Earlier, in shipping the automobiles were carried on general cargo ships and bulk carriers with just a few vehicles onboard. Cars were loaded with net slings wrapped all around the wheels and stowed mostly on open decks. The cars were usually covered with plastic or polythene to shelter them from the weather. Possibility of damage was always there. Cross lashings made up of hemp or manila rope was doubled up and twisted at forward and rear end of the cars. Lashings were often done in the manner recommended by shippers. Every time, the quality of lashings would differ from port to port or rather hand to hand. The lashing sometimes, was effective for a limited period of time. Masters had to keep a good eye on the weather.
The general cargo ships carried about 5 to 20 cars on main deck or under-deck. The car carriers, now generally carry over 2000 units but often over 3500 units. Bigger of the car carriers could be carrying over 6000 units. A number of PCCs, PCTCs and RO-ROs have come in the market.
The roll-on/roll-off ship is defined in SOLAS as being “a passenger ship with Ro-Ro cargo spaces or special category spaces…” As the name of the system implies, even big trucks can drive straight on to a Ro-Ro ship at one end, drive off on the other side.
Today’s pure car carriers are box-like superstructures running the entire length and breadth of the vessel, fully enclosing and protecting the cargo. Pure car carriers have their dimensions ranging from length up to about 230 m, breadth up to 32 m and drafts of up to 10 m. The size is comparable to medium sized bulk-carriers and tankers of about 45,000t. The PCCs are of GRT about 50,000 and deadweight over 20,000 t. They are usually fast ships of speed over 20 – 21 kn.
A PCC has 10 to 12 decks. Most of the decks are permanent. Some may be collapsible or liftable (called “panels”) to increase the clearance to accommodate the cars of large heights.
The PCCs generally have at least two ramps. The stern ramp on most ships is on the starboard quarter with SWL ranging from 50 to 150 t. The amidship-ramp is at about the mid-length and has a SWL of 50 to 75 t. The midship-ramp on most PCCs is movable (adjustable) to at least two different heights, for the ease of loading at various decks and also to adjust it to different levels of tide and wharfs.
Some PCCs have four ramps, two on each side. The modern PCCs have ramps of SWL as high as 450 t and carry heavy equipments such as trailers, tractors, railway engines, containers, knock-down aero planes, boilers, palletized steel coil-rolls, newsprint rolls, etc.
The PCCs are considered very risky. This is because of the large external doors, with the opening near the waterline, many vehicle decks and just a few transverse bulkheads. These ships however, are as stable as any other ship on the high seas. The ship’s staff has to ensure that all water-tightness is attended to, before leaving for a voyage. The ‘Herald of Free Enterprise’ in 1987, is the apt example of the door being unattended properly. Cougar Ace listed by 80 degrees but it did not sink. On 23 July 2006, she was en route from Japan with a cargo of 4,812 vehicles. During an exchange of ballast water south of the Aleutian Islands, she lost stability and developed a 60° list to port. There were reports of a large wave striking the vessel during the ballast transfer, but it is unknown, what effect this had on the loss of stability. US CG successfully rescued the 23 crew members. Cougar Ace later arrived at Portland for unloading.
The turn around period of a PCCs is very fast. A consignment of hundreds of cars can be loaded in a few hours. This includes the time taken for the lashing of the cars. A round voyage is of about a month long for a PCC of 20 knots, loading and discharging at 4 to 5 ports. The cargo loaded at each port is about 800 to 1000 cars.
In most of the ports, the gangs trained and specialized in the methods of loading, lashing and discharging the cargo are mandatory as per required safety standards.
First, the lashing gear (light and heavy straps, chain-lashings, bar-lashing etc.) is collected in bundles with each bundle containing 10 to 20 straps. These are stowed on steel bars on the ship-side, in the holds and in various decks, at uniform distance apart. This is to ensure easy availability for lashing the cars during loading operations. This also gives a chance to make a tally of the gear. The lashings are kept on the side of the ‘loading track-way’ of the next port’s stowage area.
Cleaning of Decks:
All decks are cleaned free of dust, oil stains and the other remains from previous load. Most of the vessels have motor operated sweepers (broom and vacuum suction). Oil stains can be caused mostly from used cars. It is important to have the decks absolutely clean.
Bilges are cleaned and tested at the end of each voyage. Pumps and motors for the ramps are tried out at the commencement of each voyage.
Decks & Deck Panels & Part Open Decks:
Most of the decks are non-movable types. Some of the decks are fully or partly liftable. The panels may be lifted to make way for high cars at decks with inadequate height. Part of the deck may thus be open. These decks are to be fenced off with guard lines.
