Sunday, December 9, 2012

SEGREGATED BALLAST AND BALLAST EXCHANGE ON CHEMICAL TANKERS- CAPT AJIT VADAKAYIL




SBT ,  BALLAST WATER MANAGEMENT , SHEAR FORCES AND BENDING MOMENTS - CAPT AJIT VADAKAYIL

Ballast water is used in tankers to increase the draft and thus the seaworthiness and stability. It also equalises stresses on the hull, and improves manoeuvrability and fuel economy.

Some ballast plans have the additional objective of reducing vibration underway.  Vibrations of the PV stack can cause the Nitrogen blanket to escape.

To minimise hull stresses, ballast tanks should be filled in the order indicated by the ship’s ballast plan, and in proper coordination with the discharge/ load bar diagrams.


Normal ballast plans produce a trim of between one and three meters by the stern.  Careful attention to the trim of the ship can add as much as 0.5 knot to the voyage speed.  A good trim is essential for good draining while tank washing.  

The master is responsible for selecting a ballast plan for a safe and economic passage, keeping in mind the seasonal weather. Slamming must be avoided and also ME rpm fluctuation ( and over speed trip )  due to airborne propeller.

Before ballasting/ deballasting check the air pipes to ensure free venting. These vents must be checked immediately after starting the operation to double check that the tanks are venting freely.

Whenever possible the initial filling of ballast tanks should be by running in ballast from the sea by gravity .

In general segregated ballast tanks are to be filled to one hundred percent (100%) full. Avoid overflowing the tanks. This can be achieved easily if 2 sets of tanks are ballasted together with off set soundings.

When segregated ballast has to taken  in muddy rivers ,or  polluted waters the ballast should, where practicable, be changed for clean sea water as soon as possible. 

This is to —
Prevent accumulation of mud in DB tanks which are difficult to clean, they also choke the draining holes , thus increasing the ballast ROB.  Most chemical charterers calculate the deadweight of the ship ,when the ship is constrained by draft restrictions or has to load to the loadline marks..

Achieve  the full efficiency of cathodic protection systems in tanks which rely on this method of corrosion protection

SBT ballast shall not be discharged into the sea without first checking the contents using the sampling ports. The sampling hole should be a single screw type . Port State Control will not accept a sampling port where 4 nuts and bolts have to be removed with spanner.  Use your sense of smell too.

If oil pollution of segregated ballast is found the discharge should only proceed when all appropriate precautions have been taken to ensure that no oil is discharged overboard.
Deballasting at loadport must commence immediately on berthing. Do not wait for surveyor to finish his rounds.

When ballasting/ deballasting is done bleeding off from Framo juice, make sure the cargo work is not affected by such diversion.

Ballasting ( SBT ) deballasting times must NOT be entered in the SOF.

No ballast tank must be entered unless the valve is lashed and a sign put---“ Do not open , men inside ”

Unlike oil tankers where the cargo ingress floats on top of sea water ballast, on parcel chemical tankers the cargo could be insoluble but heavier or fully soluble and invisible or partly soluble etc .

The sounding book on chemical tankers must have a column for pH value.

Unlike other types of ships , there are several small SBT ballast tanks on chemical tankers—please remember—the empty refill method is tedious.  

As for the flow through method—bear in mind-- if the cargo is water reactive or  having high MP  ( cold interface ) or if tank preparation is going on elsewhere on ship astern , or riming takes place on deck in freezing weather with heated cargoes underneath, this effort may not be worth it.  You may have to choose the lesser of the two evils.

The arrival SBT ballast shall be the minimum compatible with safe manoeuvring, the bow thruster must be fully  submerged.

Modern chemical tankers have SBT tanks with overflow orifices ( with valves ) on ship side plating about 60 cms below the main deck plating.  This prevents danger of tank rupture when overflowing the ballast.


BALLAST WATER MANAGEMENT


Ballast water log must be maintained in the highest California format on our chemical tankers.

Chief Officer is the ships Ballast Management Officer.

He is responsible for making out the Ballast water exchange plan , maintaining the BWM log and ensuring the ship’s BWMP is ship specific.

Ballast water exchange is mandatory since Feb 2004 in most countries.

