The manner in which the UK, for political reasons, denies some whistleblowers[14] the dignity due to persons as ‘ends in themselves’ - impermissible in any circumstances - is especially wicked when there are more appropriate alternative ways of satisfying those reasons, albeit some that would require more effort, less self-interest and less cowardice on the part of our ruling elite. They, who impose sacrifices upon others, never seem willing to make sacrifices themselves.
Saturday, 7 December 2019
Means, Ends and Dirty Hands
The manner in which the UK, for political reasons, denies some whistleblowers[14] the dignity due to persons as ‘ends in themselves’ - impermissible in any circumstances - is especially wicked when there are more appropriate alternative ways of satisfying those reasons, albeit some that would require more effort, less self-interest and less cowardice on the part of our ruling elite. They, who impose sacrifices upon others, never seem willing to make sacrifices themselves.
Tuesday, 17 May 2011
Saturday, 19 March 2011
The 1966 Load Line Convention and the loss of the MV Derbyshire [*]
Background
1966 Load Line Convention
The UK’s material objectives were to seek deeper loading (reduced freeboard) for tankers and dry cargo ships with steel hatch covers.
The Ministry of Transport and the UK delegation did all that reasonably could be done to obtain agreement to enhanced hatch cover strength. The failure to persuade a majority of the 52 national delegations to accept these proposals has to be seen against the background …etc.
...The principal change is that new ships as defined in section 32(4) of the 1967 [Load Line] Act are required to comply with more stringent constructional requirements (conditions of assignment) specified in Schedule 4. This qualifies them for reduced freeboards under Schedule 5, thus enabling them to be more deeply loaded than heretofore.
- Regulation 27(7)(c) of the 1966 International Load Line Convention was partially omitted from the text of the UK’s 1968 Load Line Regulations (the part that is underlined below). This regulation was very important in that it stipulated minimum standards for hatch cover strength when reduced freeboards were allowed (as in the Derbyshire’s case)
27(7)(c)… provided that the Administration is satisfied that:
(c) the covers in positions 1 and 2 comply with the provisions of regulation 16 and have adequate strength…”
This omission meant that there was no statutory requirement for the hatch covers on UK bulk carriers, with reduced freeboards, to have adequate strength; the UK regulations merely stated that the hatch covers should comply with the strength requirements of regulation 16. In regulation 27(7)(c), the Convention clearly stipulates that it is the responsibility of individual Administrations (e.g. the UK Government) to satisfy themselves that, on ships with reduced freeboards, the hatch cover strength is adequate.
- Regulation 16 of the Load Line Convention, which lays down minimum hatch cover strength requirements, was also applied improperly by the UK in that the authorities allowed an erroneous formulation for hatch beam section modulus to be used to determine hatch cover strength - one which would consistently underestimate hatch cover stress levels by about 10% (the error could lead to deficient hatch covers being installed on UK ships and, as discussed previously [LINK] the hatch covers installed on the Derbyshire were deficient in strength because of this error - see Appendix 1).
- The UK’s Load Line regulations, which entered force in 1968, contained a lower strength requirement for bulk carrier hatch covers than that contained in the regulations they superseded (the UK’s requirements for hatch cover strength were reduced by about 15% when the 1968 regulations came into force - see Appendix 1.)
- In 1966 the UK’s merchant fleet was the largest in the world and the UK Government of the day (Harold Wilson’s Labour government) looked upon the 1966 Load Line Convention as a commercial opportunity that would enable deeper drafts to be assigned to cargo vessels in the UK fleet.
- At the time of the 1966 Load Line Conference, the UK delegation proposed a significant reduction in freeboards (~ deeper drafts), which did not gain the support of other maritime nations and the resulting regulations for freeboards were far more modest in scope (for a vessel like the Derbyshire the difference between the freeboards initially proposed by the UK and the freeboards that were included in the 1966 Load Line Convention would amount to about 5000 tonnes in lost cargo capacity).
- A provision for enhanced hatch cover strength was also included within the UK’s proposals for reduced freeboards, however, when their proposal on freeboards did not find support, their case for increased hatch cover strength was dropped.
- The 1966 Load Line Convention’s final regulations contained a minimum strength standard for hatch covers, together with a provision whereby this minimum strength could be increased on vessels that were assigned reduced freeboards. The UK did not implement this provision.
- If the UK Government had been seriously concerned about hatch cover strength standards on bulk carriers with reduced freeboards, then they could have taken action to impose higher standards on UK ships – the regulations of the 1966 Load Line Convention actually encouraged such a practice but left the detail of such standards to the discretion of individual nation states. On page 153 of the Derbyshire final report, Justice Colman accepts that the UK Government could have applied more stringent hatch cover strength standards than those laid down in the Convention, but then justifies the authorities’ subsequent inaction with the dubious notion that, had more stringent standards been adopted by the UK, then this would have resulted in “serious damage to the British national interest as a leading merchant marine flag state”.
(Though it is difficult to accept that a few extra tonnes of steel on the hatch covers of a large, new, bulk carrier would have led to the collapse of the UK merchant fleet!)
- The main conclusion that emerged from the Derbyshire public inquiry was that the 1966 Load Line Convention regulations for hatch cover strength were seriously deficient and that it was this factor, together with severe weather, that led to her loss.
- We would suggest that, if the regulations of the International Load Line Convention had been implemented in full and also interpreted correctly by the relevant UK authorities, it is possible that the Derbyshire would have survived the perils of Typhoon Orchid.
Appendix 1
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“16.7 In so far as material to the loss of the “DERBYSHIRE” was the design of the hatch covers of the “DERBYSHIRE” in accordance with the standards applicable at the time she was built?
- Yes.
16.8 Is that design satisfactory in the light of what is now known?
- No: seriously deficient.”
Saturday, 12 March 2011
The emerging pattern
- Evidence presented in court that could lead to a finding of fault or blame (and which could lead to litigation) was suppressed, while evidence supporting the government’s preferred outcome was promoted. Nonetheless, the possibility of negligence or errors on the part of the crew (who obviously could not defend themselves) was always a theme that the court’s official investigators were happy to explore.
- Over many years, public officials have treated the families of the deceased in an offhand, uncaring manner and actively thwarted their aspirations to learn the truth of what had happened and what caused those tragedies.
- A number of personnel/experts/organisations have been repeat players in two or more of these public inquiries, while in the field of physical and computer modelling and tank testing the same overseas research facility has always been chosen to deliver crucial technical input to each investigation.
- The government (the DfT), although responsible for setting and enforcing safety standards on UK ships, has been effective in distancing itself from even the slightest hint of criticism in each and all of these public inquires
the UK Government cannot be criticised for failing to secure agreement…
On page 21 we find that:
This report does not recommend that the UK Government should act unilaterally…
On page 24 we read that:
The long delay […] in organising an underwater survey cannot be the basis of any criticism of the UK Government
And from page 151 we learn that:
…the UK Government cannot be criticised for reaching this solution. The Ministry of Transport and the UK delegation did all that reasonably could be done to obtain agreement to enhanced hatch cover strength.
Tuesday, 1 September 2009
Unfinished Business
Sunday, 4 January 2009
Non-compliance with the Standards
Synopsis
In 2000, the Re-opened Formal Investigation (RFI) into the loss of the Derbyshire concluded that that the Tees built bulk carrier had been lost, during typhoon Orchid, as a result of significant hold flooding following the structural failure of the vessel’s main cargo hold hatch covers due to heavy seas.
The Court also concluded that although the vessel’s main cargo-hold hatch covers had been designed to meet the international strength standards applicable at the time she was built, those strength standards were severely deficient, and it was this regulatory deficiency that was crucial to the vessel’s loss.
Extracts from sections 7 and 16 in the final report of the RFI:
"7.16 At the time of the DERBYSHIRE’s last voyage her
hatch covers complied with the minimum strength requirements of ILLC 66 and of the Lloyd’s Register of Shipping Rules.
[…]
16.7 In so far as material to the loss of the “DERBYSHIRE” was the design of the hatch covers of the “DERBYSHIRE” in accordance with the standards applicable at the time she was built?
- Yes.
16.8 Is that design satisfactory in the light of what is now known?
- No: seriously deficient. The design strength was inadequate to withstand the green water loads likely to be sustained during extreme sea conditions, which a vessel might encounter during her service life."
