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
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 ....
ReplyDeletehi sar,
Deletepunch into google search-
EVERY BREATH YOU TAKE , I'LL BE WATCHING YOU- VADAKAYIL
capt ajit vadakayil
..
Thanks Capt.
DeleteCould you please share your thoughts on 'Nine Unknown Men' - a group created by Mauryan Emperor Ashoka?
hi suneil,
DeleteWhen 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
..
Ajit sir,
ReplyDeleteKindly post a blog with your opinion on music composer AR Rahman and his music.
hi jagan,
Deletepunch into google search--
WHERE YOUR HEART LIES - VADAKAYIL
capt ajit vadakayil
..
Dear Capt.,
ReplyDeleteif possible can u have reader's comment column highlighted which facilitates on latest comments on topics posted earlier.
Sheela
hi sheela,
Deletesometimes 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
..
Hi Sir,
ReplyDeleteCan 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
hi mahai,
Deletesome 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
..
Thank U sir.
ReplyDeletehello sir
ReplyDeleteanother 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
hi bhoj,
DeleteAAA ) 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
..
Thank you very much sir
ReplyDeleteYour articles and comments are always interesting
i wish you and your family a very happy new year
reciprocated in full measure, bhoj!
Deletethanks.
capt ajit vadakayil
..
kindly can you post a blog on chemical cargo planning with multiple parcels.
ReplyDeleteThanks,
Haris
hi haris,
Deletemy next post
capt ajit vadakayil
..
i could not find this theory on the net do you have any information about it.Ballast water management plan
ReplyDeleteYour 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.
ReplyDeleteDear Capt Ajit Sir,
ReplyDeleteMy wife keeps getting bad dreams...and she wants to know why ?
RN Murthy
hi rm,
Deletetell her to do pranayama and walk 5 km daily.
capt ajit vadakayil
..
Sir, please dont stop blogging ... what you are doing is not only for those living now .. but also for those who arent born yet ... for their sake .. pls do not stop blogging .. one your queation about comparison between you and vivekananda .. its no comparison .. your contribution is like the mighty amazon whereas vivekanandas is like a small poodle of water ... additionally wanted to thank you in your explanation of vanaprqsta and sanyasa stages .. would be grateful if you could also describe how should one go about vanaprasta stagge .. how can onr devide which ashram to join .. considering many are not really hindu ashrams .. could you describe this as well 🙏
ReplyDelete