The ballast water exchange form must be sent to the proper authority prior entering the territorial waters in the proper format—in USA the format is electronic and checking is automatic. If the form is not filled the right way, it will be returned by the shore computer.

The rules regarding depth of sea and distance away from land for exchange varies from country to country, check the BWMP and if in doubt ask the agent.

Canada and California USA has stringent rules with 200 miles / 2000 metres.  In California the reporting has to be done to USCG as well as SLC.  Some other countries have 50 miles / 200 metres.  

Better check with the local agents well in advance-- be careful--fines are heavy.  

More countries are jumping into the Ballast exchange bandwagon--like ROPME.


Any change in the status of tanks after the first report must be followed up by an amended report prior arrival port. Failure to comply can result in huge fines—especially in USA, Australia, Brazil, Canada , Europe etc.

All officers shall read the Company ballast water management plan and also the class approved ballast water management plan which is ship specific and contains the pumping plan.

The entire crew shall read and understand the various BWM posters stuck in the alleyways.

Samples may be drawn from the approved sampling points and tested ashore for salinity, micro-organisms etc –to verify that the exchange is indeed done.

Training records with signatures must be filed in the BWM plan. The training record shall have the following columns—
Date/ Name/ Rank/ Sign/ Verified by/ Status ( on board / signed off )

No deballasting shall be done at port unless the BW exchange plan has been acknowledged by the ballast water authority.

Ballast exchange can be done by –

1) Sequential method or Empty-Refill: Empty and refill tanks. The SF/BM of the ship shall be recorded by the Chief officer .  Undue list and slamming must be avoided for safety of life/ ship.  This procedure is a weather permitting procedure.  If weather does not allow safe exchange the parameters for distance / depth are reduced . This information must be obtained from the relevant source.

2) Flow through method: Overflow tanks using the approved means, without structural damage. Minimum 3 times exchange is required . The capacity of the pump and the volume of the tank must be considered.

3) Treatment with Sodium Hypochlorite or Alternate Method —100 gms / ton or Calcium Hypochlorite 14 gms/ ton. Usually done in rivers of Argentine compulsorily—even if exchange has been done at sea.

Ballast tanks having excessive mud must be cleaned out in the ocean.

Rinse anchors and anchor chains prior entering sensitive ports.

The BW log is different from the ship’s sounding book.

The BW log must have the following essential information:
Separate page for each and every Ballast tank—a running page with information for last 2 years.
Name of ship/  Flag/  IMO number/  Ballast tank number/  Ballast tank capacity on the header.
The columns are—
Start and End point date
Start and End point time
Start and End point Location Lat/ Long ( make sure it is allowable distance )
Volume 
Operation of pump Ballast or Deballast ( Load/  Discharge/  Internal transfer )
Exchange method –Empty-Refill or Flow-through
Temperature of sea water in Celsius.
Specific Gravity of ballast water in tank – NOT outside sea-water.
Sea Depth ( make sure it is more than allowable depth )
Signature of Chief Officer
Remarks— a) >300% flow through
                  b) Internal transfer to correct list.

Each ballast movement must be in a separate line.

The BW exchange form submitted in written or electronic form must have all the relevant columns filled like
Date
Port of Arrival
Agents name
Total number of ballast tanks
Capacity
Quantity of Ballast on board
The number and identity of tanks to deballast
If any alternate method is used like treatment/ filtration.
History of Ballast water source
History of BW exchange
History of Ballast water to discharge---wrt ---Tanks/  Date/  Posn of ship/  Volume/  Temp/  Method /  Sea depth/  SG / % exchanged


The ships Ballast water management plan shall include the following contents—

International, Federal and state ( California )regulations
Discussion on how the ship will comply with the law
Vessels ballast schematics including location of sampling points
Indicate location of BW posters
Training log
Familiarisation contents—pumping plan/  sounding and air pipe plan/  flow through release/  safety precautions/  recording of soundings and stresses.


Safety precautions:
No over pressurisation / Vacuum in tanks
Free surface effect
Riming precautions and cold weather precautions
Stability
Shear forces and bending movements
Torsional forces
Min/ Max drafts ford and aft
Wave induced hull vibrations
Contingency procedures for pump failure , loss of power
Time taken to complete the job
Continious  monitoring.
Understanding when ballast exchange should not be done—for ship safety.