The outcome of the RFI was, thus, able to deflect any suspicion of blame away from the vessel’s builders and the Classification Society, both of whom could have been subjected to hostile litigation, had the design or construction of the hatch covers been found to fall short of the required norms.
However, independent calculations show that the court’s conclusion, that the Derbyshire complied with the standards applicable at the time she was built, is not wholly correct. The results of these calculations are summarised in the pages that follow below.
Hatch Covers - applicable standards
Strength Calculations
It is unfortunate that the Derbyshire was not constructed to meet the version of Lloyd’s Rules that was in force prior to the introduction of their 1968 Rule amendments, as that earlier version (first introduced in 1963 and valid until 1967) contained more stringent requirements for ore carrying deep draught vessels such as the Derbyshire.
What is more unfortunate, however, is that, as our calculations show, she didn’t comply with the standards that were introduced later (i.e. at the time of her build). This latter non-compliance was not acknowledged during the course of the 2000 RFI, and whether or not the Derbyshire would have survived, had her hatch covers met the relevant standards, remains, therefore, debatable.
Extracts from Lloyd’s Rules 1967
Ships specially
designed for carrying ore
Para 6020 (page 254)
“Hatch Covers
Steel hatch covers are to be in accordance with D 2326 and the
scantlings determined from the formulae given in table 43 note 6. When a draught in excess of the cargo ship draught is desired, the section modulus and moment of inertia of the stiffeners and thickness of the plating are to be increased by 15 per cent.”
In 1968, Lloyd’s rule requirements for hatch cover strength were reduced by 15% to bring them into line with the requirements of the 1966 Load Line Convention.
In the following pages the strength of the Derbyshire’s number one cargo-hold hatch covers has been evaluated and compared to the minimum strength required by both the Load Line convention and Lloyds Rules. The minimum strength requirements that were given within the Load Line Convention and Lloyd’s Rules were the ‘standards applicable at the time she was built’. No other standard is relevant.
The summarised results from the strength calculations that are given below include values obtained from classical manual calculation methods (simple beam theory), empirical methods (to give section modulus required by Lloyd’s rules) as well as finite element modelling and analysis.
The results from each of the above methods show that the Derbyshire’s No. 1 hatch covers did not meet the minimum strength ‘standards applicable at the time she was built’.
Derbyshire no.1 hatch cover construction (mild steel)
The Derbyshire’s number 1 cargo hold hatch opening was protected by two hatch covers arranged Port and Starboard of the vessel’s centreline which slid outboard to open and inboard to close. When closed, each hatch cover was supported on three of its sides by the upper deck hatch coaming structure. The fourth side of the port hatch cover mated with the fourth side of starboard hatch cover at the vessel’s centerline. There was no structural support for the fourth side of the hatch covers at the vessel’s centreline other than at their fore and aft ends where they sat upon the hatch coamings.
Each hatch cover panel was arranged with steel top plating and four side plates around its perimeter. Longitudinal and transverse stiffening members were provided on the underside, i.e. ten main, fore and aft longitudinal stiffeners and three main transversal girders (side, centre, side); these stiffening members were ‘simply supported’ at their ends by the four hatch cover side plates.
Main fore and aft hatch cover stiffeners – strength and stress calculation
Strength
1. Stress calculation using simple beam theory:
The stresses within the hatch stiffener can be calculated from the section properties that are detailed above in conjunction with the loading that is given within the Load Line Convention:
The fore and aft stiffeners are simply supported at their ends by the hatch coamings:
(1) For mild steel, maximum allowable stress = 4100/4.25 = 965 kg/cm2
Hatch cover fore and aft stiffener spacing = 0.994 m
Total pressure load on one stiffener = W = 14.72 x 0.994 x 1.75 = 25.605 tonnes
Approximate self weight of one stiffener = Section Area of 1 stiffener x L x density:
Self weight of stiffener = (0.994 x 0.011 + (0.61 + 0.46)/2) x 0.0105 + 0.28 x 0.025) x 14.72 x 7.8 = 0.351 x 7.86 = 2.725 tonnes
From simple bending theory: the maximum bending moment in the stiffener is at its mid point = WL/8
M = (25.605 + 2.725) x 14.72/8 = 52.1272 tonne metres
Simple bending theory:
M/I = σ/Y = E/R => stress = σ = bending moment/section modulus
Maximum bending stress = 52.1272 x 105/4799.43 = 1086.11 kg/cm2 (this exceeds the maximum allowable stress in (1) above)
Load Line Convention requirements:
The minimum required Section Modulus (I/Y) to give stresses below 965 kg/cm2 can be easily determined:
From simple bending theory (M/I = σ/Y) => M/σ = I/Y = 5212720/965 = 5402 cm3
Summary of strength standards:
The table below provides a summary of the strength standards that were current during the period in which the Derbyshire was designed and built. The shortfall in the required strength of the hatch cover stiffeners is also indicated.
