One marks

1. Production design is a
a) Basic design
b) Detailed design
c) Concept design
d) None of the above
Ans: b) Detailed design
2. Pre-panel fabrication related with
a) Block fabrication
b) Machinery arrangement
c) Piping design
d) All the above
Ans: a) Block fabrication
3. What is Thermo chalk
a) Chalk piece for writing in board
b) Type of wrench
c) Machine foundation
d) Chalk used for measuring temperature
Ans: d) Chalk used for measuring temperature
4. What is a rivet
a) Metal Joining Process
b) It’s a process of plate bending
c) It’s a process of metal tampering
d) None of the above
Ans: a) Metal Joining Process
5. WPQ is
a) Welding precaution Quay
b) Welding predefined question
c) Welding paint quicker
d) Welding procedure qualification
Ans: d) Welding procedure qualification
6. WPS is
a) Welder practical sheet
b) Welding procedure specification
c) Wonder park Switzerland
d) Written and proven system
Ans: b) Welding procedure specification
7. How does Strength of Fillet weld Ensured
a) By ensuring proper welding process
b) By ensuring adequate throat thickness
c) By ensuring qualified welder welding
d) All the above

Ans: d) All the above

8. Panel fabrication is

a) A bulkhead with stiffeners & girders

b) A deck with stiffeners & girders
c) A side shell with stingers, stiffeners and girders
d) All the above

Ans: d) All the above

9. In block fabrication how members levelled after assembly with deck plate

a) By employing skilled worker

b) By monitoring the assembly frequently
c) By using a water in tube and plumb
d) None of the above

Ans: c) By using a water in tube and plumb

10. Purpose of stiffener in a panel

a) Avoid distortion of bulkhead

b) Ensure corrosion resistant
c) Avoid engine starting glitch
d) Ensure adequate drinking water on bard ship

Ans: a) Avoid distortion of bulkhead

11. Welding is a Process of

a) Joining two similar metals

b) Joining two dis-similar metals
c) Joining two Different grades metals
d) All the above

Ans: d) All the above

12. The lifting plan of particular block is done based on

a) Person fabricated the block

b) WCOG of the block
c) Weather of yard
d) None of the above

Ans: b) WCOG of the block

6 Marks

1. Briefly discus principles of design for production in ship building.

Ans: Production Design: The detailed specification of manufactured items parts and their
relationship to the whole procedure design needs to take into account how the item will
perform intended function in an efficient safe and reliable manner.
Principle of design for Production Ship building: Design to reduce production cost to a
minimum compatible to the requirements of the vessel to fulfil its operational functions with
acceptable reliability and efficiency.
Primary objectives:
 To produce a design which represents acceptable compromise between demands of
performance and production and where appropriate take into account the needs of
overall repair and maintenance
 To ensure that all design feature is comfortable with known characteristic of the
shipyard facilities
 To apply the individual design for production principle and procedures in so far as
they are relevant to particular vessel and the particulars shipyard where the vessel is to
be built
Co-ordinates the inter relationship between the making electrical outfitting works with
the structure work in order to create fully integrated design.

2. Explain in brief about welding edge preparation?

Ans: Edge preparation:
 Edge preparation is very important for welding (joining) thicker sheets and plates
heavy pipes and solid material.
 Size and shape of edge preparation or groove depends on what material is used and
joint design.
 Edge preparation is dependants on strength required or load bearing of the joint single
square groove will not penetrate full thickness of the joint but double v groove will
get full thickness
 Edge preparation consists of removing material along edges of metal surfaces. You
must prepare edges for welding when parts and assemblies require certain strength.
To achieve full welding penetration, you must cut the edges of the metal.
When to Bevel or Groove:
Bevelling or grooving is especially desirable for butt joints thicker than 5/8 in. bevelling is
sometimes used for material as thin as 1/4 in. where it can assist in tracking the weld seam
with knife edged wheel followers. In positioned tee joint or comer joint fillet welding where
complete root penetration is desired, the abutting member is generally bevelled if the depth of
fusion desired for each weld exceeds 3/8-in.
Flame or Plasm arc Cutting may be done manually or with flame planers or cutting machines
All loose scale and slag resulting from cutting must be removed before assembly and
welding. It is not necessary to remove the oxide film formed on cooling. In fact, it is good
practice to allow this oxide film to remain on the edges if the plates are to be stored for some
time before welding since it will assist in preventing rusting.

3. Explain in brief about structural design & prefabrication with examples?

Ans: Structural design: The design of ship structure is the process of applying rules and
experience to integrate individual structural components into efficient and easily constructed
assemblies, modules, and hull. The design of a ships structure has a major influence on the
construction cost of the ship through the work content and the quantity of material. Many
ship structural designers use standard structural details which they may have borrowed from
other designers in another shipyard.
For naval ship, they may simply copy the old BUSHIP standards, which are over 20
years old. Chances are that the decision to use a particular detail will be made without any
regard to producibility requirements for the shipyard involved.
Pre-fabrication: Small pre-fabrication involves the assembly, where necessary by
welding, of sheet metal and pipe work to form small-sized pieces such as walkways etc. The
welding is either done electrically or using gas in inert atmospheres. The main aim of large-
scale pre-fabrication, which can be done both in parallel and in series with small pre-
fabrication, is the construction of semi-worked items which make up elements in the base
structure and plating. When assembled with the appropriate walls of insulation and sound-
proofing this type of pre-fabrication can produce almost complete “blocks” which are then
used to construct the ship.
Example: A Bulkhead may have Girder or stringer which will be grouped and pre-fabricated
& A shell may have Girder or stringer which will be grouped and pre-fabricated

