SECTION 11: ISM RISK MANAGEMENT
CONTENTS
11.1. GENERAL
11.2. RISK ASSESSMENT AND MANAGEMENT OF CHANGE
11.2.1. WHY USE RISK
ASSESSMENT?
11.2.2. BACKGROUND TO RISK ASSESSMENT
11.2.3. INTRODUCTION TO THE RISK ASSESSMENT PROCESS
11.2.4. METHODS OF HAZARD IDENTIFICATION AND RISK ASSESSMENT
11.2.5. RISK ASSESSMENT IN PRACTICE
11.3. CHANGE MANAGEMENT AND CONTROL
11.3.1 DETERMINING THE NEED FOR CONTROLS
11.3.2. RECORDING
AND DOCUMENTING THE RESULTS OF CHANGES
11.4. ONGOING REVIEW
11.5. RECORDS
ANNEX - A A STEP-BY-STEP APPROACH TO RISK AND CHANGE MANAGEMENT
ANNEX - B LIST
OF HAZARDS
ANNEX - C TUG PROCEDURE (AN EXAMPLE OF
FOLLOW-UP PROCEDURE TO AN EXISTING RISK ASSESSMENT)
Any risk assessment will be completed through a procedure, which will be finally delivered onboard through a ‘Standing Instruction’
ISM Code
1.2.2 Safety management objectives of
the Company should, inter-alias:
.2 assess all risks to ships, personnel
and the environment and establish appropriate safeguards.
At
MSC 85, IMO adopted a number of amendments to the ISM Code. Among those changes
was a revision of clause L2.2.2, which introduces for the first time a formal
requirement for companies to assess the risk to ships, personnel and the
environment arising from their shipboard operations.
The
revision has prompted the following questions:
1. How should
companies respond and what should they do to demonstrate compliance?
2. How should
auditors interpret the new requirement and what evidence should they look for
to satisfy themselves that companies have addressed it adequately?
Although
it is not often referred to as such, the development and implementation of a
documented safety management system is an exercise in risk management. The
drafting or amendment of written procedures involves looking at the company's
activities and operations, identifying what could go wrong, and deciding what
should be done to try to prevent it. The documented procedures are the means by
which the controls are applied.
The
implementation of a risk assessment process in the context of ship and fleet
management generally will include a definition of processes, as well as hazard
identification, including a risk assessment. The underlying philosophy is to
help develop an effective safety culture in companies and on board ship, where
the human element is given regular and effective consideration. Its purpose is
to facilitate and embed a culture of continuous improvement in safety
performance without the requirement for additional regulation.
The
Company will need to apply the process of hazard identification and risk
assessment to determine the controls that are necessary to reduce the risks of
incidents. The overall purpose of the risk assessment process is to recognize
and understand the hazards that might arise in the course of the organization's
activities and ensure that the risks to people arising from these hazards are
assessed, prioritized and controlled to a level that is acceptable
(requirements are included in different standards like ISM Code, IS09001:2008,
ISO 14001:2004, OHSAS 18001:2007, MLC 2006 ...).
The
focus of the newly ISM Code amendment is therefore on the application of the
risk management process for assessing and improving ship operation with respect
to the reduction of fatalities, damage and environmental damage.
Companies
holding a DOC will need appropriate procedures to fulfill the requirements of
the ISM- Code. Hazard identification and risk assessment methodologies vary
greatly across maritime industries, ranging from simple assessments to complex
quantitative analyses with extensive documentation. Individual hazards can
require that different methods be used, e.g. an assessment of long-term
exposure to asbestos can need a different method than that taken for equipment
safety or for assessing an office workstation.
Each
organization should choose approaches that are appropriate to its scope, nature
and size, and which meet its needs in terms of detail, complexity, time, cost
and availability of reliable data. In combination, the chosen approaches should
result in an inclusive methodology for the ongoing evaluation of all the
company's risks.
The management of
change needs to be considered for changes m assessed risks determination of
control or the implementation of controls. Management review should be used to
determine: whether changes to the
methodology are needed overall To be effective, the organization's procedures
for hazard identification and risk assessment should take account of the
following:
-
hazards,
-
risks,
-
controls,
- management
of change,
- documentation,
- ongoing review.
Risk assessment
techniques can be applied m almost all areas of maritime industries. Ship owner
know that to be successful they must have a good understanding of their risks
and how risks impact the people associated with their operations, their
financial performance and corporate reputation.
Those objective
values might be used in an optimization process to:
-
achieve a reduced level of risk with a
prescribed amount of money,
-
reduce the costs
that are required to achieve a target risk level.
