Cargo planning guideline for modern chemical tankers
Chemical data sheet means a document, in accordance with the IMO Codes and usually from the manufacturer of the cargo,
(Cargo Information Form) that contains necessary information about the properties of the chemical for its safe
carriage as cargo.
Careful study of such data sheets are essential in cargo planning of various chemical cargo , safe stowage and any segregation requirement etc.
Every chemical tanker must have a Procedure and Arrangements Manual that gives Procedures for compliance with Marpol Annex II when noxious liquid substance cargoes are handled on board.
Every chemical tanker must have a Procedure and Arrangements Manual that gives Procedures for compliance with Marpol Annex II when noxious liquid substance cargoes are handled on board.
The
following sequence outlines a general cycle of operations, and supplementary comments are made
where relevant.
Outlined below some needful guidance for handling various noxious liquids . Should be considered as general guidance only, as there are considerable variation in the design of cargo containment and cargo handling systems. Specific instructions in the form of Critical Operations Checklists should be prepared for individual vessels.
The cargo containment and handling systems have been designed and constructed in accordance with the requirements of the IBC/BCH codes, the SOLAS convention and the MARPOL 73/78 convention to safely transport and handle the chemicals the ship is certified to carry.
Fig: Modern Chemical tanker underway
However, the required levels of safety in cargo-operations can only be achieved if all parts of systems and equipment are maintained in good working order. Similarly, the personnel involved in cargo operations must be fully aware of these instructions, their duties and be thoroughly trained in the correct procedures and handling of the equipment.
Before and during all operations involving the cargo, ballast and bunkering systems, the Master must ensure that the precautions required by the company safety management system and relevant checklists are fully observed. Reference is to be made to the publications listed bottom of this page as well as equipment operating and instruction manuals.
Each vessel, which is certified for the carriage of noxious liquid substances (NLS) in bulk, is provided with a Procedure and Arrangements Manual (P & A Manual). All substances permissible for carriage onboard are listed in this manual and are approved for and on behalf of the flag state government that the vessel is registered under, usually by a Classification Society acting on its behalf.
The purpose of this Manual is to identify the arrangements and equipment to enable compliance with Annex II of MARPOL 73/78 and to identify for the ship’s officers all operational procedures with respect to cargo handling, tank cleaning, slops handling, residue discharging, ballasting and deballasting, which must be strictly followed.
If the vessel has been nominated to load a cargo that is not listed in the P&A Manual, this should be notified to the vessel's operator. They will then liaise with the Class Society to determine whether a note of acceptance or a dispensation is possible for this cargo.
The details of permissible substances for carriage onboard are detailed in an attachment to the `Certificate of Fitness', which is also issued by the flag state and usually delegated to a Classification Society acting on its behalf. The P&A Manual must be updated as necessary to reflect any changes to the vessel’s structure; tank coatings etc and any alterations to the Manual are to be Class approved.
A check list is given below, which might be useful when discussing cargo planning in your ship.
The following reference publications provide useful information while planning cargo:
Related Info:
Voyage planning and related considerations
Prior commencement of a voyage a ship master is by law and in practice ultimately responsible for the correct stowage of the cargo. He must take all parameters such as, but not limited to, the following when deciding on which tanks to use for the stowage of a particular cargo; ....
How to prepare a cargo loading or discharge program ?
For quick reference throughout the cargo operations onboard chemical tanker it is responsibility of ships chief officer to prepare a loading/discharge programme , which is to include, but not be limited to, the following (note additional information can be appended): ....
Main Info pages!
Home page ||| Chemical hazards ||| Cargo planning & Stowage ||| Cargo loading ||| Cargo documents ||| Safe stability ||| Cargo care ||| Preparation for unloading ||| Inert gas systems |||Gas freeing ||| Nitrogen handling ||| Chemical handling Safe practice |||Handling equipments ||| Cargo & Ballast pumps ||| Cargo tanks |||Tank cleaning |||Special cargoes |||Spills emergencies |||Fire protection
Chemicaltankerguide.com is merely an informational site about various aspects of chemical tankers and safety tips that may be particular value to those working in: Chemical Handling, Chemical Storage, Liquefied Chemical Suppliers, Chemical Shipping, Chemical Transportation, Chemical Terminals, Bulk Chemical Services and Chemical Processing. If you are interested in finding out more about chemical tanker guideline please visit IMO official website. For any comment please Contact us
Copyright © 2011 Chemical Tanker Guide.com All rights reserved.
- Preparation for cargo loading
- Inerting/purging
- Loading
- Transport
- Preparation for discharge
- Discharge
- Ballasting
- Tank-cleaning/gas-freeing.
