Safe Key sequencing systems (interlocking) for access control

These serve as safety devices on equipment and access points for:

- access to dangerous machinery

- access to hazardous areas

- maintenance

- electrical panels / switchgear

- catenary

- loading / unloading



Main Circuit Breakers
Mechanical interlocks are fitted to main circuit breakers to prevent racking-out if still in the ON position. Care must be taken not to exert undue force the breaker will not move, otherwise damage may be caused to the interlocks and other mechanical parts.
Electrical interlock switches are connected into circuit-breaker control circuits to prevent incorrect sequence operation.
When a shore-supply breaker is closed onto a switchboard.
The ship’s generator breakers are usually interlocked OFF to prevent parallel running of a ship’s generator and the shore supply.

CO2 Control
The CO² extinguishing system needs to be isolated and put in a safe state (towards atmosphere) before entry to the area

Starting and testing emergency generator
An interlock is required so that the emergency generator and Main power of the ship cannot be supplied together

Interlocking Switchgear
Interlocking switchgear ensures that personnel remain safe and equipment is operated to the correct
procedures. Using a well-designed interlocking scheme will ensure that personnel cannot access
potentially dangerous areas without the switchgear system being put in a safe state. A good interlocking
scheme will also ensure that the system operates correctly and there is no chance of, for example,
switching two incoming feeds on to a common bus bar. This ensures that the equipment is not damaged
and the risk of fire and arc flash are greatly reduced.
Processes where interlocking in switchgear are particularly relevant are:
•Personnel access
•Earthing systems
•High, medium and low voltage hazards
•Switching incomers on to common supply busbars
•Switching UPS systems and generators on to common supply busbars
•Controlling the supply from multiple incomers

Running direction interlock
Interlocks are the blocking devices which ensure that the engine is started or reversed only when some conditions are fulfilled or satisfied. Running direction interlock is an essential trait that prevents the injection of fuel to the engine when the telegraph doesn’t synchronise with the running direction of the engine. It is an important application in the crash manoeuvring when the starting air is used to apply brakes on the engine by reversing the operation.

Turning gear interlock
Turning gear interlock is another important thing that prevents the admission of starting air to the engine cylinders when the turning gear is engaged. If the starting air is admitted with the turning gear engaged, then the turning gear along with the motor will fly off puncturing the bulkhead. Thus the interlock is necessary to prevent such accidents.

Valve interlocks
Valve interlocks prevent human errors and guide valve operator through predefined valve operating sequences. Unique keys are used to only allow the right valves to be opened or closed in the correct order.

Ship to shore power
Interlocks can be used in many process or procedural systems within Ports involving the transmission of electricity, including crane movement, ship to shore power, and local substations or backup generators.

Key Management
With Smart key Management
A key management combination with real-time traceability. Using RFID technology to guarantee a high level of reliability, the Smart Key Manager can accept multiple key modules, controlling a total of 128 keys.
The system indicates which keys are present in or absent from the cabinet, who has taken each key and when. Via email, managers can choose to be kept informed of key movement, inform others and monitor several levels of administrators.
Full or partial access to keys can be given remotely via the interface, ensuring that individuals can only access keys relevant to them. The Smart Key Manager offers three levels of security by requiring users to prove their identity with a badge, PIN code or a combination of the two.