4. Write a brief note design for welding in shipbuilding?

Ans: There is still a need for designers to be more aware of whether the Design for Build
concept is being actively followed. This has been highlighted when building vessels with a
significant proportion of thin plate in the structure. A basic principle in building these
structures is to minimise the heat going into the structure, as this tends to induce the
phenomenon of thin plate distortion. Consequently, the effects are seen as rework and
possibly build schedule impacts. One issue was the use of intermittent welding on non-
structural bulkheads the application of intermittent welding will reduce the amount of heat
going into the structure by about 50%. However, there appeared to have been non-structural
areas where this had not been applied, and also wet spaces where double continuous welding
had been carried out to remove the possibility of corrosion occurring in the unwelded spaces.
The wet spaces were subsequently produced using intermittent welding and a silicone sealant
in the area between the welds.
Swedged bulkheads were also a low heat input option for non-structural areas. The welding
of very thick plate to very thin plate caused significant distortion problems due to the
differences in heat transfer between the two thicknesses setting up thermal stress, which
manifested itself as distortion. These issues and others need to be highlighted at a much
earlier stage as rework creates additional cost and, if not carried out correctly, could create
undesirable metallurgical structures in the plate. This need has been identified by some
shipyards as being the domain of a Production Engineering Group. In the case of an
outsourced design strategy then this will become a much more critical interface to be
managed. The outsourcing of design has been highlighted as an increasing trend, but a
number of drawbacks have also been raised. Such issues as language barriers, time
differences and lack of knowledge of build yard capabilities have been cited. It is highly
unlikely that ships are designed with potential distortion effects as a major consideration.
Structural distortion is traditionally regarded as a problem generated by welding. However,
this is not always the case. It is very pertinent to look into the influence that ‘design’ has no
distortion. This is to be noted that distortion has to be addressed at the concept design stage
followed by detail design.
The role of designers in adopting a “design to reduce distortion” philosophy is also
significant in the overall scheme of this problem. In the places like double bottom margin
plate and shell plate in bilge strake region the connection is very typical where access will be
a big problem and has to be taken into consideration while designing the block. In skeg
region the access for welding will be a problem which the designer has to consider and give a
suitable design for construction of skeg of a ship In forward region of ship where we have the
bulbus bow of the and the flare region will have lot of structural members internally to take
heavy loads in the forward due to forces like panting, pounding, etc., So construction of the
forward block will be not similar to all other blocks due to its structural complexity where
welding of all member and shell plate and structural integrity to be considered by the
designer while designing.

5.Discuss in detail about quality control in shipyard?

Ans: Shipbuilding Quality Control (SQC):
 The main aim of Shipbuilding Quality Control (SQC) is to check and control the
different processes or procedures carry out in the manufacturing of a ship, as
shipbuilding demand an accurate, precise and accident free work, so that to minimize the
wastages of materials, instruments and tools
 QC put efforts to make possible efficient working by proper inspection of equipment’s,
tools, and various tests for materials, so that to use high quality of materials during
manufacturing.
Ship Repair Quality Control (SRQC):
 In the repair or replacement of parts or materials in a ship, QC tries to use high quality
materials, therefore reducing risk to a high percent.
Engineering Quality Control (EQC):
 The quality check for the all the steel works carried out in Shipyards are properly
checked and controlled in EQC.
 The different manufacturing works carried out consist of developing/manufacturing high
pressure vessels, rollers for sugarcane and cement industries, etc
In all the production departments, Quality is checked with the help of the following
two main methods:
 Destructive Testing (DT): Destructive Testing, tests are carried out to the specimen's
failure, in order to understand a specimen's structural performance or material behaviour
under different loads. These tests are generally much easier to carry out, yield more
information, and are easier to interpret than non-destructive testing.
 Common DT methods used at Shipyards are:
 Stress tests
 Crash tests
 Hardness tests
 Metallographic tests
 Non-Destructive Testing (NDT): Non-destructive testing or Non-destructive testing
(NDT) is a wide group of analysis techniques used in science and industry to evaluate the
properties of a material, component or system without causing damage
 Common NDT methods used at Shipyards are:
 Visual Inspection
 Magnetic-particle Test (MPT)
 Dye penetrant Test (DPT)
 Radiographic Test (RT)
 Ultrasonic Test (UT)

UNIT-II

One marks
1. Accuracy is
a) State of being correct
 b) State of being tolerant
c) State of being vigilant
d) State of being adamant

Ans: a) State of being correct

2. Engineering Tolerance is

a) Being ideal
b) Being social
c) Permissible limit of variation in a physical dimension
d) All the above

Ans: c) Permissible limit of variation in a physical dimension

3. What is theodolite

a) Surveying instrument.
b) It’s a Lamp
c) It’s an Engine Running Device
d) It’s the foundation of engine

Ans: a) Surveying instrument.

4. Why Flow Chart are used

a) To study a man
b) To study a process flow
c) To study the specific gravity of a liquid
d) None of the above

Ans: b) To study a process flow

5. What is a process

a) A series of actions
b) A series of movies
c) A series of books
d) All the above

Ans: a) A series of actions

6. Why Green Metal is Provided in Hull Construction

a) To compensate the distortion and human errors

b) To compensate the block building capacity
c) To compensate the workers
d) To compensate the management

Ans: a) To compensate the distortion and human errors

7. Where Laser-measuring Technique used in Ship Construction

 a) Levelling of blocks
b) Levelling of ships keel
c) Propeller shaft alignment
d) All the above

Ans: d) All the above

8. What Is Process Analysis

a) Review and gaining an understanding of business process

b) Process of shaft alignment
c) Process of shell alignment
d) Process of billing a work

Ans: a) Review and gaining an understanding of business process

9. Production Design is done by

a) Ship Yard
b) Owner
c) Third Party Deign Agency
d) All the above

Ans: d) All the above

10. What is Process Selection

a) Worker decision of process

b) The way chosen to produce its good or services
c) Supervisors order on the product
d) None of the above

Ans: b) The way chosen to produce its good or services

11. What is the use of Assembly chart in block construction

a) Gives overall man power used for fabrication

b) Gives overall cost of fabrication
c) Gives overall assembly, sequence and procedure
d) All the above

Ans: c) Gives overall assembly, sequence and procedure

12. What is flow process chart

a) Representation of the activities performed on the work

b) Representation of the manpower performed on the work
c) Representation of the cost on the work
d) All the above

