CHEMICAL TANKER MANUAL -...

19
CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page Page 1 of 19 2.1. VOYAGE PLANNING & STOWING OF CARGO A. Operating Procedures Certain operators may issue their own operating procedures. A copy of such procedures should be made available to the company. These procedures will be studied by the company to identify if any gaps or conflicts exist with our own procedures. If operators procedures are found to be in conflict to the procedures and policies detailed in the company SMS then the Company’s procedure shall take precedence. Company will take up the matter with the charterers / operators. B. Charter Party and Voyage Orders Usually vessel has to comply with the Charter Party and the Voyage orders at all times. In case of any difficulty in complying these orders or conflict of instructions with company policy, the vessel shall contact the concerned Technical / Marine superintendent for guidance. The ruling charter party must be fully read and understood by the Master, Chief officer, Chief Engineer and Second Engineer at the least. Voyage and Cargo instructions will be issued by the Charterer / Operator (hereinafter term “Operator” covers both) to the vessel and must be acknowledged on the day of receipt. If operators instructions are found to be in conflict to the procedures and policies detailed in the company SMS then the Company’s procedure shall take precedence. If there is any disagreement with the instructions the Operator and the company are to be advised. Copies of the current voyage order should be made available on the bridge in a file for review by all Deck Officers, Chief Engineer and Second Engineer who shall read and sign the voyage instructions to take away information relevant to their responsibility on board. It is recommended that relevant sections of the charter party and voyage instructions are clearly identified using highlighters. Uncontrolled when Printed

Transcript of CHEMICAL TANKER MANUAL -...

Page 1: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 1 of 19

2.1. VOYAGE PLANNING & STOWING OF CARGO

A. Operating Procedures

Certain operators may issue their own operating procedures. A copy of such procedures should be made

available to the company. These procedures will be studied by the company to identify if any gaps or

conflicts exist with our own procedures.

If operators procedures are found to be in conflict to the procedures and policies detailed in the company

SMS then the Company’s procedure shall take precedence. Company will take up the matter with the

charterers / operators.

B. Charter Party and Voyage Orders

Usually vessel has to comply with the Charter Party and the Voyage orders at all times. In case of any

difficulty in complying these orders or conflict of instructions with company policy, the vessel shall contact

the concerned Technical / Marine superintendent for guidance.

The ruling charter party must be fully read and understood by the Master, Chief officer, Chief Engineer

and Second Engineer at the least.

Voyage and Cargo instructions will be issued by the Charterer / Operator (hereinafter term “Operator”

covers both) to the vessel and must be acknowledged on the day of receipt. If operators instructions are

found to be in conflict to the procedures and policies detailed in the company SMS then the Company’s

procedure shall take precedence. If there is any disagreement with the instructions the Operator and the

company are to be advised.

Copies of the current voyage order should be made available on the bridge in a file for review by all Deck

Officers, Chief Engineer and Second Engineer who shall read and sign the voyage instructions to take

away information relevant to their responsibility on board.

It is recommended that relevant sections of the charter party and voyage instructions are clearly identified

using highlighters.

Uncontrolled when Printed

Page 2: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 2 of 19

This will avoid several issues which are caused due to lack of proper review of the charter parties and

voyage instructions like timely notifications, NOR, missing out of tendering letter of protest, providing

notices to various parties etc.

Voyage Orders Contents:

Typical voyage orders will contain the following elements:

Voyage

IMO ship’s type number

Rotation (Loading –Discharge ports)

Cargo quantity, commodity and options

Charterer’s requirements for tank preparation for next cargo

Wall wash requirements

Load port and discharge port

Specific gravity of the cargo at 20°C

Heating instructions

Inerting, Padding and/or purging instructions

US Coast Guard number and pollution category

C/P date

Laycan (Laydays and cancelling date)

Special requirements by charterers

Special characteristics of ports/berths

Stowage proposal by Charterers

Bunker proposals

Any additional relevant information.

Tank cleaning information

The Master must advise the management office of any doubt, disagreement or inability to

comply, with the instructions.

