Transverse Stability of Ships: an Introduction (SCQF Level 6)

National Unit Specification

General information

Unit title: Transverse Stability of Ships: An Introduction (SCQF level 6)

Unit code: J5D9 46

Superclass: ZS

Publication date: May 2021

Source: Scottish Qualifications Authority

Version: 02

Unit purpose

This unit is suitable for leaners who aspire to a career in the merchant navy or in associated seagoing marine related occupations. This unit has been designed to provide the leaners with an understanding and knowledge of the principles of a ship’s transverse stability and the practical applications of these principles. Whilst the unit is primarily intended for those who intend to seek employment in the merchant navy, it could be studied by someone with an interest in the subject area.

Outcomes

On successful completion of the unit the learner will be able to:

1 Apply the basic principles of hydrostatics to calculate a vessel’s displacement. 2 Describe the conditions of equilibrium at small angles of heel. 3 Apply the movement of a vessel’s Centre of Gravity (G) to a vessel’s statical stability. 4 Explain the reasons for load lines.

Credit points and level

1 National Unit credit at SCQF level 6: (6 SCQF credit points at SCQF level 6)

J5D9 46, Transverse Stability of Ships: An Introduction (SCQF level 6) 1 National Unit Specification: General information (cont)

Unit title: Transverse Stability of Ships: An Introduction (SCQF level 6)

Recommended entry to the unit

While entry to this unit is at the discretion of the centre, leaners would normally be expected to have attained a physical Science qualification at SCQF level 5, e.g. one of the following:

1 National 5 Physics at Grade C or above 2 National 5 Engineering Science at grade C or above 3 Pass in National 5 Physics free-standing units 4 Pass in National 5 Engineering Science free-standing units

Core Skills

Opportunities to develop aspects of Core Skills are highlighted in the support notes for this unit specification.

There is no automatic certification of Core Skills or Core Skill components in this unit.

Context for delivery

If this unit is delivered as part of a group award, it is recommended that it should be taught and assessed within the subject area of the group award to which it contributes.

Equality and inclusion

This unit specification has been designed to ensure that there are no unnecessary barriers to learning or assessment. The individual needs of learners should be taken into account when planning learning experiences, selecting assessment methods or considering alternative evidence.

Further advice can be found on our website www.sqa.org.uk/assessmentarrangements.

J5D9 46, Transverse Stability of Ships: An Introduction (SCQF level 6) 2 National Unit Specification: Statement of standards

Unit title: Transverse Stability of Ships: An Introduction (SCQF level 6)

Acceptable performance in this unit will be the satisfactory achievement of the standards set out in this part of the unit specification. All sections of the statement of standards are mandatory and cannot be altered without reference to SQA.

Outcome 1

Apply the basic principles of hydrostatics to calculate a vessel’s displacement.

Performance criteria

(a) Explain Archimedes Principle and state the Law of Flotation. (b) Define with the aid of a sketch the terms, waterline length, length between perpendiculars, breadth, draught, AW, CW, CB and freeboard. (c) Calculate the displacement of a box or ship shape vessel. (d) Carry out a load line calculation.

Outcome 2

Describe the conditions of equilibrium at small angles of heel.

Performance criteria

(a) Explain with the aid of a sketch the terms, Centre of Buoyancy (B), Centre of Gravity (G), initial transverse metacentre (M), righting lever (GZ) and metacentric height (GM). (b) Sketch and describe how a vessel in either a stable, neutral or unstable condition of stability would expect to behave after being inclined by an external force to a small angle of heel. (c) Describe the rolling period of a stiff or tender condition of stability. (d) State the disadvantages of a stiff or tender condition of stability. (e) Sketch a vessel at an angle of loll and state the dangers of this condition.

Outcome 3

Apply the movement of a vessel’s Centre of Gravity (G) to a vessel’s transverse statical stability.

Performance criteria

(a) Explain how a vessels Centre of Gravity will alter after loading, discharging or shifting weights and describe how the vessel’s transverse statical stability will change. (b) Explain with the aid of a sketch the effect of free liquid surfaces on the transverse statical stability of a vessel. (c) Explain the dangers of free surface.

J5D9 46, Transverse Stability of Ships: An Introduction (SCQF level 6) 3 National Unit Specification: Statement of standards (cont.)

Unit title: Transverse Stability of Ships: An Introduction (SCQF level 6)

Outcome 4

Explain the reasons for load lines.

Performance criteria

(a) Sketch a vessel’s load line marks stating relevant dimensions. (b) Determine a vessel’s draught. (c) Explain the reasons for load lines and relate this to maintaining freeboard. (d) Explain the reasons for load line zones.

Evidence requirements for this unit

Evidence is required to demonstrate that learners have achieved all outcomes and performance criteria.

Written and/or recorded oral evidence should be produced to demonstrate that a learner has achieved all outcomes and performance criteria.

