CLIMBING THE HILL
This feature looks first at the potential for multi-loading systems at ro-ro terminals, and secondly at the market for, and recent developments in, the ro-ro tractor sector.
The efficiency of a ro-ro service depends on the speed of turnaround. A faster turnaround allows more services to use a particular berth and linkspan/s and in some cases it enables additional voyages to be achieved. The key to faster turnarounds is unimpeded access to the vehicle decks on the ship and reliable, sufficiently powerful and manoeuvrable port tractors with low emissions. Access can be improved by means of wide multi-lane linkspans, multi-deck linkspans and combined side and end loading linkspans with the associated ship access openings/doors. Loading and unloading times can also be improved by lower gradients on the linkspans and any approaches.
Currently the majority of unaccompanied freight ro-ro operations are achieved with port tractors shuttling single road trailers, cassettes or roll-trailers from a trailer park to the vehicle deck on the ship. This method allows a cycle of a single road trailer to be picked up in the park, transported to the ship and dropped by the port tractor with the port tractor returning to the park in about 5 minutes (lashing assumed to operate concurrently). A 150 trailer ro-ro ship with three access lanes and nine port tractors can then achieve a turnaround of about three hours. [Ref: POSPORT RMS software model by Royal Haskoning].
Improvements to this time can only be achieved by more port tractors or by multi-unit loading systems. More port tractors will result in congestion both in the park and on the vehicle deck of the ship and cycle times will increase with little saving in overall turnaround time.
Multi-unit loading systems require powerful port tractors. Although many modern port tractors are capable of towing a number of fully loaded port trailers on the level, additional power and better braking systems would be required to haul multi-trailer units up the gradients found on many ro-ro linkspans, ship ramps and internal ramps. In addition most road trailers, roll-trailers and cassettes are not designed to be easily connected into trains. Therefore the use of multi-trailer systems would either need some special connector (incorporating a fifth wheel for standard road trailers) or cargo would need to be loaded onto specialist multi-unit rolltrailers. This double handling would reduce the effectiveness of multi-unit systems. The best system would be with wheeled platforms that could 'pick up' road trailers without requiring any re-handling of cargo.
For multi-trailer systems to operate satisfactorily circulation areas in trailer parks and on the approaches to linkspans would have to be relatively straight or have slow radius bends. The linkspan would also have to be straight and in line with the vehicle deck. It is likely that the multi-trailer system would require some sort of guide kerb both on the ship and in the trailer park. The guide kerb on the ship might incorporate a 'locking' system to provide a means of lashing the trailers. In order to allow recovery of the port tractor it may be necessary to push the multi-trailers onto the ship. Ideally the wheeled platforms would also be recoverable and able to be withdrawn from the ship for re-use in the trailer park or to withdraw import trailers already on the ship.
The complexities of the multi-trailer system and wheeled platforms lead to the consideration of rail mounted wagons or trailers. The 'FastShip' concept developed by TTS Handling has demonstrated how such a system might be adapted for ro-ro terminals. The platform trains (CP-Train) can negotiate fairly tight rail curves which would better suit existing ro-ro terminals. However the system requires the cargo to be loaded onto the platforms. Although this might suit cargo transported within the terminal on roll-trailers or cassettes it is not very suitable for road trailers which would need cargo to be rehandled. This is relatively straightforward for containers on skeletal road trailers but more difficult and time consuming for cargo in conventional van type trailers or flexible sided trailers.
To overcome the need to re-handle cargo on road trailers, the platforms would need to be adapted to accommodate a loaded road trailer. There are some advantages in this, in that the road trailer could be 'lashed' to the platform in the trailer park, thus saving time and labour on the ship. The platforms are assumed to incorporate some form of automatic mechanical locking system on the ship. The disadvantage may be that the adapted platform would raise up the road trailer and therefore require increased headroom on the vehicle deck.
The implications for the design of ro-ro terminals in order to accommodate multi-trailer systems are considerable. Firstly ships would probably have to be loaded through full width stern doors to avoid manoeuvring. Secondly the linkspan or multi-deck linkspan would have to be sufficiently wide at the ship end to allow such loading and, together with any approach roadway or ramp, would have to be wide enough throughout its length to allow steering of the trailer train, particularly as the trailer train will probably have to be pushed on board. Thirdly the port tractors would have to be sufficiently powerful to push or pull the trailer train up the gradient required for the linkspan to accommodate tidal movements of the ship and the slope of any ramp to the upper levels of a multi-deck linkspan. Finally the trailer park and circulation roadways would have to be laid out with generous bends to allow satisfactory manoeuvring of the long trailer trains.
