The project involved 150 staff and crew from Dredging International, four trailing hoppers and a dipper pontoon. Located at the east coast of South Africa and bordering the Indian Ocean, Durban is the busiest port in sub-Sahara Africa. The port upgrade works were tendered by Transnet and executed by a joint-venture which included the local civilian contractor Group Five (the Group is also involved in the construction of the new stadium for the World Cup Football in Durban). Dredging International was the managing partner of the consortium. The total contract value was Euro220 million (DEME’s involvement amounted to Euro90 million).

Work carried out
A northern and southern breakwater of respectively 500m and 800m protected the port of Durban. The northern breakwater had to be demolished and rebuilt some 100m further down; the southern breakwater was strengthened. These preliminary works allowed for the port entrance channel to be widened from 120m to 220m, and to be deepened from the previous minus 12.8m to -19m in the outer channel and -17m in the inner port. As a result, it will be possible for the next generation of container vessels, up to 9,400 TEU, and vessels of equivalent size, to call at Durban port. A total of more than 10 million m³ had to be dredged,  part of which was used for the foundation and the reinforcement of the breakwaters. Up to 850 men and women were committed, including 150 staff and crew from Dredging International. Besides the mega dipper Pinocchio and the two split barges DI 68 and DI 69, DEME assigned no less than four trailing suction hopper dredgers: the TSHD’s Marieke, Krankeloon, Orwell and Pallieter. Since the stone dumping vessel Pompei was unavailable due to hijacking by Somali pirates, stone dumping operations were executed by using a split barge, a customised platform (in fact an adapted spud-pontoon), and a cable crane operating from the shore. The port upgrading and modernisation in Durban was an outstanding example of a multi-disciplinary approach: dredging, beach nourishment, reconstruction of the second breakwater, demolition of several quay walls and the removal of ship wrecks in the approach channel (including the clearing and cutting of a huge wrecked ship in the outer channel). It was specifically characteristic for this project that this one assignment led to securing several other contracts: the maintenance dredging in all South African ports between 2007 and 2011; the maintenance dredging in neighbouring countries such as Mozambique and Namibia; and a beach nourishment on behalf of the city of Durban. In view of the upcoming World Cup Football and the tourist promotion of the city of Durban, Dredging International will yet again carry out extra beach nourishment.

Safety first
Safety on site was the main concern. The consortium Dredging International/Group Five reached the 1 million LTI (Lost Time Injury) milestone, which is an international standard for absence off work caused by accidents: one million working hours were performed without any serious accident. Since a tourist beach and the world famous aquarium uShaka with dolphins and sharks were quite close to the site, special care was given to the environment. Peculiar challenges in Durban included the absolute need for good planning and co-ordination of the various, complex activities; the execution of the works with a variety of plant in the very busy, narrow entrance channel to the port of Durban; the limited space that could be used for all land-based activities; and finally the rough weather and frequent storm conditions in the Indian Ocean –especially when working in the outer channel and at the southern breakwater.

This article was published in May 2010 issue of World Port Development. To receive a pdf of the article in its original format including charts and pictures please send an email to archive@worldportdevelopment.

Conveyor systems makers transfixed by the ‘R’ word

Ray Dykes reports on how manufacturers of conveyor systems are focused on recovery.

The world’s manufacturers of conveyor systems have their focus clearly on the “R” word – and that’s no longer the dreaded recession but rather recovery. And there are signs, albeit small ones so far, that they have turned the corner after the ravishing of the bottom line caused by the global economic meltdown most knew as the worst recession they had experienced in their lifetimes. Surprisingly, some major firms such as conveyor systems market leader, ContiTech of Germany, still made a profit in 2009 as a group; some, such as Italian CVS Ferrari, a maker of heavy port handling equipment, have sought insolvency proceedings while they try to sort out finances. Others were reluctant to talk about their fortunes in what has been a tough period for the bulk handling industry in general. “Not this time,” was a common response to questions from World Port Development about reviewing their performance through the recession months.