Uncontrolled when Printed

Page 3: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 3 of 19

C. Cargo Quantity

The vessel should prepare a stowage plan on the basis of the contract / voyage order quantity. The

Operator may send a proposed stowage plan. This proposed stowage plan must be thoroughly checked

and proposed changes (if any) must be communicated to the Operator soonest, giving reasons for the

changes.

It may happen that vessel learns from terminal after arrival at berth that the cargo quantity to be loaded is

in excess or short of the nominated quantity. Such matters should be referred to the Operator for

instructions / guidance keeping the company additionally advised.

The voyage order must be reviewed carefully for all information contained therein especially cargo

nomination quantities, properties of the cargoes, intended discharge sequence, notices to be issued, any

notification procedures in the event of an emergency.

D. Notification to the Office

The following information from the Voyage orders must be notified to the Technical / Operations

department following a review of the current voyage Charter Party / Voyage Instructions on each

occasion such instructions are issued and upon change of command.

1. Quantity and grades of cargoes being loaded.

2. Charterer.

3. Vessel routing and if any restrictions are imposed.

4. Any specific requirements for MARPOL compliance in the area of trade (eg. ECA, CARB etc).

5. Emergency notification procedures if any from the charterers.

6. Always provide the office with a copy of the voyage instructions.

7. Any specific cargo operational requirements identified (e.g. Blending, water plug, etc).

8. Any other relevant matter.

Uncontrolled when Printed

Page 4: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 4 of 19

2.2. CARGO INFORMATION

A ship will normally receive orders giving cargo details and destinations direct to the vessel from the ‘Time

Charterers’ or ‘Voyage Charterer’. It is important that Office is immediately advised of the vessel’s

destinations, nominated agents, cargo nominations, etc. At the time of receipt of voyage orders, Master

must also request for Voyage Charterer’s Emergency contact details.

In the event of the vessel being issued with instructions which appear unacceptable due to quantity,

incompatibility, unacceptable trim or stresses, the Charterers and Office must be immediately informed of

the difficulties and suggested changes.

For each chemical listed in voyage orders, identification of the product and a review of the carriage

requirement shall be carried out to confirm the following:

1. Subject cargo is included in vessel’s ‘Certificate of Fitness’ or has a letter of authorisation from

the administration.

2. Coating Compatibility data / Stainless Steel Resistance List has been checked to confirm cargo

is acceptable.

3. MSDS sheets and cargo specific voyage instructions such as inerting / heating instructions

have been provided.

4. The following documents are also to be referred to ensure that necessary information for the

safe carriage of the product is available.

a. IBC Code

b. Latest MEPC. 2 / Circular (when applicable)

c. FOSFA / NIOP Lists of Acceptable and Banned Previous Cargoes

d. P&A Manual

e. Compatibility Guide and USCG cargo compatibility / CHRIS Code.

(NOTE – Exceptions are listed under Appendix 1b of the USCG compatibility table, same shall be

referred to.)

A product must be shipped under the product name listed in chapter 17 or 18 of the IBC Code or in the

latest edition of MEPC.2/Circular (commonly referred to the tripartite agreement).

Uncontrolled when Printed

Page 5: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 5 of 19

If the product is neither listed in the IBC Code, nor published in the MEPC.2/ Circular, it is necessary to

check whether the product has already been provisionally assessed by tripartite agreement by contacting

the Administration / Classification Society.

Where special requirements 16.2.6 – 9 are mentioned in column “O” of Chapter 17 of the IBC code for

any of the parcels to be loaded, it is the duty of the Master to ensure that a shipping document is provided

by the Shippers / Charterers to the vessel indicating the cargo viscosity at various temperatures and

melting point as applicable.

In case of non-availability of information, head office should be contacted for further information

pertaining to safe carriage of the product.

The vessel shall not load till such time that sufficient cargo information and procedures have been

provided and it has been confirmed that the vessel can safely load, carry and discharge the

intended cargo.

If neither the Master nor the Chief Officer has previous experience of handling cargoes with

similar properties a Risk Assessment with office approval is required.

2.3. JOINT PLANNING

In all operations connected with cargo, ballast, tank cleaning, bunkering etc., it is the responsibility of all

Senior Officers to ensure sound joint planning and control so that maximum co-operation amongst the

various departments is achieved in order that the operation may be brought to an expeditious and

successful conclusion, compatible with safety.