Furthermore,
compared with traditional root cause analysis approaches, risk analysis/
assessment is proactive (e g, 'pro-active' means that hazards are identified
before the un-wanted event occurs), hi that sense risk analysis helps to avoid
fatalities, environmental pollution and economic losses.
Safety barriers
and controls.
One of the
fundamentals of all safety systems is the understanding of the safety barrier
principle Whenever we design safety critical systems we provide them with a
certain recovery potential If a hazard occurs it might not affect the system because of pre-installed
safety barrier. Those barriers do not have to be a physical protection . such
as safely boots or gloves they can also be of organizational nature, etc. An overview is given
below:
 |
When barriers are designed and
integrated in the systems one has to pay specific attention to the nature of the target of a hazard: the ship, the
cargo, the crew or other humans involved, external target (e.g.
port facilities, other ships etc,), the environment. Different hazards and
targets require different
barriers.
Safety
management is therefore a continuous process of assessment of safety barriers
because the existing barriers are monitored constantly. After accidents an
analysis of the function of our pre-installed safety barriers is carried out.
These barriers were not always installed basal on previous experience . They
can also be installed based on personal judgment etc . It is therefore vital to
analyze if the safety barriers in each system have the right dimensions . Accidents,
unfortunately , are practical tests for our barriers . If they did not function
, We have to improve them .
Before
we install safety barriers we assess our systems ; risk management is a complex
process , which consists of the following phases :
- Risk analysis and estimation
- Risk assessment
- Risk management and control
During
the analysis the vital components of technical/ operational systems and
potential hazards endangering the functionality of those systems are
identified.
The
next step is concerned with the estimation of frequencies of the appearance of
these hazards and the resulting consequences . During risk assessment suitable
Risk Control Options (RCOs) are identified , evaluated , and the most
appropriate Risk Control Measure (RCM) selected . The selected . RCMs are the
barriers that should prevent a hazard from hampering the vital components in
our technical / operational systems .
The
risk management process is clearly illustrated on the next page.
Risk
analysis, is a decision-making aid (How safe?)- it can be of
great help in considering alternatives .but it fails if it is not known which
questions have to be answered. The main advantage of a risk analysis is that it provides a structured
access or identification to the hazards combined with a system or a process and
thus Providing a decreasing quantity of not realized hazards.
Risk
Assessment (How safe is safe enough?), follows the risk
analysis. The main task of the nsk assessment is the risk evaluation (i.e.: to
decide if the estimated risk is acceptable) The usual procedure m risk
calculation involves addition or multiplication of the parameters frequency and
severity". The qualitative results are then presented m a risk matrix The
evaluation requires an acceptance criterion.
Risk
management and control {How to achieve an adequate level of
safety?), as the whole process, which includes the risk evaluation - the
judgment whether a risk is acceptable or not is the process whereby decisions
are made to accept a known or assessed risk and/or the implementation of action
to reduce the consequences or probability of occurrence.
The
hazard identification and risk evaluation are key elements of the risk assessment.
In this context the terms acceptable and unacceptable risk are important. In
order to demonstrate that a specific risk is
ALARP
(As Low As Reasonable Practicable) so-called risk control measures are analyzed
Risk
Measures
are introduced to reduce the risk to an acceptable level.
11.2.4. Methods of Hazard
Identification and Risk Assessment.
For any practical
approach, the identification of hazards is the first and most important step in
risk
estimation.
The "typical
methods" are to be understood as practical risk assessment instruments. In
general, the methods are based on checklists and primarily permit qualitative
risk identification. It should be noted ^ designations and implementation of
individual methods may vary, the fundamental
principles remain
unchanged.
The hazard
identification may be performed, dealing with the question "What can go
wrong?". Hazard or danger is posed
by a situation in which there is an actual or potential threat for the crew, the ship or
the environment.
The question
"When is the risk small enough to be ignored?" can really only be answered by your conscience / judgment; personal experience cannot be
ignored! Nonetheless a distinction must be made between unknown risks and those, which are accepted for
reasons of expense. Due to the pressure of cost and time, many unknown risks remain
unspecified.
Incidents and
accidents are reality. Incident investigations provide important information of
significant risk contributors. Appropriate methods are include:
-
Analysis (statistical) of historical data
-
Root-cause analysis.
A simple example
using a few of these terms regarding risks associated with an electrical power
supply line:
Hazard » High voltage
incident » Wire gets exposed
Accident Personal » contact resulting in shock
Consequence» Burns / electrocution
11.2.5. Risk
Assessment in practice.