Recovery
However, the first hint of recovery for some conveyor makers, whose business dropped as much as 75% in 2009, is a marked increase in bid or study requests. These time-consuming efforts could end up in Requests for Proposals and are seen as a welcome sign of better times ahead that many in the bulk handling equipment industry were seeking. It means that projects shelved over the past 16 months or so were being dusted off, revisited, and perhaps, readied for action once more by bulk materials customers. “The market appears to be turning around, but we’re not back to where we were one or two years ago,” says Greg Andrew, Chief Engineer Mechanical for Worley Parsons Vancouver BC office, a consulting engineering firm specialising in bulk handling systems around the world. “There are projects that appear to be coming back on line again.” Worley Parsons is experiencing a higher number of “study type jobs” rather than detailed design contracts and the hope is that some of them will turn into “real projects.” Andrew says the study work is still a “good sign” as usually one out of every 10 study projects “will end up going somewhere.”

Large projects
The mood was echoed on the United States east coast where conveyor system specialists, Knight Industrial Equipment of Florida, has experienced a jump in requests for budget studies domestically and on large projects, particularly in Europe,  Morocco and Peru, involving conveyors serving port facilities. And it’s just as well there is a growing surge of interest as Knight’s business in 2009 was down 70% on normal. Only backlog work and a major gypsum project with Georgia Pacific in Savannah, Georgia, kept them going. That project handles gypsum from Nova Scotia at an incoming rate of 2,000 tonnes per hour and to the plant at 600tph. The Knight system included a steel pan type apron feeder, 48 inch and 36 inch wide belt conveyors, tripper, magnets and belt scales. With 26 years in the conveyor system business, Bob Knight, Knight Industrial’s founder and President, says he is expecting a total turnaround by the end of the year.

Growth opportunity
At ContiTech in Germany, which manufactures or develops its conveyor belt technology at 10 locations throughout the world including Chile, China, Germany, Greece, Hungary, India, Mexico, Slovakia and at home, the global recession is being used as an “opportunity for growth.” At the end of 2009 it actually had increased its worldwide workforce to 22,079 – up slightly on 2008, while remaining profitable despite sales being down from Euro3 billion to Euro2.4 billion for the group. In Europe, ContiTech lays claim to being the market leader in conveyor belts and conveyor belt service materials used for the cleaning, splicing and bonding of belts, as well as for wear protection. And in April 2009, ContiTech purchased the Serbian conveyor belt company Univerzal Kolubara d.o.o. as a building block to establishing a firmer foothold in the Eastern European market. ContiTech intends to invest in production at Veliki Crljeni, just south of Belgrade, and has its eyes on the lignite rich region nearby, which helps power much of the country’s electricity generation needs.

Major order
All is far from gloomy at Denmark’s Cimbria Contec, a major global supplier of conveying expertise and a significant supplier of screw conveyors. Cimbria Contec is a member of the Danish Cimbria Group of companies and a sister company, Cimbria Bulk Equipment, delivered 29 extraction and transport screw conveyors to Hey’di in Norway as it expands a cement plant. The tubular screw conveyors are designed for high throughput and for conveying bulk materials with abrasive characteristics such as cement, lime, sand or slag. The 29 screw conveyors are all equipped with greased for life, high quality SKF stand-off bearings and adjustable packing boxes, which is standard detail on all heavy duty screw conveyors when carrying abrasive products or powders, or when handling high temperature products. The project also saw the supply of conveying equipment for transporting the finished goods to a road tanker, Big-Bag or a sack-filling system.