2.4. CARGOES WHICH ARE NEW TO THE COMPANY/VESSEL

It is likely that a cargo being nominated for carriage on the vessel is new to the vessel and the company. This should be considering the below 2 possibility :

1. Cargo is listed in the COF , however the vessel and the company does not have any experience

with the carriage requirement for the cargo

2. There are circumstances where the cargo may not yet be included in IBC Chapter 17 & MEPC

Circ. 2/latest circular ,

For the second possibility necessary flag state and class approval needs to be taken for the carriage of

the cargo.The cargo should be included in the vessel’s certificate of fitness prior to carriage

Uncontrolled when Printed

Page 6: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 6 of 19

A complete HSE review must be carried out prior the cargo is carried on board. The review must include

check of the adequacy of company procedures, skill and level of expertise of the crew, limitations of the

vessel’s equipment etc. A suitable risk assessment must be carried to identify the risks and measures to

mitigate such risk.

‘Risk Assessment’ as a minimum must review the following:

1. The hazards of the Chemical.

2. Adequacy of the fire fighting medium.

3. Conditions of carriage and that vessel is able to meet the requirements.

4. Tank cleaning procedures.

5. That adequate safety / handling procedures are available.

6. That the new cargo is included in vessel’s COF or authorized by the administration.

7. That staff on board and ashore have the adequate capability to load, carry and discharge the

cargo safely.

2.5. CARGOES NOT LISTED IN THE CERTIFICATE OF FITNESS (COF)

If the voyage orders contain a Cargo not listed in the Certificate of Fitness, Head office should be

contacted for further information pertaining to safe carriage of the product. The Office will gather new

cargo safety / operating instructions through charterers / industry guidance such as MEPC 2 Circular

where required and will liaise with the vessel’s Flag state / Classification to have the cargo included in the

COF or obtain a letter of authorisation from the administration.

‘Management of Change’ and ‘Risk Assessment’ will be carried out by the office to ensure that vessel is

suitable to load subject cargo which will include as a minimum a review of the following:

1) The hazards of the Chemical.

2) Adequacy of the fire fighting medium.

3) Conditions of carriage and that vessel is able to meet the requirements.

4) Tank cleaning procedures.

5) That adequate safety / handling procedures are available. (Drager tubes, Antidotes and any

specific equipment which shall be required for safe handling of this cargo)

6) That the new cargo is included in vessel’s COF or authorized by the administration.

7) That staff onboard and ashore have the adequate capability to load, carry and discharge the cargo safely.

Uncontrolled when Printed

Page 7: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 7 of 19

2.6. MATERIAL SAFETY DATA SHEET

It is to be ensured that shipper specific material safety data sheet of all cargoes carried on board are

available to the Master and these should include following information:

- Cargo should not be loaded without MSDS from the Terminal or Charterers.

- Shipping Name. MSDS may not always have the Proper Shipping Name.

- Full description of physical and chemical properties of the cargo (including viscosity and melting point

data).

- Action to be taken in the event of spills and leaks.

- Countermeasures against personal contact.

- Fire fighting procedures and media.

- Procedures for cargo transfer, tank cleaning, gas freeing and ballasting.

- For cargoes required to be stabilized or inhibited, full information of the additive being added to effect

such stability or property of inhibition. Where used, a separate MSDS for inhibitor / additive shall be

provided onboard.

It is the responsibility of the Shipper / Charterer of each cargo to be loaded to provide the above data and

the Master shall ensure that the same is provided onboard.

- If such information is not available Office is to be informed at the earliest and cargo loading should not

commence until Office permission is obtained.

- MSDS should be stowed in conspicuous locations which are publically accessible.

2.7. DOUBLE VALVE SEGRAGATION

This section applies to compatible cargoes of different grades. Vessel shall always load within the

limitations of vessel’s natural segregation. Master shall ensure that vessel is able to maintain

minimum two valve segregation between each cargo, parcel or grade during each stage of

operation such as loading, during the voyage and discharging and shall provide a separate pump

and line for each cargo and grade.