Risk Assessment and
control is a continuous process . Hence,
written risk assessments should be subject to
periodic formal reviews to confirm the validity of the assessment and whether the
risk controls are still effective and adequate (e.g. relating to type of ship,
the nature of operates and the type and extent of the hazards and risks).
The focus of this
risk assessment is on the:
-
implications to the existing system,
-
interrelation to other changes and
development.
Assuming that a
complete risk assessment exists we re-assess:
-
how the likelihood is affected,
-
how the consequences change,
-
how existing barriers are affected.
The risk assessment
should follow the steps given in ANNEX-A.
What should be assessed?
The assessment
should cover the risks arising from the work
activities on the ship. The assessment is not expected to cover risks that are not reasonably
foreseeable. Employers are advised to record the
significant findings of their risk assessment. Suitably experienced personnel,
using specialist advice if
appropriate, should carry out the process of risk assessment.
Risk
assessment should be seen as a continuous process.
In practice, the risks in the workplace
should be assessed before work begins on any task for which no valid risk
assessment exists.
This risk assessment has to be
documented; the form or checklist for risk assessment may be used and has to be
filed. The risk mitigation measures resulting from the risk assessment have to
be taken up m the records.
RISK= FREQUENCY x CONSEQUENCE
|
In other words, risk has two components: likelihood of occurrence
and severity of the consequences. And thus risk is always expressed with a
time dependent dimension. The risk matrix (used for the determination of the RPN - risk
priority number) shows a simple method for estimating risks according to the
potential seventy of and the likelihood, as described above.
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Risk level acceptable
|
Risk level tolerable
|
|
Risk level is not tolerable
|
Having
determined the significant risks, the next step is to decide what action should
be taken improve safety, taking account of precautions and controls already in
place.
The
outcome of a risk assessment should be an inventory of actions. Any action plan
should be reviewed before implementation, if the revised controls lead to
tolerable risk level.
|
Table I Rating Scale - Severity
|
Risk
Assessment and control is a continual process. Hence, written risk assessments
should be subject to periodic formal reviews-to confirm the validity of
the assessment and whether the risk controls are still effective and adequate
|
Frequency Index
|
Frequency
|
Definition
|
|
4
|
Frequent
|
Likely to occur once per month on one ship
|
|
3
|
Reasonable probable
|
Likely to occur once per year in a fleet of 10 ships, a few times in
a ship life
|
|
2
|
Remote
|
Likely to occur once per year in a fleet of 1000 ships, once in the
total life of
several similar shins
|
|
1
|
Extremely remote
|
Likely to occur once in 10 years in a fleet of 10000 shins
|
The Company should:
-
manage and control any changes that can
affect or impact its hazards and risks. This includes changes to the
organization's structure, personnel, management system, processes, activities,
use of materials, etc. Such changes should be evaluated through hazard
identification and risk assessment prior to their introduction.
-
consider hazards
and potential risks associated with new processes or operations at the design
stage as well as changes in the organization, existing operations, products,
services or suppliers.
The following conditions that should initiate a management of change
process:
* new or modified technology (including
software), equipment, facilities, or work environment,
* new or revised procedures, work practices,
designs, specifications or standards,
* different
types or grades of materials, cargo etc.
* significant changes to the site's organizational structure and
staffing, including the use of contractors,
* modifications of health and safety devices and
equipment or controls.
11.3.1 Determining the need for controls
Having completed a risk assessment and having taken account of
existing controls, the organization should be able to determine whether
existing controls are adequate or need improving, or if new controls are required.
If new or improved controls are required, their selection should be determined
by the principle of the hierarchy of controls, i.e. the elimination of hazards
where practicable, followed in turn by risk reduction (either by reducing the
likelihood of occurrence or potential severity of injury or harm), with the
adoption of personal protective equipment as a last resort.
The following provides examples of implementing the hierarchy of
controls:
1.
Elimination - modify & design to eliminate the hazard, e.g. introduce
mechanical lifting devices to eliminate the manual handling hazard;
2.
Substitution - substitute a less hazardous material or reduce the system energy
(e.g. lower the force, amperage, pressure, temperature, etc.);
3.
Engineering controls - install ventilation systems, machine guarding,
interlocks, sound enclosures, etc.;
4.
Signage, warnings, and/or administrative controls - safety signs, hazardous
area marking, photo luminescent signs, markings for pedestrian walkways,
warning sirens/lights, alarms, safety
5.
procedures, equipment inspections, access controls, safe systems of working,
tagging and work permits, etc.;
6.
