Jump to content

User:Quantpole/Sandbox

From Wikipedia, the free encyclopedia

The Walkway collapse at Port Ramsgate was a failure of a ship-to-shore structure for the transfer of foot passengers onto ferries. It collapsed in the early hours of 14 September 1994, causing the death of six people amd seriously injuring seven more. The investigation into the accident revealed that the same basic miscalculation had been made by both the designer, Swedish firm FKAB, and certifying organisation Lloyd's Register. The parties involved, including the client, Port Ramsgate, were prosecuted and fined a total of 1.7 million pounds, which at the time was the largest fine in the United Kingdom for a breach of health and safety laws.

Background

[edit]

Port Ramsgate had entered into a deal for roll-on/roll-off ferries to embark from the port to travel to Belgium. The proposal required modifications to an existing pontoon, incorporating an additional linkspan (for vehicles to enter the ship) at a higher level, and a walkway to segregate foot traffic. Swedish firm FKAB had designed the original structure so it was natural for them to be involved again. FEAB, like FKAB a subsidiary of the Mattson Group, were employed as contractors to construct the linkspan and walkway under a design and build contract.

The walkway was constructed in three spans: one from the passenger building on the shore to a pontoon; one along the pontoon; and one from the pontoon to the boat. The pontoon supports moves vertically with the tide, so the walkway was articulated at each support. The articulation provided for all the degrees of freedom apart from roll. It was assumed that the walkway was torsionally flexible enough to accommodate the roll within the span of the structure.

Collapse

[edit]

At 00:45am on 14 September 1994 the main span of the pontoon fell about 30 feet when the last of approximately 400 passengers were boarding the Prins Filip for its crossing to Ostend. There were no apparent extreme conditions to cause such a failure. It appeared that the shore side of the span had become dislodged. Eyewitnesses reported that the walkway opened up at the support prior to falling. Five people were killed at the scene, with one person dying in hospital. Seven people were injured and others had to be rescued by the emergency services.

Investigation

[edit]

The Health and Safety Executive carried out inspections of parts of the collapsed structure, reviewed the calculations by both FKAB and Lloyds Register and questioned those involved in design and procurement.

The investigation revealed that welds to the bearings had failed in fatigue. FKAB had assumed in their design that the connection was only subject to shear loads, whereas it also had to withstand bending moments, which significantly increased the stresses in the weld. The design also assumed that the forces at all four bearing points were equal. However, as the walkway was a box type structure it was very torsionally stiff, meaning that when subjected to roll one support could lift, giving higher forces on the adjacent support.

Lloyds Register had carried out their own check calculations and independently came to the same incorrect assumption for the load path at the supports.

Trial

[edit]

A trial was convened at the Central Criminal Court (better known as the Old Bailey) in January 1997, with FEAB, FKAB, Lloyds Register and Port Ramsgate all facing prosecution for breaching Section 3(1) of the Health and Safety at Work Act, which states:

It shall be the duty of every employer to conduct his undertaking in such a way as to ensure, so far as is reasonably practicable, that persons not in his employment who may be affected thereby are not thereby exposed to risks to their health or safety.

Port Ramsgate faced a further charge against the port under the Docks Regulations. Though FEAB and FKAB had cooperated with the investigation into the accident, they did not attend the trial or offer a defence. A not guilty plea was assumed in their absence. Lloyds Register entered a guilty plea early in the trial, whilst Port Ramsgate plead not guilty.

The case against the port centred around the following: whether they had done all that was reasonably practicable to ensure the safety of the passengers; the extent to which they were responsible for design and construction by commissioning the walkway; the lack of a quality assurance clause in the contract; whether they should have fitted safety chains which would have prevented the walkway falling off its supports.

The jury returned guilty verdicts for all of those charged. The judge, in his summing up said the following about FKAB and FEAB:

FKAB and FEAB were responsible for what were gross errors in the design. In short, they were guilty of gross negligence

Regarding Lloyds Register he stated:

In my judgement, the facts in the instant case demonstrate gross negligence on the part of Lloyd's register or, more accurately, its employees.

The judge agreed with the jury's finding regarding Port Ramsgate and went on to say:

...it seems likely to me that failure to fit chains is not the only basis upon which it was convicted, but it was also convicted on the basis that it should have ensured proper quality assurance provisions were included in the contract with FEAB in order to satisfy itself so far as possible that FEAB and its sub-contractor had proper checking systems in place.

In sentencing, the judge fined FEAB £750,000, FKAB £250,000 (with £251,500 costs between them), Lloyds Register £500,000 (with £252,500 costs) and Port Ramsgate £200,000 (with £219,500 costs). The fine imposed on the port was mitigated by the fact that they had employed contractors who were experts in the field. At the time this was the highest fine imposed in the United Kingdom for breaches of health and safety regulation. It was also the first time that Lloyds Register had received a criminal conviction.

Aftermath

[edit]

The Construction Industry Research and Information Association released a good practice guide in 1999 to address some of the technical and managerial aspects of the tragedy. A code of practice, British Standard 6349-8, has also been written to give recommendations for the design of such structures.

The Swedish companies involved did not pay the fines levied, as they were not under the jurisdiction of the British court. As a result of this, and the non-payment of a fine on an Austrian firm involved in the Heathrow Express tunnels collapse, a framework agreement was introduced throughout the EU to allow for the collection of fines imposed in other member states.


[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15]

References

[edit]
  1. ^ http://www.independent.co.uk/news/ferry-walkway-disaster-blamed-on-inept-design-1284771.html
  2. ^ http://news.bbc.co.uk/1/hi/uk/4319390.stm
  3. ^ http://www.nce.co.uk/weak-management-blamed-for-ramsgate-tragedy/819507.article
  4. ^ http://books.google.co.uk/books?id=MC22ZHjJME0C&pg=PA27&lpg=PA27&dq=ramsgate+walkway&source=bl&ots=f_20qgZSX2&sig=ptiMnAwQT0DQgyJ2Y4u-lOdN90I&hl=en&ei=fEGFSpuSNceZjAfd-YWiCw&sa=X&oi=book_result&ct=result&resnum=6#v=onepage&q=ramsgate%20walkway&f=false
  5. ^ http://news.bbc.co.uk/1/hi/uk/405090.stm
  6. ^ http://www.nce.co.uk/euro-rebuke-for-ramsgate-collapse-firms/843208.article
  7. ^ http://hansard.millbanksystems.com/written_answers/1998/may/06/ramsgate-walkway-disaster
  8. ^ http://www.ginfo.pl/more/267730,hse,publishes,report,of,the,walkway,collapse,at,port,ramsgate.html
  9. ^ http://www.nce.co.uk/funds-secured-for-post-ramsgate-walkway-code/813382.article
  10. ^ http://www.independent.co.uk/news/ramsgate-port-operators-guilty-1279236.html
  11. ^ http://www.cnplus.co.uk/news/euro-fines-delayed-by-terror-plan/889059.article
  12. ^ http://www.telegraph.co.uk/news/worldnews/europe/1484406/New-EU-law-means-no-escape-for-drivers-caught-speeding-abroad.html
  13. ^ http://www.nce.co.uk/ramsgate-design-lessons-in-limbo/839931.article
  14. ^ Chapman, J.C. (1998), "Collapse of the Ramsgate Walkway", The Structural Engineer, 76 (1)
  15. ^ http://www.independent.co.uk/news/uk/gap-opened-in-ferry-gangway-before-fall-witnesses-claim-walkway-seemed-unstable-before-the-tragedy-christian-wolmar-and-simon-midgley-report-1448830.html