Saturday, January 1, 2011

CHEMICAL TANKERS, CARGO OPERATIONS -- CAPT AJIT VADAKAYIL




Initial loading plan should supply the following information. The name of the cargo to be loaded. If a proprietary name, such as SHELLSOL, MOBIL STOCK , BRIGHTSTOCK etc is used, it’s chemical/product name must also be identified.

Instructions from charterers regarding quantities, grades and ports must be acknowledged promptly. If the instructions are grossly unacceptable , the sender of the instructions must be informed along with suggested solutions. If serious differences still arise , the operator must be informed for guidance and advise.

Master should forward a copy of his proposed stow to the chemical operator with  info--
Cargo density at 20oC
Correction factor per o/centigrade
Carriage temperature (if any) Min/ Max carriage temperatures(if any)
If Nitrogen is required either to inert the tank(s) before loading or to maintain a blanket during the voyage, then on board Nitrogen stock and intake capacity should be checked and arrangements made to supply any additional requirements.
Draeger tubes should be checked and if necessary ordered- especially if the VP/ TLV ratio is high.
USCG Group.
Marpol category; XYZ or Annex I. (Certain ports like Rotterdam have their own Marpol categories).

The following steps should be carried out ( just a few major items ) :-

Identify the cargo should be identified using the US Coast Guard book.
The relevant MSDS sheet must be read in detail.
Recheck the density and correction factors .
For PRE calculations, the maximum quantity and the maximum anticipated temperatures should be used not the loading temperatures . Any lesser quantities/temperatures will of course require less cubic capacity.
Coating compatibility for the product required to be carried to be checked.
Adjacent bulkheads should be checked for product compatibility.
The required volumetric capacity should be checked against the available capacity in the nominated tanks.
Loading restrictions i.e. deck tank weight loading, high density loading and tank filling limits etc.
Checked for any special requirements, i.e. nitrogen, heating, non-heating, inhibited,
Antidotes required should be checked and replenished if necessary.
Draeger tubes for the product--if applicable. The Drager list should be checked for expiry dates and tubes ordered as required
FOSFA banned list, NIOP banned list.
Back loading should be anticipated. For example. If a cargo is discharged and is being prepared for the next cargo before adjacent tanks are to be discharged, can hot water and/or steam be used for cleaning?
Company policy requires that no tank is loaded to a volume of greater than 98% at any time. For cargoes like wine, take the permission of the chemical operator.

Letter of Protest:

Present Letters of Protest to terminal personnel for following, if applicable:
Slow Loading Rate
Free Water In Cargo
Ship / Shore Figures Discrepancy
Flow Rate Restrictions
Loading / Discharging Connections
Manifold Pressure Restrictions
Delay Due High Back Pressure
ROB After Discharge
Refusal To Sign Vessel’s Cargo Documents
General LOP for any other condition you feel is protecting the owner’s interests. eg. terminal delays, unsafe berth, etc.

If the vessel is encountering a very high back pressure and is only using a small percentage of her pumping power available, a protest should be issued.  A discharge can take several days because of excessive back pressure and the ship may only be able to run cargo pumps at reduced speed
If in your opinion, the ship tanks are rejected at load port in an unfair manner immediately advise the chemical operator by mobile phone who will take immediate steps to give you assistance in cleaning or rectifying the situation. You should if unable to make the phone contact , place the parties concerned on written notice

If terminal does not give the labour to connect hoses, issue a letter of protest before telling ships crew to do so.

During discharge if manifold pressure drops ,increase the pump speed or put more pumps in line.
Protest for discharge restrictions to ship and shore delays must be issued without fail

Proposed load should be entered into the ship’s loadicator for stresses. Any draft restrictions  seasonal loadlines etc. should also be checked. Also check load/ discharge sequence  to avoid list/trim/draft/stress problems and loss of berth time.

Bear in mind--actual density and temperatures may not be supplied until after loading has commenced.

The use of flexible hoses must be minimized, with fixed U/Y pieces used wherever possible. The cargo hose test certificates should be available for perusal.