Cargo stowage wherein vessel is notable to maintain double valve segregation or if voyage instructions

allow vessel to maintain single valve segregation should be brought to the Head office attention and such

stowage shall not normally be considered acceptable. However it may be allowed only against express

Uncontrolled when Printed

Page 8: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 8 of 19

permission from owners. The risk of handling different products against a single valve segregation is

significant hence cargoes which are distinctly different in quality and properties cannot be carried in this

manner. Each case of stowage involving a single valve segregation of the cargo should be brought to the

knowledge of the office and approval must be sought.

2.7.1. Reactivity with Other Cargoes

This section applies to products which vigorously react with other products to produce heat, toxic fumes

or excess pressure. Accidental mixing of such cargoes may cause injury to personnel, damage to the

environment or ship. For the purpose of safe carriage of these products the US coast guard has used

information provided by the National Academy of sciences to identify and categorise the cargo into

various reactive and nonreactive groups.

USCG compatibility guide is the most commonly used compatibility guide. This information is updated

annually by the USCG and available in CFR 46 part 150. Master must ensure that the current edition of

this publication is available on board the vessel at all times and should be referred to when planning

stowage. The ship’s officers should also be aware of the exceptions to the compatibility chart which are

detailed in the CFR.

To prevent accidental mixing, incompatible cargoes on the same vessel must be carried out with extreme

caution. The cargoes must be kept strictly separated from each other throughout the handling and

stowage system using two barriers between them. This segregation must be applied to slops, draining in

the drip tray on spill containers, stowage in tanks and stowage of samples.

A Risk Assessment is to be carried out when a vessel loads two or more incompatible cargoes.

The ship’s master shall ensure that the stowage of the reactive cargoes meets the following

requirements:

(a) The containment system must separate the two incompatible cargoes by two barriers such as formed

by a:

(1) Cofferdam;

(2) Empty tank;

(3) Void space;

(4) Cargo handling space;

Uncontrolled when Printed

Page 9: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 9 of 19

(5) Tank containing a compatible cargo; or

(6) Piping tunnel.

(b) Isolation across a cruciform joint is equivalent to isolation by two barriers.

(c) The containment system for the hazardous material must not have a piping or venting system that

connects to a containment system carrying a cargo with which the hazardous material is incompatible.

Any such piping or venting system must have been separated from the containment system carrying the

incompatible cargo by:

(1) Removing a valve or spool piece and blanking off the exposed pipe ends, or

(2) Installing two spectacle flanges in series with a means of detecting leakage into the pipe

between the spectacle flanges.

For the purpose described above, two valve segregation is not acceptable as two barriers.

Case Study : Clipper Lund explosion, Source: Accident Investigation board Norway.

One crew member killed as a result of an explosion caused due to violent reaction between Aniline and

Nitric acid. Aniline was being transferred from the drip tray to the storage tank through the drain line. Nitric

acid was remaining in the drain valve in the transfer line which reacted with the Aniline to cause an

explosion.

2.7.2. Offset Corrugated Bulkhead

While a cruciform boundary is considered an acceptable double barrier, an “OFFSET CENTRELINE

BULKHEAD” is not considered to provide suitable segregation.

On vessels fitted with offset corrugated centerline bulkhead, care shall be taken to avoid loading

of two non-compatible cargoes in the tanks wherein small section of diagonally opposite tanks is

shared with same bulkhead.

Uncontrolled when Printed

Page 10: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 10 of 19

Below diagram provides necessary guidance.

2.7.3. Segregation from Other Tanks Loaded with Heated Cargoes

Heated cargoes should never be loaded adjacent to cargoes with self-reactivity such as polymerisation,

decomposition, thermal instability, etc. as heat will shorten the life of the stabilizing inhibitor. Heating

accelerates self-reaction and results in a dangerous situation besides deterioration in quality.

It is advisable that stowage of heated cargoes adjacent to tanks containing toxic cargo is avoided

to minimize the possible release of toxic cargo vapour into atmosphere.

Uncontrolled when Printed

Page 11: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 11 of 19

It is also advisable that a cargo requiring heating is not stowed adjacent to cargo tank, which

contain a cargo of low boiling point because the excessive evaporation of the cargo will result in

cargo loss and possible vapour hazard in deck area or main deck.