Personal protective equipment (PPE) - safety glasses, hearing protection, face
shields, safety harnesses and lanyards, respirators and gloves.
In
applying the hierarchy consideration should be given, to the relative costs,
risk reduction benefits, and reliability of the available options.
11.3.
2 Recording and documenting the results of change
The
process for such change management shall be documented in a formal documented
procedure; risk assessment is a part of
the change process and therefore has to be documented too As a
consequence
of this the verification of the change management process must part of the ISM
certification
(during document verification, office audit and shipboard audits).
The
following types of information should be recorded and retained in SMS' files'
- identification of hazards,
- determination of the risks associated with the identified hazards
- indication of the levels of the risks related to the hazards,
- description of, or reference to, the measures to be taken to
- control the risks,
- determination of the competency requirements for implementing
- the controls .
11.4.
ONGOING REVIEW
It
is a requirement that hazard identification and risk assessment be ongoing where conditions have
changed
and / or better risk management technologies have become available,
improvements should be
made
as necessary. It is not necessary to perform new risk assessments when a review
can show that
the
existing or planned controls remain valid.
The
Company decides to perform annual risk assessment within the limits prescribed
in the annual internal audit schedule.
11.5.
RECORDS
SMM/CH.11
01/01 Rev:01 Issue date: Jul.2010 Identified
risk proposal form
SMM/
CH.11 01/02 Rev:01 Issue date: Jul.2010 Identified risks' record
Risk guide - a practical step-by-step
approach to risk and change management
Step
1 Classify work activities.
Investigation about
hazards, key process, detailed task, subtask
Step
2 Identify hazards for the
work activity (see Annex - B).
Consider
different scenarios under different conditions e.g. new crew, darkness, stormy
weather, rain
Step
3 Identify risk controls.
Safeguards
against risk, safe working practices, procedure's and instructions,
familiarizations
Step
4 Determine risk. Assess
likelihood and potential consequences of the scenarios.
Determine the
potential severity of harm and the likelihood that harm will occur, apply the
IACS rating scale for severity, scale for frequency to decide on likelihood ...
Step
5 Decide if risk is
tolerable.
Calculate the
Risk Priority Number (RPN) by use of risk matrix, evaluate the risk I and
decide on further action ...
Step
6 Prepare a risk control
action plan to improve risk controls as necessary.
Develop
additional Risk Control Options-RCO, list measures to implement changes, ensure
that risk is reduced to ALARP [As Low As Reasonable Practicable] level.
Step
7 Review adequacy of action
plan, confirm whether risk are now acceptable or tolerable.
Investigate the
effect of the additional Risk Control Measures (RCM), compare the benefits with
time and efforts.
Step
8 Ensure risk assessments and
risk control measures are effective and up to date.
Monitor
implementation, review change, regular review the adequately and effectiveness
of the risk controls
ANNEX –B
LIST OF HAZARDS
The
hazard list may help with the identification of hazards for work activities.
The list is not exhaustive and should be updated as soon as new
hazards have been identified and which are not
the
list.
1.
FOR SHIP OPERATION
1.1
Human-related hazards
1.1.1.
Personal factors
- reduced ability, e.g. reduced vision or hearing
- lack of motivation, e.g. because of a lack of incentives to perform
well
- Lack of ability, e.g. lack of seamanship, unfamiliarity with vessel,
lack of fluency of the language used onboard
- fatigue, e.g. because of lack of sleep or rest, irregular meals
- stress
1.1.2.
Organizational and leadership factors
-
Inadequate vessel management, e.g. inadequate supervision of work, lack of
coordination of work, lack of leadership
-
Inadequate ship owner management, e.g. inadequate routines and procedures, lack
of resources for maintenance, lack of resources for safe operation, inadequate
follow-up of vessel organization
-
Inadequate manning (e.g:. too few crew, untrained crew)
-
Inadequate routines (e.g.: for navigation, engine room operations, cargo
handling, maintenance, emergency
preparedness)
1.1.3.
Task features
-
task complexity and task load, i.e. too high to be done comfortably or too low
causing boredom
-
unfamiliarity of the task ambiguity of the task goal different tasks competing
for attention
1
1.4. Onboard working conditions
-
physical stress from (e.g.: noise, vibration, sea motion, climate, temperature,
toxic substances, extreme
-
environmental load's, ( night - watch)
-
ergonomic conditions (e.g. inadequate tools, inadequate illumination,
inadequate or ambiguous information,
badly-de-signed human-machine interface)
-
social climate (e.g.: inadequate communication, lack of cooperation)
-
environmental conditions (e.g.: restricted visibility, high traffic density,
restricted fairway)
1.2
Shipboard hazards to personnel
-
inhalation of harmful substances (e.g. toxic gases)
-
burns from substances like acids
-
electric shock
-
person falls from height or slips
-
person falls overboard
-
other injuries, etc.