Outcomes 1, 2, 3 and 4 may be assessed on an individual basis, as a combination of outcomes, or as a single, holistic assessment covering all four outcomes.

When designing a holistic assessment instrument to cover all four outcomes, assess all performance criteria from outcome 1 and two performance criteria each from outcome 2, 3 and 4.

The total time for assessment(s) of the four outcomes must not exceed two hours.

Assessment(s) must be conducted under supervised, closed-book conditions in which leaners use reference materials in the form of a formula sheet provided by the centre but are not allowed to bring their own notes, handouts, textbooks or other materials into the assessment.

A different sample should be used on each assessment occasion.

J5D9 46, Transverse Stability of Ships: An Introduction (SCQF level 6) 4 National Unit Specification: Statement of standards (cont.)

Unit title: Transverse Stability of Ships: An Introduction (SCQF level 6)

Outcome 1

Learners will need to provide evidence showing that they can:

 Explain the Archimedes Principle and the Law of Flotation  Define with the aid of sketches, from a sample of four, the terms: — waterline length — length between perpendiculars — breadth — draught — AW — CW — CB — freeboard  Calculate the displacement of a box or shipshape vessel. In any calculation AW, CW or CB must be given  Carry out a load line calculation, learners must calculate two components from TPC, FWA and DWA

Outcome 2

Learners will need to provide evidence showing that they can:

 Explain with the aid of a sketch from a sample of three, the terms: — Centre of Buoyancy (B) — Centre of Gravity (G) — Initial transverse metacentre (M) — Righting lever (GZ) — Metacentric height (GM)  Sketch and describe how a vessel would expect to behave after being inclined by an external force to a small angle of heel  Differentiate between the rolling period of a stiff or tender condition of stability  State the disadvantages of a stiff or tender condition of stability  Sketch a vessel at an angle of loll and state the dangers of this condition

Outcome 3

Learners will need to provide evidence showing that they can:

 Explain how a vessels centre of gravity will move after loading, discharging or shifting weights and state the effect on the vessel’s transverse statical stability  Explain the effect of free liquid surfaces on the transverse statical stability of a vessel  Explain the dangers of free surface

J5D9 46, Transverse Stability of Ships: An Introduction (SCQF level 6) 5 National Unit Specification: Statement of standards (cont.)

Unit title: Transverse Stability of Ships: An Introduction (SCQF level 6)

Outcome 4

Learners will need to provide evidence showing that they can:

 Sketch a vessel’s load line marks stating relevant dimensions  From an image or text determine a vessel’s draught  Explain the reasons for load lines and relate this to maintaining freeboard  Explain the reasons for load line zones

Drawings need not be to scale but should be in proportion and of sufficient clarity to allow the assessor to confirm that the learner has met the evidence requirements.

J5D9 46, Transverse Stability of Ships: An Introduction (SCQF level 6) 6

National Unit Support Notes

Unit title: Transverse Stability of Ships: An Introduction (SCQF level 6)

Unit support notes are offered as guidance and are not mandatory.

While the exact time allocated to this unit is at the discretion of the centre, the notional design length is 40 hours.

Guidance on the content and context for this unit

This unit forms part of the National Qualification Group Award in Maritime and Shipping Operations at SCQF level 6, but may also be offered on a free standing basis.

The content of this unit reflects the content of International Maritime Organisation’s Standards of Training Certification and Watchkeeping (STCW ’78 as amended).

This unit is targeted at learners looking to work in the maritime sector who do not have mathematics at SCQF level 6; for example:

 Phase 1 merchant navy cadets  Merchant navy pre-cadetship learners  Anyone wishing to work in the maritime industry

Outcome 1

Learners will understand the basic principles behind why vessels float in water and the relationship between mass, volume of displacement and water density.

This is initially done for box shaped vessels and the concepts required to transfer these principles to ship shapes will be developed.

Learners will then apply this basic knowledge in different scenarios which will enable them to determine the draught at which a vessel loading to a particular load line will float in water of a given density.

Outcome 2

The criteria for vessels being in a stable or unstable condition or having neutral stability will be investigated.

The relative positions of a vessel’s centre of gravity and centre of buoyancy as a vessel heels will be investigated.

The implications of a vessel initially being in an unstable condition and the concept of an angle of loll will be considered.

J5D9 46, Transverse Stability of Ships: An Introduction (SCQF level 6) 7 National Unit Support Notes (cont)

Unit title: Transverse Stability of Ships: An Introduction (SCQF level 6)

The concept of stiff and tender vessel’s will be investigated, and disadvantages of both conditions will be discussed along with the rolling period of these conditions.

Outcome 3

This outcome covers the effect of vertical and horizontal movement of weight and its effect on the vessel’s centre of gravity and changes to the initial stability of the vessel.

The concept of free surface will be introduced and its importance in determining the final stability of the vessel emphasised. Understanding of the dangers of excessive free surface will be developed in the outcome.