A difference of 10oC between the boiling point of the non-heated cargo and the maximum

temperature of the heated cargo stowed in an adjacent tank should be sufficient as a safe margin

in planning adjacent stowage. This means; a heated cargo with maximum heating temperature

less than 54.5oC may be stowed adjacent to methanol (boiling point = 64.5

oC) when such stowage

is inevitable.

Maximum permitted heat adjacent should be taken into consideration while stowing cargoes in

adjacent compartments to heat sensitive cargoes where heat may affect the quality of the

cargoes.

While carrying heated cargoes the temperatures of all tanks on the vessel should be monitored to

verify there is NO inadvertent heating taking place in any non heated cargo tank. When heated

Cargoes are carried onboard, all non heated tanks are to be isolated. The ullages of tanks carrying

low density cargoes stowed adjacent to tanks carrying heated cargoes should be recorded daily.

Segregation of Cargoes Reactive With Water

Certain cargoes react violently with water and moisture which causes dangerous conditions on board or

affects the quality of cargoes.

Cargo tanks loaded with such cargoes must be segregated from the tanks loaded with water such

as fresh water (for tank-cleaning purposes) or clean sea water (taken in as heavy weather ballast).

Cargo tanks to be loaded with the cargoes, which react dangerously with water should be

completely cleaned and dried to eliminate any residual water.

The pipelines and other associated fittings also need to be dried accordingly. The heating coils

should be blown dry and blanked. The ballast and deballasting sequence should be planned in

such a manner that at no time is water present in the ballast tanks adjacent to tanks with water

reactive cargoes.

Uncontrolled when Printed

Page 12: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 12 of 19

Note: Refer to Paragraph 15.16.2 of IBC Code for carriage of cargoes reactive with water.

Compatibility and Tank Cargo History

While planning stowage of the cargoes, previous cargo history of the tank should be reviewed. Certain

cargoes especially in coated tanks can adversely affect the quality of the subsequent cargoes. An

example is Methanol cargo loaded after a cargo of Styrene Monomer. In case of edible vegetable oils

certain previous cargoes are not acceptable for stowage, in some cases the previous “acceptable” cargo

has to be loaded to a minimum level after history of an unacceptable cargo. Carriage of high specification

chemicals after carriage of lube oils, vegetable oils or petroleum products may entail extensive cleaning

requirements. In all cases last three cargoes should be declared to the load port through the agents in

order to obtain approval of the tanks prior vessels arrival in port.

Master in the process of planning cargo carriage must refer to the previous cargo to identify the suitability

of the tank for carriage of Edible products as requirements of FOSFA. A list of acceptable and banned

FOSFA cargo is available in the Annex 1 of this manual.

Stowage Plan

The Chief Officer must prepare a stowage plan, which should be approved by the Master. When planning

cargo stowage, the flow charts on the following two pages should be used to systematically review the

various carriage considerations and requirements.

First Stage

Checking suitability of stowing the proposed cargo: This involves checking cargo compatibility with

respect to the ship’s COF, IBC code, adjacent cargoes, cargo history, cargo tank coatings, heat

compatibility, etc.

Second Stage

Checking suitability of carrying the proposed cargo: This involves checking conditions like sloshing,

ambient weather conditions experienced during the voyage. Review of stowage basis various conditions

that may be experienced during the voyage.

It should be noted that the cargoes are listed on the certificate of fitness with their proper shipping names.

If the cargo is listed on the vessel’s certificate of fitness, then the vessel and its equipment is complying

Uncontrolled when Printed

Page 13: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 13 of 19

with IBC requirements for the carriage of the said cargo. However this does not include compatibility with

tank coating. The suitability of carriage of this cargo should be verified against suitability list provided by

the coating manufacturer.

Uncontrolled when Printed

Page 14: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 14 of 19

Uncontrolled when Printed

Page 15: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 15 of 19

2.8. CARGO OPERATION PLAN

Cargo Operation Plan MUST be prepared using OP-CHEM-01(Cargo Operation & Tank cleaning Plan)

prior carrying out cargo transfer operations. Such plan must be discussed with all concerned crew

members for their understanding and compliance and signed by them. Upon vessel’s arrival, if any

changes are noted during ship-shore conference, cargo transfer operation should not be carried out

unless the cargo operation plan has been revised and discussed with the concerned crew members.