Good news
There was plenty of good news, too, for ThyssenKrupp Fordertechnik, of Germany, which has successfully commissioned a pipe conveyor for handling raw materials at the first aluminum smelter to be built in the sheikhdom of Qatar in the Persian Gulf. Four other systems will follow as the plant construction for Qatar Aluminum (Qatalum) continues through to completion by the end of 2010 and other bulk handling plants are built. The first shiploads of powdery alumina and lumpy petroleum coke were successfully handled by the pipe conveyor in January 2010. The conveyor takes the raw materials from ship to the plant over one kilometer and at elevations up to 80 meters – without transfer points – to storage silos near the smelter at a rate up to 2,000tph. With a pipe diameter of 590mm, the conveyor is one of largest systems to be built by ThyssenKrupp. Following the success of the Qatalum plant conveyor, ThyssenKrupp has the contract for conveying systems at two other new Qatar plants – two pipe conveyors are under construction for the Qafco 5 for the Qatar Fertiliser Co and two further pipe conveyors for Qafco 6 (another urea plant), which are still in the design stage. The big Qafco 5 contract for general contractor Saipem of Italy, included a shiploader, a scraper-reclaimer, and the complete conveyor system, including two large pipe conveyors. Qatar Fertiliser is a world-class producer of fertiliser and the world’s largest single site urea producer at its Qafco 5 plant in the city of Qatar about 40 kilometers south of Doha, the capital city and seat of government. For ThyssenKrupp, the recent urea contract through Saipem continues a long-standing, successful cooperation with the Italian company, which has also seen them working together in similar projects for Bahia Blanca, Argentina, and OMIFCO, Oman. And, also in 2009, ThyssenKrupp commissioned a new belt conveyor for operation at a coke oven plant for HKM Huttenwerke Krupp Mannesmann (HKM) at Duisburg, Germany, which boasts the world’s largest inland harbour. The system also allows for the supply of coal to HKM’s new pulverized-coal injection plant located at the rear of the coke plant by making use of the port conveyor running in the reverse direction.

Going green

Meanwhile, conveyor systems are increasingly being used to help companies go green by replacing the need for polluting and inefficient truck hauls and to speed up ship load and unload times, thus reducing marine emissions and saving customers ship delay fees. In one case Knight Industrial Equipment saved Cargill Fertilizer in Tampa Florida the cost of
conveyor system capital expense through the reduction in ship demurrage charges alone. There are other benefits, too, and as Knights says: “As the tonnage goes up on conveyor systems, the cost per tonne drops dramatically.” As for innovation, the ContiTech Conveyor Belt Group has developed a special rubber compound which it says minimises rolling resistance of conveyor belts, achieving a 20% reduction in energy consumption during raw material transportation. The smoother belts also reduce CO2 emissions significantly and Hanover University Institute for Transport and Automation studies confirm that 3,000 kilowatts of input power can be saved on a five-kilometer conveyor system. That means that the amount of energy saved in 1.5 hours is equivalent to the consumption in one year by an average four-person household in Germany. “Although the results so far are very good, we are still keeping the topic of energy-optimised conveyor belts on our agenda,” says ContiTech’s head of R&D, Wilhelm Schrand. “We’re constantly working to further improve our solutions so as to make an even bigger contribution towards making raw materials handling systems even more economical, more eco-friendly, and more sustainable.” ContiTech showcased its energy-saving belts at the April Bauma 2010 in Munich, the international industry trade show for construction and building material machines, which is held every three years.

Braking energy
And with worldwide demand for raw materials growing at a reported 4% a year, ContiTech climate and eco-friendly conveyor belt units are also capable of generating electricity by transforming braking energy into electrical energy. In Jamaica, for example, a RopeCon conveyor is in operation hauling more than 1,200 tonnes of bauxite an hour over 3.4 kilometers as it drops 470 meters to port. The transformation of braking energy into electrical energy yields 1,300kw and the current is fed into a local power grid. Furthermore, the system replaces up to 1,200 truck runs a day and eliminates the corresponding amount of CO2 and particulate emissions. Dust control, particularly at transfer points, is also improving according to Bob Knight of Knight Industrial. He adds that there’s now more attention to better methods of cleaning belts and in general “just working on housekeeping methods to reduce spillage or contamination.” Totally enclosing belts is also becoming more common as the industry does its best to help protect the environment.