Ans: a) Representation of the activities performed on the work

6 Marks
1. Explain about Theodolites used in shipbuilding industry?
Ans: Theodolites have been adapted from the field of surveying to be used as industrial
measuring tools. The theodolite is a rugged but (at a minimum) accurate instrument for
measuring horizontal and vertical angles (transits measure only horizontal angles). They are
usually set up in pairs and referenced one to the other. Aimed simultaneously at a single
target, the position of the target is determined by means of triangulation, the best modem
systems for industrial measurement employ electronic theodolites tied into a computer with
software to quickly compute the positions the instant both "guns" are set on the target
The operators must have reasonable visual access to the target along most of the
surface being measured. Theodolites can be moved and reset to cover different parts of a
difficult to cover target, but such a procedure increases measurement time. Items are usually
targeted so that both theodolites are positively aimed at the same point. Movement of heavy
machinery near the measurement site can upset theodolite calibration and should be
minimized.
The best 0.5 arc second theodolites could produce an accuracy on the object of about
0.001" at 40 FT. With most theodolites at the 1 second accuracy level, targeting, heat
distortion, and manual sighting, an accuracy of around 0.005" is a better expectation and
within requirements of the shipbuilding industry. Set up may take two to three hours
depending on the number of targets, lighting, and calibration of the theodolites to the object.
An efficient team for a theodolite measurement operation consists of two sighter/readers and
one recorder. One person could conduct a measurement with a great deal more time. The
future trends with manual systems are for more accurate instruments.

2. Explain problems of accuracy with block construction process?

Ans: Assembly accuracy detection in the process of building ships, it has long been known
that in manufacturing components in accordance with design drawings, the dimensions of
these components may vary to an extent that adjustments have to be made during the
construction process to arrive at the vessel depicted in the design. These adjustments can
include a significant amount of re-work, including trimming of excess material, inserting
additional material, pulling, straightening and bending structure to suit alignment, and in
some cases discarding components which are too distorted to be reasonably utilized, The
setting of accuracy goals and the understanding of the actual accuracy attainable in various
manufacturing processes in the shipyard has been identified as a means of pre-determining
some of the aforementioned problems and to avoid them by adjustments during the
manufacturing process.
hull construction typically about 5 % of workhours are required for parts cutting, 50%
for sub-assembly and block-assembly, and 45% for hull erection. focused on statistical
accuracy control and line heating as means to reduce the work hours associated with the large
percentages. This ultimately led to the need provide shrinkage compensation both for flame
cutting and for subsequent welding operations. In contrast, shipyard managers elsewhere
focused on the least amount of work hours with N/Cutting and ultimately direct computer
control of cutting machines.
Continued to look for devices to force fits without significant drop in sub-assembly,
block assembly, and hull-electioneer-hours, without improvement in safety, and with the
continuance of locked-in stresses. The most modern approach which has been taken to
achieve accuracy control in shipbuilding is termed Statistical Accuracy Control.
 In this procedure, the manufacturing processes throughout the shipyard are closely
monitored, dimensional data of components is collected and a data base established. This data
is then statistically analysed and based on theme an dimensions and standard deviations
exhibited by any repetitive production process, adjustments are made to the “designed”
dimensions of components so that “adjusted” dimensions can be used in the production
process to enable components to be produced having dimensional characteristics that are
within anticipated mean values and variance.

3. Briefly explain process planning in shipbuilding?

Ans: Process planning systematic determination methods by with product is to be
manufacture economically and on schedule function which established process on parameter
to be used convert a raw material finding between defect intermediate stages between
designing manufacture.
Main Information of process planning:
 Product specification and quantity of work
 Quantity of work to be completed
 Available of raw, material tools equipment’s personnel
 Sequence production
 Standard time
 Machine on which process will be for performed will be for performed
 Schedule of the process
Process planning procedure:
 Preparation of working drawing so geometrical shape dimension tolerance surface
tension surface finish surface coating information or inspection identification material
specification
 Make or buy decision
 Process selection based on automation kind of work flow quality level, delivery agencies
etc
 Machine capacity and machine selection
 Selection of material fixtures auxiliary equipment’s
 Prepare document like operation and roots sheets.
Process planning procedure control: Shipbuilding process is
 Complex.
 Long cycle operation.
The most important objective in shipbuilding is maintained delivery schedule in few of above
point proper planning essential determine very sequence and inter related operations and
activities or derived construction.

4. Briefly explain interconnection between production design and process planning is

shipbuilding?
Ans: Production Design:
 Design information reinforce made internal for production process
 Design is made according material available limitation is suitability
 Structure design is given important
 Optimize initial of crane in short facilities
  Minimize material usage
 Good accessibility is use of transport storage
 Component easy to assemble and act
 Modification structure components design difficulty
 Bulbous made mini pies
 Hull design is optimizing
Process Planning:
 Product specification and quantity of work
 Available of raw material tools equipment’s personnel sequence production
 Standard time
 Machine on which process will be performed
 Process selection based on automatic kind of work flow quality level delivery agencies
etc
 Make or busy decision
 Prepare document like operation and root sheets
 Machine capacity and machine selection
 Schedule of the process.

5. Explain Flow process chart with sketch

Ans: A Flow process chart is a chart of all the activities involved in a process it is similar to
the operation process chart except that more details is been shown by including transportation
delays as well as operation, inspections and storages. Thus, this chart is been made (or)
mapping is been done for the identification of delays during production of a vessel and for
improvement of it by minimising time delays.

UNIT-III
One marks
1. What is Process Planning

a) Process is planned as the act of preparing Engine room

b) Process is planned as the act of propeller action of a ship
 c) Process is planned as the act of preparing processing documentation for the
manufacturing
d) All the above

Ans: c) Process is planned as the act of preparing processing documentation for the
manufacturing

2. Scheduling is

a) Process of arranging, controlling and optimizing work and workloads

b) Process related to Starting ships engine
c) Process related to controlling ships thruster
d) All the above

Ans: a) Process of arranging, controlling and optimizing work and workloads

3. Manpower estimation is

a) Estimating money required for a project

b) Estimating human resource required for a project
c) Estimating material requirement for a project
d) All the above

Ans: b) Estimating human resource required for a project

4.How manpower of a work is assigned in a ship yard

a) Its owner’s owner wish

b) Labour will assign himself
c) By existing database of similar work done before
d) None of the above

