MARA005
Maintain vessel stability


Application

This unit involves the skills and knowledge required to determine the stability and trim of a vessel to ensure that stability conditions of vessel comply with intact stability criteria under all conditions of loading.

This unit applies to the work of a Watchkeeper Deck, Master up to 500 gross tonnage and Master up to 80 metres Near Coastal.

This unit has links to legislative and certification requirements.


Elements and Performance Criteria

1

Calculate stability

1.1

Vessel stability data book is accessed and checked for endorsement

1.2

Data is interpreted to determine vessel safety parameters

1.3

Stability is accurately calculated using data extracted from vessel stability data book

1.4

Stability calculations are checked to ensure they correlate with data set out in vessel stability book

1.5

Spurious or incorrect information is recognised and recalculated

1.6

Trim, draughts and list are adjusted as required

1.7

Stability calculations are conducted at a time, frequency and scope appropriate to voyage

2

Manage weight distribution

2.1

Stability calculations are used to plan weight distribution to ensure assigned load line conditions are not exceeded

2.2

Weight distribution is controlled to maintain vessel within acceptable stability and stress limits for loading operation and at all stages of voyage

2.3

Appropriate action is taken when weight distribution is compromising vessel safety

3

Maintain records of stability management

3.1

Data and information related to stability management is accurately recorded

3.2

Data and information related to stability management is filed and stored according to organisational procedures

Evidence of Performance

Evidence required to demonstrate competence in this unit must be relevant to and satisfy all of the requirements of the elements and performance criteria on at least one occasion and include:

applying knowledge of stability, trim and stress tables, diagrams and stress calculating equipment

carrying out calculations required when determining vessel stability and trim

managing the loading and weight distribution of a vessel to ensure assigned load line conditions are not exceeded

managing vessel stability in a range of conditions

reading and interpreting vessel specifications and design drawings

recognising problems affecting vessel stability and trim.


Evidence of Knowledge

Evidence required to demonstrate competence in this unit must be relevant to and satisfy all of the requirements of the elements and performance criteria and include knowledge of:

calculation of vessels stability using the inclining experiment

effects of angle of loll

effects of beam and form coefficient on the stability of a vessel

effects of density of sea water on the draught and freeboard of a vessel

effects of free surface on the stability of a vessel

features of the load-line and draught marks of a vessel and methods for performing related calculations

fundamental actions to be taken in the event of partial loss of intact buoyancy

fundamentals of watertight integrity

principal stresses that act on the structure of a vessel

principal structural members of a vessel and the proper names for various parts

problems related to the control of trim, stability and stresses of vessels and appropriate action and solutions

sections of the International Maritime Organization (IMO), Standards of Training, Certification & Watchkeeping (STCW) and Australian Maritime Safety Authority (AMSA) Marine Orders related to intact stability criteria

stability, trim and stress tables, diagrams and stress calculating equipment

theory and calculations of vessel stability and dynamics

use of computer programs in calculating stability

work health and safety (WHS)/occupational health and safety (OHS) requirements and work practices.


Assessment Conditions

Assessors must satisfy National Vocational Education and Training Regulator (NVR)/Australian Quality Training Framework (AQTF) assessor requirements.

Assessment must occur in workplace operational situations where it is appropriate to do so; where this is not appropriate, assessment must occur in simulated workplace operational situations that reflect workplace conditions.

Assessment processes and techniques must be appropriate to the language, literacy and numeracy requirements of the work being performed and the needs of the candidate.

Resources for assessment must include access to:

tools, equipment, machinery, materials and personal protective equipment currently used in industry

applicable documentation such as legislation, regulations, codes of practice, workplace procedures and operational manuals

range of relevant exercises, case studies and/or simulations.


Foundation Skills

This section describes those language, literacy, numeracy and employment skills that are essential to performance.

Foundation skills essential to performance are explicit in the performance criteria of this unit of competency.


Range Statement

Specifies different work environments and conditions that may affect performance. Essential operating conditions that may be present (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) are included.

Range is restricted to essential operating conditions and any other variables essential to the work environment.

Stability calculations must include:

calculation of areas under the curve

changes in draft and trim due to differing water densities

correction for free surface effect

draft and trim

metacentric height

moment of statical stability at small angles of heel

transverse and longitudinal stability

values for righting levers and construction of the curve of stability

Appropriate action includes one or more of the following:

amending the vessel loading plan

ballast management

reduction of free surface

Data and information related to stability management includes one or more of the following:

cargo stowage and loading plan

records of stability calculations

safety management system

stability and trim booklet


Sectors

Not applicable.


Competency Field

A – Handling Cargo and Vessel Stability