1.3
Hazards to the vessel
1.3.1 Loss Of Watertight Integrity (LOWI)
-
contact or collision
-
fire / explosion
-
flooding
-
grounding or stranding
-
loss of hull integrity, structural failure
1.3.2
Hazards external to the ship
-
storms
-
lightning
-
uncharted submerged objects
-
other ships
-
attacks (pirates, terrorism)
-
war
1.4
Hazardous substances on board ship
1.4.1
Accommodation areas
-
combustible furnishings
-
cleaning materials in stores
-
oil/fat in galley equipment
1.4.2
Deck areas
- cargo
- paint,
oils, greases etc. m deck stores
1.4.3
Machinery spaces
- cabling
- fuel
and diesel oil for engines, boilers and incinerators
- fuel,
lubricating and hydraulic oil in bilges, save ails etc
- residual
oils , refrigerants
1.5
Potential sources of ignition
1.5.1
General
- electrical
arc
- friction
- hot
surface
- incendiary
spark ^
- naked
flame
1.5.2
Deck areas
- deck
lighting
- funnel
exhaust emissions
- hot
work sparking
1.5.3
Machinery spaces
-
engines exhaust manifold
- boiler(s)
exhaust
2.
FOR CARGO OPERATION
2.
1 Hazards of cargo
-
flammability
- toxicity
- density
- corrosion
2.2
Operational Hazards
- pollution
- static
electricity
- smoking
- naked
lights
- use
of electrical equipment
-
use of tools
- use
of communication equipment s
- spontaneous
combustion
- enclosed
spaces
ANNEX-C
TOWAGE TECHNICAL WORKING PROCEDURE
CONTENTS:
TRAINING AND KNOWLEDGE
Firstly
it has to be stressed that Towage Survey is neither a classification nor a
statutory survey, but Surveyor acting as a third party. There are four reasons
why towage surveys are done, namely warranties, safety, pollution prevention
and success of project. Despite the different motives, all towage surveys look
at the same things-the tug, the connection and the route, and then tow itself.
The
towing vessel may be an ocean tug, costal tug, ship, fishing vessel or other
vessel of opportunity, m each case, its suitability should be judged against
the following criteria:
Main
Engines
Type
of Propellers
Bow
Thruster
Towing
winches
Type
of radio installation
VHF
Radar
Other
navigational aids
Echo
Sounder
Gyro
Auto
pilot
Portable
Pumps
Fixed
Salvage Pumps
Searchlights
Total
Estimated distance of Tow
Distance
between bunkering Ports
Estimate
speed
Bunkers
carried
Daily
consumption
Water
available
Victuals
available
General
Condition of tug
The
vessel must be seaworthy for the intended voyage. Hull
Propulsion
may be conventional, cyclical, azimuth thruster or a combination. Thruster and
cycloidal tugs, are generally as suitable for offshore towage as conventional
tugs due to their comprehensive maneuverability, ability to reconnect tow when
lost in poor conditions, and the fact that their arrangements. Some tugs with
non-conventional propulsion are steered only by individual control of the main
units. If this requires the constant attention of an experienced officer, then
such a tug may not be suitable for anything other than short tows
There
are various formulae for calculating the power required for a tow. Approximate
formulae for ship shapes.
(a)
Resistance of tow R= [2,5 (Ri + R2 + R3)]/ 2240 in tons
R1
= FSV2 F = 0.01
S
= Wetted surface in ft2
V= Speed of tow
in knots
R2
= D2 x V2 x N D
= prop diameter in feet (of tow)
|
Size of vessel
|
Angle of
|
Resistance to
tow (tons)
|
|
|
being towed
|
yaw
|
Speed through
water 2kn
|
Speed through
water 3 kn
|
|
24.000 tons
deadweight
|
0°
10°
20°
30°
|
2,3
5,5
8,7
13,0
|
4,3
11,4
18,7
28,3
|
|
68,000 tons
deadweight
|
0°
10°
20°
30°
|
4,7
10,8
17,3
25,8
|
8,5
25,5
37,0
56,0
|
|
112,000 tons
deadweight
|
0°
10°
20°
30°
|
6,2
14,8
23,4
35,0
|
11,3
30,5
50,2
76,5
|
|
260,000
deadweight
|
0°
10°
20°
30°
|
7,9
15,2
39,6 J
51,8
|
14,0
30,0
85,0
112,7
|
V= Speed
N = number
of propellers
R3
= 0,1 R2 R3
= allowance for towing gear
(b)
BHP required = [A R x V2] / 120 A
= displacement of tow.