The ship is not required to deviate from or delay its voyage in order to comply with the above requirements and should not be required to carry out ballast water exchange if it would threaten the stability or safety of the ship or its crew.

Weather conditions should be such, that in the Master's judgement, the ballast exchange can be safely accomplished without adverse effects of vibrations or sloshing. 


In the event of actual or anticipated heavy weather, it may be necessary to alter course, reduce speed and/or heave-to, in order to avoid these conditions, if the timing of ballast exchange operations cannot be changed.


-------CAPT AJIT VADAKAYIL
29 YEARS IN COMMAND

21 comments:

  1. Hi Capt, I recently got introduced to ur blog by a friend of mine. Since then no turning back on them. Some articles evoke a sense of déjà vu whilst others r truly fascinating. Would appreciate if you could spare some thoughts on relationship between knights Templars and the Rothschilds although I suspect that there's a strong one.....keep going ....

    ReplyDelete
    Replies
    1. hi sar,

      punch into google search-

      EVERY BREATH YOU TAKE , I'LL BE WATCHING YOU- VADAKAYIL

      capt ajit vadakayil
      ..

      Delete
    2. Thanks Capt.

      Could you please share your thoughts on 'Nine Unknown Men' - a group created by Mauryan Emperor Ashoka?

      Delete
    3. hi suneil,

      When Alexander the Great followed Greeks Pythogaras , Plato etc and came to India it was clear that soon foreigners would come to India to steal our precious Vedic books on science , astronomy, metallurgy, advanced stealth vimana technology, vedic maths, medicine, surgery, philosopy etc.

      When Chandra Gupta Maurya ( grandfather of Emperor Ashoka ) was about to renounce his throne , become a monk and starve himself to death , he entrusted the job of safeguarding some of these books in his charge to a few trusted men.

      1000 years ago a Pope Gerbert Sylvester II came to India and was able to access some of the amazing knowledge in these books.

      It must be known that Jesus Christ was in Kerala to awaken and raise his Kundalini, 2000 years before –

      --and 3000 before some of this Vedic knowledge was with King Solomon of Jerusalem.

      Knowing that Pope Sylvester was so far ahead of his time, and his trip to India , a novelist wrote a book “ NINE UNKNOWN MEN”.

      The power of the atom ( Rutherford ) , the fact that energy and matter is inter convertible ( Einstein ) , modern EMPs and scalar interferometry howitzers ( NikolaTesla) , speed of light, diameters of 9 planets and distances from earth , modern quantum physics double slit experiment’s observer etc -- is all in there our ancient 7000 year old texts.

      You may get a glimpse of what I mean by punching into Google search

      THE FLIGHT OF THE VEDIC VIMANA- VADAKAYIL

      capt ajit vadakayil
      ..

      Delete
  2. Ajit sir,
    Kindly post a blog with your opinion on music composer AR Rahman and his music.

    ReplyDelete
    Replies
    1. hi jagan,

      punch into google search--
      WHERE YOUR HEART LIES - VADAKAYIL

      capt ajit vadakayil
      ..

      Delete
  3. Dear Capt.,

    if possible can u have reader's comment column highlighted which facilitates on latest comments on topics posted earlier.

    Sheela

    ReplyDelete
    Replies
    1. hi sheela,

      sometimes my readers ask me for my advise on VERY sensitive personal matters.

      after i finish the exchange -- i delete the comments.

      my wife sometimes asks me SINCE WHEN HAVE YOU BECOME AGONY AUNT?

      capt ajit vadakayil
      ..

      Delete
  4. Hi Sir,

    Can you throw light on 2002 Riots in Gujarat. and what was Modi's Role actually.?
    I believe it was a Tit for Tat to the Godra.. But still Modi and his role,and what are the consequences which led the riots is still a mess to me.

    and Sir with ur permission i would like to know who is the most beautiful lady you have ever seen till date? (ab yeh math bolna ki aap ki Dharam Patni ji hain.. Unke alawa..)

    Thank You

    ReplyDelete
    Replies
    1. hi mahai,

      some muslim terrorists locked the doors of the railway compartment of hindu karsevaks (who had gone to babri masjid at ayodhya) --sprayed kerosene via the windows , and set the compartment on fire , roasting alive 25 WOMEN, 15 UNDERAGE CHILDREN and 18 men.

      and hindu hating sonia gandhi and her pseudo hindu stooges put a committee who did sham investigations and called it an accidental fire.

      the riots were a reaction-- a backlash.

      hindus have been tolerant in their entire past history--

      even tolerance has a limit--

      where is the bravery in killing women and children?

      if modi has a role -- why has sonia gandhi's stooges been unable to pin him?

      beauty has NO yard stick. i may find a woman beautiful today, but after 3 years i may not give her a second glance.

      a beautiful woman will have long hair, large eyes, full mouth ( cannot be a thin lipped one like anushka sharma ) , slender arms , wide hipbones, not too white complexion ( blue veins on legs is UGGGHHHH for me ) , cannot be a MANchester--

      -- and she should blush and yawn as soon as she sees me.

      why yawn?

      is she bored ?

      punch into google search BODY LANGUAGE SECRETS -- VADAKAYIL

      capt ajit vadakayil
      ..

      Delete
  5. hello sir

    another great article

    there was a theory told to us during re validation, that the marine organisms were compared to a human being and proved that---though they are harmless in their natural environment, when exposed to a foreign environment the same organisms turns destructive.
    i could not find this theory on the net do you have any information about it.

    2)does the drip tray segregation (partitions) affect the load plan

    kind regards

    ReplyDelete
    Replies
    1. hi bhoj,

      AAA ) dont believe these re-validation gurus too much.

      most of them are unfit at sea--and in the class room.

      for example when i did my re-validation the SBT lecturer , a proper ex-chief engineer was goin' on and on about FILTER FEEDING FISH, how they feed on the sea suction filters etc.

      then i had to stop him and tell him that this FILTER belongs to the fish's body and NOT on the ship's hull.

      this relates more to RED TIDE where shell fishes ( mollusca ) entrap toxins in their gill filters .

      for example a lot of US marines died in the strait of magellan as they had a barbecue with such fish.

      even in kerala in extreme summer we in kerala do NOT eat shell fish-- as when sea water has the right temperature the algae or phythoplanktons , over blooms and toxins get entrapped in the gills ( filter )of shell fish.

      you can read about RED TIDE in wikipedia.

      i had one ex-master ( senior one ) giving bull about ship's SQUAT-- till i got up and told him that squat is related to UKC, and not what he is alluding to.


      or a VERY senior ex-master giving bull about ship's having collison in open sea due to magnetic effect of ship's hull. i got up and told him that this is NOT possible-- unless you are dreaming.

      after 5 years he was giving the same bull, when i went for my next re-validation. this time i went to the dean and told him -- if the re-validation is NOT a money making racket--please -- have proper teachers-- or atleast techers who are willing to be corrected from sailors who know better.

      BBB) yes-- for example , as you can see sulphuric acid is reactive with almost everything -- so on parcel tankers we do NOT allow non-compatible chemical contact even inside the manifold drip tray.

      a mixture of sulphuric acid and salt water entrapped in a pipeline can make a hole in the pipeline ( weld seams ) within 48 hours.

      this is the reason why annex 2 overboards on sulphuric acid carriers usually get holes on the length between the UW overboard and the level of the sea surface.

      it should be possible to blank this length from the inboard part of the annex 2 overboard--for on board repairs.

      capt ajit vadakayil
      ..


      Delete
  6. Thank you very much sir

    Your articles and comments are always interesting

    i wish you and your family a very happy new year

    ReplyDelete
    Replies
    1. reciprocated in full measure, bhoj!

      thanks.

      capt ajit vadakayil
      ..

      Delete
  7. kindly can you post a blog on chemical cargo planning with multiple parcels.

    Thanks,
    Haris

    ReplyDelete
  8. i could not find this theory on the net do you have any information about it.Ballast water management plan

    ReplyDelete
  9. Your blog is really very interesting. I am totally impressed with this. So keep posting.horse feeders. I found your blog web site on google and check just a few of your early posts. Continue to keep up the excellent operate.

    ReplyDelete
  10. Dear Capt Ajit Sir,

    My wife keeps getting bad dreams...and she wants to know why ?

    RN Murthy

    ReplyDelete
    Replies
    1. hi rm,

      tell her to do pranayama and walk 5 km daily.

      capt ajit vadakayil
      ..

      Delete