Bio fuels
But, not all is well in the green kingdom. As more and more plants switch to run on bio fuels there can be increasing handling problems, says Greg Andrew of consulting engineers Worley Parsons. While Europe has been using bio fuels for years, the switch to bio fuels from former coal handling systems isn’t easy, he says. British Columbia and Ontario are embracing bio fuels more and more in Canada, but the eco-friendly fuels are proving a lot more difficult to handle. “We have had incidents of handling wood pellets that lead to fires and explosions and not infrequent deaths due to oxygen deprivation,” warns Andrew. “The systems are much more complex than handling coal or grains.” While bio fuels are becoming a larger percentage of materials conveyed around the world, Andrew says the conveying systems still need more work to get them to a more acceptable safety level.

The reform also involved transferring handling operations to private operators under a procedure for handing over public equipment. Understandably, the last few years have presented challenges for the French maritime industry which has had to contend with the above-mentioned reform, repeated strike action and then a global economic recession. But despite all this the ports of Marseilles and Le Havre are standing firm and looking to the future with optimism and determination.

Marseilles Fos
Container volumes and a revival in local steel and chemicals production helped leading French cargo port Marseilles Fos to total throughput of almost 21.5 million tonnes in the first quarter, a 3% increase on January-March last year. Container volumes rose 17% to 245,029 TEU, marked by a 31% jump to 63,933 TEU in the Marseilles harbour area’s mainly intra-Mediterranean traffic. The deep-sea Fos terminal added 13% on 181,096 TEU and is set for further gains with the introduction of two new lines – the Med-Gulf Express serving the US and Mexico, which started in mid-March, and CSAV-Norasia’s Asia-East Mediterranean service, which now extends to Fos. Container tonnage was up 20% at 2.42MT and general cargo rose 18% to 3.8MT, with ro-ro contributing 0.9MT (-1%) and conventional trades soaring 52% to 0.53MT on the back of renewed demand for steel products. A 154% increase in raw materials for the steel industry – which typically represent 60% of dry bulks traffic – drove the sector to 2.72MT and a 70% improvement on Q1 2009. Meanwhile the chemicals industry underpinned a 47% rise in liquid bulks, where the 0.89MT total included 0.25MT (+31%) in the thriving biofuels market. The oil sector was the only main category in decline, down 9% for the period on 14MT reflecting of current difficulties in the French refining industry.  Crude for national refineries held on 7.4MT (-1%) but pipeline deliveries to Germany and Switzerland plunged 23% to 2.1MT and refined products also fell by 23 points to 2.6MT.  With LPG 5% worse on 0.7MT, LNG was the sole improver on 1.3MT (+10%). In a bid to boost trade links, Marseilles-Fos is establishing commercial representation in Brazil to further enhance links with its main trading partner in South America, which currently contributes some 4.5MT a year. The announcement by newly appointed development director Dirk Becquart came in early April during a three-day trade mission in Brazil. Key trade targets include the container, foodstuffs, biofuels and 4MT per year dry bulks sectors. Port officials presented details of the three new container terminals that are being developed – the twin facilities at Fos 2XL due on stream in 2011 and the Fos 4XL project to be operated by world leader Hutchison Port Holdings from around 2017/2018.  They also described progress at the Fos Distriport logistics zone, where a third of the initial 600,000m2 warehouse space is now in service. The potential for Brazil’s biofuels traffic was underlined by stressing that, as the world’s third largest oil port with annual throughput of 60MT Marseilles Fos offers major production and storage capacity. At the beginning of the year Marseilles was reporting that a major rail upgrade at the port was on the horizon. Development and financing strategy for major upgrades to the port rail network had been agreed in principle by the Marseilles Fos supervisory board. Total costs are estimated at EUR250-300 million over the next ten years. The main management proposals under consideration included the rapid completion of projects already under way within the 2007-2013 regional development plan to improve rail access to the Marseilles and Fos harbour areas; the launch of network modernisation projects such as the addition of two new rail lines serving the Graveleau container terminal at Fos; the development of combined transport terminals at the port’s container facilities and at the Lavera petro-chemical complex. Within the next few months, the port is to seek tenders regarding Mourepiane container terminal in Marseilles and will also start studies relating to Graveleau; and finally a current study into a road/rail terminal serving trailer traffic in Marseilles should be completed. The board gave the go-ahead for further studies and called for a timetable and financing details for each project. It also agreed in principle that the port’s existing 110km rail network should be extended by 60km in a project to enhance services in the Fos port-industrial zone. In addition, the board requested research into appointing a rail operator to handle local traffic flows by 2010, as recommended under the national rail freight policy presented to government in September. The port said its rail plans responded to this policy, which aims for a modal shift from road, as well as the French port reform requirement for internal rail systems to be managed by port authorities, which Marseilles Fos implemented in September 2008. It also stressed that, under its strategic plan to 2013 published earlier this year, rail is scheduled to take 30% of multimodal traffic compared with 13.7% in 2008. Sixteen proposals towards this aim were presented by the port’s development board in September and were noted at the supervisory board meeting.  