Ans: c) By existing database of similar work done before

5.Is Manpower estimation done according to any Rule or law

a) Yes, its according to Labour law

b) Not necessary
c) Its optional
d) None of the above

Ans: a) Yes, its according to Labour law

6. ILO is

a) International lock on
b) International load operation
c) International liquid oil
d) International labour Organization 

Ans: d) International labour Organization 

7. Material control management in a yard is to

 a) Better support production
b) Eliminate non-value-added efforts
c) Ways to reduce material costs efforts
d) All the above

Ans: d) All the above

8. industrial relations

a) Relation of individual as group of employees and Ship owner

b) Relation of individual as group of employees and Ship Captain
c) Relation of individual as group of employees and employer’s
d) None of the above

Ans: c) Relation of individual as group of employees and employer’s

9. Plant Safety

a) Prevent accidents at plants

b) Prevent machinery at plants
c) Prevent usage of welding electrodes in plants
d) All the above

Ans: a) Prevent accidents at plants

10. Personal management

a) Managing Fabrication
b) Managing work flow
c) Managing Assembly of products
d) None of the above

Ans: d) None of the above

11. Training human relations

a) Training in Material handling

b) Training in Work technically
c) Training in emotional and social competence in organizations
d) All the above

Ans: c) Training in emotional and social competence in organizations

12. Production control is

a) Monitoring and controlling any particular Worker

b) Monitoring and controlling any particular production or operation
c) Monitoring and controlling any particular Machinery
d) All the above

Ans: b) Monitoring and controlling any particular production or operation

6 Marks

1. Discus about Process Planning.

Ans: Process planning is a systematic determination of methods by which product is to be
manufacture economically and on schedule formation manufacture economically and a
schedule formation which establish process and process parameter to be used covered the raw
materials into finish product defined like intermediate stages between designing and
manufacturing
Main Information of process planning:
• Product specification and quantity of to be completed.
• Accessibility of raw materials tools equipment and personnel.
• Sequence of production.
• Standard time.
• Machine on which process will be perform.
• Schedule of the process.
Process Planning Procedure:
Preparation of working drawing showing geometrical shape dimension tolerance type
of surface formation surface coating information for inspection identification code materials
specification. Process selection based on level of automation kind of work flow quality level
delivery agencies etc. Machine capacity and machine selection of materials jig fixture
auxiliary equipment. Requires documents like operation and roll sheet

2. Explain Gant Chart with sketch

Ans: A Gantt chart is a horizontal bar chart developed as a production control tool in 1917 by
Henry L. Gantt, an American engineer and social scientist. Frequently used in project
management, a Gantt chart provides a graphical illustration of a schedule that helps to plan,
coordinate, and track specific tasks in Projects

A Gantt chart is constructed with a horizontal axis representing the total time span of
the project, broken down into increments
Horizontal bars of varying lengths represent the sequences, timing, and time span for
each task. As the project progresses, secondary bars, arrowheads, or darkened bars may be
added to indicate completed tasks, or the portions of tasks that have been completed. A
vertical line is used to represent the report date.

3. Briefly explain Procedure control and system control of production?

Ans: Production control is responsible for monitoring cost and schedule the while leak in
progress the production control origination is generally responsible for issuing man hour
budget to be used to control the ship building process relates actual work completed and
actual mon hours spent their data are covered by control group in order to monitor expended
man hour production progress and productivity and to feedback system oriented data for
estimation for ship building projects thus particular indene for monitoring expended man
hour progress and productivity are sufficient.
Man, hour Expensive
The character of man power index (man hours per unit time) is the same for the
various control group of work packages which apply to all work categories.
Production progress
Production progress use different measures (weight, welding parameter, laid cable
length etc) per time factor it is sometime necessary to apply more than one index for each
group of work packages.
When compared to period schedules they are the basis for short term adjustment such
as shifting workers or using overtime when the shipyard organisation it is practical to
delegate such control to the part of delegates such control to the managers gets of parts
fabrication shop and assembly section.
Productivity indices
productivity indices utile both man hours expended and the measures used for
monitoring production process (Weight, Welding, parameters, cable length etc).Each of the
latter is usually an average based on the performance with the specific control group of work
packages any curve which appears above this efficiency indicates man hours expensive an
above average rate Productivity evaluation can be simplified by a productivity control group
(PCG) concept it eliminates consideration of specification man power control group and the
same indices to man power expensive progress and productivity apply within each
manufacturing level.

4. Explain Management cycle of a shipyard

Ans: Project definition-visualization the complete project a true structure. Vender pre-
Qualification -define and track process store result for future projects Design Approval-Make
visible approval comments in the building phase to assure vessel is built to connect design.
Building-important hull paint and outfitting. Delivery-documentation and structure
immediately. Operation-Expensive feedback to new project hull maintenance conversion.
System and zone oriented in management cycle indicates primary focus system or
zone of each phase in the cycle during planning okay transformation from system orientation
to zone orientation through execution and some testing to manner in which the work is
performed
1. Estimation
2. Planning
3. scheduling
4. Execution
5. Evaluation
5.Explain about maintenance of ships
Ans: Maintenance Work is Done Onboard a Ship Maintenance is one thing that keeps any
mechanical equipment or machinery going. Weather it is a small machine or a large structure,
efficient maintenance can help with prolonged life and favourable outcome. On a ship,
maintenance is one thing that keeps machinery up to date and is smooth running condition. In
this article we will learn as to how maintenance is being carried out on a ship.
In a ship’s engine room, where the maximum machines are located, engineers and crew
carry out the maintenance for safe and efficient operation. Each machine on board a ship
requires maintenance which has to be carried out at regular intervals of time. In the earlier
days, the number of crew members and engineers on a ship were large and so the
maintenance was carried out fast and easily. However, in the present scenario, the number of
crew members and engineers on the ship has reduced drastically. Many ships carry only 3-4
engineers on board a ship and even the time required to carry out maintenance on the ship has
reduced.  Maintenance requires manpower and time which may not be available all the time
as the number of crew members is less and the amount of machinery is more. It is for this
reason important to plan the maintenance of the machinery in advance so that the machinery
can be overhauled and maintained properly. Generally, second engineer is required to plan
the schedule of maintenance on a ship. Efficient planning and adequate usage of equipment’s
is the key to productive maintenance.