Ideally each trailer train would be as long as the vehicle deck on the ship and therefore might be at least 10 trailers long. Perhaps this would be too ambitious for the port tractors and the trailer trains should be restricted to 5 to 6 trailers/platforms. With such a system a 150 trailer ro-ro ship might then be turned round in one hour with nine powerful port tractors. Thus two hours could be saved on the turnaround for each sailing.
In order to introduce these time saving ideas a shipping line would need to develop a particular trailer train system and build ships and a specialist terminal at each end of the route to handle the system. The StoraEnso Baseport system has already shown what can be achieved and the introduction of the FastShip terminal will demonstrate an alternative approach. Port operators need to be aware of the potential for such developments when planning their terminals.
Royal Haskoning continue to monitor research in the area of ro-ro cargo handling and innovative ro-ro ship design in order to be able to assist ports in planning for the future. Now is there anybody out there who has already invented a system with the features described above?
4X4 BY FAR These high-torque workhorses transfer trailers and other heavy rolling loadsoff and on the ship via the often steep gradients of the terminal's linkspan and the ship's main and internal ramps. They're evolving all the time with innovation concentrated on a number of areas such as better fuel economy coupled with reduced engine emissions, safety features, ergonomics, tighter turning capabilities and better traction.
Now as ever, ro-ro is very much a European phenomenon. Terberg's sales director, George Terberg, confirms this bias: "Ro-ro is so far a typically European activity though we sincerely hope it will happen in other parts of the world." Timo Matikainen, product manager at Kalmar, concurs: "The market depends on where the ro-ro ships are trading and the main market is definitely northern Europe and the UK.
However Mediterranean ports such as Marseilles, Barcelona, Valencia, Genoa and other Italian ports are all pretty busy now." Kalmar's Finnishbuilt range of Sisu trucks and its US-built Magnum and Ottawa terminal tractors are all now marketed internationally as Kalmar machines - although the Ottawa name was retained for the local North American market. Kalmar's worldwide terminal tractor operations are to be combined under one organisation: Trailer Logistics whilst the first terminal tractors rolled out of its Shanghai assembly plant last year.
Business is buoyant so far this year says Terberg: "We see clear signs that the market is improving compared with 2003. The order book is pretty well full. Last year in Europe there was a slowdown.
Investment is now improving compensating for what was not spent last year. "2003 was very slow for UK but it has returned to exceed previous levels. We have booked two big orders and a number of small ones already. Purfleet for example has ordered 28 ro-ro tractors - RT222 and RT282 4x4s."
AND FOR THE TECHNICALLY INCLINED For Kalmar, the TRX-182 4x4 is the company's workhorse.
Innovations include a load sensing hydraulic system using a variable displacement pump meaning the engine is only loaded when necessary and more power is available for machine operation. And to meet EU emission controls, air-to-air after-coolers and other modifications have been made to the range.
The TRX-182 also comes with a fully swivelling seat, important because as much of the tractor's work is performed in reverse as in forward motion. By the same token, Matikainen stresses the importance of having the same transmission speeds for both forward and reverse. The TRX-182 has eight speeds forward and eight reverse, divided between low and high ranges. But even more important in Matikainen's view is manoeuvrability and a small turning circle for turning tractor and trailer inside the ship.
"Tractive effort is also important, " he adds. "Tractors with their trailers run up and down the ship's ramps and often have to stop on the gradient so you have to have the force to continue." Visibility is another key factor for both ease of cargo handling when pushing the trailers into "the tight spots", and for safety purposes.
For heavier loads Kalmar produces the TRX-242 and TRX-252.
These models have heavier chassis, longer wheelbase and bigger power trains. The TRX-252 was originally designed for Stora Enso's BasePort cassette system at Gothenburg based around the Stora Enso Cargo Unit (SECU) which, at 95 tonnes each, requires heavy-duty tractors.
