In light of experience with the transport of road vehicles on ro-ro ships, IMO MSC published guidelines for securing road vehicles on board such ships.
Securing points on ships’ decks
he ship should carry a Cargo Securing Manual, while the decks of a ship intended for road vehicles should be provided with securing points.
The arrangement of securing points should be left to the discretion of the shipowner provided that for each road vehicle or element of a combination of road vehicles there is the following minimum arrangement of securing points:
- The distance between securing points in the longitudinal direction should in general not exceed 2.5 m. However, there may be a need for the securing points in the forward and after parts of the ship to be more closely spaced than they are amidships.
- The athwartships spacing of securing points should not be less than 2.8 m nor more than 3 m. However, there may be a need for the securing points in the forward and after parts of the ship to be more closely spaced than they are amidships.
- The maximum securing load (MSL) of each securing point should be not less than 100 kN. If the securing point is designed to accommodate more than one lashing (y lashings), the MSL should be not less than y x 100 kN.
Securing points on road vehicles
Securing points on road vehicles should be designed for securing the road vehicles to the ship and should have an aperture capable of accepting only one lashing. The securing point and aperture should permit varying directions of the lashing to the ship’s deck.
However, the same number of not less than two or not more than six securing points should be provided on each side of the road vehicle.
Securing points on vehicles should be so located as to ensure effective restraint of the vehicle by the lashings.
Furthermore, securing points should be capable of transferring the forces from the lashings to the chassis of the road vehicle and should never be fitted to bumpers or axles unless these are specially constructed and the forces are transmitted directly to the chassis.
What is more, securing points should be so located that lashings can be readily and safely attached, particularly where side-guards are fitted to the vehicle.
Additionally, the internal free passage of each securing point’s aperture should be not less than 80 mm, but the aperture need not be circular in shape.
Depending on the area of operation, the predominant weather conditions and the characteristics of the ship, road vehicles should be stowed so that the chassis are kept as static as possible by not allowing free play in the suspension of the vehicles.
This can be done, for example, by compressing the springs by tightly securing the vehicle to the deck, by jacking up the chassis prior to securing the vehicle or by releasing the air pressure on compressed air suspension systems
says the IMO.
The air pressure should also be released on every vehicle fitted with such a system if the voyage is of more than 24 hours duration. If practicable, the air pressure should be released also on voyages of a shorter duration.
If the air pressure is not released, the vehicle should be jacked up to prevent any slackening of the lashings resulting from any air leakage from the system during the voyage
Stowage should be arranged in accordance with the following:
- The parking brakes of each vehicle or of each element of a combination of vehicles should be applied and locked.
- Semi-trailers, by the nature of their design, should not be supported on their landing legs during sea transport unless the landing legs are specially designed for that purpose and so marked. An uncoupled semi-trailer should be supported by a trestle or similar device placed in the immediate area of the drawplate so that the connection of the fifth-wheel to the kingpin is not restricted. Semi-trailer designers should consider the space and the reinforcements required and the selected areas should be clearly marked.