The handling procedures including the maximum loading or unloading rates must be agreed in writing. Complete and sign the appropriate safety check list, showing the main safety precautions to be taken before and during such operations and also the action to be taken in the event of an emergency .

The Master has a responsibility to check that the terminal has also made proper preparations for the safe operation .

The number of valves to be closed during the topping off period should be reduced to a minimum. Always give the shore min 10 minutes warning of completion of loading.

Chief Officer should be identify the type of pump(s) being used for loading at the pre load  conference and understand and agree emergency shutdown procedures.  Topping up by gravity is the best , or even a centrifugal pump .  A positive displacement pump like reciprocating or screw pump will continue to build up  pressure until the hose bursts.

When connecting flanges, bolts should be cross tightened, to ensure that the flange faces are mated properly.
All connections must be pressure tested to check for any leakages. Leaks can be detected by pressurising the connection with either air or nitrogen and then brushing soapy water around the gasket. The connections must be de-pressurised before adjustments are made to the connections.

The pre-loading meeting should include the following written  information:--

The sequence of transfer operations.
The agreed loading/discharge rate. These rates must not exceed the vessel’s capabilities at any time and loading rates must take into account that the vessel may load through her cargo pumps,
Details of the shore the lines to be used.
Critical stages, ie Topping off rate.
Standby time for topping off
Shore tank changes
Line blowing
Local terminal/port authority regulations ( say fire wire height )
Emergency procedures
Containment procedures
Reporting procedures
Shut down procedures

The cargo discharge / load plan must be signed by all deck crew.The manifold rigging plan and the bar diagram must be made .The ship shore safety checklists, preloading/ discharge, during, after checklists must be familiarized. In USA the cargo transfer procedures must be posted in the approved format. Pre-loading cargo calculations must take into account the shore tank temperatures , so that the SG of cargo at observed temperatures can be calculated.  Take into account if the surveyors calculations are based on ASTM method or by the density correction based on temperature difference.

Ullages, temperatures and water dips of all cargo tanks are to be taken jointly by ship and shore personnel, using closed sampling and gauging equipment and the net quantity of cargo on board calculated:

on completion of loading
before commencing discharge
on completion of discharge if same bottom cargo remains on board
prior to loading if same bottom cargo is already on board from a previous port
prior to and immediately after any transfer of cargo

The net quantity of cargo on board is to be agreed between the ship and terminal representatives:

before disconnecting the last cargo hose on completion of loading
before commencing any cargo discharge

The Chief officer must personally cross check that the ship’s cargo system has been configured properly for the cargo and all plugs and drains have been re-positioned.

A usual problem is lack of clear instructions and information being given to Duty Officers who will be involved with cargo operations. Many chief officers try to keep total control and monopoly of the cargo and ballast operations and the Duty Officer learns very little about cargo and port procedures. And then while appraising the junior officer at the end of his contract he is termed as  “ useless—not to be re-employed ” which is not true. 

As we have bridge team management, the same way we must have cargo team management. Chief officers should delegate the duties in a proper manner to the duty officers whilst still maintaining overall control. This will allow the junior officers to gain knowledge and confidence and prevent the chief officer from getting fatigued.

All Deck Officers and the Pumpman shall commit to memory the arrangements of all cargo , ballast and other piping systems , so that they may deal immediately with any emergency situation .

All valves in the cargo piping systems and ballast systems shall be CLOSED at all times except when they are required to be OPEN for operational reasons.  Valves, which are OPEN, shall be CLOSED as soon as operational requirements permit

Manifold valves must not be OPENED until hoses are connected and must be CLOSED before hoses are disconnected.

Remote valves which cannot be lashed to maintain its status quo shall be temporarily labelled  "DO NOT OPERATE"

No loading / discharging can be done without pre-planning by mans of a bar diagram.

Tank entry tagging system must be there on all ships. HHR board must be filled.

The OOW must be given additionally a load/ dischg plan plus a bar diagram for cargo/ ballast operations.