V = speed in
knots
(c)
Guide figures from OCIMF Towage Publication 'RESISTANCE TO TOW IN STILL WATER
CONDITIONS' (For sea conditions, the forces can be three times greater than
those tabulated ).
(d)
Rule of thumb information from tug masters indicates that, up to 40.000 tones displacement,
the tow urn. requires approximately 10 tones bollard pull per10,000 tones displacement.
For
larger vessels the following figures give guidance:
Displacement
of tow bollard pull required
50
000 tonne 60 tonne
100.000
tonne 80
tonne
150',000
tonne 94
tonne
900.000
tonne 105
tonne
250,000
tonne 115
tonne
(e)
other factors
Fouling
of hull of tow, which may increase resistance substantially.
Resistance
of towing gear - the catenary may increase overall drag by 10 %
Yawing
of tow increase stresses dramatically.
Wind
area of tow . . ,
Storm
conditions may cause towing forces three times calculated,
(f)
non-ship shapes
Resistance
of Towing force for non-ship shapes is difficult to calculate hut may be double
that of an equivalent size ship shape.
In
General tugs have become more powerful, and industry standards have risen with what
is available. This means that, for ship tows, power is rarely a problem , in
fact too much power may be available.
For non-ship shapes the situation is made more complex. Here it is often
Preferable to have multuiple tugs rather than beefing up a single tug a
decision must be made as to the basis of the calculation . is the tug required
only to hold the tow in bad weather or is it required to make good a certain
speed in reasonable conditions?
The
directional stability of the tow may be
poor, again increasing power requirements to cope with the tow sheering about.
(g)
Bollard null or BHP are not the sole measure of towing ability The hull form
and displacement can compensate for lack
of horsepower and is important for ocean and bad weather tows. .
The
relationship between BHP and bollard pull is not fixed depends on the propulsion
system and vessel size . for conventional screw vessels where bollard pull
figures are not available, an estimated 1 tone static bollard pull per . 100
BHP can be used as a guide. Vessels with propellers operating in Kort-type
nozzles may generate up to 1,3 tones per 100 BHP.
2.5
stability
Towing
vessels must be able to withstand girting moments if the tow comes abeam or
must have an efficient means to prevent this happening.
The
Gobbing device is the means of restraining the towline near to the aft end of
vessel to prevent girting. It can be a fixed lead, a pipe frame, a chain or wire
or a wire lead to a powered winch.
Trawlers
generally have good stability and tow wires lead through low leads right aft,
acting as gobbing devices.
The
means by which the tow can be released in an emergency should be inspected. The
emergency may be the sudden sinking of the tow or the failure of the gobbing
device allowing as capsizing moment to occur. Tugs have been lost through both
causes.
Many
modern tugs are fitted with a button in the wheelhouse, which releases the
winch brake in an emergency. This is good practice.
If
there is no remote quick-release device, the gobbing device must be ubstantial,
and suitable arrangements for the manual release of the tow must be
demonstrated.
Very
large tugs often have sufficient stability to be able to resist the largest
possible girting moment.
Calculations
showing upsetting moments at the breaking strain of the tow wire superimposed
on the GZ curve may be called for in doubtful cases.
The
tug must carry an acceptable workboat / rescue boat.
If
the workboat is an inflatable, check that the outboard power is matched to the
boat specifications. The outboard should preferably have a shrouded propeller.
It is good practice to have a back-up outboard available.
Protective
gear and working lifejackets for the boarding crew should be provided.
The
tug should have a searchlight or signal lantern capable of illuminating the tow
or workboat.
An
efficient means of communicating between the tug and tow and workboat should be
agreed upon.
"Wallcy-Talky"
portable radios-should be provided but must be a back-up signal system if these
fail.
There
must be sufficient spare gear to reconnect a broken tow using spare gear
throughout.
A
spare towing wire readily accessible must be on board.
Navigation
gear must be adequate, charts to adequate scale and up-to-date.
Food,
water and bunkers should show a reserve of 100 per cent for costal tows and
between 50-20 per cent for ocean tows.
Medical
stores must be to legal requirements.