UNIT-IV

One marks
1. Capacity is

a) Amount that has to be given to labour

b) Amount of hull fairing
c) Amount that something can produce
d) None of the above

Ans: c) Amount that something can produce

2.What is capacity planning

a) Planning required to ensure all the resources are available for the production
b) Planning required to hull modelling
c) Planning required to Stability of ship
d) All the above
Ans: a) Planning required to ensure all the resources are available for the production

3. CGT
a) Compensated growth tonnage
b) Compensated grease tonnage
c) Compensated gross tonnage
d) None of the above
Ans: c) Compensated gross tonnage
4. Design capacity is
a) Based on design
b) Based on Classification society
c) Based on owner
d) Based on ship type
Ans: a) Based on design
5. Effective capacity is

a) Capable of completing a work in a given period

b) Hull related term
c) Machinery related term
d) All the above
Ans: a) Capable of completing a work in a given period
6. Operational Survey Is Done
a) In presence of owner representative
a) In presence of class surveyor
b) In ships operating condition
c) All the above
Ans: d) All the above
7. Utilization in yard
a) Utilization of yards money
b) Utilization of yards electricity
c) Utilization of yards to its maximum Capacity
d) None of the above
Ans: c) Utilization of yards to its maximum Capacity
8. Strategy is used to improve capacity in shipyard
a) Stability of ship in still condition
b) Stability of ship in damaged condition
c) All the above
Ans: a) Stability of ship in motion
10. Under which draft condition the Manoeuvring trial for tanker made
a) Shipyards decision
b) Owners decision
c) Ship in the full load condition at zero trim
d) All the above
Ans: c) Ship in the full load condition at zero trim
11.Minimum till what degree ship should turn recommended by ITTC while performing
turning circle test
a) 540 degrees
b) 90 degree
c) 180 degree
d) 260 degree
Ans: a)540 degrees
12.what is head reach in Stopping test
a) distance travelled in the direction of the ship's initial course
b) distance travelled in the direction of the ship's final course
c) distance travelled in the direction of the ship's medieval course
d) all of the above
Ans: a) distance travelled in the direction of the ship's initial course
6 Marks

1. Procedure of rudder tested using ZIG-ZAG Manoeuvre test

Ans: With the ship in trial condition
and proceeding ahead into the wind
at the maximum trial shaft RPM,
with either steering power unit,
move the rudder at maximum rate
and perform the following
maneuvers:
1) Move the rudder from centre
to 10 degrees right - hold until
ship's heading is 10 degrees to
the right of the original course.
2) Move the rudder from 10
degrees right to 10 degrees left hold until ship's heading is 10 degrees to the left of the
original course.
3) Move the rudder from 10 degrees left to 10 degrees right hold until the ship's heading is 10
degrees to the right of the original course.
4) Move the rudder from 10 degrees right to centre hold until original heading is restored.
Steady on original course.
The following data should be recorded or derived:
1) Time of test and base course.
2) Time rudder is held at each position.
3) Shaft RPM at beginning and end of test.
4) Depth of water and sea condition.
Recorded data are tabulated and plotted for rudder position and ship's heading changes during
the maneuver. Indicate the tactical dimensional characteristics as illustrated in Figure below
figure. Tests may be specified at different ship speeds, depths of water, ballast conditions,
and rudder angles if more data is required.

2. Write down the procedure of crash stop testing

Ans: With the ship at trial drafts and proceeding ahead at maximum trial shaft RPM and
normal machinery operating conditions, signal "Full Astern" while maintaining the rudder in
 the amidships position. Reverse the throttle at maximum allowable rate or move the
automatic control lever in one motion to the full astern position. When the ship gains
sternway, continue with the scheduled tests.
The following data should be recorded on data sheets
1) Time of test and base course.
2) Prime mover parameters immediately prior to "Full
Astern" signal.
3) RPM, torque, and significant prime mover
parameters at frequent intervals during the
maneuver.
4) Time of issuing astern order.
5) Time when propeller stops prior to reversal.
6) Time shaft starts astern or the propeller pitch is
positioned for astern way.
7) Time to stop ship "Dead-in-Water".
8) Time to reach required maximum astern shaft
RPM.
9) Ship's position at suitable intervals from GNSS
equipment, so that a diagram of the reversal
maneuver showing track and heading may be
plotted.
10) Depth of water and sea condition.
11) Wind direction and velocity.
12) Ship's drafts.
For the purpose of obtaining operating data, additional stopping tests may be conducted
from other initial speeds and using other stopping aids such as rudder cycling, as agreed.
Figure displays the plotted trajectory.

3. How Turning circle test is done give its procedure?

Ans: Turning circles should be performed to both right
and left with 35 degrees rudder angle or the maximum
design rudder angle permissible at the test speed. The
essential information to be obtained from this maneuver
consists of tactical diameter, advance, and transfer. Also,
of interest are the final ship speed and yaw rate in the
"steady state" of the turning circle. A turning circle of at
least 540 degrees should be completed to determine the
main parameters of the maneuver and allow correction
for any drift caused by a steady current or wind.
With the ship in the trial condition and
proceeding ahead at the maximum trial shaft RPM, with
either steering power unit, move the rudder at maximum
rate and perform the following maneuvers:
1) Move rudder to Hard over Right and hold until
ship's heading has changed 540 degrees
2) Resume a straight course and restore speed.
3) Move Rudder to Hard over Left and hold until
ship's heading has changed 540 degrees.
4) Resume a straight course.
The throttle setting for single-screw ships should not be changed during the test. For
multi-screw ships, the throttle may be adjusted as necessary to correct unacceptable
overspeed or over torque. If throttle adjustment has to be made during the turn, the maneuver
should be repeated at a reduced approach RPM to determine the maximum speed at which a
hard turn can be made without throttle adjustment.

