Abstract. 1 Introduction

Transcription

1 Developments in shipping and their consequences on port planning and design H. Ligteringen Faculty of Civil Engineering and Geosciences, TecWca/ (7mWrj;Yy D#, f.o. Box The Netherlands H.Lizteringen(a).ct. tudelft, nl Abstract Waterborne transport of cargo and passengers is showing remarkable developments, driven by reasons of economy, environmental advantage and safety. Such developments make existing ports unsuitable and demand innovative new facilities and solutions for the older port areas. An overview of the shipping developments is followed by a discussion of the most important consequences. 1 Introduction It is long ago that ships were built to the physical constraints of natural harbours. Nowadays the shipping industry is driving the technological developments to which ports adapt in order to keep or attract the business. Adaptation means the creation of new facilities, which are able to cope with the dramatic increase of transport capacity across the berth. It also means the need for re-orientation of the existing port areas and terminals, to avoid obsolescence. The most striking developments in waterborne transport are: (i) The growth of container vessels coupled with increasing productivity of portainers, leading to a 5-10 fold berth

2 338 Maritime Engineering and Ports productivity (in terms of tons per year) compared with traditional general cargo operations. (ii) (iii) The growing share of barge transport of maritime containers to and from the hinterland, creating new intermodal opportunities. The introduction of large high-speed vessels for transport of Ro- Ro units and passengers, with their revolutionary short turnaround time. The following key issues in the adaptation of ports to these changes are treated: The increased productivity on the waterfront requires innovative terminal designs and must be met by the transport capacity of hinterland connections. The environmental concerns related to any type of infrastructure development must be clearly balanced by the positive effects of cultural, social and economic improvement in the old port. 2 Maritime container transport The "economies of scale" in maritime container transport lead to unexpected results. While only some years ago 6000 TEU vessels were considered to be futuristic, not before the turn of the century, several of these jumbos have meanwhile come into service. And 8000 TEU ships are on their way. The shift of general cargo into containers and the steady increase of world trade lead to an exponential growth of the number of boxes carried around the globe. The consequences for this trend are felt in all ports. Most obvious are the increased water depth requirements and the larger cranes needed to reach across the beam. But the greatest impact is on the terminal shape and the logistical requirements. The following example will illustrate this. The existing general cargo terminal in Figure 1 has a berth length of 320 m allowing two vessels to be handled simultaneously. The average berth occupancy is 60% and by employing 3 gangs per ship during 16 hrs per day an annual throughput of 200,000 ton can be achieved. The terminal area of 5 ha is sufficient for this throughput.

3 c c a general cargo b. containers Figure 1. Surface area for different types of terminals. Changing this terminal into a single berth container terminal for 4500 TEU vessels requires a total area of 20 ha. Assuming the same berth occupancy and number of working hours, and taking an average load of 8 ton per TEU the throughput of this terminal may easily reach 1 million tpa. The implication of these figures are quite clear: In most ports an expansion of surface area behind the quays by a factor 4 is physically impossible, because the wharf areas are boxed in by the surrounding city. # An increase of the transport to and from the terminal by a factor 5 is in many cases difficult to realize, because the existing roads and railways are already saturated. The solution depends on the existing port layout and connections. In some cases additional terminal area can be created by filling part of the port basin. If access to the terminal can be achieved, the container terminal can stay in the old port area. In most cases these conditions can not be fulfilled and the container terminal is developed at a new site, without the limitations of the existing location.

4 340 Maritime Engineering and Ports \^i ""' I*-' fth"«^i-u; i Figure 2. Genoa Port Masterplan It should be recognized that in both situations port area comes available for other activities. The container terminal can handle the same amount of cargo of 5 traditional terminals with a total length of 1600 m. Even if a future increase of cargo throughput by a factor 2 is taken into account, only 640 m berth length suffices. This paradox is very important, because it creates opportunities for revitalization of old port areas as elaborated in Section 5. A good example of the conversion of general cargo terminals to container terminals is found nearby: the Sampierdarena area in the port of Genoa. Figure 2 shows the existing layout, a typical example of a conventional port layout with quite a number of narrow piers and basins, and an extensive network of railtracks along the quays. Byfillinga basin between two piers one obtains the required surface area for a modern container terminal as shown on the inset. This concept formed the basis for the overall masterplan, including improved rail and road access. The potential growth of throughput is substantial, as explained above, but can be achieved in

5 Maritime Engineering and Ports 341 number of units needed for 12,000 ton cargo 4-barge push tow barge 6.5 railwagon trailer 600 transport length for 12,000 ton cargo (km) Figure 3. Transport length for different models phases. And this growth potential facilitates the discussion between port authority and the city regarding restoration projects in other areas of the old port. 3 Inland water transport of containers The share of IWT of containers from Rotterdam to Germany has increased from 10% in 1982 to 25% in And like in the previous case the developments in shipping are an important factor in this growth. Another factor is the environmental consideration. The same amount of cargo carried by one push tow combination requires 600 trucks with a total length of almost 7 km (see Figure 3). The energy consumption and cost per ton km of barge transport compare very favorably with other modes. The negative aspect, which for a long time hampered container transport by barge, was the fact that it represents an extra shackle in the transport chain with relatively high capital and operational costs in the seaport and at the river terminals. To overcome this hurdle and establish thefirstterminals a number of large forwarders were needed. From there on the network could be

6 342 Maritime Engineering and Ports extended and improved and this is where the shipping side comes into the picture. Several lines of development can be mentioned: It was recognized that special barge terminals were needed next to the large sea terminals, with interterminal transport of containers. This was first realized at ECT's Delta terminal on the Maasvlakte, Europoort. It reduces the need for barges to travel from one terminal to another in order to collect or discharge their cargo. Along the Rhine dedicated container terminals are created with efficient ship-to-shore cranes, thus reducing the time for loading and unloading. Plans for fully automated terminals are on the drawing board, but these need more throughput before becoming economically viable. An interesting idea is the Barge Express: a dedicated service between the seaport and one or more river hubs, for which a jumbo barge is developed with a beam of 22.8 m (8 rows of containers) and a total capacity of 620 TEU. The increased beam provides more stability during loading/unloading, thus paving the way for automated handling. Its limitation is that this vessel can only operate on the main rivers and canals, thus losing some flexibility. The present regulations do not permit such a large vessel on the river Rhine, although it is technically no problem. As an intermediate step, within the legal framework, a barge of 135 m length and 16.8 m width carrying 400 TEU has recently come into service, the Jowi (see Figure 4). 4 High-speed ferries The last innovation in ship design worth mentioning in this context is the High-speed ferry developed by Stena Line, which started service between Rotterdam and Harwich in The Stena HSS has a load carrying capacity of 1500 ton, about 5 times as much as the largest catamarans in service till then. It can carry 50 trailers and 100 cars at the same time and has enough space for 1500 passengers. The vessel has a cruising speed of more than 40 knots and makes the trip across the North Sea in 3.5 hours, twice as fast as the traditional ferry service. This allows two return trips per day and makes the service again competitive with the Chunnel in terms of time.

7 Maritime Engineering and Ports 343 Figure 4. River barge Jowi A key element in maintaining the schedule is the extremely short turnaround time of 30 minutes in the ports on both sides. To achieve this and still have sufficient time for unloading and loading of trucks, cars and passengers, the time allowed for docking had to be limited to several minutes. This necessitated the development of an entirely new mooring system of which the main elements are: a very accurate positioning system (< 1 m) by means of camera's and radar at the stern of the vessel. a linkspan with two hydraulically operated hooks, which form the only mooring device under normal weather conditions (i.e. no mooring lines). The linkspan is positioned at the correct height before arrival of the ferry. a key on the linkspan prevents transverse movement of the catamaran. In the vertical plane the connection is hinged to allow for tidal variation and vessel pitching due to waves. The design aspects are presented in a paper by Terpstra.* The mooring layout is given in Figure 5. It shows the two hooks and the shear key. While the HSS concept is designed to have no need for

