ISO/TC 67/SC 7/WG 7 Site Specific Assessment of MOU’s

Editing / Review Panel

Report on Meeting of30th September - 3rd October 2008

30thSeptember - 2nd Octoberat Transocean, 4 Greenway Plaza, Houston, Texas

3rd Octoberat ABS, 16855 Northchase Drive, Greenspoint, Houston, Texas

Meeting Report by Mike Hoyle

Background and Attendance

The meeting was scheduled during the previous meeting of24th - 27thJune, 2008.

The attendeescomprised:

Rev 0 - 22nd October 2008Page 1 of 22

Mike Hoyle (Convenor, UK)

Dave Lewis (USA)

Andrea Mangiavacchi (USA)

John Stiff (USA)

Doug Stock (USA)

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ISO/TC 67/SC 7/WG 7 Editing/Review Panel. Report on meeting of 30th Sept -3rd Oct 2008

Objectives / Agenda

Per the forward plan from the previous meeting & calling notice of 29thAugust 2008:

1.Minutes of last meeting.

2. Information Exchange.

3.Status/close-out of action items from last meeting, not otherwise addressed.

4.Carry forwards from June meeting:

  • Add an Annex containing draft contents list for a site assessment report.
  • Check list in 6.5 against other sections.
  • Actions are required for 8.8.5 / A.8.8.5, 9.3.2, 9.3.6, Figure A.10.4.2, DAF definitions.
  • The load factor for, and calibration of, load levels for one-shot analyses requires further debate.
  • The use of resistance / capacity & MSL v/s MWL (or were these resolved? ).
  • Insert effective length charts provided by Andrea from 19902 in A.12.4 (if not already done by Mike).

5.Address any new inputs from the Panels.

6.Issues from Phase 1 benchmarking.

7.Continuation of formal A-Z ISO-speak editing.

8.Confirmation of actions.

9.Forward plan for the next stages of editing.

Meeting Report

Note: The minutes are in Agenda order. The running order differed.

  1. Minutes of last meeting
  2. There were no comments on the minutes of the last meeting.
  3. Information exchange, etc:
  4. Mike advised that, at the previous week's SC7 meeting, he had been requested to nominate a WG7 member of WG1, which has been reconstituted with Canadian Convenor and secretariat, to address the updating of 19900. It is understood that WG1 meetings will typically occur just prior to SC7 meetings. After some discussion it was suggest the Mike and/or Alan Spackman be nominated. To be discussed at WG7.
  5. Mike also advised that SC7 has requested information as to how 19905-3 will be developed. As the document is not expected to be extensive, drawing significantly on 19901-7 (and perhaps 19904-1), it is likely that the topic can be addressed by a new Panel.
  6. The exclusions to coverage of jack-ups in 19901-6 (Marine Operations) were also reviewed/discussed and it was concluded that there are no real worries arising.
  7. John's amusing and enlighteningcirculation of the NOAA"cartoon"re Tidal levels was noted - and the key thoughts were later borrowed/embodied in the 19905-1 text re MHWS and MLWS.
  8. The effects of hurricane Ike on offshore structures was discussed; 3 jack-ups lost/off location, on floater missing a total of some 50+ structures severely damaged. It was noted that the storm had generated larger waves that had previously been predicted in the western area. API RP2 INT MET will need to be updated.
  9. John advised that he had been unable to spend the time he had intended on Clause 12.
  10. Dave advised that he had been unable to complete his Clause 12 action wrt column curves for HSS.
  11. Mike advised that progress had been made on the recommendations for the kinematics reduction factors. The executive summary is complete, the report requires a certain amount of updating in other areas.
  12. Status of action items last meeting, not otherwise addressed:
  13. Project funding (previous 3.1):
    Doug advised that his proposal for testing of the seismic text is in still hand and will be submitted to Rupert soon. Action: Doug
  14. Issues re ISO CS (previous 3.2)
    Mike has yet again failed to discuss with ISO CS the presentation of symbols by Clause (the method used by other documents for the bibliography appears to meet our needs without change). Andrea had previously advised him to contact Stephen Kennedy. (In Beijing we were advised that his boss Alain Samne has recently been replacedby Trevor Vyze, ex BSI). Action: Mike
  15. Review, and aim to resolve, inputs from the initial Clause 12 benchmarking (Previous3.5).

