Article - Issue 25, December 2005
Responses to ‘Safety and Performance’ and the flooding of New Orleans
Safety and performance response
Could I offer my support for your Editorial article ‘Safety and Performance’ in issue Ingenia 24. I noted particularly the comments about balancing safety and performance and the lack of training available to people seeking to interpret knowledge in making effective decisions.
In any safety-critical industry a basic business case would contain certain primary objectives. And these objectives would be valid whether one was transmitting oil down a pipeline or delivering the required number of people, in a state of good health and on time, from station A to destination B on our railways. These would be:
deliver the product on specification, on volume and on time
maximise an asset’s service life to provide the expected return on investment
operate within corporate and societal obligations for safety of life and environmental protection.
In order to achieve those objectives there is a requirement to deliver the required reliability, maintainability and availability of the system for the planned period of operations. There is also a need to retain technical integrity.
These principles are the basics of engineering asset management which, essentially, are about maintaining the balance between technical integrity and performance.
It gets a little more complicated when we realise that behind this lies a rather complex business risk management exercise which, in turn, relies heavily on sound asset information management to underpin the data to decision-making audit trail. The business processes associated with these activities support both safety and performance and the two should not be considered as separate entities with one bolted onto the other.
Taking an holistic view, there are those who would see the primary objectives mentioned above as supporting the principles of sustainable development, and I agree. Similarities also exist with another topic of the moment, Corporate Responsibility.
However, there is perceived overlap, and much in engineering asset management, sustainable development and corporate responsibility that leaves room for confusion and therefore the potential for unnecessary cost.
The engineers of tomorrow need to have this overlap clarified and an understanding of the underlying business processes included as part of their basic training. If this were the case I believe that the challenges outlined in your editorial would be heading towards being resolved.
Rail Safety and Standards Board
Could the devastation of New Oorleans happen in the Thames Estuary?
The Thames Barrier situated near Greenwich has been called into use more than 90 times since it was built in 1982 © Nick Burka (iStockphoto)
Since the devastation caused by the hurricanes Katrina and Rita, I have been repeatedly asked: could it happen in the Thames Estuary and how prepared are we? Clearly the UK would not expect the large scale hurricanes that form in the Atlantic and gain so much energy from passing over the extensive warm waters in the Gulf of Mexico. However, the low-pressure weather systems forming in the Atlantic, passing around Scotland and coming down the North Sea can cause an increase in the sea level on the East Coast and up the Thames Estuary. More rarely these surges are caused by weather systems coming round the south coast and into the Thames Estuary.
The devastating storm in 1953, which caused deaths in both England and Holland, led to the standards of the defences being raised in the Thames Estuary. However, it is not enough just to construct to this standard initially: the banks,walls, gates and warning arrangements must be fully maintained and the moveable barriers operated to complete the defences’ integrity when needed.
This maintenance will reduce the chances of a structural failure when the system is being subjected to loading from severe weather events but contingency plans must be prepared and practised to raise awareness of the flood risk in both individuals and organisations, so that they can make the necessary preparations. It is vital that people understand and react appropriately to warnings, but memories of big events need to be kept in the forefront of peoples’ minds without causing undue alarm. It is a difficult concept for many people that flood defences do not prevent all flooding but reduce the risk of flooding. It has to be understood that defences can be overtopped by an event which exceeds the design capacity of the system and also that failure of a defence can occur.
As New Orleans showed, flood water that gets trapped behind the defences, either through a breach or by overtopping by exceeding the design capacity, fills up lowlying areas and needs to be pumped away after the event. It is vital that the specialised equipment needed and appropriately trained staff are readily available (and floods do not respect Bank Holidays), which must be borne in mind in the continuous change which now occurs within and between the many organisations with differing responsibilities.
Examination of the Thames river walls reveals evidence of them being raised in reaction to past flood events, whereas the current TE2100 project of the Environment Agency is taking a pro-active approach by actively planning for the flood risk management needs of the Thames Estuary for the next 100 years, the 21st century. A complex and challenging project.
The capacity required to warn about, evacuate from, rescue from and restore a flooded area must be considered, planned, practised and kept in a state of preparedness with the attendant funding. The recent bomb events in London emphasised the dependence of Londoners on the public transport system. Lessons learnt in the UK from exercises such as Triton must be revisited in the light of the New Orleans experience and put into practice sooner rather than later. The old adage of ‘plan for the worst but hope for the best’ is partially true as we must not just hope for the best but actively maintain and improve the flood risk management of the Estuary and our capital, London.
Jean Venables OBE
Institution of Civil Engineers Chair
Thames Estuary 2100