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The Intercept Term of Linear Models

6.1 General

6.1.1 Lifting appliances for cargo handling as specified in 4.2.3 are to be provided with the controls, alarms and safety arrangements required by this Section as appropriate.

Alternative arrangements which provide equivalent safeguards will be considered.

6.1.2 Means are to be provided to ensure safe and effective control of speed, direction and stopping of the lifting appliance or ramp.

6.1.3 Each control station is to be provided with means such that the operating area of the lifting appliance and the load being lifted can be observed.

6.1.4 An emergency stop, independent of the controls required by 6.1.2, is to be provided at each control station to stop the motion of the lifting appliances in an emergency.

This emergency stop is to be clearly identified and suitably protected to prevent inadvertent operation.

6.1.5 An alarm is to operate in the event of failure of the operating power and means are to be provided to automatically hold the lifting appliance and load in position.

6.1.6 Indication of the operational status of running and standby machinery, if fitted, is to be provided at each control station.

Engineering Systems

Sections 5 & 6

6.2 Lifts and ramps

6.2.1 Arrangements are to be provided to prevent activation of the control and drive circuits when:

(a) Any covers are not retracted.

(b) The lift is overloaded.

(c) Vehicle barriers are not closed.

6.2.2 Continuous audible and visual warning is to be given within the operational area during operation of the lift or ramp.

6.2.3 Where a lift or ramp is secured by retractable locks, means are to be provided to ensure that power is not disconnected until all locks have been engaged, and descent is not possible until all locks have been disengaged.

6.2.4 Where a quayside access ramp is fitted in addition to a stern door, the ramp is to be less than 10° to the horizontal before opening or closing of the stern door.

6.2.5 The maximum inclination of the access ramp when in its operating position is not to exceed a predetermined angle from the horizontal and an alarm is to operate should this maximum permitted angle be exceeded.

6.2.6 Where remotely controlled locks are used, alterna-tive means are to be provided to secure the lift or ramp in the event of failure of the lock controls or latching mechanism.

6.2.7 A continuous safety trip wire or equivalent is to be fitted beneath sides and ends of cargo lift platforms, and beneath sides and ends of the deck openings. Means are to be provided to automatically stop and hold the lift platform in position immediately the trip is operated.

6.3 Mechanical lift docks

6.3.1 Means are to be provided to indicate at each control station that the motion of the dock platform is maintained in the horizontal plane. An alarm is to give warning in the event that tilt or skew of the dock exceeds a pre-determined limit.

6.3.2 In addition to the normal quay level stop units, independent means are to be provided to automatically stop the lift dock movement in the event of upper or lower overrun.

6.3.3 Where multiple winches or jacks are employed, means are to be provided to:

(a) Synchronize their operation.

(b) Display the load on individual units at each control station.

6.3.4 The total load on the dock is to be displayed at each control station.

6.3.5 Means are to be provided to automatically hold the dock platform in position and operate an alarm in the event of a slack hoisting rope or chain.

6.3.6 Where a dock is secured by retractable locks, pawls or latches, means are to be provided to ensure that power is not disconnected until all locks, pawls or latches have been engaged, and descent is not possible until all locks, pawls or latches have been disengaged.

6.4 Derrick winches

6.4.1 Where a speed change gear is fitted and the hoisting drum is free to rotate when the gear is in the neutral position, means are to be provided to prevent the gear accidentally disengaging during operation. An automatically applied brake is to operate on the drum side of the change gear when neutral is selected.

6.4.2 Where a single motor is employed to position both the jib and the load, means are to be provided to interlock the jib when the motor is being used for hoisting.

6.5 Cranes

6.5.1 Means are to be provided for the control of hoisting, Iuffing angle, slewing angle and the positioning of travelling cranes as applicable.

6.5.2 Means are to be provided for emergency operation, to enable any load to be safely lowered and positioned.

6.5.3 Protective devices are to be provided, as applicable, to operate alarms, automatically cut off operating power and hold the crane and load in position in the event of a failure of the operating controls for the following:

(a) Hoist travel.

(b) Hoist speed.

(c) Luffing angles.

(d) Slewing angles.

(e) Travel of crane along its track.

(f) Longitudinal and transverse movement of the trolley on its gantry.

6.5.4 For variable load/radius cranes a load indicator which automatically displays a maximum safe load at a given radius is to be fitted. An alarm is to operate when the load reaches 95 per cent of the SWL and at 110 per cent of the SWL the operating power is to be automatically cut off.

6.5.5 Slack rope switches are to be fitted to each rope system. A suitable time delay may be fitted when operating conditions necessitate this feature. Operation of a slack rope switch is to initiate an alarm, automatically cut off the operating power and hold the crane and any load in position.

6.5.6 Where controls are located on the crane mast, means are to be provided to enable the operator to summon help in an emergency.

6.5.7 In the case of travelling cranes a continuous audible warning is to be given within the operational area when the crane is to move/is moving along its track.

Engineering Systems

Section 6

6.5.8 In the case of offshore and floating cranes the following is to be provided:

(a) A wind speed indicator and alarm when wind speed exceeds a predetermined limit for a given time.

(b) Crane level indication with operating limits. (When conditions of list or trim are specified).

(c) Means of communication between the crane operator and the signalman such that control of the crane is not impaired.

(d) A hook load indicator.

Engineering Systems

Section 6

2.1.4 The material is to be identified to documents signed by LR's Surveyors certifying compliance with the Rules and Regulations for the Classification of Ships.

2.2 Alternative specifications

2.2.1 As an alternative to 2.1.1, and subject to agreement, materials which comply with Section 3 may be accepted provided that these specifications give reasonable equivalence to, and the survey is carried out in accordance with the Rules for Materials.

■ ■ Section 3

Materials to national or