Annex A of the Noble Denton report contains comments on the Clause 12 text. Some actions have been handled by Panel, ERP or Mike. The remaining topics are in progress or have been tasked (largely to PAFA). John advised that will be chasing up on non-funded actions from the May meeting. Action: John

3.4.November meeting actions (Previous 3.6):

Actions from November - carried forward to April then June.

The action to switch the usage of F and Q to F=action & Q=capacity remains with P4 who had tasked Guy Houlsby/Mark Cassidy. Given the substantive changes to 9A.9 arising from SAGE inputs considered at the June meeting, they had been supplied with the latest text.

Mike advised that he had recently received inputs to A.9 from Mark Cassidy just prior to the meeting. An initial review indicated that they were based on an old version of the document. Mike agreed to look their inclusion overnight. His review indicated that the implementation into the latest draft is not straight-forward, and so an e-mail requesting a fresh attempt was drafted and sent. This provoked some further correspondence from Mark's co-author Guy Houlsby. Action: Patrick

3.5.Actions from April meeting c/f to June , October:

April Item 4:Confirm changes from last meeting [& more … ].

The required P4 input to A.11.3.1 is presently a place-holder and is still required.
Action: Patrick/P4

The action on P4 and P3 to address the torsional stiffness of the foundation and equivalent leg models has not been completed. Action: Pao-Lin/P3 & Patrick/P4

Item 5Address any initial issues arising from Stage 1 benchmarking.

John advised that his action to make the ABS jack-up primer more widely availableis in hand, but that it will take time before it can be progressed. Action: John

3.6.Actions from June meeting (not addressed elsewhere):

Item 7: Mat units. John advised that he has yet to progress his draft text for either an Annex or a TR addressing mat units. Action: John

  1. Carry forwards from June meeting:
  2. Add an Annex containing draft contents list for a site assessment report.

Doug and John prepared a first-pass draft for future enhancement.

4.2.Check list in 6.5 against other sections.

The meeting decided that this action has been completed as a by-product of other activities.

4.3.Actions are required for 8.8.5 / A.8.8.5, 9.3.2, 9.3.6, Figure A.10.4.2, DAF definitions.

The meeting considered and updated the subject clauses together with a significant number of related clauses.

Clarifications were made regarding the use of P-Delta when determining DAF's.

Mike has yet to update the DAF figure.Action: Mike

4.4.The load factor for, and calibration of, load levels for one-shot analyses requires further debate.

The matter was the subject of strenuous debate. Having agreed the way forward a number of edits were made across the document - including 8.8.1, 10.5.3, and A.10.5.3. Annex B may need to be updated?

4.5.The use of resistance / capacity & MSL v/s MWL (or were these resolved? ).

The use of these terms was reviewed and resolved as far as was deemed necessary, including review/revision of related definitions and terms, including LAT.

The usage of:

metocean v/s environmental;

P-delta, P- and P-

were also reviewed and rationalised.

4.6.Insert effective length charts provided by Andrea from 19902 in A.12.4 (if not already done by Mike).

The meeting agreed that only the most applicable of the charts be included. After review of the final content of 19902, it was agreed that only the column alignment chart need be included. The guidance in Table A.12.4-1 is adequate for X-braces, and the charts in 19902 do not provide any added value for geometries relevant to jack-ups.

4.7.Address any new inputs from the Panels.

See item 3.4.

Otherwise, there were no other panel inputs.

  1. Issues from Phase 1 benchmarking.

Mike advised that there were no substantive new items in the draft report, which should be issued soon (an near-complete draft had been issued to Alan Dixon/HSE). Hopefully the Panels will be able to address any substantive issues at the October meetings.

  1. Continuation of formal A-Z ISO-speak editing.

The meeting carried on with a formal review from Clause7 of the Normative.

The review of Normative Clauses 7 through 13 was exhaustive. The Normative is therefore complete, excepting review of completion of place-holders and other Panel actions. During the course of the review some time was spent considering the guidance to use intrinsic wave periods and the implications thereof. Contact was made with Jim Stear in an attempt to understand the differences between API and ISO terminology*. The ERP concluded that period adjustments to account for the effects of current are not appropriate. The only way to obtain the correct excitation period and kinematics is to model the wave with its intrinsic period on a move current carpet.