Outlined below some needful guidance for handling various noxious liquids . Should be considered as general guidance only, as there are considerable variation in the design of cargo containment and cargo handling systems. Specific instructions in the form of Critical Operations Checklists should be prepared for individual vessels.
The cargo containment and handling systems have been designed and constructed in accordance with the requirements of the IBC/BCH codes, the SOLAS convention and the MARPOL 73/78 convention to safely transport and handle the chemicals the ship is certified to carry.
Fig: Modern Chemical tanker underway
However, the required levels of safety in cargo-operations can only be achieved if all parts of systems and equipment are maintained in good working order. Similarly, the personnel involved in cargo operations must be fully aware of these instructions, their duties and be thoroughly trained in the correct procedures and handling of the equipment.
Before and during all operations involving the cargo, ballast and bunkering systems, the Master must ensure that the precautions required by the company safety management system and relevant checklists are fully observed. Reference is to be made to the publications listed bottom of this page as well as equipment operating and instruction manuals.
Each vessel, which is certified for the carriage of noxious liquid substances (NLS) in bulk, is provided with a Procedure and Arrangements Manual (P & A Manual). All substances permissible for carriage onboard are listed in this manual and are approved for and on behalf of the flag state government that the vessel is registered under, usually by a Classification Society acting on its behalf.
The purpose of this Manual is to identify the arrangements and equipment to enable compliance with Annex II of MARPOL 73/78 and to identify for the ship’s officers all operational procedures with respect to cargo handling, tank cleaning, slops handling, residue discharging, ballasting and deballasting, which must be strictly followed.
If the vessel has been nominated to load a cargo that is not listed in the P&A Manual, this should be notified to the vessel's operator. They will then liaise with the Class Society to determine whether a note of acceptance or a dispensation is possible for this cargo.
The details of permissible substances for carriage onboard are detailed in an attachment to the `Certificate of Fitness', which is also issued by the flag state and usually delegated to a Classification Society acting on its behalf. The P&A Manual must be updated as necessary to reflect any changes to the vessel’s structure; tank coatings etc and any alterations to the Manual are to be Class approved.
A check list is given below, which might be useful when discussing cargo planning in your ship.
- Load the vessel so that positive trim is ensured during discharge, preferably without filling ballast in cargo tanks, particularly not in port. Try to find out the receiver's desired sequence of discharge. Keep an eye on hogging /sagging!
- Inter-reactive cargoes must not be placed in neighbouring tanks. Piping systems must be separated by double blind flanges to prevent erroneous handling of valves. Check the cargoes for cargo compatibility.
- Toxic cargoes must not be placed in neighbouring tanks with edible products (human or cattle). Separate the piping systems by means of double blind flanges
- Check with the tank coating manufacturer's list of permissible cargoes for coatings in each tank. The
general rules are: Zinc silicate coatings are resistant to strong solvents (aromatics, alcohols, ketones etc).
Zinc silicates are not resistant to caustic soda or alkaline cleaning chemicals.
Epoxy coatings are resistant to petroleum products, caustic soda, vegetable oils, wine, seawater, fatty acids, limited resistance to alcohols and aromatics. Coal tar epoxy is resistant to sea water, crude oil and petroleum products in general but should not be used for jet fuels or light oils as they tend to be contaminated by bleeding tar. - In certain cases the tank coating manufacturer gives a limited acceptance for a product (time and/or temperature). Avoid then placing heated products on the otherside of the bulkhead. Let epoxy weather out properly after solvent cargoes. Do not fill ballast water immediately after methanol in the same tank.
- Polymerizable products (e g styrene, vinyl chloride) should never come in bulkhead contact with heated cargoes. The same refers to drying vegetable oils (e g linseed oil) .
- Volatile products (aromatics, ketones, alcohols etc) should not be put into bulkhead contact with heated cargoes in order to avoid unnecessary evaporation losses.
- The cargo tanks are normally inspected and approved prior to loading. This does not necessarily relieve the vessel of responsibility for contaminations. The master/ owner carries the responsibility in taking due care of the cargo. To protect ones own interest the vessel's own inspections should be recorded in the deck log.
- After cargoes with a strong odour (fish oil, phenol, octanol, tall oil, turpentene, molasses) the tanks should not be used immediately for odoursensitive cargoes such as glycols, ve getable oils,
- After leaded gasoline, cargoes for human or animal consumption must not be loaded as the next cargo, neither "virgin naphta feedstock". Lead compounds may adhere to the bulkheads after several intermediate cargoes even in coated tanks. Wine cargo may dissolve lead remains, which are many intermediate cargoes ''old".