Le Havre
In 2009 the Port of Le Havre, the largest French port for external trade and container trade and fifth biggest North-European port, handled 74Mt (2.2 million TEU), down 10% on the 2008 figure of 2.49 million TEU. Due to its outstanding location and accessibility Le Havre is the first port of call when sailing the English Channel/North Sea route through which a quarter of the world cargo trade passes in transit. To further improve its efficiency the port took delivery of four new container gantry cranes in early May to equip the Terminal de France of GMP, one of the Port 2000 operators. The new facilities provided by Port 2000 after their commissioning in 2006 have allowed container traffic through the port of Le Havre to grow considerably. As the operator of the Terminal de France, GMP (Générale de Manutention Portuaire) is directly responsible for that growth. After entering service in April 2006, the Terminal de France currently offers 700 meters of quay length, equipped with six Super-Post Panamax gantry cranes and three railway cranes. Boosted by the confidence of its customers, GMP says it will now focus on optimising the competitiveness of its offer and thereby fuel further growth. The work on the second phase of the Port 2000 scheme, supervised by the Grand Port Maritime du Havre as the contracting authority, will allow terminal operators to invest and increase their cargo-handling capacity. At the Terminal de France, the four new gantries made in China by ZPMC have reached their port of destination, after leaving Shanghai on 3 March aboard the Zhen Hua 14, and should start up service in early summer. With this new milestone in its development, GMP joins the exclusive club of major operators of container terminals in Northern Europe. The company’s offer now includes 10 Super-Post Panamax gantry cranes and 3 railway cranes on its Terminal de France in Port 2000. 2010 is an important landmark year for Le Havre as the port expects to have completed the final stage of implementation of the French government’s port reform by September. The final stage of the reform which involves the conclusion of an agreement with its unions regarding the transfer of port authority terminal personnel to the payrolls of terminal operators still has to be completed but signs are that will go ahead without obstacles as there the basis for a “good” agreement. Commercial and Marketing Director Hervé Cornede has been quoted as saying that he was confident that negotiations with the unions would be completed by June in time for the port to begin a new commercial initiative in September.

