1.1.5 Ro Ro Ships.

1.1.5.1Sketch and label an elevation of a Ro Ro Ships. 1.1.5.2On the above diagram show mid ship ramp arrangement, stern ramp arrangement, car decks, D.B. arrangement, slope ways & gastight zones.

Ship Construction & Stability; Unit-1 DNS - UG/NS/MS/T/204Learn MoreFor use as reference with Side by side workbook

5/12Ver 1Sketch and label an elevation of a Ro Ro Ships. On the above diagram show mid ship ramp arrangement, stern ramp arrangement, car decks, D.B. arrangement, slope ways & gastight zones.Diagram-1: Profile of a Ro Ro Ship

Note: Cadets to Practice drawing this diagram

What are Ro Ro Ships?Roll On / Roll Off - A vessel designed to carry vehicles, so arranged that the vehicles may be loaded and unloaded by being rolled on or off on their own, on ramps fitted either on the sides, bow or stern of the vessel.Where are the cars/vehicles stored? Are their cargo holds?Ro Ro vessels have car decks instead of holds. The vehicle decks run the entire length of the vessel. This makes loading and unloading a simple matter but it does present a number of safety issues, which are unique to this type of ship.

Where are the transverse Bulkheads? What about flooding and spread of fire?Ro-Ro ships do not have transverse bulkheads. The absence of subdivisions is compensated by assigning a greater statutory freeboard. However this does not pose a problem as these ships are never limited by weight, rather they are limited by space or volume.The entire cargo area is well protected by appropriate fire detection & fire fighting system.The accommodation area & living quarters are designated as Gas Tight Zones.

There must be some real advantages of these ships, what are they? For the shipper, the Ro-Ro ship offer a number of advantages over traditional ships, notably speed of cargo handling. As the name of the system implies, cars and Lorries can drive straight on to a Ro-Ro ship at one port and off at the port on the other side of the sea within a few minutes of the ship docking. Ro-Ro ships also integrate well with other transport development, such as containers, and the use of Customs-sealed units (first introduced in the late 1950s) has enabled frontiers to be crossed with the minimum of delay, thereby further increasing speed and efficiency for the shipper.

Diagram-2: Ro Ro Ship

Are there any special features on Ro Ro Ships?The most noticeable feature on a modern Ro Ro ships are the huge ramps often seen on the stern of Ro-Ro ships. These ramps can accommodate two lines of traffic so that loading and discharging can proceed simultaneously. While it is true that the provision of a stern ramp only necessitates the ship lying stern-on to the quay many ships now have ramps over the quarter so that the ship can lie alongside while the ramp provides a skew bridge between ship and quay. The latest large Ro-Ro's have stern ramps which can be slewed through about 42 degrees of arc on either quarter.

Diagram-3: Ramps on a Ro Ro Ship

Note: Cadets to Practice drawing this diagram

Diagram-4: A fixed stern ramp ship docked by the stern

Diagram-5: A QUARTER RAMP SHIP ALONGSIDE

What about side ramps and side doors?Some Ro Ro ships are fitted with side doors/ramps and car elevators. The vehicles once received on the elevators can be transferred to any deck.Diagram-6: A SHIP WITH SIDE RAMP AND ELEVATOR

How are vehicles shifted through decks?On board the Ro-Ro ship there may be two or three vehicle decks and it is quite usual for only one or two of these to be fixed decks. The other 'decks' are formed out of hinged platforms which fold up along the inside of the hull when not in use and which, when lowered, may be height-adjusted to provide adequate clearance for the vehicles on the main deck. Access to these platform decks is by ramps or lifts to and from the main decks.Diagram-7: FOLDING TYPE PLATFORMS FOR MOVING VEHICLES BETWEEN CAR DECKS

Note: Cadets to Practice drawing this diagram