Chief Officer is the Cargo officer and is responsible for Cargo planning and preparing the Cargo operation

plan. Cargo Operation Plans should be reviewed, agreed and approved by the Master.

Large deviation from the Builders ‘Trim and Stability’ data should not be practised. While preparing the

Cargo Operation Plan, stress & trim must be calculated for each stage & particular attention must be paid

to limiting drafts.

The Cargo Transfer Operation MUST strictly adhere to the ‘Cargo Operation Plan stage by stage. Any

deviation from the Plan should be informed to the Chief officer and Master. The Chief Officer must be

present in the CCR during Critical stages of the operation. If Chief Officer is unable to be present due to

rest hours or other requirements, Master shall be present in lieu.

Note: Ballasting of cargo tanks adjacent to tanks with Heated cargoes or water reactive cargoes is

prohibited.

2.9. LOADING LIMITATION OF CARGO

Filling Limits for Cargo Thermal Expansion

In calculating the ullage or filling limit to which the tanks are to be loaded, due allowance must be made

for thermal variation during the voyage either from climatic conditions or cargo heating.

Cargo should be loaded in such a manner that at any stage of the voyage the volume in the tank should

be less than 98% of the total capacity of the tank. The loading must be planned to achieve this taking into

consideration the expansion of the cargo due to change in ambient temperature or direct heating of the

cargo or through indirect heating from adjacent tanks.

The cargo tanks can be loaded up to a liquid level corresponding to the maximum filling ratio obtained

from the following formula.

Uncontrolled when Printed

Page 16: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 16 of 19

Max. Filling ratio (% full) = 100 (1 - R x T) - S

where;

R: Coefficient of cubical expansion per oC (see the data sheet)

T: Expected maximum temperature rise (oC)

S: Safety margin, usually 2% of capacity

Caution: "Shore stop" should not normally be accepted when the last cargo tank is to be filled to it’s filling limit.

Filling Limits for Cargo Tank Design Specific Gravity (Dsg)

Design Specific Gravity (DSG) is the design specific gravity of vessel’s tanks and defines the maximum

specific gravity of cargo to be safely loaded to 100% capacity of the tank. However any increase in

specific gravity will require a proportional reduction in quantity such that the weight in the tank does not

exceed the safe design parameters. The DSG is usually given in either the loading manual or in a

certificate issued by the Classification Society. This information should be readily available in the cargo

control room and referred to during planning.

Max. Filling limit can be calculated by the following formula.

Max. Filling ratio (% full) = DSG / SG x 100

Example of calculation

DSG - 1.4

SG = 1.48 (Chloroform)

Then filling ratio is 1.4 / 1.48 x 100 = 94.6%

Filling Limits for Sloshing Strength of Cargo Tank

In general, partial loading between 20% and 80% of filling ratio is prohibited to avoid an excessive

sloshing load in the tank structure.

However, if partial loading is involved in the intended plan, cargoes should be loaded to the extent of safe

loading percentages as determined after referring to the sloshing calculation shown on Vessel's Loading

Uncontrolled when Printed

Page 17: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 17 of 19

Operation Manual. Ships on which the sizes of the tanks are small may have no restriction in loading

quantities.

Greater the SG of the cargo, bigger the effect of sloshing on vessel's structure.

Stability and Stress

In accordance with regulations all vessels are supplied with a Trim and Stability (Loading Manual) Booklet

approved by the Flag administration or the Classification Society, which indicates the various conditions

of loading and ballasting with weight distribution structure resulting in the minimum stress being imposed

on the Hull structure. It also gives ballast distributions for arrival, departure and light ship conditions, and

contains full deadweight, stability, capacity and hydrostatic particulars.

Tankers have a tendency to sag in the fully laden condition, and hog in the light condition. If these

tendencies are further aggravated by the unsatisfactory distribution of cargo, bunkers or ballast,

unnecessary stresses will be put on the structure of the vessel. This effect is cumulative and if made a

regular practice can result in structural failure.