The following data should be recorded and tabulated:

a) Time of test, and base course.
b) Rudder angle.
c) Compass reading to nearest degree every 10 seconds that ship is in the turning
maneuver.
d) Time elapsed and advance from start of rudder movement and clearing base
course using GNSS data
e) Ship's position at suitable intervals from GNSS equipment. If GNSS
equipment is not installed, ship's track should be obtained by radar, shore
station tracking, or visual observation of the wake. Observation intervals
should coincide with heading data intervals.
f) Shaft RPM at beginning and end of each circle.
g) Depth of water and sea condition.
h) Wind direction and velocity.
i) Trial draft fore and aft.
Turning circle tests may be specified at depths, drafts, speeds, and rudder angles other
than those given if ship's manoeuvring characteristics require further exploration. At the
completion of each of the turning circle tests a pull-out test may be performed to provide
information on the ship's dynamic stability.
Turning circles should be plotted and tactical dimensions reported as illustrated in
Figure shows the historic test resulting in measures of advance, transfer, and tactical
diameter. Using today’s high precision position tracking systems, maximum ship advance
and transfer measurements.

4. Write down the procedure for Pull-out Test

Ans: The pull-out test gives a simple indication of a ship's dynamic stability on a straight
course. The ship is first made to turn with a certain rate of turn in either direction, upon which
the rudder is returned to amidships. If the ship is stable, then the rate of turn will decay to
zero for turns to both left and right. If the ship is unstable, then the rate of turn will reduce to
some residual rate of turn. The pull-out tests must be performed to both left and right to show
possible asymmetry. Normally, pull-out tests
are performed at the end of the turning circle
tests, "Z" Maneuver, and initial turning tests,
but they may be carried out separately.
Each test consists of a left and right run as
follows:
1) Attain a steady turning rate with a
fixed rudder angle of approximately
15 degrees to 35 degrees. The engine
control settings are kept constant.
2) Return rudder to amidships position,
and record time.
3) Record heading, ship speed, and
propeller RPM at 10 second intervals.
These recordings should be continued
for 12 readings, i.e., 120 seconds, past the interval in which steady state, i.e., a
constant rate of turn, is obtained.
 4) The resulting data should be tabulated and plotted in a figure as shown.
This test is to be conducted at “a fixed rudder angle of approximately 15 to 35 degrees.
ISO specifies a rudder angle of 20 degrees. Running the test at other rudder angles may be
useful.

5. describe in brief about the procedure for Spiral Manoeuvre test

Ans: The direct spiral test is an orderly sequence of turning tests to obtain a steady turning
rate versus rudder angle relationship. With the ship in the specified trial condition and
proceeding ahead at the designated speed and on a steady course, using either steering power
unit, conduct the maneuver as follows:
1) Turn the rudder 20 degrees to right and hold until the turning rate becomes steady.
2) Move the rudder to the following settings and hold at each until the turning rate in
degrees per second becomes steady: 20oR,
15oR, 10oR, 5oR, 3oR, 1oR, 0o, 1oL, 3oL,
5oL, 10oL, 15oL, 20oL, 15oL, 10oL, 5oL,
3oL, 1oL,0o, 1oR, 3oR, 5oR, 10oR, 15oR,
20oR
A steady turning rate is the difference between
successive ship headings and should be noted as
the test progresses. When these differences are
reasonably constant for at least six consecutive
readings, data is recorded and the rudder is
ordered to the next setting.
The following data should be recorded and
tabulated:
a) Before starting the test:
1. Time of test and base course.
2. 2) Ship speed and corresponding
RPM.
3. 3) Wind velocity and direction.
4. 4) Depth of water and sea
condition.
5. 5) Trial draft.
b) During the test:
1. Rudder angle.
2. Gyro compass reading every 10 seconds to the smallest fraction of degree
readable.
Rate of change of headings should be plotted for each rudder position. For a stable
ship the plot of turning rate versus rudder angle will appear as shown in Figure. In cases
where the ship is dynamically unstable the plot of the turning rate will appear as shown in
Figure. As the rudder angle is reduced the ship will continue to appear to be turning steadily
in the original direction even after the rudder is turned to the opposite side. At a certain stage
the yaw direction will abruptly change to the other side and the yaw rate versus rudder angle
relation will not be defined by a single curve. Upon completion of the test the results will
display the "hysteresis loop," as depicted in Figure.

UNIT-V

1.Which of the following is a manoeuvring device

a) Windlass
 b) Fuel pump
c) Fire main pump
d) Rudder

Ans: d) Rudder

2.What shape dose cross-sectional area of manoeuvring device

a) Rectangular
b) Circular
c) Spiral
d) NACA Profile

Ans: d) NACA Profile

3. Why Rudder Angle Limited to 35 Degrees

a) Because it’s a standard

b) Suggested by Class
c) Suggested by IACS
d) None of the above

Ans: d) None of the above

4. Why Steering Rudder angle is tested for 35 degree to 30 degree

a) At that angle the steering machinery performance will be maximum

b) At that angle the steering machinery performance will be minimum
c) It’s as per rule
d) None of the above

Ans: a) At that angle the steering machinery performance will be maximum

5. what is the Pivoting Point of Ships

a) The point by which ship rotates while turning

b) The point by which ship propeller passes through
c) The point by which ship main machinery centre passes through
d) All the above

Ans: a) The point by which ship rotates while turning

6. Why Astern Turning Moment much less than ahead

a) Propeller thrust adds to the force on the rudder when going ahead

b) Propeller thrust adds to the force on the rudder when going astern
c) Propeller thrust adds to the force on the rudder when going nowhere
d) None of the above

Ans: a) Propeller thrust adds to the force on the rudder when going ahead

7. Where does the pivoting point of ships is located

 a) Its situated in midship
b) Situated at galley of ship
c) Situated in superstructure
d) situated about 1/3 rd to 1/6 th of the ship length from forward

Ans: d) situated about 1/3 rd to 1/6 th of the ship length from forward

8. What is broaching in terms of ship motion

a) Removal of material
b) Addison of material
c) Uncontrolled turning during surf-riding
d) Type of welding

Ans: c) Uncontrolled turning during surf-riding

9. Torque on Rudder Stock more on going astern because

a) Centre of pressure from turning axis increases

b) Trailing edge of rudder becomes leading edge
c) Flow of water to rudder is unobstructed causing point of action of force
d) All the above

Ans: d) All the above

10. Why Rudder is situated Aft of the Ship

a) Because it’s a rule

b) Because to maintain aesthetic value
c) because of its hydrodynamic efficiency
d) None of the above

