body plan" (корпус).

3. Look carefully at the three projections on the lines plan and say which of them shows the following lines of a ship hull: stem, sides, keel line, stern, flare of the bow, sheer, camber, deadrise, deck line, waterlines.

4. Study the lines drawing (fig. 5) of a cargo ship and speak on all three projections of it.

Fig. 5. Lines Plan of Cargo Ship

Section 3. Supervision activity

Words and Terms to be Remembered

Read the text and find the answers to the following questions.

1. What is a classification society?
2. What does classification imply?
3. What principle classification societies in the world are known?
4. When are classification certificates issued?

CLASSIFICATION SOCIETIES

Every ship is designed and constructed to the certain class and is operated in the conditions related to the given class. Class means the character assigned to a vessel by a classification society, depending on the design of the vessel, the quality of materials employed, the scantlings of the various structural members, and the outfit and equipment, all of which should be up to the standard specified by the society's rules. To ensure that the condition and seaworthiness of classed ships are maintained they are examined periodically and upon the result of such survey depends the continuance of the class.

Classification society is a special institution which has as its purpose the supervision of vessels during their construction and afterwards, in respect to their seaworthiness and upkeep, and the placing of vessels in grades or "classes" according to the society's rules for each particular type of vessel. The principle classification societies are: Lloyd's Register, London; American Bureau of Shipping, New-York; Bureau Veritas, Paris; Germanischer Lloyd, Berlin; Norske Veritas, Oslo; Japanese Marine Corporation, Tokyo; Russian Maritime Register of Shipping, St. Petersburg. Lloyd's Register of shipping is the largest and oldest British classification society, established in 1834.

The Classification Societies are known to have a profound influence on shipping, ship design and ship safety. The fundamental purpose of classification is to ensure maintenance of seaworthiness of all classed ships. Withdrawal of a class means cessation of the Register supervision when renewal of a class seems impossible for the Register. The class might be withdrawn by the Register at the shipowner's desire as well. The Classification societies operate throughout the world and publish rules and regulations directly related to the structural efficiency of the ship and the reliability of the propelling machinery. Classification implies the ship and the machinery to conform to the standards published in the rules of the Society.

Classification societies' rules are not absolutely rigid in every detail, as the progress of shipbuilding methods and materials makes it necessary that a certain amount of latitude be allowed. They represent the minimum standards which the society considers necessary for a particular type of vessel. In classed vessels the materials and the actual construction are under the supervision of the society's surveyors. At the completion of the building and after trials at sea, classification certificates are issued and handed to the owners.

Classification certificate states that the ship has been found to comply with the rules of the society. It also mentions the class granted to the ship and the conditions which have to be complied with if the class is to be maintained. The record in the Register Book is given in symbols.

100A.1. indicates the highest class for steel ships and is assigned to all vessels built under survey and in accordance with the society's rules and regulations. The figure 1 after letter A indicates that the anchors and cables have been tested by the society's surveyors and are in accordance with the rules and in good condition. If there is anything amiss, it is replaced by a dash, so "100A.1." and "100A.-" respectively. The class 100A.1. is followed by the descriptive notation, such as "oil tanker", "bulker", etc. The Maltese cross indicates that the vessel has been built under survey.

L.M.C. signifies that a "Lloyd's Machinery Certificate" has been granted.

Surveys, repairs and any alterations to the hull or machinery of the vessel are mentioned on the certificate. Two certificates are issued to the mechanically propelled vessels, one for the hull and another for the engines and/or boilers.

Exercises and assignments

Ex. 1. Form the nouns from the following verbs. Find them in the text and translate the sentences in which they are used.

Ex. 2. Arrange the given words into the pairs of synonyms. Find in the text the sentences in which they are used and translate the sentences into Russian.

Ex. 4. Review the vocabulary items. Match the explanations with vocabulary items.

Date: 2014-12-28; view: 1504