In order to reduce stresses to a minimum, weight distribution for various conditions of loading are detailed

in the manual and verified by computerized approved loading computers.

Where a computerized calculation system is provided on vessel, the system should be checked at least

once every three months against the approved loading conditions. During every cargo operation the

vessel’s actual condition of drafts and trim must be verified visually against the conditions on the loading

computer at least twice.

All tankers must comply with IMO conditions of intact stability through the voyage and during cargo

operations. This should be verified by systemic planning of the cargo operations in port by evaluating

various stages of cargo operation. Records of the monitoring of stability condition should be maintained

on the vessel.

Uncontrolled when Printed

Page 18: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 18 of 19

Damage Stability Criteria

Damage stability calculations assess the survival capability of the vessel in case of damage sustained in

the loaded passage. The damage stability characteristics must be understood and there must be

evidence that the damage stability has been assessed for the loaded voyages.

Some loading computers are incorporated with Damage Stability calculations so these are easier to

assess. Where the damage stability is to be calculated manually, the procedure for this must be clearly

understood. This procedure may involve calculating KG under various conditions of damage given in the

loading manual and comparing this with the maximum allowable KG under the various loading conditions.

Master or Chief Officer as his nominated deputy must carry out calculation for each loaded condition prior

vessel is put to sea. He should also be aware of the worst case scenarios of intact and damage stability.

Stress Monitoring

During cargo / ballast operations, duty officer must monitor and record vessel’s draft, stress and stability

condition regularly and should be recorded in “OP-CHEM-28 - Hourly loading / discharging rate log”. This

data should be compared with the cargo / ballast operation plan, to provide a proactive warning of any

unplanned or unobserved deviations from the plan, so that appropriate corrective action can be taken.

Where an online gauging system is not fitted or in-operational, the duty officer must regularly update the

tank quantities and check stress and stability condition.

The duty officer shall control and supervise all routine aspects of monitoring tanks, pumps and equipment

in use as well as the general ship keeping requirements of moorings, gangway, draught etc.

If the circumstances demand, he may regulate tank valves and pump controls in the planned operation

but under no circumstances shall he depart from the cargo plan without approval from the Chief Officer or

Master.

The duty officer should call the Chief Officer immediately if in doubt, any unforeseen circumstance

becomes apparent or an emergency arises.

In the event of an emergency all operations shall be stopped at once.

Uncontrolled when Printed

Page 19: CHEMICAL TANKER MANUAL - Competencycompetency.synergyship.com/pdf/Chemical_Tanker_Manuals/...CHEMICAL TANKER MANUAL CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1 Date 15-Apr-16 Page

CHEMICAL TANKER MANUAL

CH. 02 CARGO STOWAGE AND PLANNING Rev. No. 1

Date 15-Apr-16

Page Page 19 of 19

The duty officer shall record the events of the operations as they occur in the ‘Port Log’ and maintain

periodic records of all the parameters monitored.

2.10. CARGO QUANTITIES

The cargo quantities are planned by the Master and checked in relation to the voyage orders with regard

to:

Loading capacity (load calculation)

International Load Line Zones in trading area

Expected trim, heel, intact and damage stability

Sheer force and bending moment stresses during the various stages of loading and

discharging

Draft and passage limitations en route, canals and in ports of destination

2.11. CARGO EQUIPMENT DEFECTS:

It is the Master’s responsibility to inform the management office immediately regarding any cargo

equipment defects which might influence cargo stowage. This is to prevent cargo commitments being

made to which cannot be adhered to as a consequence of these defects.

2.12. OIL AND HAZARDOUS MATERIAL TRANSFER PROCEDURE:

Prior to each transferring of oil or hazardous cargo to or from the vessel and from tank to tank within the

vessel the Chief Officer has to prepare and submit to the Master for approval an Oil or Hazardous

Material Transfer Procedure as required by 33 CFR 155.720. The contents of Transfer Procedure should

comply with the requirements detailed in 33 CFR 155.750.

On Company managed vessels the requirements of this section are applicable to all hazardous material

transfer operations irrespective of the ship’s trade area, and are not limited to US waters only.

Uncontrolled when Printed