8 344 Maritime Engineering and Ports fenders or additional mooring lines, the wave conditions at the berth location of Hook of Holland appeared to be too high during some periods of the year and lateral support was needed. In view of the light-weight structure of the HSS, the high level of the belting (8 m above the water surface) and the requirement that no extra time is lost in berthing/deberthing, a special system of fenders and emergency mooring was designed and built. The fenders consist of UMHW-PE panels, 1.65 m wide and 9.5 m high, reaching a height of 9.4 m above the quay. The fender system is very soft. The emergency mooring system is only employed, when wave heights are above 0.5 m. The principle, depicted in Figure 6, is a constant tension force in the mooring line, realized by a deadweight and a pulley. This force provides the counteracting moment at the location of the HSS-linkspan connection, which keeps the forces in the hooks below their allowable limit. The berthing system has been in operation since June 1997 and functions satisfactorily. It is unique in the world and a very good demonstration of innovative berth design in response to a revolutionary vessel design. 5 Port revitalization In Section 2 port revitalization was mentioned as a consequence of the change of traditional general cargo handling to container operations. But there are other reasons for deterioration of port areas and the subsequent need for change. Unlike in the previous cases the primary cause is not a change of vessel design: (i) (ii) loss of cargo volume due to external reasons (shift of trades from one port to another or the complete extinction of a trade). Loss of certain port related industries, due to economic reasons (e.g. the loss of shipbuilding and -repair in many western countries) or due to environmental regulations (increased standards make high investments necessary and relocation is a better solution). Very often it is a combination of several causes, which make a port area obsolete. It is the task of any port authority to take timely measures to prevent this. Revitalization of old port areas can take many shapes and

9 Maritime Engineering and Ports 345 STENA LINE TERMINAL EMS Quay wall LINKSPAN PLATFO, River T = Tension hook S = Shear key H = Axis of hinged connection EMS = Emergency Mooring System IH IH Figure 5. Schematic mooring layout. U I Figure 6. Principle of emergency mooring system.

10 346 Maritime Engineering and Ports requires careful analysis and planning to decide which is best under given circumstances. When external factors can not be reversed and no alternative trades can be attracted, the only solution left is to give the areas back to the city. Revitalization becomes then "conversion" into urban development such as large-scale office areas (London Docklands in the U.K. and Boston Harbour in the U.S.) or small scale industries and recreational facilities such as in Goteborg, Sweden [see Ekman^). In most cases the port function can be retained by creating the right conditions for new activities. This requires investment by the port authority and municipality, but has the advantage that there is no decline. A good example of this is the conversion of the Waal/Eemhaven area in the port of Rotterdam (see Figure 7). This area occupies about 10% of the overall leasable port area, but the employment of over 11,000 jobs represents about 18% of the total in the port. Parts of the container operations were relocated to the Maasvlakte some years ago. Traditional Infrastructure impmvement Terminal relocation Figure 7. Waalhaven/Eemhaven revitalisation

11 Maritime Engineering and Ports 347 general cargo was declining due to reasons explained in Section 2. But cargo forecasts predicted growth for certain types of neo-bulk such as forest products and steel. Most important however is the implementation of the government policy to promote short-sea traffic, the import and export of intra European cargo. This is expected to generate new volumes of containers and Ro-Ro cargo, provided that the terminals are clustered to facilitate transfer. Conversion to urban functions would make many workers jobless. But the opportunities for a port-based revitalization were good and an action plan was developed by all parties concerned [as described by den Dunnenet.al/]. Very often the planning of port revitalization is not dominated by technical issues, but by institutional aspects. How to deal with the existing occupants, disputes over land ownership with municipalities, environmental pollution and its cost, governmental requirements, these need to be solved in a orderly way. In the Waal/Eemhaven project the Open Plan process has been applied with remarkable success sofar. It would be very interesting to study the institutional aspects in more detail, as they have been resolved in various cases around the world. 6 Conclusions Some general conclusions can be derived on the relation between shipping developments and port planning and design: (i) In most cases the shipping industry dictates the adjustments needed in the port infrastructure. Not responding to this means decline of throughput. (ii) Conversion of general cargo container handling provides room for growth of throughput, but leaves in addition space for other activities. The latter may be urban functions, recreation or port related industry. (Hi) There is substantial scope for IWT of containers, where seaports connect to the hinterland by means ofcemt Class V Waterways. (iv) The need for port revitalization affects (parts of) all ports at regular intervals and requires and active role of the port authority. (v) The institutional aspects of port revitalization are often more difficult to solve than technical issues. A plea is made for more research into the former aspects.

12 348 Maritime Engineering and Ports References 1. Terpstra, J.D., HSS-Terminal at Hook of Holland, PIANC Bulleting No. 96, p 29-34, Ekman, J., Goteborg - The friendly city, Proc. Int. Conf. on Rehabilitation of harbour Areas, PIANC Portuguese Section, p Den Dunnen, P. and Ligteringen H., Revitalisation of port areas within the overall development of the Port of Rotterdam, Proc. Int. Conf. on Rehabilitation of Habour Areas, PIANC Portuguese Section, p , 1998.