Outcome 4

The learners will be able to read a vessels draught as well as sketch and label a vessel’s load lines stating dimensions.

The relevance of not loading beyond a vessel’s load lines and the relationship with freeboard will be discussed. The concept of reserve buoyancy, structural strength, protection of the crew, will be covered in this outcome.

The reasons for load line zones will be investigated.

Guidance on approaches to delivery of this unit

This unit contains knowledge and skills which are critical to the safe operation of any vessel. This unit could be delivered by combination of class teaching, tutorial work and practical application cargo loading equipment.

It is therefore vital that all learners are thoroughly familiar with the principles detailed above. It is suggested that the delivery follows the sequence of the outcomes as they develop the required knowledge and skills in a sequential order.

Guidance on approaches to delivery of this unit

J5D9 46, Transverse Stability of Ships: An Introduction (SCQF level 6) 8 National Unit Support Notes (cont)

Unit title: Transverse Stability of Ships: An Introduction (SCQF level 6)

Guidance on approaches to assessment of this unit

Centres are reminded that prior verification of centre-devised assessments would help to ensure that the national standard is being met. Where learners experience a range of assessment methods, this helps them to develop different skills that should be transferable to work or further and higher education.

Assessment will be on a sample basis. Outcomes 1, 2, 3 and 4, will be under supervised open-book conditions lasting no longer than two hours and consist of a mixture of short answer/structured questions and a load line calculation.

A different sample should be used on each assessment occasion.

For elements (c) and (d) of Outcome 1 learners shall be provided with a formulae sheet and sets of displacement, deadweight and TPC tables.

Opportunities for e-assessment

E-assessment may be appropriate for some assessments in this unit. By e-assessment we mean assessment which is supported by Information and Communication Technology (ICT), such as e-testing or the use of e-portfolios or social software. Centres which wish to use e-assessment must ensure that the national standard is applied to all learner evidence and that conditions of assessment as specified in the evidence requirements are met, regardless of the mode of gathering evidence. The most up-to-date guidance on the use of e-assessment to support SQA’s qualifications is available at www.sqa.org.uk/e-assessment.

Opportunities for developing Core and other essential skills

This unit has the Using Number component of Numeracy, and the Critical Thinking component of Problem Solving embedded in it. This means that when learners achieve the unit, their Core Skills profile will also be updated to show they have achieved:

 Critical Thinking at SCQF level 6  Using Number at SCQF level 6

J5D9 46, Transverse Stability of Ships: An Introduction (SCQF level 6) 9 History of changes to unit

Version Description of change Date 2 Additional Information added to the evidence requirements 14/07/2021 for this unit

This publication may be reproduced in whole or in part for educational purposes provided that no profit is derived from reproduction and that, if reproduced in part, the source is acknowledged.

Additional copies of this unit specification can be purchased from the Scottish Qualifications Authority. Please contact the Business Development and Customer Support team, telephone 0303 333 0330.

J5D9 46, Transverse Stability of Ships: An Introduction (SCQF level 6) 10 General information for learners

Unit title: Transverse Stability of Ships: An Introduction (SCQF level 6)

This section will help you decide whether this is the unit for you by explaining what the unit is about, what you should know or be able to do before you start, what you will need to do during the unit and opportunities for further learning and employment.

This unit is designed to introduce you to the terms and principles applicable to a ship’s stability and prepare you for the next level of the Advanced Certificate which you will undertake in Phase 3 of a cadetship.

The unit will allow you to apply Archimedes Principle and The Law of Flotation to acquire the underpinning knowledge and principles of ship stability for box and ship shape vessels to routine situations.

On successful completion of the unit you should be able to:

 Apply the basic principles of hydrostatics to calculate a vessel’s displacement.  Describe the conditions of equilibrium at small angles of heel.  Apply the movement of a vessel’s Centre of Gravity (G) to a vessel’s transverse stability.  Explain the reasons for load lines.

The unit is divided into four main subject areas, each one of which is the subject of a separate outcome. Each of these outcomes contains elements which will provide a sound under pinning knowledge for further studies.

Assessment of this unit will be open-book and under supervised condition, normally not exceeding two hours. Assessment will allow you to demonstrate that you have attained the required level of mathematical expertise to successfully achieve the unit.

It is good to recap on the mathematics and science in your school leaving qualification before you start on this unit as this unit has a lot of application of these topic areas. It is also important to ask questions in the lessons or outside of lessons, discuss concepts with your peers to clarify any of the new concepts or terminology you come across in this unit so that you have a very good foundation for the next level of qualification you will progress to.

Learners will develop Using Number through calculations involving several variables and multiple interdependent steps. This may be assessed with the unit assessment but there is no automatic certification of Core Skills implied.

J5D9 46, Transverse Stability of Ships: An Introduction (SCQF level 6) 11