We caught up with Chris Menkiti is a Senior Partner at GCG, a technical consulting firm in London, UK, after his presentation at Shipping Transformation Asia, to find out more about the complexities of liquefaction and future trends which may reduce the risk to vessels and their crew.
Chris was a member of the Global Bauxite Working Group (GBWG) and co-authored its international report for the IMO that led to new schedules for bauxite and bauxite fines. Prior to this, in 2012 to 2013, Dr Menkiti conducted research into the liquefaction risk of iron ore cargoes, work that contributed to new IMO Schedules for iron ore and iron ore fines. He has also participated in some legal cases involving cargoes and their interaction with water and air.
Watch his interview or read the transcript below.
Iain Gomersall: What determines a material’s susceptibility to liquefaction?
Chris Menkiti: Liquefaction of cargoes is a complex problem. You have cargo which is usually partially saturated, meaning there is a mixture of air and water in the pores.
For these materials to liquefy a combination of factors needs to occur. In my opinion, the primary factor is the density of the cargo. When a cargo is loose and composed of many small particles, as this material deforms there is a tendency for the particles of the cargo to move into the pore spaces. At the same time, if the pore spaces are filled with water, then the water in the pore spaces becomes compressed, and the water pressure rises.
As a result, the inter-particle forces affecting the cargo become reduced, and the cargo can then behave in an unstable manner, which can lead to liquefaction. If liquefaction occurs, it will be triggered by the input of energy. For example, in the case of cargoes in the hold of a vessel during a storm.
There are a number of factors which are also relevant, such as the plasticity of the material and the grade and shape of the particles (which will affect the permeability and compressibility of the material).
In short, there are a host of factors that interact in a complex way to define the behaviour of cargo in liquefaction scenarios.
IG: Is there anything which aggravates the risk of liquefaction at sea?
CM: Assuming the cargo has been tested and loaded adequately, in principle liquefaction should not occur as the IMSBC code – which governs the loading and handling of such cargoes – is aimed at screening out risky cargoes.
Incidents where liquefaction does occur can often be related to mistakes made in the water content measurement or in determining the parameters of the cargo. The experience of the vessel in storm loading or order-dynamic loading could then trigger liquefaction.
In most cases, the rule of law has not been followed in that the prescribed IMSBC code processes have not been followed or have been falsely declared.
IG: Are current regulations and guidelines enough to protect crew and cargo? Is there anything that could be done better?
CM: As mentioned earlier, the problem of liquefaction in the maritime industry is a complex one as the science is complicated. The steps which are available – the IMSBC code and its implications – involve approximation and judgement. Nevertheless, I do believe these measures are adequate to protect the cargo and the crew if implemented in full.
Where liquefaction occurs and there is a loss of vessel or life, the crux of the problem is where the mandatory measures have not been implemented in full – either willfully or deliberately breaking the law.
The most critical aspects which I think can be done are to extend the remit of the rule of law. In some of the most distant outposts, we find the IMSBC code being completely ignored, attempts to measure water content being falsified or not carried out or duplicated, or agents going about their lawful business of implementing procedures to safeguard the ship being threaten or abused.
If the rule of law can be extended to those areas and the code applied as intended, I believe the risk of liquefaction will be substantially reduced.
IG: What are the challenges with achieving this?
CM: Some isolated outposts are controlled by rebel groups or armed gangs and are beyond the remit of the authorities or the legal government. Until these political problems and issues are really addressed, it is difficult to see how they could be controlled otherwise.
I suppose this is more a societal problem, than one being directly linked to liquefaction.
IG: What do you think are the future trends that will affect the shipping industry with regards to liquefaction risk?
CM: I am quite excited about this topic as I feel there are several trends – that are visible – which will play a significant role in the future.
There are technologies in existence in other areas which I think will translate really easily and make a difference. They may not solve the problem on their own, but as an aggregate, they will contribute as a whole.
For example, in civil engineering, there has been a lot of progress recently to monitor infrastructure projects.
As aircraft, or most modern cars, use sensors to tell you the condition of the vehicle at any time. There could be something leaking or a loss of air pressure, and that has driven technology for instruments needed to get more out of existing or aging infrastructure. Sensors have been developed to measure movement, noise, heat, vibration and so on, which can translate to the shipping industry.
Some of these sensors are miniaturised and are no bigger than your thumb and yet they can pick up water pressure and movements.
Imagine distributing this in the hold on a cargo heap? It will tell you how the heap behaves, whether you have movement, settlement, and expression of water. For Group B cargoes, these sensors could inform you where there might be heat, noxious gases generated, or risk of fire.
In addition, camera technology has progressed significantly. Infrared cameras are readily available and even used to look at metro tunnels at night where you can view detailed images of the tunnel lining and the tracks for leakage of water or other potential issues. There is no reason why these cannot be installed in cargo holds where the master would be able to inspect all the cargo heaps within the vessel on a continuous basis from the bridge.
There are also other recent developments which the IMO has been looking into. For example, drone vessels which can be remotely controlled or controlled by AI. While these vessels could still be subject to cargo liquefaction risks, it would be on a reduced level. With intelligent programming voyages can be made more efficient, storms could be more effectively avoided, and of course the risk to life for the crew would almost be eliminated as the number of human-beings on these vessels could be greatly reduced.
These are some of the more relevant developments. There are also techniques which are available for water measurements, using electro-magnetic techniques for example. This technology is available in principle but would need to be adapted for cargoes.
Taking in the aggregate, there are new technologies which are on the horizon which may contribute significantly to reducing the risk of cargo liquefaction.
IG: Why are events of this nature important to the industry?
CM: I think these events are really useful as there is a risk in this industry – as with many others – of working in silos. Events like this bring people with a broad range of skills within the same industry together to learn from each other and to develop and improve the approach of the industry.
I come from a geotechnical background and I am able to interact here with people from all areas of the maritime industry – master mariners, naval architects, people in the insurance industry, and people in the lab testing side.
It’s really about bringing our resources together so that we can make the best progress in this intractable problem.
IG: What kind of conversations have you had today?
CM: I think the interactions which come from events like this have been very helpful. Firstly, there is the opportunity for people from different backgrounds to mix and exchange ideas, and this is a good contributor to finding solutions moving forward.
It’s about pooling ideas and resources from a multi-disciplinary background, and by doing this we take big steps forward.
I have a personal interest in research into liquefaction related issues due to my geotechnical background. Here I am able to speak to specific people about the problems they have experienced, and I am able to speak with lawyers on the legal aspects and what is and is not feasible and where the responsibility lies.
It is through the combination of conversations and hearing the experiences of others that I am able to see how best I am able to contribute towards this problem and find the areas of common interest where I can follow my personal interest in this issue.