* It would appear that the Lloyd’s Register formulation for minimum section modulus does not include an element for the stiffener’s self-weight. This implies that their rules at that time would consistently give strength requirements that would fall below that set to meet the stress criteria of the 1966 Load Line Convention. The strength required to support the stiffener’s own self weight is significant (on the Derbyshire each stiffener weighed approximately 2.5 tonnes and was 14.7m long); neglecting this factor would mean an approximate 10% shortfall in required strength when the Lloyds formulation was used.
Although the percentages shown in the above table do not appear to be dramatic, it should be noted that these are shortfalls on a strength standard that is meant to provide a statutory minimum. There is no reason, other than cost savings, why designers should not exceed this statutory minimum by a comfortable margin.
The above concludes the summary of the traditional ‘rule - based’ approach to determining hatch cover strength requirements.
2. Strength and stress analysis of the Derbyshire’s hatch covers using the finite element method
It should be noted that the hatch covers on the Derbyshire were not solely provided with fore and aft ‘I’ section stiffening members (as discussed and examined previously) in addition three deep transverse girders were provided, arranged as indicated in the sketch on page 3. Effectively, this arrangement of longitudinal stiffeners and transverse girders formed what is known as a ‘grillage’ in structural analysis terminology.
ii) The port side hatch cover model
Undeformed stiffener model viewed from underside
Undeformed stiffener model viewed from above
Deformed model with seawater loading at 1.75 Tonnes/m2 (plus self weight) - Viewed from above
Deformed model with seawater loading at 1.75 Tonnes/m2 (plus self weight) - Viewed from the underside
Port side hatch cover model: this model revealed that the three main transverse girders were effective in reducing stresses in the longitudinal stiffeners to satisfactory levels. However, the girders themselves, together with the inboard hatch cover side plate to which they were attached, were not strong enough to take the additional loads that had been shed from the 10 longitudinal stiffeners. Stress maxima in the region of 1300 kg/cm2 were developed in the two transverse side girders, stress maxima in the region of 1400 kg/cm2 were developed in the single transverse girder, and stress maxima in the region of 1350 kg/cm2 were developed in the main inboard hatch cover side plate.
Undeformed hatch cover model viewed from above
Undeformed hatch cover model viewed from underside
Hatch cover - original and deformed structure
Hatch cover - original and deformed structure
Hatch cover - deformed structure - views
Hatch cover - deformed structure - view from above
Hatch cover - deformed structure - view of the underside
Conclusions
The stress levels in the transverse girders and longitudinal inboard side plate, as revealed by the FE analysis, significantly exceed the allowable stress levels that are given within the 1966 Load Line Convention. It is notable, that the stress levels in some areas are more than 40% above the statutory maxima. Elevated stress levels indicate that the hatch cover’s factor of safety against catastrophic collapse may have been significantly reduced. And a failure in the longitudinal inboard side plate could lead to a domino-like collapse of the remaining hatch structure.
On the basis of the calculations summarised above, it is clear that the strength of the Derbyshire’s hatch covers did not comply with the standards that were applicable at the time she was constructed, and that, therefore, the RFI statement to the contrary was incorrect.
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[1] Re: Strength
i) The required ‘strength’ standard within the 1966 Load Line Convention was the minimum strength that, when the hatch covers were loaded at a rate of 1.75 tonnes/m2, would produce stresses below the ultimate breaking strength of mild steel divided by 4.25 (a notional factor of safety of 4.25).
ii) The required strength standard that was contained within Lloyd’s Register’s construction rules was expressed as ‘minimum required section modulus’ - the rule requirements allowed the maximum stress values, that were permitted by the Load Line Convention, to be governed by a single parameter which could be calculated for each girder in each hatch cover ie if the main hatch girders had a section modulus that exceeded xxxx cm3 then the maximum stress levels within that girder would not exceed the values permitted by the load Line Convention when the cover was loaded at 1.75 tonnes/m2.
