Not Logged In, Login,

Saturday, October 20, 2018


Last week’s Weekly NEWS No. 5/2001 gave a report on the provisional assessment on the three-day IMO Intersessional meeting on the Conditional Assessment Scheme (CAS). From the number of requests from the members, it is apparent that this issue is of prime interest. Therefore follows a more extensive and comprehensive review of this issue than our usual summary format.


An increasingly number of questions have been raised on the purpose of the Condition Assessment Scheme (CAS) and whether the developments since October 2000 have fulfilled the initial objectives for CAS.

In this respect, in the aftermath of the Erika, the French Government and later the EU Commission singled out one measure, namely the accelerated phase-out of single hull tankers from EU waters at a similar pace as the OPA 90 phase out (for the large tankers).  The EU were fully aware that these proposed measures, if brought to the IMO, would have an enhanced impact on the worldwide tanker fleet, and did this with considerable industry support.

Then came the proposals to IMO from some of the EU Member Governments on an even more accelerated phase-out of single hull tankers. Basically, these proposals would have removed ALL single hull tankers from the market by end of year 2009. This reaction prompted the IMO Secretary-General to call an IMO governed analysis on the feasibility of such proposals. The result of this analysis raised considerable concern as to whether the market could replace tonnage equivalent to 300 VLCCs in the period 2003 and 2004 and another 300 VLCCs up to the end of 2009.

Thirdly was the “troika” intervention (Denmark, The Netherlands and UK) which in a joint effort between governments and industry prudently tried to find a solution that still would phase-out single hull tankers but co-ordinated with an optimal solution to replace tonnage so as not to disrupt the distribution of oil.  The proposal was to keep the 2005 and 2010 as final dates for the phase-out of pre-MARPOL and MARPOL single hull tankers respectively, but that some of these vessels could continue to trade for two (pre-MARPOL) and five (MARPOL) years, on the condition that they pass the so-called Condition Assessment Scheme (CAS) inspection.

Thus CAS was primarily brought as an integral part of the amendments to Regulation 13G with the objective to alleviate the initial proposal for the stringent phase-out scheme which would have created considerable logistical problems.


Since the CAS discussions at MEPC 45 in October 2000, each party has used the opportunity to evaluate and draw up a system which enhance the checking procedure of the tanker structure.  INTERTANKO took the initiative to immediately gather a government/industry group to develop and finalise CAS before end of year 2000. INTERTANKO organised two meetings on 30 October and 5 December drafting a final draft of what it is now seen as CAS together with the “troika” representatives, IACS and other industry groups.

In addition to measures taken to increase the scope of the inspections on tankers, as proposed by the IACS Council, INTERTANKO believe that a number of procedures need to be incorporated. In this respect, INTERTANKO proposed a specific text that would make it easier to audit the final result of the inspection.

Unfortunately, IACS did not agree with INTERTANKO and Governments failed to fully comprehend the benefit of INTERTANKO’s proposal.  As a result, EU Governments chose to use a ‘second opinion’ as the vehicle for checking the veracity of the CAS inspection results. This means that a second class society should check the work done by the initial class society on CAS.   IACS does not agree to this method either.  The best interpretation to the compromise solution on the ‘second opinion’ is that the second class society would only audit the work done by the society which performed CAS.

What is new in CAS?

CAS is still under development and needs to be finalised in the coming weeks so as to be able to present it as a package to MEPC 46 for formal approval as part of the amendments to Regulation 13G.  There are differences of opinion with respect to the CAS result and clarification on some of these points follows:

Criterion for acceptance

The criteria to pass CAS are as laid down in amended IMO Resolution A.744(18).  Then what is new? There are quite a few new issues in CAS that are yet to be implemented in the Guidelines of the Enhanced Survey Programme (A.744). Before nominating these additional measures, one need to understand that CAS is needed as a stand-alone document in the new 13G for clear political reasons. At the same time, it makes sense that the CAS procedures would become the new inspection regime for ALL tankers, not only for single hull tankers. Thus, any measures to enlarge the scope and the extent of the inspection on tankers need to be inserted in A.744 as soon as IMO procedures permit.

What new does CAS bring?