"The cross combination weight of tractor, trailer and the cassette with its load, can be up to 120 tonnes, " says Matikainen. "There is a situation where the tractor has to pull the whole load up a 7 degree ramp and there stability is the critical factor. A normal tractor might have the force to do the job but not the longer wheelbase and optimum centre of gravity." The TRX-252's have also been supplied to the other end of the SECU paper trade, at Zeebrugge.
Because each project is different, Kalmar has a range of ready modules available. "We have the basic tractor then a long list of options whereby the user can analyse the project's requirements and choose what is needed. We haven't delivered a completely standard tractor for fifteen years."
Safety and emission controls are points taken up by George Terberg. "We have a line of engines available fulfilling the requirements and in addition to the diesel engines we have an LPG version too."
Ease of maintenance which is reflected in the total cost of ownership, has been a Terberg selling point from the start. "This is apparent from the way we manufacture our tractors because they are very easily accessible for service and use the simplest possible and most reliable techniques, " says Terberg. "It is also apparent in the continuing improvement in oil change intervals for engines and gearboxes. For example, the new Mercedes OM906LA engine has an oil change interval of 900hrs when using an approved synthetic oil which automatically gives a lower environmental load."
Terberg fits fully emission-compliant engines in all tractors built for Europe as well as in the majority of the tractors going to non-emission controlled countries -this in order to give the lowest possible load on the environment. Its Cummins, Caterpillar, Mercedes and Volvo engines are all used in the latest available emissions-approved versions.
Terberg sees a clear trend towards higher loaded smaller cylinder capacity engines seen also in private cars and trucks and made possible by the extended use of electronics for the engine fuel and control system which leads to good control and protection of the engine which should still give acceptable engine life. A positive effect on the fuel consumption figures can also be seen when changing from engines with a mechanical fuel system to engines with an electronic fuel and control system.
And Terberg believes that a transmission with integrated Lock-Up clutch, as used on all Allison transmissions and on the ZFtransmission in its heavy RT382, always gives the best possible fuel economy. They point also to engine brake availability on the RT382 which improves control and gives safer operation of the tractor when used with extremely heavy loads on ramps. It also has a positive effect on the lifetime of the brake linings giving a lower cost of ownership as well as a lower environmental load.
Terberg's Safeneck enables the safe working capacity of a ro-ro tractor to be increased considerably making it suitable to safely handle heavier loads on ships' ramps. The SafeNeck is attached to the tractor by means of a separate coupling in the conventional fifth wheel elevating boom. This coupling is placed in front of the existing fifth wheel reducing the 'tipping-back' effect on the tractor by 200-300% in comparison with a conventional gooseneck system. The lock-up construction of the SafeNeck in the lift boom of the tractor can be fitted to existing tractors. These tractors can be used in a multifunctional way, whereby high volume trailers can be handled, conventional ro-ro cargo can be transported and SafeNeck applications can be handled too allowing the use of one multifunctional tractor for a variety of applications.
MAFI's new ro-ro tractor MT 30/36, F-series launched last year features a spacious cabin with good views, no matter if the steering wheel is on the right or left side. There is only one front corner post at each side and the window is curved. Its AC-unit is integrated in the cabin for driver comfort. The swivel seat has an additional 40infinity position and the new instrument panel situated around the driver does no longer needs a column between the driver's legs thereby facilitating driver access. Noise levels of 73 dB(A) inside the cabin improve the driver's work environment. The instrument panel offers informs the driver of battery capacity, operating hours, tank filling, pressure indication of all three brake circuits, maintenance intervals, etc. Even the phone number of the service station is programmable and the steering wheel is adjustable from the instrument panel.
MAFI has designed a device with which semi-trailers lower than 800 mm as well as megatrailers can be lifted and transported with a standard MAFI tractor (see Figure A). The F-series has a robust frame making it suitable for heavy-duty operations and with special tyres, enables it to shunt megatrailers so a lowrider is no longer required meaning "one fits all".
MAFI claims that due to low service and maintenance costs the customer's return on investment is improved and its tractors achieve the best resale price. The firm has recently delivered two MT 45 4x4 units to Saga Fjordbase in Norway to be used together with an elevating trailer. They will be capable of towing steel pipes with a capacity of 140 tons for use in the North Sea oil industry.
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