One company exploiting this opportunity is Modern Port Technologies in Canada. Through their senior container terminal operations and planning specialist, Alex Goussiatiner, the company is ‘testing the water’ for an underground container storage facility.Over the years operators have been faced by container storage issues, albeit a lack of [expansion] land or simply a lack of funds to invest. In Hong Kong, operators have had to contend with the problem of container storage capacity shortage. With a lack of land there seemed no where to go but up, so the obvious solution was to stack the containers higher. But high density stacking comes with some associated risks including the threat of strong winds (typhoons in Hong Kong and neighbouring countries) but despite the risks it was a solution that became globally accepted by terminal operators who were facing a similar situation. Now it seems there could be another solution to the space shortage problem – instead of ‘up’, why not go ‘down’? Welcome to the UCS – the underground container storage system. Out of the box thinking or simply a brilliant idea – the concept of storing containers underground that is being floated here might seem very simple but is it? According to Alex Goussiatiner, planning specialist at Modern Port Technologies in Canada, the disadvantage of high density stacking of containers leads to extensive unproductive reshuffling moves. This might be true to a certain degree but with a good yard planning system the containers should be allocated in the right way to avoiding reshuffling moves. In addition, Goussiatiner claims that high density stacking of loaded containers increases the static load on the surface and often requires additional investment into the surface structure. Although this might be a valid point, for container terminals with for example RTGs/RMGs operations the surface structure would have been taken in to account at the design phase, so his argument might only be applicable for terminals that change their use – for example from break-bulk to containers. Therefore this point could also be neglected.
The concept
Before we go any further it might be worth looking at the design features of the UCS concept. The idea is simple; loaded and empty containers are stowed below deck up to 10-high on a container vessel and therefore theoretically it seems logical that the same arrangement could be duplicated on dry land. This concept could create a high density stack below the surface of the blocks serviced by RTGs/RMGs or ASCs. According to Goussiatiner this underground solution would avoid the high stacking of containers that are subject to high winds and could also reduce the number of moves for export and trans-shipment stacks as this requires much less selectivity and theoretically can be designed for high density. So, where in the past the stacking was for example 5-high above ground you can now double the container capacity if you stack 5-high underground with the underground storage system (total 10-high). This might influence the gantry cranes working above the UCS and Goussiatiner points out that some slight modifications need to be made including extending the load wires and increasing the size of the hoist drums and housing. But these ‘minor’ modifications will not compare to the capital expenditure for the construction of the system. The main civil engineering (and financial) challenges might include the construction of the retaining walls, storm water drainage systems, upgrading of adjacent crane foundations (if applicable) and construction of the barriers for mobile container handling equipment (avoiding them to ‘drive’ into the UCS).
Concerns
There are numerous issues that have to be addressed before such a concept can become reality. It is therefore no surprise that many consultants, operators and consultants have raised several questions regarding the proposed concept. First, the issue of storm water drainage seems to cause everybody a major headache and many responses included considerations that have to be given to maintenance and energy costs of running the storm water engineering system. In countries with winter snow conditions the need for additional equipment and operating expenses related to snow removal have to be considered. But what happens when the drainage system fails completely? “A state of the art drainage system that cannot fail must be in place as well as the design of a system that mitigates and avoids unproductive container moves,” said Jan Scheele, Division Manager Marine and Consultancy, at PT Carsurin Surveyors and Consultants in Indonesia. “The cost of construction of an underground container yard could prove to be un-economical as it definitely will increase the cost of storage and handling,” he added. Costs seem to be another major hurdle to overcome when we look at the design of the system. “Very good retaining wall arrangements would be needed as the gantry is running along one edge. This suggests such an arrangement might be very expensive to build,” observes John Hunter, Director at Armor Business Solutions. “There would need to be some form of cast-iron safety guarantee to convince gantry drivers that it was absolutely impossible to drive over the edge! It may sound excessive, but think of the driver who is looking down into a deep hole. This suggests RMGs rather than RTGs.”
Hunter also sees a potential difficulty of stacking 10-high (see diagram )pointing out that if these are exports as suggested is possible, this could mean stack weights of a possible 30 tonnes per container. “On ground that is often of poor quality, that could be a problem, and any instability of the ground will be very difficult to rectify in what is, in effect a deep pit,” he concluded. Avnash Iyer, Head of Operations at Chennai Container Terminal, India added his concerns about the working height and the liability posed to the terminal if there is a failure in the storm water drainage system [flooding] and the hazards the RTG driver would be exposed to given the “well” stacking and very low tolerances for driver errors (even if using dgps). Mohamed Habib, Equipment Training Supervisor at Suez Canal Container Terminal in Egypt also expressed his concerns for the safety of the RTG driver. “The RTG and truck lanes need to be wider to be safer during gantry movement and driving. Also consideration should be given to re-enforce the side wall between the blocks especially if you design the yard back to back.”
Conclusion
Despite the concerns raised here there are also some positive responses to the UCS concept although most of these responses include ‘one shared concern’ and that is about the investment that has to be made. “This looks like a really good idea, but there are a number of engineering, operational and commercial challenges to overcome, as with all innovations,” said Richard Willis, App Consultant, Logistics, Jade Software Corp, Australia. “The considerable cost and efforts of a scheme like this may make using floating storage an attractive option too – barges or even old cellular tonnage could be used to a similar effect. This too has many challenges of cost and flexibility, but it would be interesting to weigh up the benefits of either approach.” And although Goussiatiner is confident that the estimated capital cost will be comparable with the investment of the construction of a new surface stack, he confirms that the UCS is viable for certain types of container terminals. But when asked – as a general measurement – what the annual container throughput has to be to make such a project viable, Goussiatiner prefers to keep his cards close to his chest.