Some critics question as to whether there is much new in CAS as compared with the Enhance Survey Programme (ESP). INTERTANKO does not share this criticism.  Firstly, because the ESP procedures were good enough to have avoided the Erika accident. The cause was the lack of implementation of the ESP rules. Secondly, CAS brings quite few new elements, such as:

Survey Planning

This was also an ESP element but never properly enforced. Therefore there would be no CAS inspection if planning is not performed as requested. INTERTANKO has requested that two standard documents need to be added to CAS: Questionnaire to Owners that would provide the necessary information to Class 6 months before the commencement of the Survey and a standard format for the Survey Planning which should be jointly prepared by Class and Owner. Owners should certify and sign the Survey Planning at latest 3 months before the commencement of the CAS Survey. In addition, the Owner should notify the Administration and Class of the intention to perform CAS on a tanker no later than 12 months before the commencement of the CAS Survey (NB. INTERTANKO will suggest to reduce these time frames for notification, especially the 12 months for practical reasons). The standard format for the Questionnaire to Owners was provided by IACS and it is contained on the draft CAS document. The standard format for the Survey Planning will be developed by IACS and INTERTANKO at a meeting on 12 February.

Thickness measurement firms

The ESP voluntary guidelines on standards of such firms are made mandatory under CAS.  As a result of an INTERTANKO initiative, only firms licensed by Class Societies can be selected to perform thickness measurement. IACS added to this a condition that a surveyor is onboard to credit the work of thickness measurement.

Extent of thickness measurement – within the cargo area:

  • increase from 2 to 3 transverse sections
  • each bottom plate at any survey (ESP called this from the 4th special survey)
  • 30% of the web frames for each wing cargo tank (ESP requires all web frame rings in one wing cargo tank and one web frame ring in each remaining cargo wing tank commencing with the 3rd special survey)
  • 30% of the deck and bottom transverse in each centre cargo tank (ESP requires one deck and bottom transverse in each cargo centre tank commencing with the 3rd special survey)

In addition, there would be thickness measurements of the internal structure in the for and aft peak tanks.


A number of specific procedures are laid down to document the decisions and the work done by at least two surveyors.

Close-up Surveys – again increased extent as compared with the ESP:

  • 30% of the web frames in each wing cargo tank (ESP requires all web frame rings in one wing cargo tank and one web frame ring in each remaining cargo wing tank commencing with the 3rd special survey)
  • 30% of the deck and bottom transverse in each centre cargo tank (ESP requires one deck and bottom transverse in each cargo centre tank commencing with the 3rd special survey)


After CAS Survey is performed and only after all outstanding recommendations and conditions rectified, a CAS Final Report would be submitted to the Flag State. The Flag needs to verify this work (this is the moment where a second opinion is required). Upon its satisfaction, only the Flag Administration could issue a Statement of Compliance which would be attached to the tanker’s IOPP Certificate and a CAS notification is sent to IMO. The Flag Administration cannot delegate the issuance of the Statement of Compliance.

INTERTANKO future activity

The final draft on CAS is now available from IMO. The immediate action from INTERTANKO is to draft together with IACS a standard format for the Survey Planning. INTERTANKO intends that the standard Survey Planning would indicate who would lead the activity on each element of the plan, either the Class or the Owner or both. This would harmonise and thus further improve the preparation of the inspection. INTERTANKO acknowledges that the Owner has the ultimate responsibility for completion of the plan and its submission in due time.

INTERTANKO will also analyse the draft CAS and will make a few suggestions for improvements or corrections. As previously stated, the time requested for notification and submission of different documents seem too long and thus impractical. Secondly, INTERTANKO will suggest that the MEPC Resolution through which these amendments will be approved seeks for recognition of an earlier implementation of CAS than the legal time frame from the IMO. This will allow owners to synchronise the CAS surveys with the due dates for the ESP surveys.

The CAS Survey will apply from 1 January 2005 for pre-MARPOL tankers and 1 January 2010 for MARPOL single hull tankers. Its period of validity will be over 39 months (2 ½ years + 3 months as a interval between a special survey and a intermediate survey under ESP). The pre-MARPOL tankers will basically perform one single CAS before they reach the due date for phase-out. The MARPOL single hull tankers may have to undergo 2 or 3 CAS surveys before they are phased-out. This is another element of CAS as compared with ESP – the inspection regime is more stringent than the current special survey and it will be repeated every 36 or 39 months.

For further information, please contact Dragos Rauta: