Sunday, December 12, 2010

JETTISON OF CARGO, CHEMICAL TANKERS-- CAPT AJIT VADAKAYIL

                              JETTISON


Order for jettison can be given by Master only. A risk assessment must be done as per company SMS.

###################

This risk assessment must be done on a safety matrix of SEVERITY versus PERIOD OF IMPACT/ CERTAINTY-- not the corny security matrix format chosen by your company.  (At sea you are ruled by pretenders -- who pretend to have invented the chemical Periodic tables).

DEFINITIONS: 

Period of impact: 
-- when you stub your toe , you get excrutiating pain and you are may sit on a wheel chair for 3 seconds -- which you dont mind.
-- when you break your spine you are confined to wheel chair for life-- which you do mind, though the severity of pain is NOT like the toe stub.

Certainty:
--  if you step off the top floor of empire state building you will certainly 100% die.
--  if you step off the bridge wings , you may survive.

################### 

Jettison of cargo is an extreme measure, when all all solutions are impossible.  

Jettisoning cargo is to be taken when it is the ONLY means to save life, prevent personal injury or to prevent an even greater loss of cargo due to the ship breaking up.

If it is necessary to jettison cargo in the foregoing circumstances, whenever possible, the Master must notify local authorities of the intention to jettison and explain the likely consequences of failure to jettison.

Such notification is not a request for permission to jettison.  This is Master’s decision as the man on the spot.

If an emergency dictates the jettisoning of cargo it is essential that full information is entered in the Master's Official Log Book and the Deck Oil Record Book. Particulars to be recorded include the following:

-grades of cargo quantities
-ullages and temperatures in tanks before and after jettisoning
-leaks from tanks before and after jettisoning
-cargo valve settings
-time required to jettison
-draft before and after jettisoning
-position of ship
-all other pertinent information.

Jettisoning of cargo must be reported to the nearest coastal state authority.

There are cargoes like Acrylic acid or Propelene Oxide ( violent polymerization ) which may have to be jettisoned for safety of LIFE at sea.

Jettison must be done in concurrence with the Chemical operator , unless an explosion is imminent and time does not permit.

Engine room personnel should be alerted. Consideration should be given to changing over engine room intakes from high to low level and  to opposite side of ship.

All non-essential intakes should be closed.   Set up water spray curtains with fire hoses , if relevant.

Not to be done underwater—but discharge from manifold with cargo hose set out as much as possible and as close to water level.

Engine sea suction must be from opposite side.

Make sure wind is from aft and go astern

All safety precautions , which involve the presence of flammable/toxic gas in the vicinity of the deck, must be observed. Keep SCBA bottles, EEBD, Oxygen resuscitators in readiness.

A GMDSS  warning should be broadcast.

Crew involved must wear PPE.

Potential sources for ignition must be verified.

Every year one “jettison” emergency drill shall be reported to OOPS as a ‘QI Notification’, on Chemical tankers.


A SAMPLE PROCEDURE:--

ACRYLIC ACID JETTISON PROCEDURE

A:     Should the Cargo Temperature rise to 34C, inform the chemical operator.
Begin checking the temperature every 30 minutes. Plot on graph paper. Notify Goodwood.
If adjacent tanks or any tanks in vicinity are being heated stop heating these tanks. If adjacent tanks are empty fill those with ballast if possible, provided sea water temperature is between 18-30C.
Line up for circulation either through existing drop line or rig portable hoses.
B.      Should the cargo temperature rise to 41C.
Begin circulation of the cargo.
Continue temperature monitoring.
C.     Should the cargo temperature rise to 45C.
Prepare to pump cargo overboard.
Add cold fresh water to tank as void space permits. Continue circulation. Continue adding fresh water until tank is full, as fresh water supply permits. Closely monitor temperature.
NOTE: SALT WATER WILL NOT DISSOLVE POLYMER MAKING PUMPING MORE DIFFICULT.
D.     Finally at 49C do not wait – Jettison—
 DO IT !-  IF YOU WIMP OUT, YOU LOSE LIFE YOU WERE ENTRUSTED WITH!!
Begin pumping cargo overboard.
Continue adding fresh water while cargo is being discharged overboard, as FW supply permits.
When tank is empty start cleaning with cold water and continue cleaning until tank is clean.



No.
Action
1
Master informed ( the order for jettisoning may be given by 
the Master only in extreme emergency when all other 
solutions are impossible )
2
Ascertain the cargo quantity and identity of tanks that 
has to be jettisoned
3
Read the MSDS sheets of cargo involved
4
Fill up the risk assessment form
5
Work out the resultant list and change of trim
6
Work out the corrective measures like internal cargo, bunker 
transfer or ballast
7
Notify local authority/ port state authorities ( territorial 
waters / EEZ ) about the intention to jettison and the 
likely grave consequences to life of NOT doing so.
8
For reporting procedures, contacts with shore 
authorities and chemical operator.
9
Display light or shapes according to COLREG 72 as 
amended
10
Inform the Engineer officer in charge of the watch
11
Fix ship position before commencing the operation and 
note the time
12
Ascertain the wind, tide, current, sea and weather forecast
13
Check the proximity of shore land, heritage reefs etc
14
Warn ships in vicinity on VHF channel and broadcast 
URGENCY by GMDSS
15
Keep continuous watch on channel 16 VHF
16
ER to change over intake from high to low on opposite side
17
Shut off all non-essential intakes
18
Close all accommodation doors and ports and all ventilation 
(other than closed-cycle recirculation)
19
Set up fire hoses in order to create a water fog curtain in 
the vicinity of jettisoning point to dissipate and prevent 
the return of vapours toward the ship
20
Fire fighting system operational and fire station manned
21
Appropriate EEBD, SCBA sets,filtersand resuscitation 
equipment ready
22
Personnel involved in the operations wear protective 
equipment
23
Potential sources of ignition are identified and isolated
24
The ship should keep the wind speed from astern or 
move astern so that the superstructure and afterdecks 
remain clear of the cargo vapour
25
The cargo hoses are to be lowered to the sea level as 
close as possible and properly rigged
26
The manifold not connected to the cargo hoses used 
for the jettison must be blanked and fully bolted
27
Make entries in OLB and cargo record book
28
Inform P@I club

-------CAPT AJIT VADAKAYIL ( 28 YEARS IN COMMAND )



No comments:

Post a Comment