* During the course of the conversation it emerged that Colin Grant is to replace Chris Shaw as Convenor of the core P2 and Jim Stear now chairs the API metocean task group. There is to be a further GoMex hindcast study using synthetic storms based on corrections to past records to correct the intensity deficit.

Mike was tasked with making a global edit to remove the term "unit" (as in jack-up unit) wherever possible. Post Meeting Note: Done.

The meeting also removed references to WSD as they were encountered, recognising that, if required, the SC7 resolution on the subject would allow their reinstatement at a later date.

It was recognised that there are issues regarding the inclusion of the leg inclination moment in Stochastic analyses. It was agreed that the deletion of this term this should be debated at WG7 level, and also raised with Alan Dixon ahead of the WG7 meeting. Post Meeting Note: Done, but only just in time. Response received. Action: Mike

There are also issues regarding the assumption that Class adequately addresses joint strength in the manner assumed by the present text. It was agreed that this should be raised at WG7 level, and Alan Dixon advised ahead of the WG7 meeting. Post Meeting Note: Done, but only just in time. Response received. Action: Mike

Some cosmetic edits were made to the text on Hull Elevation. It was agreed that this should be raised with Alan Dixon ahead of the WG7 meeting. Post Meeting Note: Done, and response received. Action: Mike

  1. Confirmation of actions,

The actions noted above were confirmed. Additionally Mike undertook to update the collation of the in-text actions in < > and their status, see Attachment 2.

  1. Forward plan and date & subject matter of next meeting

The goals of the December meeting will be:

  • Close-out actions from this meeting
  • Address inputs from October Panel & WG7 meetings
  • Address anyissues that may have emerged from the final Phase 1 benchmarking report
  • Pursue the ISO-speak editing of Informative

with the aim of ensuring that the document is as ready for Phase 2 benchmarking as possible, so that Phase 2 can be initiated.

It was anticipated that editing of the DIS can be completed prior to the May 2009 meetings. Thus, provided WG7 and its constituents, including the IADC JUC, are sufficiently comfortable with the results from the benchmarking that has been completed at that time, the final panel inputs can be addressed and the text submitted to ISO CS at the end of May 2009.

To achieve this goal, the schedule of future meetings, starting at 08:30 each day, was agreed as:

December 9th- 12th,

February 10th-13th,

March 24th-27th.

At least one of these is likely to be round a Thursday IADC meeting.

Post Meeting Note: The location for the December meeting has since been set as Transocean at Greenway Plaza for the first few days and ABS at Greenspoint on the last day.

The draft Agenda for the September/October meeting is:

  1. Minutes of last meeting.
  2. Information Exchange
  3. Status/close-out of action items fromlast meeting, not otherwise addressed.
  4. Ongoing items from previous meeting(s):
  • Address WG7 feedback re leg inclination and joint checks.
  • Review John's further inputs re Accidental and Seismic to Annex containing draft contents list for a site assessment report. Check this contains Tn's and DAF's). Compare against SNAME reporting format.
  • Review John's text re Mat units.
  • One-stage or one-step ??
    Does Annex B need updates for this?
  1. Inputs from the October 2008 Panel & WG meetings.
  2. Issues from Phase 1 benchmarking.
  3. Continuation of formal A-Z ISO-speak editing.
  4. Confirmation of actions.
  5. Forward plan for the next meetings.
  1. Epilogue

The panel considered that good progress had been made. Thanks were due to Pharr & Mayra of Transocean and John & Allison of ABS for hosting the meeting.