The
towing should normally be on a suitable winch; small coastal tjaws may be
carried out on a hook
There
should be an efficient means of recovering the tow connection when
shortening
m and letting go. Particular attention should be paid to Ms when towing on a
hook is proposed
2.7 Manning
Manning
must comply with flags state requirements ,
coastal state requirements and the STCW convention and IMO Resolution A
481. However these specify minimums for
safe navigating only. What is important for towag is that the officers have
sufficient previous experience of similar tows, and that adequate hands are
carried for handling the gear.
Deck
crew requirements are relatively easy to assess, in terms of the heaviness of
the towing gear, deck space and machinery More difficult is the experience of
the officers an assessment of the way the tug is run. access to logbook and captains and officer's
seaman's books, and some delicate questioning will
often
give a good idea of what the crew is like. If in doubt, there are tow ways out
. one is to stay outright that the officers are inexperienced and must be
replaced . The other is to beef up the whole project in other ways - better tug
better connection etc. It is a very sensitive area, but it is the most important.
A
good
seaman can nurse a tug and tow home m less than optimum conditions whilst an
inexperienced master may put the best-arranged project m danger
3
The Connection
3.1
Materials
The
connection maybe of wire, chain or rope or a combination of all of these All
the gear, m use and spare, must be m a good condition.
Records
of the following should be kept:
Main Towing Wire Or Rope
Spare
Towing Wire
Wire
Pennants
Chain
Pennants
Man-made
Pennants
Other
Ropes
Towing
Shackles
The
size of tow connection should be related to the bollard pull of the tug.
For small tugs Breaking Strain = 3 x Bollard
Pull
The
safety factor may be reduced to 2 x Bollard Pull or less for large tugs.
Odds
– shaped vessels yaw considerably ; so particular attention should be paid to
the strength of the gear used .
Conventional
rigs are usually made up of a wire from the tow winch , shackled to a wire
pennant and / or a polypropylene or nylon pennant , which in turn is fixed
to
a short chain. This chain is made fast to the bow. The chain may form a bridle
or be a single part. The use of a bridle is recommended as it reduces yaw by 60
- 90 per cent. Some tug masters like to have a pennant in the connection of a
slightly lower breaking strain than their main wire, to protect the wire.
Applied
seamanship is required to decided on the correct rig for" the tow. In
general, a chain should be used if possible at the tow end to avoid chafe, and
there-should be a shot of chain or a man-made fiber pennant in the gear to
provide elasticity.
Shackles
should be of the pin type, properly locked or moused. Screw shackles should be
avoided, as they may be difficult to undo subjected to heavy loads.
Man-made
fiber towlines may be used when it is important to have a light connection, e.g. if the trim of
the tow may be easily affected by a heavy rig.
The
required length of the towing gear is a function of swell length, tow size and
distance. 500m is good minimum for ocean tows.
The
connection to the tow must be examined. Lugs or bollards used must be well
connected to the tow's structure and backed up. Keep a sketch or photo of the
arrangement.
The
fairleads are important and must be strong enough to bear the yawing stresses
imposed on them, and to resist chafing. Panama
4 The Tow
Except
in the case of small vessels, the tow should be manned if possible. The
following criteria apply to all tows, with additional requirements for unmanned
tows show in the section (4.4)
4.1
Seaworthiness (Use this section as a checklist, noting details)
Name of Craft
Displacement
Tonnage
Length
/ Breadth / Depth
Sailing
Draughts (Fore, Aft, Mid)
Freeboard
Type
of Vessel
Date
built
Number
of Decks
Number
of Transverse Watertight Bulkheads
Number
of Longitudinal Watertight Bulkheads
Position
of Engine Room
Number
of Double Bottom Tanks
Number
of Hatches or Weather Deck Openings
Tonnage
and disposition of oil on board
Other
Pollutants
Last
Dry-docking place/ date
Last
Construction Survey
Last
Load Line Certificate issued
Owner
Master
Vessel
manned / unmanned
Number
of crew / runners
Number
and type of working pumps on board
Fuel
supply for pumps (number of hours)
Condition
of Craft
State
of shell plating and decks
State
Machinery spaces
State
of Bulkheads
Nature
of any damage to craft
Note
of any spaces flooded
Note
of spaces under air pressure
Bilges
should be clean and dry. If not note reason
All
spaces to "be checked for loose gear
Note
that the following are secured and watertight
All
upper deck hatchways, doors and scuttles.
Deep
tank cover.
Double
bottom tank manholes.
Fuel
tank covers.
Watertight
doors.
Goosenecks.
Ventilators
as necessary.
Port
holes in shell and lower decks of accommodation.
On
barges, particular attention to be paid to manhole covers.
Check
that any windows in vulnerable positions are suitably protected by steel or
timber shutters.
All
derricks, cranes, etc to be in the stowed position and properly secured.
