BS EN 13852-3:2021 pdf free download – Cranes – Offshore cranes Part 3: Light offshore cranes.
c) where fitted, heave compensation systems and or constant tension systems shall be overridden, i.e. activation of these systems shall be prevented.
5.10.5 Back-up brake
Winches used in luffing and hoisting systems for the lifting of persons shall be equipped with a mechanically and operationally independent back-up brake, with separate control circuits.
The back-up brake shall preferably act directly on the winch drum, but a fully independent load path is considered acceptable.
Means shall be provided for the user to conduct independent testing of the back-up brake.
The back-up brake shall fulfil the requirements given in Annex F (normative) for the rated capacity for lifting of persons.
5.10.6 Back-up motion limiters
Unless the hazard of malfunction of motion limiters are eliminated by other means, back-up motion limiters shall be provided.
5.10.7 Emergency operation system (EOS)
5.10.7.1 Single and common cause failures
Light offshore cranes for the lifting of persons shall be equipped with an EOS to bring the crane and the persons to a safe position in case of an emergency that interrupts or prevents normal operation to be continued. Such emergency includes any single and common cause failures in the main power supply, main power unit or main control system, see Figure 4.
NOTE For practical reasons, such failures need not to include machine actuators (counter balance valves, power transmission elements etc.) or working parts (winches, brakes, hydraulic cylinders etc.), outside the control system as shown in Figure 1.6.
The EOS system is illustrated in Figure 4.
5.10.7.2 Performance
The EOS system shall have capability to operate the light offshore crane with its rated capacity up to and including R0.
The EOS system shall be capable of moving the light offshore crane and its load from any position to a safe position.
The emergency power supply may be a redundant main power supply, an independent secondary power source from the installation, or a from stored energy such as a battery pack in the crane.
The emergency power unit and emergency control system shall be additional to and independent of the main power unit and control system.
The minimum hook velocity for all main functions of the EOS shall be 10% of the values specified in Annex B (normative).
NOTE Limiting and indication devices, as well as protective systems, need not be available during operation of the EOS.
5.10.7.3 Outfitting and marking
Activation controls (switches or handles) tor the EOS shall be of “hold-to-run” type, and clearly and permanently marked for their purpose. Only one main motion needs to be operational at a time.
An emergency stop for the EOS system shall be arranged at the place of operation to shut off the power supply and stop all motions without delay. The emergency stop shall be clearly and permanently marked and may be combined with the ordinary emergency stop, ref. 5.6.5.
A clear and unambiguous procedure for operation of the EOS shall be permanently displayed at the control station (permanent location).
5.10.8 Duplication of components in reeving systems for luffing
Reeving systems for the lifting o’ persons shall be duplicated to prevent uncontrolled dropping of the boom in the event of a single failure in a load bearing component.