MJRH 23rdJuly 2008

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ISO/TC 67/SC 7/WG 7 Editing / Review Panel. Report on meeting of 30th Sept -3rd Oct 2008
ATTACHMENT 1

ATTACHMENT 1

Appendix A of ND report with ERP responses - After June 2008 ERP meeting

Highlighted- where action is still required

Updatesmade to April 2008 textin June 2008 in red - No change Sept/Oct 2008

A :Notesand Comments on ISO-19905 Clause 12 Sections

Section / Notes and comments / ERP Action/response
General / The equation numbering will be resolved.
Where applicable, we intend to retain references to the source AISC equations, using the latest edition (unless the equation appears only in an older edition).
A.12 / Structural Strength
A.12.1 / Applicability
A.12.1.1 / General
Line 5, grammar, “are include” should be “are including” or “include”
In 3rd para reference is made to the components combined in a typical section. It refers to Table A.12.2-1 as showing examples. The examples shown are typical of chord sections but the diagrams of plastic and elastic stress distribution are clearly more appropriate to building sections where bending is predominantly in one direction. We foresee difficulty in analysing these sections when the neutral axis is likely to be different for each load case considered, - particularly for those elements which are considered as slender. / Deleted "include".
We accept that the approach is difficult. However it needs to be exercised - and Class 3 and 4 results compared to SNAME before we come to a decision.
A.12.1.2 / Truss type legs
A.12.1.3 / Other leg types
A.12.1.4 / Fixation system and/or elevating system
A.12.1.5 / Spudcan strength including connection to the leg
A.12.1.6 / Overview of the assessment procedure
A.12.2 / Classification of member cross-sections
A.12.2.1 / Member type
A.12.2.2 / Material yield strength
Fyeff defined here is not used anywhere else in Clause 12 / Yes, but we intend that it will be used later with full section properties in place of present use of Fymin with Aeff, Seff, etc..
A.12.2.3 / Classification definitions
A.12.2.3.1 / Tubular member classification
A.12.2.3.2 / Prismatic member classification
Equation numbers are missing.
When defining “Internal Components” a distinction is drawn between “flange internal” and “web internal” components. For the purposes of a jack-up chord this is a confusing distinction since bending may occur about any axis through the section.
It is not clear what procedure should be adopted if not all the elements in a section are of the same slenderness class. (but see also A.12.3.1)
The equation supplied to check for need to consider torsional buckling is missing an equation reference number:

Several typical chords do not pass this test and therefore require checking for Lateral Torsional Buckling (LTB) - see notes for Section A.12.6.2.6.
Considering the usual types of chords, as shown in Table A.12.2-1~3, concepts of base plate, side plate, rack plate, split tubular components and stiffeners, etc., may be better than web and flange when used for classification.
In Table A.12.2-1~3, Fy has not been non-dimensionalised and has no units defined (MPa was assumed in the review though)
In Table A.12.2-1~3, stress distribution pattern drawn as I -shaped beam which is difficult to associate with real chords. Moreover, the true stress reacted across the chord section may not be about the major and minor bending axes assumed in Tables and thus very difficult to be used for the classification.
Classification for class 4 - slender section needs to be counted in this section. / Yes - fixed MJRH Jan08.
Noted
See normative 12.2.3 !
Yes - fixed MJRH Jan08..
We agree that a more appropriate check is required.
Noted
Done by PAFA.
Noted
C4 added to tables.
A.12.2.3.3 / Reinforced components
The illustration under this section (Figure A.12.2-1: “Definitions for reinforced plate”) shows a reinforcement typical for LeTourneau style chords. This is similar to the example of case 1 and allowed the reinforced plate to be classified as an element which placed the whole section into the “Plastic - Class 1” category.
The present requirement is for one check using an effective plate thickness. Checks of typical chords have shown that quite different results occur if the individual elements are considered. Base plate and reinforcing plate may be susceptible to local plate buckling when separated as discussed in the report.
The engineer given this task used the same procedure to take the two chord plates and two web plates found in the case 3 chord (see Error! Reference source not found.) an classified the resulting reinforced plate as “Plastic - Class 1” even though consideration of the individual web plates would have classified the section as “Non-compact - Class 3”. As this may not be the intention of the Clause 12 authors some additional clarification may be required in this part of the document. /
This was the intent
This was the intent.
Text revised to prevent the Hua/Stonor interpretation.
A.12.3 / Section properties
A.12.3.1 / General
This clause stipulates “the properties appropriate for the stiffness assessment of prismatic members shall be based on elastic considerations” by which it is understood that the full elastic section properties (without any allowance for local buckling) should be used for all prismatic sections in order to undertake an elastic analysis of the overall structure (leg) to determine the distribution of forces and moments through the structure (see also para 2 of A.12.3.4.1). Is this interpretation correct?