Normally,
propeller shaft should be locked.
Disconnecting
propeller shaft may reduce tow load, at discretion of tug master, and tow
owner. If connected, check lubrication arrangements.
Is
stem gland watertight?
Is
rudder secure?
If
rudder carrier is situated below the waterline, check for leakage.
Is
cargo well stowed and secure?
In
instances where very large items of cargo are involved, the owners should
provide stress calculations for the sea fastenings. Check that the assumed
values of roll, pitch and heave are reasonable.
A
line to be painted in a sharply contrasting color to the hull on each bow and
each quarter to indicate the draught on sailing, and to be of such a size as to
be visible form the tug.
Sea
valves and manifolds not in use to be secured.
Note
extent to which power is available for any of the ship's machinery.
Are
runners and tug engineer familiar with
the operation of pumps on board?
Test
the pumps.
Electric
circuits not in use to be isolated.
Check
whether any circuits in use are in apparent good order.
Check
whether lifeboat securing devices are in good condition.
4.2 Ballasting
Stability
booklet or calculations to be signed; if none available, surveyor's assessment
of the situation. In doubtful cases an inclining test to be carried out.
Note
probable range of stability
Craft
to be upright within reasonable limits. Any list noted.
Number
of slack tanks to be kept to a minimum. Any free surface effect to be checked
against stability information. Note tanks in use.
Note
ballast plan. Do not allow undivided tanks to be part ballasted.
Tow
should be ballasted to give a stern trim of at least 0,75% LBp for ship shapes.
4.3 Equipment
An
emergency bridle, which should be a duplicate of the main bridle if possible,
should be rigged. The bridle should be connected to a pennant and a messenger.
The emergency rig should be stopped in place with a light line ready to make a
re-connection of the tows parts.
Runners
to be supplied with up-to-date safety equipment.
Firefighting
appliances, particularly extinguishers, to be ready for use. Emergency fire
pump to be tested and proven in good working order.
Navigation
lights as per international regulations to be in working order. Daytime signal
to be displayed if tow over 200 meters.
Fog
signal to be tested and ready for use.
A
suitable anchor to be safety available for use.
Power
on windlass desirable
Pilot
ladder to be ready for use.
Cooking
facilities with sufficient food and water to be provided.
Lighting
and heating to be provided. If gas used, bottles to be outside of
accommodation.
Pyrotechnic
distress signals and signaling lamp with a battery to be provided.
Copies
of general arrangements and / or capacity plans to be available aboard tug and
tow.
All
spaces to be sounded frequently and results recorded.
Full
inspection of the vessels to be made at least once per day and reported to tug
master.
Towage
connection to be inspected at least twice per watch and fairlead to be greased
if necessary.
All
sea valves and manifolds to be secured chained shut and tested for water
tightness.
Pumps
shall be on board and tested before sailing.
The
messenger to the spare towing pennant and bridle should be stopped off outside
the rails and attached to a highly visible pick-up buoy, which should be
trailed astern.
Efficient
long-burning navigations lights to be installed and tested. Daytime towing
signal to be displayed if tow is over 200 meters.
Emergency
anchor to be considered except in minor tows where surveyor deems it
unnecessary and where there is no threat of pollution.
One
ladder to be rigged over side each side either as temporary or permanent
structures.
Tug
master to be provided with a copy of the general arrangement and / or capacity
plan.
Surveyors
should discuss the proposed route with the tug master. The depth of water
en-route should be considered in relation to the expected depth of catenary.
Formulae and computer programs exist for calculating catenary depth,
which
is a function of speed, length and make-up of gear. When considering depth, as
a rule of thumb the conventional wire/chain tow connection may have a catenary
of + 50m depth over a 500m length.
The
proposed distance off the coast should be sufficient to allow time to reconnect
the tow or rescue the runners in the event of the tow parting. The possibility
of a stranded tow causing oil pollution should be borne in mind.
The
tug master should be aware of the latest navigational warnings and the route
should be planned to give a wide berth to offshore structures and operations
A
weather window may be specified for certain operations, particularly if the
vessel is not suitable for unlimited conditions. Seasonal limitations must be
considered, particularly for long deep-sea passages.
5.3 Communications
The
coastguard, port authority and coast radio stations whose areas of
responsibility cover the proposed route should be informed before departure,
and kept informed of any changes to the schedule. Navigation warnings may be
broadcast for some tows.
Upon
satisfactory completion of the Towage Survey, the attending Surveyor shall
issue
the
Towage Survey Certificates, which shall be valid only for the particular towage
taken into account.
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