Signs for speed limits, traffic cones etc. are placed at various positions to regulate speed and guide the route to the loading area.
Rubber mats are placed below the ramps to prevent the damage to jetty during the surging of the vessel. Ramps are properly manned, as this also serves as the entry point for visitors. Some ramps have a passage on the side of the ramp, while others have the walk-way fenced by guard-line. Walkways are painted yellow. Ventilation is switched on at least 30 minutes prior loading commences and is kept on through the entire cargo operation and also till at least 30 minutes after the cargo operations are completed. This is to ensure that the space is free of fumes and Carbon-Monoxide.
The Car-Carrier trade is a ‘fast turn around’ trade. The ship’s head-office has the complete deck plan of the vessel and also the details of the bunkers, ballast and fresh-water. Office is also informed of the sequence of consumption from the tanks. The office has experienced Masters who do the stowage planning ashore; simulate the weights on the computers; and work out the stability.
Most car-trading companies have developed a Stowage Planning System (SPS), by which a stowage plan can quickly be put on the screen of a personal computer. The drawing of each ship and the models of vehicles are fed into the PC along with the details of ballast, FW and bunkers. The office mails this to the Master for approval, well before the vessel’s arrival at the load port.
Pre-Load/Discharge Meeting of Ship’s Staff:
Once the loading plan and the Stability is worked out by the shore planners, it is double checked by the Chief Officer and then approved by the Master. The mate has a meeting with the deck officers, deck crew and cadets. Each of the ship’s staff is aware of the loading plan and the sequence. The ship’s staff is also aware of the positioning of ramps. The laying out of dunnage, lashing chains etc. and the vertical clearances are also noted by each. The Chief Engineer is informed of the time of loading and the requirements for blower.
Most importantly, the tidal prediction for the port is worked out by the Second Mate and is given to the Chief Officer, duty officer, duty-AB, and all concerned. The ramp angles and the middle ramp are adjusted to avoid any damage or delay.
Pre-Load/Discharge Meeting of Ship’s Staff with Stevedores:
Time is an important factor in the highly competitive PCC trade. Therefore, a very professional system is adapted to conduct the cargo operation. A pre-load/discharge meeting is held in the ship’s cargo office between the Stevedore and the Chief Officer. The Duty Officer, bosun and the cadets are also made to attend the meeting. Safety is always of paramount importance in the entire planning.
The sequence of cargo operations viz. opening of hold doors, setting of internal ramps and their operation is discussed amongst the concerned. The cargo plan; the number of gangs to be employed; the details of cargo operation; the probable time and the time required by the stevedores for securing; is also discussed. With all this information in hand, booking of the linesmen, pilot, tugs can be done accordingly. Stability is an important issue discussed during the meeting between the ship-staff and the stevedore. If required, the necessary changes are incorporated.
Whilst the cargo operations are in progress, the lashing/unlashing is done as and when necessary.
The problem areas
Although Ro-Ro s are very successful type vessels, somewhere the safety is not given it’s deserved status. The whole design & many other elements make Ro-Ro ferry a vessel different from the rest. Some of the salient features being:
- Only a few internal bulkheads:
Since, the vehicles normally should be driven to reach the slot allotted, large decks are required. These spaces prove very hazardous in the event of hull breach & even in case of fire.
- Cargo access doors:
The cargo access doors are often at the stern and bow, weakness in the areas most vulnerable to damage. Watertightness can get impaired upon slightest of denting, bending, etc especially when door also serves as a ramp.
The movement of heavy vehicles; ingress of water following damage or from faulty watertight doors; large windage areas; etc. are the areas of concern.
- Cargo access doors very close to the waterline:
Heavy rolling, pitching, adverse list / trim, etc. can get the water enter the hull with the slight leakage.
- Cargo stowage and securing:
A heavy load which breaks loose can cause havoc, even breaking the other lashings. A 10 tonner trailer can move to shipside like a torpedo.
- High casualty index:
Ship’s rapid listing in post damage times; the lack of adequate familiarization of passengers of the ship; makes the casualty number very high.
- Status of subdivision at the time of damage:
There is a fair possibility of the subdivision not maintained in the sea going state, owing to good weather; short routes; close distance from port; convenience for crew or passengers; maintenance reasons, etc. The post damage time available though (to close the doors), is always short.
Among the difficulties which cargo stowage presents to the Ro-Ro operators are the following:
- Advance readiness of lashing material: To keep the lashing material ready is difficult because the space has also to be provided for vehicles to drive & reach the final stow position. Also the range of sizes which may have to be accommodated is really not known.