- In case of doubt of purity of cargo to be loaded: take cargo samples also from the loading manifold upon loading and have them sealed and identified for future reference.
- In tanks which have contained products with a high boiling point and/or low water solubility (e g lubrication oils) there will be minute amounts of cargo left after washing. These tanks are then not suitable for a ''sensitive" cargo such as methanol.
- Consult the cargo trim and stability book. There may be restrictions with regard to cargo distribution and stabllity in hypothetical damaged condition.
- When one and the same pipe has to be used for several consecutive products: Start with the lighter products, going on to more viscous ones. The pipe may have to be drained and steamed in between, therefore try to arrange an open loop. The most sensitive cargoes may have to be loaded "over top" through the hatch.
- The needed temperature of the cargo should be kept throughout the loading/discharging operation and during transit.
- Cargo tanks should imply stripped as soon as the liquid is below the level of the heating coils.
- Clear heating guidance should be given to the master. Any ambiguities should be addressed sooner rather than later.
- The cargo plan should incorporate instructions for stripping heated cargo. Adequate trim and temperature of the shipment should be maintained. Shippers should be mindful that heat loss increases as the level of the cargo drops.
- Heat loss is also quickened if the cargo tank is in contact with the ballast in the adjoining ballast tank. Ballasting should be suspended until the stripping is completed, if it is safe to do so.
- Load temperature should always be increased gradually.
- Overheating of the cargo should be withdrawn.
- Cargo should not be stored at a temperature higher than the ship is devised to carry.
- Cargo temperatures should be checked daily at different levels and the temperature record must be maintained.
- Over-reliance on remote temperature reading equipment should be avoided and temperature should be compared with other means to check accuracy.
The following reference publications provide useful information while planning cargo:
- SOLAS (latest consolidated version)
- MARPOL 73/78 (latest consolidated version)
- International Safety Guide for Oil Tankers and Manuals (ISGOTT)
- ICS Chemical Tanker Safety Guide
- Procedure and Arrangements Manual (Approved by Class)
- Certificate of Fitness for the Carriage of Dangerous Chemicals in Bulk
- Certificate of Class (re tank strength for high density cargoes)
- Ship’s “VEC System Operating Manual” (Approved by Class)
- BCH/IBC Code
- CFR 33 Parts 124 to 199
- Guide to Port Entry
- Ship to Ship Transfer Guide (Petroleum)
- Safety in Oil Tankers
- Safety in Chemical Tankers
- IMDG Code
- Supplement to IMDG Code (Including MFAG and Ems)
- SOPEP / SMPEP
- Clean Seas Guide for Oil Tankers
- FOSFA (for Oils, Seeds and Fats)
- Tank Coating Manufacturer’s Compatibility Lists
- Prevention of Oil Spillage through Cargo Pumproom Sea Valves
- CHRIS (Chem Hazardous Response Info Systems) Guide (USCG)
- USCG Chemical Data Guide for Bulk Shipment by Water
- MSDS for particular cargo carried
- Tank Cleaning Guide
Related Info:
Voyage planning and related considerations
Prior commencement of a voyage a ship master is by law and in practice ultimately responsible for the correct stowage of the cargo. He must take all parameters such as, but not limited to, the following when deciding on which tanks to use for the stowage of a particular cargo; ....
How to prepare a cargo loading or discharge program ?
For quick reference throughout the cargo operations onboard chemical tanker it is responsibility of ships chief officer to prepare a loading/discharge programme , which is to include, but not be limited to, the following (note additional information can be appended): ....
Main Info pages!
Home page ||| Chemical hazards ||| Cargo planning & Stowage ||| Cargo loading ||| Cargo documents ||| Safe stability ||| Cargo care ||| Preparation for unloading ||| Inert gas systems |||Gas freeing ||| Nitrogen handling ||| Chemical handling Safe practice |||Handling equipments ||| Cargo & Ballast pumps ||| Cargo tanks |||Tank cleaning |||Special cargoes |||Spills emergencies |||Fire protection
Chemicaltankerguide.com is merely an informational site about various aspects of chemical tankers and safety tips that may be particular value to those working in: Chemical Handling, Chemical Storage, Liquefied Chemical Suppliers, Chemical Shipping, Chemical Transportation, Chemical Terminals, Bulk Chemical Services and Chemical Processing. If you are interested in finding out more about chemical tanker guideline please visit IMO official website. For any comment please Contact us
Copyright © 2011 Chemical Tanker Guide.com All rights reserved.