Ans: c) because of its hydrodynamic efficiency

11. Why Full Astern Power is usually less than Full Ahead Power

a) In astern direction angle of attack is high on back of blade

b) Due to the engine power
c) due to propeller manufacturing quality
d) All the above

Ans: a) In astern direction angle of attack is high on back of blade

12. The rudder is tested at what depth after water after construction

a) 2.45 M above the top of the rudder

b) 3.25 M above the top of the rudder
c) 4.55 M above the top of the rudder
d) 1.45 M above the top of the rudder

Ans: a) 2.45 M above the top of the rudder

6 Marks

1. Explain any one type of ruder with sketch

Ans: Spade or Balanced Rudder: Spade rudder is basically a rudder plate that is fixed to the
rudder stock only at the top of the rudder. In other words, the rudder stock (or the axis of the
rudder) doesn’t run down along the span of the rudder. The position of the rudder stock along
the chord of the rudder (width meaning, from the forward to
aft end of the rudder) actually decides whether the rudder is
balanced of semi-balanced one. In balanced rudders, (which
spade rudders generally are) the rudder stock is at such a
position such that 40% of the rudder area is forward of the
stock and the remaining is aft of it.
The centre of gravity of the rudder will lie somewhere close
to 40% of its chord length from its forward end. If the axis of
the rudder is placed near to this location, the torque required
to rotate the rudder will be much lesser than what is required
to move it, had the axis been placed at the forward end of the
rudder. So, the energy requirement of the steering gear
equipment is reduced, therefore lowering the fuel
consumption of the ship.
Unbalanced Rudders: These rudders have their stocks attached at the forward most point of
their span. Unlike balanced rudders, the rudder stock runs
along the chord length of the rudder. The reason is simple.
In this case, the torque required to turn the rudder is way
higher than what is required for a corresponding balanced
rudder. So, the topmost part of the rudder has to be fixed
to the spindle so as to prevent it from vertical
displacement from its natural position. However,
unbalanced rudders are not widely used now. in case there
was a failure of the steering gear mechanism while turning a
ship. The rudder would remain still with its angle of attack in that condition. The solution to
this was found in designing an optimized Semi-Balanced Rudder.
Semi- Balanced Rudder: the rudder you see on most ships are semi-balanced in the modern
industry. The name semi-balanced itself implies, that the rudder is partly balanced and partly
unbalanced. A portion of the chord length from the top is unbalanced, and the remaining
chord length is balanced. The top part being unbalanced
will help in acting as structural support to the rudder from
vertical displacement. And the balanced part will render
less torque in swinging the rudder. As a result, a semi-
balanced rudder returns to the centreline orientation on its
own if the steering gear equipment fails during a turn.
Semi-balanced rudders are again of two types depending
upon the depth of the horn (which affects the response
and torque characteristics of the rudder). A shallow horn
rudder will have a horn which extends hardly half the
chord length of the rudder from the top. Whereas, a deep horn rudder will feature a horn
deeply extending up to more than 50 % of its chord length from the top of the rudder.
2. Explain in brief about Vertical Axis Propeller
Ans: There are two types of such a propeller. One, the Kirsten-Boeing, has its blades so interlocked
by gears that each blade is constrained to make a half-revolution about its axis for each revolution of
the whole propeller, the action being as shown in Figure (Kirsten, 1928). The propeller is assumed to
be advancing from left to right with uniform velocity V0 and rotating with uniform angular velocity in
the counter clockwise direction. A mechanism by which the blades can be set at will to any of the
dispositions shown, as well as intermediate dispositions, is incorporated in the design, and it is
therefore possible not only to propel the ship but to steer it also.
The second type, the Voith-Schneider, introduced in 1931, differs in that the blades describe a
complete revolution about their own axes for each revolution of the disk, the point C is a point to
which the blades are connected by linkages and which can be moved to different positions in the plane
of the disk. A mechanism to alter the position of C while the propeller is in operation is incorporated
in the design, so that again the ship can be propelled and steered
at the same time. The distance of C to the centre 0, made
dimensionless with the radius R, is called the eccentricity. It is
always smaller than unity for Voith-Schneider propeller.
Propellers of this type have been fitted to a considerable number
of ships and have proved entirely practical. They have also been
used at the bow to
assist in manoeuvring.
The advantage
of vertical-axis
propellers lies in the
fact that the propeller
thrust can be used for
steering and stopping the ship without stopping or changing
the direction of rotation of the main engine. This makes it
eminently suitable for the propulsion of ships that operate in
crowded and restricted waters, requiring large steering
power at low speeds.

3. Explain in detail about forces and torques acting in Rudder

Ans: The various rudders have the common requirements that:
 strength be adequate for the dynamic loads in a turn.
 the bearings for transverse loads and for vertical loads (weight and flooding water in
the rudder) be of adequate capacity and low friction.
 deflections under loading conditions should not cause binding.
 there be adequate clearance to allow for normal wear in bearings, preferably for the
life of the ship, but at least for several years of operation.
The maintenance requirements should be simple. Strength calculations involve the
transverse force ap proximately normal to the rudder, and the torque, or twisting moment,
required to turn the rudder against the pressure of the water flowing past it, all at the highest
designed speed, plus propeller race effects where applicable. In addition, rudders withstand
similar, but probably greater, forces resulting from the impact of seas in heavy weather. In
practice, rudders are designed only for the normal turning forces anticipated, with margins of
strength for heavy weather as found necessary by experience. These margins are greater than
for most shipboard structures, because failure of a rudder, particularly in a single-screw ship,
may mean the loss of the ship. Rigorous calculation of forces is complex, requiring
estimating flow velocity as affected by the boundary layer and propeller race, geometric
shape factors, streamline shape factors, gap between hull and top of rudder, true angle of
attack of flow as affected by the ship turning, Reynolds Number, and seaway effects.
Detailed information is given by Mandel (1967) and by Taplin (1960). For an understanding
of the magnitude of forces on rudders, the usual basic dynamic flow formula may be applied:

where the symbols have the following meaning:

FR = total force
CR = total non-dimensional force coefficient for the
angle of attack
p = mass density of the fluid
A = total moveable rudder area
v = fluid flow velocity over the rudder
A simple approximate formula for rudder force at 35 deg rudder with ship speed in knots can
be derived using the above formula, and estimating CR = 1.05 (a reasonable value for 35 deg
rudder with drift angle). Also, the speed over the rudder can be estimated as 1.17 times ship
speed, to allow for propeller race effects.
when: VK is the ship speed in knots:
FR = 196 A VK 2 Newtons when A is in m2
FR = 4.08 A VK 2 1b when A is in ft2

4. Write brief about handling of ships in shallow water?

Ans: A ship’s manoeuvrability depends on the water depth h of the navigation area in
relation to the draft of the vessel. The effect of depth restrictions is noticeable in medium
deep water, is very significant in shallow water, and dominates the ship’s behaviour in very
shallow water navigation areas, characterized by limited depth and width, sea-going vessels
are often confronted with completely different environmental conditions compared to
navigation at sea for which most ships are designed and optimized. Besides the effects of the
restricted depth, a ship also has to deal with the vicinity of banks, the presence of other
shipping traffic, currents, speed restrictions, and so on. In such situations, the advice of a pilot
with thorough knowledge of the local situation is often required in order to guarantee a
successful operation.
Water-depth limitations will change considerably the pressure distribution around a
moving vessel and will mostly cause an increase of the hydrodynamic forces due to the ship’s
motion through the water. Besides an increase of the ship’s resistance, water-depth
restrictions in general result in a decrease of her manoeuvrability, manifesting itself in the
results of standard maneuvers. However, most ships perform such maneuvers only during the
trials, which are always executed in deep water. Information about trials in limited water
depth is therefore mostly based on simulations or model tests. Full scale test results are very
rare. Compared to deep water, the characteristic dimensions of the turning circle in general
monotonically increase with decreasing water depth the trials have a much longer duration as
the yaw rates are significantly lower in the case of shallow water.
Water depth also has an effect on the course-checking ability of a ship: in (very)
shallow water, overshoot angles during zigzag tests are considerably smaller compared to the
deep-water case. the advance is slightly smaller compared to deep water. Moreover, the
overshoot angles observed during zigzag tests may increase in the medium water depth range.
This behaviour is generally observed for full ship forms. In exceptional cases, the turning
circle may even become smaller with decreasing water depth, a ship with wide beam (small
L/B) and small draft (small T/B) appears to turn easier in shallow than in deep water. Water-
depth limitations also influence the straight-line stability in shallow water the dynamic
stability increases with decreasing water depth. Especially in natural waterways (rivers,
estuaries) where the water depth may vary significantly, both over the length of the channel
and over the tidal cycle, a ship’s manoeuvring characteristics may be subjected to important
changes during a transit through the channel.
Hull forces: The dynamic equilibrium of a moving ship requires a balance between the
inertial forces and moments and the hydrodynamic actions on the ship’s hull, propeller(s),
and rudder(s). For a maneuvering vessel, the kinematics and dynamics in the horizontal plane
are of main concern, although the six degrees of freedom are not independent. This implies
that the study of maneuvering focuses on lateral forces and yawing moments.
Control forces: The increased wake reduces the inflow, while on the other hand, the higher
propeller loading increases the propeller-induced velocity. Both effects counteract each other,
which almost results in a status-quo in most cases.
Bank effects are defined as the forces and moments acting on a ship due to a motion that has
a mainly parallel orientation with respect to the bank.

5. Discuss in detail about the dynamical stability of a submarine?

Ans: Modern submarines can travel at high speed but sometimes their mission requires them to move
very slowly. These two speed regimes pose quite different situations as regards their dynamic stability
and control in the vertical plane. The submarine's static stability dominates the low speed performance
but has negligible influence at high speed. For motions in the horizontal plane the submarine's
problems are similar to those of a surface ship except that the submarine, when deep, experiences no
free surface effects. At periscope depth the free surface becomes important as it affects the forces and
moments the submarine experiences, but again mainly in the vertical plane.
A submarine must avoid hitting the sea bed or exceeding its safe diving depth and, to remain
covert, must not break surface. It has a layer of water in which to manoeuvre which is only about two
or three ship lengths deep. At high speed there is little time to take corrective action should anything
go wrong. By convention submarines use the term pitch angle for inclinations about a transverse
horizontal axis (the trim for surface ships) and the term trim is used to denote the state of equilibrium
when submerged. To trim a submarine, it is brought to neutral buoyancy with the centres of gravity
and buoyancy in line.
The approach to the problem is like that used for the directional stability of surface ships but
bearing in mind that:
(1) The submarine is positively stable in pitch angle. So, if it is disturbed in pitch while at rest it will
return to its original trim angle.
(2) The submarine is unstable for depth changes due to the compressibility of the hull.
(3) It is not possible to maintain a precise balance between weight and buoyancy as fuel and stores are
used up.
The last two considerations mean that the control surfaces must be able to provide a vertical
force to counter any out of balance force and moment in the vertical plane. To control depth and pitch
separately requires two sets of control surface, the hydroplanes, one forward and one aft.
hydrodynamic pitching moment (M) and vertical force (Z) on the submarine vary with the vertical
velocity, and V is the speed:
(1) The steady path in the vertical plane cannot be a circle unless BG is zero.
(2) There is a point along the length at which an applied vertical force causes a depth change but no
change in pitch angle. This point is called the neutral point and is the equivalent of the neutral point
for horizontal motions, already referred to.
(3) A second point, known as the critical point, A vertical force applied at the critical point will cause
no change of depth but will change the pitch angle. A downward force forward of the critical point
will increase depth, a downward force aft of the critical point will reduce depth. Thus, at this point
there is a reversal of the expected result of applying a vertical force.
(4) As speed drops the critical point moves aft. At some speed, perhaps two or three knots, the critical
point will fall on the after-hydroplane position. The speed at which this happens is termed the critical
speed.
The most unique feature of submarine design stability is that unlike ships, submarine stability is
studied at two conditions:
 Surfaced Stability (when part of the submarine is above the waterline), and
 Submerge Stability (when the submarine is completely submerged, and no part or appendages are
above the waterline).