DieselShip's Online Content Library

Q1. (a) State the factors in the storage of welding electrodes which will assist in producing good quality welds. (2)

(b) Explain the importance of edge preparation before welding. (2)

(c) Sketch TWO methods of plate edge preparation. (2)

(d) A hairline crack is detected in a pipe, as Chief Engineer Officer, state the factors to be taken into account in reaching a decision on the method of repair. (4)

Q1. Describe, with the aid of an S/N curve, the relationship between applied stress and the number of applied stress fluctuations in fatigue crack propagation. (5)

Define the term Stress Raiser, giving examples and explaining the influence of a stress raiser on the propagation of a crack. (5)

Define the term Fatigue Limit, explaining, with examples, how poor maintenance and poor machine operation can result in fatigue crack propagation even though a component has been designed to avoid fatigue cracking (6)

Q8.  With reference to fatigue of engineering components;

(a) Draw an S/N curve for steel, showing the fatigue limit and two representative stress cycle condition on the graph (4)

(b) Explain how a component is designed to avoid fatigue failure, suing the S/N curve drawn in part (a) (4)

(c) Explain how poor maintenance and incorrect machinery operation can result in fatigue failure even though a component is designed to operate below the fatigue limit (8)

Q1. State a typical shipboard application for EACH of the following metals, explaining how their properties make them particularly suitable for the stated application:

(a) Stainless steel; (2)

(b) grey cast iron; (2)

(c) Titanium; (2)

(d) manganese bronze; (2)

(e) aluminium: (2)

Q1. Describe, with the aid of a graph, EACH of the following types of ferrous material failure, stating ONE practical example of EACH:

1. creep; (5)

2. fatigue. (5)

Q1. Explain the effects of the addition of EACH of the following alloying elements to improve the characteristics of steels:

(a) chromium; (2)                 (b) manganese; (2)               (c) molybdenum; (2)

(d) nickel; (2)                        (e) vanadium. (2)

Q1. (a) Materials used for hull and machinery are subject to stress and strain in service.

Define EACH of the following:

(i) THREE types of stress;  (3)                               (ii) TWO types of strain (2)

(b) Describe the tests that may be carried out on steel to be used for ships side plating.(5)

Q2. (a) Describe, with the aid of a Strain versus Time diagram, how a creep test is carried out to determine the strain rate of the material under test. (6)

(b) Explain EACH of the stages sketched in the diagram in part (a). (4)

Q2. With reference to steels used in shipbuilding and marine engineering:

(a) describe EACH of the following types of failure;

(i) Brittle failure; (2)                       (ii) Ductile failure. (2)

(b) Explain the term ductile to brittle transition stating the factor that determines ductile to brittle transition. (2)

(c) Describe a test to determine the value of brittle fracture of a specimen test piece. (4)

Q1. (a) Describe the properties of EACH of the following alloys used in marine engineering,

giving a practical example for which, EACH are suited:

(i) cupro-nickel; (2)              (ii) white metal; (2)              (iii) titanium. (2)

(b) Discuss the merits of EACH of the following alloys for use in the casting of large propellers:

(i) nickel aluminium bronze; (2)                (ii) stainless steel. (2)

Q1. (a) Describe, with the aid of sketches, how the test pieces for a Class 1 pressure vessel are obtained. (6)

(b) List the tests which are carried out on the test pieces described in part (a). (4)

Q1. With reference to machinery parts under cyclic loading, describe, with the aid of sketches, how the propagation of even the smallest of cracks can lead to total component failure. (10)