Section 5 Internal movable vehicle ramps

5.1.1 This Section applies to movable internal vehicle ramps installed on ships where the loading or unloading operation is carried out in a harbour or sheltered water, i.e. Standard Service Category.

5.1.2 Where the internal ramp is designed to operate in conditions other than those defined in Ch 6, 5.1 General 5.1.1, the design will be specially considered, i.e. Specified Service Category.

5.1.3 For the the lowered position (harbour), the ramp is to be considered for the worst possible combination of angles and support arrangement (supported by the deck and/or its hoisting mechanism) with respect to the following forces:

1. Self-weight.

2. Applied load.

3. Dynamic forces due to vehicle movement.

4. Forces due to ship’s static inclinations.

5.1.4 For raising and lowering manoeuvres (harbour), the ramp is to be considered with respect to the following forces:

1. Self-weight.

2. Applied load, where appropriate.

3. Dynamic forces due to hoisting/lowering.

4. Forces due to ship’s static inclinations.

5.1.5 For the sea-going condition, the ramp, its supports and locking mechanism are to be considered with respect to the following forces:

1. Self-weight.

2. Applied load.

3. Forces due to the ship motion and static inclination.

5.1.6 The ramp is to be considered with respect to design loads and requirements stated in Ch 6, 2 Loading and design criteria.

5.2.1 The ramp is to be considered with respect to design loads resulting from the following conditions:

1. Case 1 – Loading and unloading operating.

2. Case 2 – Sea-going or stowed condition.

3. Case 3 – Test load condition.

4. Case 4 – Manoeuvring condition.

5.2.2  Case 1: The ramp is to be considered with respect to self-weight plus the applied load multiplied by 1,1, together with the horizontal forces as defined in Ch 6, 5.1 General 5.1.3. This is represented by the following expression:

L _w + 1,1L _c + L _h1 + L _h2 + L _h3

where

5.2.3  Case 2: The movable internal ramp and locking mechanism are to be considered with respect to the force acting on the self-weight and applied load as appropriate resulting from accelerations due to ship motion and static inclination as follows:

1. Loaded sea-going condition.

2. Stowed unloaded condition.

5.2.4  Case 3: The internal ramp and locking mechanism are to be considered with respect for the forces due to the selfweight plus the test load. This case is represented by the following expression:

L _w + L _t

The ramp is further to be considered with respect to self-weight plus the applied test load as applicable to the lifting of the unloaded installation multiplied by 1,2. This is represented by the following expression:

1,2 (L _w + L _t)

where

5.2.5  Case 4: The ramp is to be considered with respect to self-weight plus the applied load, where applicable, multiplied by 1,2, together with the horizontal forces as defined in Ch 6, 5.1 General 5.1.4. This is represented by the following expression:

1,2 (L _w + L _c ) + L _h1 + L _h2 + L _h3

where

5.3.1 In general, for the sea-going condition, stowage locks are to be fitted.

5.3.2 In cases where the internal ramp is stowed unloaded and locked by interlocking the hoisting system, the arrangement must be specially considered.

5.3.3 The actuator that locks the hoisting system must be of an approved type, fitted with internal mechanical lock and has to be tested on board.

5.4.1 In cases where the ramp is lifting with a passenger, the SF for wire rope and items of loose gear must not be less than 6.

5.4.2 Means are to be provided that support the loaded ramp in a safe manner in the event of a failure of one hoisting rope, e.g. balanced double wire system. The loaded internal ramp must be supported in a safe manner and allow the passenger to get off safely.

5.4.3 A sign stating that passengers must be inside their vehicle during the operation is to be fitted.

5.4.4 Means are to be provided to prevent uncontrolled lowering in case of a hydraulic failure. Counter balance valves are to be fitted directly on the hydraulic cylinder.

5.4.5 Any Safety at Work requirements, stanchions, etc. are to be such that any risk of getting stuck is to be avoided. Remaining health and safety requirements of ILO or the appropriate National Flag Administration must be complied with as applicable.

5.4.6 A wheel deflector, preventing the cars from sliding backwards from the ramp during hoisting/lowering in harbour and during the sea-going condition, must be permanently installed. It is to be tested on board to the attending Surveyor’s satisfaction.

5.4.7 In cases where a winch is used for a hoisting system, it is to be equipped with a mechanically and operationally independent secondary brake with separate circuits. The brake is to be automatically activated in case of an emergency stop or in the event of power failure.

5.4.8 The operator is to have a total view of the ramp during the hoisting/lowering operation.