Before the Chief officer leaves the CCR/ deck for resting he must give clear written instructions in a dedicated cargo order book  to the OOD regarding the continuance of current operations and the time or circumstances when he is to be called. The OOW must be given additionally a load/ dischg plan plus a bar diagram for cargo/ ballast operations.

The OOD shall not depart from the plan without direct instructions from the Chief officer. He shall call him immediately if any emergency arises or any unforeseen circumstance arises.  In an emergency he shall not hesitate to stop all operations if he considers that the circumstances deem such a drastic action.

The OOD shall record the events of the operations as they occur in the LAN electronic log and the cargo log book. Electronic port log fed into the CCR computer is connected by LAN to other ships computers . The cargo loaded/ discharged plus the balance to go plus the ETC must be mentioned every 6 hours.

Manifold drip trays should be regularly cleaned and dried after each cargo operation to remove any spillage which may be incompatible with another chemical  spilled later.

Deck booster pumps are used when discharging homogeneous cargoes, to increase the bulk discharge rate or when discharging viscous cargoes such as molasses. Screw pumps must not be started with the delivery valve shut.
The amount of cargo to be loaded and the type quantity i.e. [ moloo/ molco/ min-max].  In the event of a min/ max cargo, the vessel should endeavor to arrange a shore stop for the product and note it down in the SOF. In other cases, the vessel should endeavor to lift the maximum cargo possible within the percentage options.

Where the ships tanks have to precleaned immediately after dischg the cleaning gear must be rigged before tank dry certificate is issued.

The chemical operator must be advised of any pipeline leaks or bulkhead structure cargo leaks. The condition of tanks including discolouration, residue , scale , sediment must be advised.

TCFW monitoring is Chief officers sole responsibility. Running out of water when ship is outside for tankcleaning in not acceptable. Of for the matter getting a TCFW tank contaminated with salt water. Tank cleaning preparation must include a bar diagram. If cargoes have to be heated steam and fuel requirement must be discussed with Chief engineer.

Do not use the vacuum side of PV valve in auto mode for discharging.

Remote gauging system should be calibrated by means of comparison with reference MMC tape after every loading and before every discharge.

New chemicals evolve almost daily . Ship should be aware of relevant cargo specs , handling procedures and tank cleaning procedures. All doubts must be addressed with the company chemical operator.

If possible load cargoes which require nitrogen blanketing first—so that time is not wasted.

Chemical must be named in all documents exactly as it is described in the bill of lading

In different berths with different  consignees, the new NOR will be when the hoses get disconnected.

In case the agents are authorized to sign the bill of lading—and the figures are unknown—
The final B/L figures should be emailed to the master for his scrutiny and agreement before the B/Ls’ are released.

Request from ship for reducing rates for topping off are not to be mentioned in the SOF but any shore reduction must be mentioned.

To prevent overloading/ underloading the dock water density must be taken before commencement of loading and just before completion

In case of pigging the pigging in quantity must be declared by shore in advance to prevent overflow of last tank

Pumping logs must be endorsed by the loading master or the terminal rep.

Manifold valve must always be opened last. Even if there is a stop of transfer for a few minutes—the manifold valve must always be shut.

Stopping transfer:  Cargo flow while loading must be stopped by shore valves and vice versa while discharging.

Avoid using common collector while handling high MP cargoes like Phenol which may freeze. Otherwise use it every time possible—unless the cargo is incompatible with the ships cargo hose.

Always take off unused spool pieces and blank them —on chemical tankers 2 or 3 valve segregation is not considered effective.

After connection test the spools with 4 kg air and soap solution. After air test make sure the pressure is released. Also the SS nuts and bolts can loosen up after a long voyage due to low friction factor—it is not advisable to grease the butterworth port bolt threads as vibration caused slack nuts/ bolts can cause sea water ingress on ships having low freeboard.

Maintain valve open board in CCR and also a valve reference strip on valve wheel ( a mark which shows if a valve is shut or open ). This is the only way the duty officer’s rounds on deck of a manual tanker with dozens of valves on deck can be termed meaningful. He should be able to see which all valves or drain cocks are open without handling them physically.

Check manifold connection at low initial flow rate— Caution: for solidifying cargoes—do NOT do this low initial rate check, lest the cargo freezes inside.