- Non standard cargoes: Many of the cargoes such as trailers and lorries are designed primarily for road usage they may not be having adequate securing points.
- Internal lashings: Sometimes, the units loaded may have cargoes within, the securing of which may be faulty & the same may not be detectable on board, may cause hazard later.
- Random arrival of cargo units: The order in which, the units arrive sometimes when not known to the ship’s officers, can cause delay & inconvenience.
- Stiff ships: Some cargo units individually may be top-heavy, whereas the ship itself may be very stiff with small roll period. This may cause the toppling of the trailers.
In 1975, IMO and the ILO published guidelines for training in the packing of cargo in freight containers & vehicles. In 1985, revised guidelines were issued. Revised guidelines were intended for valuable contribution to raising safety standards in the port and transport industries. In 1981, the Assembly adopted guidelines on the safe stowage and securing of cargo units in ships, other than container ships (resolution A.489 (XII)).
Ships should carry a Cargo Securing Manual ‘appropriate to the characteristics of the ship and its intended service. In particular, the ship’s main dimensions; its hydrostatic properties; the weather and sea conditions, which may be expected in the ship’s trading area and relevant to the cargo; may be included.
In MSC/Circular 385 issued in January 1985 a uniform approach to the preparation of Cargo Securing Manuals, their layout and content was desired. It covered details of, fixed cargo securing arrangements and location; stowage of portable cargo securing gear and methods of securing; direction & magnitude of forces, likely to act on cargo units in various positions, on board the ship.
In Resolution A.533 (13) states that cargo ‘is stowed on and secured to cargo units and vehicles in most cases at the shipper’s premises and that the cargo on cargo units and vehicles may not always be adequately stowed or secured for safe sea transport’. Also, in the later resolution, it dealt with the requirement of lashing such cargo units.
Code of Safe Practice for the Safe Stowage and Securing of Cargo, Cargo Units and Vehicles aims towards advising Masters of the specific hazards and difficulties associated with the transport of certain cargoes; the stowage and securing of such cargoes; and associated ship handling measures.
Marine Guidance Note (MGN) 19 M is regarding vehicle decks of Ro-Ro ships; accidents to personnel; passenger access; and the carriage of motor vehicles. This guidance highlights the dangers to passengers and crew from moving vehicles, during loading and unloading operations on board Ro-Ro ships. The passengers must be restricted from entering enclosed vehicle decks. The amount of fuel carried in the tanks, of motor vehicles etc must be strictly monitored.
A few more, safety related precautions:
- Vehicle deck becomes a dangerous place due to congestion and the movement of vehicles, owing to flammable fuel in these vehicles. Ship owners and employers have general duty to ensure safety of employees. The danger could be due to atmosphere or accident.
- As per SOLAS, it must be ensured that, without the expressed consent of the Master or the designated officer, no passenger is allowed access to an enclosed Ro-Ro deck, when the ship is underway, except in an emergency.
- Sometimes, at end of a voyage, say when at about two ship’s lengths from the final berth, permission may be granted. Sometimes, a passenger may be allowed for a brief period, accompanied by a crew member.
- Sometimes, it may be reasonable to allow passengers, when the vessel is on a short crossing area and where all vehicles are stowed on an open deck.
- During cargo operations, minimum number of people must be on the decks. Those who are required to be on the vehicle decks as part of their job should be well versed with dangers and the systems in operation, for their safety. They should wear ‘high-visibility garments’. Communication with drivers of vehicles is very important, especially, to alert drivers about any danger.
- Personnel involved in controlling vehicles should avoid obstructing driver’s view.
- Ship’s staff should exercise special care to guide people who are not familiar with vehicle-deck operations.
- Well illuminated, permanently marked signposted walkways should be provided. Suitable barriers should be in place adjacent to doorways.
- The tanks of vehicles are not kept full to avoid spillage. Also, the ignition is switched off. Occasionally, machinery such as a mobile generator may be carried on a vehicle. These have fuel tanks and batteries and present the same hazard as other vehicles. Similar or appropriate precautions are taken in case of motor vehicles propelled by liquefied petroleum gas (LPG) or compressed natural gas (CNG), when carried or when gas cylinders in boats etc. are carried.
- Fire patrol should be maintained on vehicle decks during the passage unless a fixed fire detection system is employed. A television surveillance system is provided.
- A high standard of crew fire drill should be maintained. Adequate air circulation / ventilation system serving the vehicle decks should be operative during cargo operation and during loaded voyage.
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