The need to produce faster, more efficient container cranes has led to the examination of each component of crane design to determine how and where improvements in performance and productivity can be found. There are many parts that make up the whole operation of a container crane and of course, each part, big or small is vital. But perhaps one element that can claim to make a major impact on performance is the energy supply cable. The main target for power supply cables for cranes has always been to increase the mechanical stresses resistance in order to permit higher accelerations, and to reduce the cable dimensions in order to save weight (that means costs) in the reeling system; unfortunately, in terms of design, these two elements are not going in the same direction. Generally speaking, reeling and unreeling movements create tensile stresses inside the cable because of the relative motion between the different inside elements (conductors, inner sheath, anti-torsion protection and outer sheath); this motion generates an uneven elongation and therefore it is possible that the conductors on the outer layer could be damaged or broken. In order to guarantee maximum performances, the cable manufacturer has to design improved products whilst at the same time keeping the design in compliance with recognised Standard References – usually in accordance with VDE Standards. Great effort must be taken to get continuous improvement in the flexibility of the cable through a special construction of the copper conductors. In this case the standard requirements (EN 60228 in Europe) are quite “large”, requiring simply a maximum electrical resistance value and a maximum diameter of the elementary wires, so it is really the designer’s “know how” that can make the difference in the final result. Reducing the wire diameter or the stranding pitch are just easy ways of getting more flexibility, and usually result in higher costs and sometimes an increased conductor diameter; indeed, a well designed and tested conductor stranding can really make a difference, in terms of flexibility as well as in terms of maximum tensile load the conductor can be submitted to.

The maximum tensile load of the cable is usually increased by using, for example, Kevlar® support or other special fibers in a central position inside the cable. This applies because of the general construction design rule (also following VDE requirements) of shortening the laying-up pitch cores, or by tightening the structure against the internal relative movement. This construction allows the cable elements to transfer the mechanical stresses to the central element that is thus reinforced to give more resistance to the whole product. Of course, part of this effect is lost if the cable connection (the fixed point of the cable) is not made in the right way, especially if twisted cores are not tightened around the central support.

Another way to increase the mechanical resistance is to improve the sheath material features. Special compounds (as inner and outer sheath) with increased mechanical features are always used in the cable design, usually referring to the best standardised qualities (for example 5GM5 quality in accordance with VDE 0207 part 21), with much better breakdown tensile loads than the usual jackets for mobile applications (as for cable type H07RN-F). A very important consideration is how long the materials keep their original features during cable use. Over the years, a cheaper chlorinated material, sometimes with a certain content of PVC, was introduced that would allow the compound to achieve a standard performance in laboratory tests, but the behaviour of the compound during the cable lifetime could not really be guaranteed.

These details in design are not standardised by the VDE requirements, or by any other standards concerning cables for these applications (generally for mobile use), and so in this case the designer’s know how and skills (and the use of the  best materials in the production) are  the key to success for these reeling cables.

Below is a comparison of 3 materials: rubber compounds (5GM3 and 5GM5 quality) and polyurethane:

From the table it is simple to conclude that polyurethane is a valid solution: to obtain a smaller cable than the rubber version but with the same tensile load and to obtain a lighter cable than the rubber version with the same outer diameter. The textile braid inside the outer sheath is also very important. In this case the standards don’t require any performance at all about this element. The geometry of the braid, coupled to the elongation features of the textile fibers is essential to the successful working of the cable. Considering the much lower elongation of these fibers, compared with the outer sheath material, it is important to understand when the braid is starting its anti-torsional work and when it is arriving at the higher limit of its elastic strain.

These mechanical stresses on the cables are directly connected with the typology of drum where they work.  An example is the comparison between a Mono-spiral Drum (single spire multi-layers – typical for harbour cranes) and a Cylindrical Drum (multi-spire multi-layers random wound, typical for mine equipment). The mono-spiral drum is ideal to guarantee the heat dissipation and the control of irregular twisting during unwinding (the limit could be the cable’s length in relation to the reel’s diameter), the cylindrical drum is the cheaper reel but the reeling and unreeling of the cable may generate torsional stresses higher than other reels. It also doesn’t guarantee the control over the layers of cable: the cable could be stacked, for example, on one side of the drum and the stresses could increase and damage it.

To avoid these problems the crane manufacturer has to rely on the experience of the internal designer, continuous tests of every component and the testing equipment in order to simulate the expected working conditions of a cable. Finally, correct installation of the cable is very important for its lifetime; the mechanical stresses can be very high and a failure of the cable could generate a short circuit or even an explosion. In order to get the best cable installation and operation, customers should always verify the crane system features with the cable manufacturer in order to choose the right cable for the crane as often it is the small details that are the basics for a good cable lifetime.