Do NOT air blow while discharging into submarine terminals--unless you want the submerged hose to rip asunder and your company to come down.

If tank lines and drains have to be opened to be proved dry then the certificate must be endorsed to show this fact.

During the voyage internal transfer of cargo must NEVER be done without charterers approval, unless in imminent and dire emergency. The checklists must be filled up and the ORB must be entered.

Residues from manifold drip trays must be transferred into slop tank , drain tank or retaining container. First ensure that the contents are compatible.

Care should be taken to ensure that cargo vapour does not enter the engine .  Internal combustion engines can over speed and destroy themselves if flammable vapour is present in the air supply, even at concentration well below LFL.
The use of mobile phones and radio pagers is prohibited except within the ships accommodation.

For visitors: Mobile phones and radio pagers should be switched off at gangway and only switched on when inside the ships accommodation. A warning notice to this effect should be posted at ships gangway.

If at any time at sea or in port an oil slick on the sea is sighted in the vicinity of the ship it shall be reported to the Master who shall ensure that the oil slick is not being caused by his ship. The Master shall also record the sighting in the Deck Log Book stating that the oil was not discharged by his ship.The Company shall be advised of this sighting in writing if the slick is major.

At least one copy of each cargo related document, which is signed by ship's personnel, is to be retained on board in the ship's files.

During loading operations, access to the accommodation is to be restricted to one entry point only and this should be agreed prior to the vessel’s arrival at the load port. All other doors and ports should remain closed throughout the loading operation.

To assist accurate assessment of the wind direction, a flag ( or a wind sock ) to be placed on deck in vicinity of the vapour emissions during venting, it should to be illuminated at night. This is not applicable for ships having a repeater of anemometer in CCR.

There shall be no work aloft POISONOUS LOAD PASSAGE carried out other than that directly related to the operational safety or navigation of the vessel and if carried out to be under the control of a hazardous task permit. Recharging of BA cylinders during loading is not to be carried out unless air quality at the compressor inlet vicinity is continuously monitored.

Prior to arrival at the discharge port the vessel must  reduce the cargo tank pressure to the lowest acceptable level in order to reduce the possibility of having to vent tanks whilst at the berth.

Times of High and Low waters must be posted at gangway.  Also minimum depth of water at berth and maximum draught permitted.  Gangway and Deck Watch must be aware of tide times.

Master should ensure that the mooring configuration suits his own vessel and get it rectified after consulting the pilot, especially if the chemical hose connections are rigid chiksan types. Most chemical tankers berth at river ports where there is strong current and tide range.  The tidal information must be available in CCR too.

If the quay fenders do not abut against the vertical shell of the vessel, the ship should be repositioned and the MOT gangway used in a safe manner. Most parcel chemical tankers have ductile steel hull with vertical corrugations of athwarthship bulkheads.  If there is danger of ship is main deck  going below the quay level, it will be necessary to completely reposition the MOT gangway for this period, under personal supervision of OOW and a proper gangway watch maintained for safe access.

When there is strong current and rigid chiksan at manifold, springs must be adjusted only under personal supervision of OOW. It must be remembered that it is not possible to pull the ship against the affects of current and wind. Commonsense dictates that springs which are slack must be tightened.

Main engines must not be tried out with air and fuel at berth, unless the OOW personally checks that the springs are taut and the gangway will not get damaged or become unsafe due to ship’s surge. During this period gangway throughfare must be prohibited, especially if the chemical cargo is harmful for humans and the environment.  As far as possible MOT gangway must be rigged aft of manifold, as close to the living accommodation as possible in a well lit area .  The gangway life buoy at manifold must NOT have the line attached to it.

On chemical tankers people who have no legitimate business must be refused access. The reason is ships security and well as distraction to limited crew on board who are all doing mandatory critical duties.  Master must liaise with agent and terminal to achieve this. The gangway watch must inform OOW if any of the authorized shore persons appear to be inebriated.



CAPT AJIT VADAKAYIL ( 28 YEARS IN COMMAND )

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