Friday, 14 November 2008
Discretion
Monday, 3 November 2008
MV Derbyshire - theories and factual evidence
The RFI loss scenario thus considered that the forward trim of the vessel (brought about by flooding of the stores spaces, chain lockers and forepeak) was the initiating factor in a chain events leading to the final loss.
Whilst the evidence indicating that the Derbyshire’s hatch covers had failed due to seawater loading is conclusive, the court was unable to demonstrate in a satisfactory manner that the vessel’s slight forward trim was indeed the causative factor of that failure.
Having noted the limitations of the MARIN model tests used by the RFI, we argue, on the contrary, that the forward trim that was taken into account would not necessarily have been sufficient in itself to bring about the tragedy.
The loss of forward freeboard due to flooding and trim, about 1.3m only (excluding flooding of the Fuel Oil Deep tank), was not of a magnitude that could significantly alter the ‘ballpark’ hatch cover loads expected to arise from the large waves and ship motions generated by typhoon Orchid. The hatch covers in this trimmed condition would still be about 8.9m above the sea surface and only about 630 mm below their normal position, with the ship in an undamaged but fully laden condition.
Therefore, the small trim by the bow could not realistically and satisfactorily explain the cycle of floodings and the resulting sinking that were suggested by the inquiry. Yet, under the label of unknown and unforeseen causes for the loss of the vessel, the RFI piled together and discarded many other possible alternatives.
Out of this class of unforeseen causes, we have now decided to present one alternative theory in which the spare propeller carried onboard the vessel, due to its position and location on the upper deck as well as due to its securing arrangements, becomes detached from its deck supports and wreaks damage to adjacent weathertight structures.
The damage to these structures, it is argued, would lead to flooding, the failure of the hatch covers, flooding and ultimately to the loss of the vessel.
Quite understandably, this alternative scenario, again, opens up discussions about liability and compensation, and this was something, which the RFI tried very hard to avoid.
(More details, explanations, diagrams and supporting evidence are contained in the attached DOCUMENT)
Sunday, 26 October 2008
The MV Derbyshire Presentation
Monday, 20 October 2008
Dry run for litigation
Sunday, 12 October 2008
MV Derbyshire tragedy
The wreck was eventually found in June 1994, during a search launched by the International Transport Workers' Federation and led by the American shipwreck hunter David Mearns. The search team were also able to deploy a ROV to survey the wreck and collect photographic evidence from the site.
Later on, using evidence from the underwater survey, the Investigation assessors purported - on the basis of a rope seen emerging from the Bosun’s store hatch opening and of an examination of the disposition of that hatch’s toggles - that the loss of MV Derbyshire had been caused by the negligence of the crew, who had allegedly failed to secure the hatch lid, which lead to fore end flooding and structural failure.
The discovery of the wreck prompted the British Government to re-open the Formal Investigation into the sinking of the vessel - investigation which began in April 2000. This time, the investigation reached the conclusion that the ship had sunk because of fore end flooding and structural failure, and as a result of inadequacies in the legislation in force at the time of build, and that the rope emerging from the Bosun’s store hatch opening was nothing more than post-casualty debris, thus absolving the crew of any responsibility for the tragedy.
The Investigation found that damage to the forward vents, hatches and equipment on the upper deck initiated the unfortunate sequence of events that led to the vessel's loss. Flooding of the vessel’s forward spaces through these damaged vents and hatches gave the vessel a trim by the bow, thereafter the main cargo hold hatch covers were subjected to seawater loading and collapsed – flooding number 1 hold first, then number 2 hold, then number 3, and so on until the vessel sank.
Several important questions, however, have remained unanswered:2. The vessel had been issued with a Load Line certificate. But did the vents comply with the requirements of the Load Line Convention?
3. Did the construction and workmanship of these vents conform to the shipyard's or appropriate British standards?
4. Did the fillet welding on the windlass seat have adequate throat thickness and, was the workmanship satisfactory?
In due course, these questions and several others will finally be addressed.