What does a control cut-out circuit breaker in the 'OFF' position signify?

A control cut-out circuit breaker in the 'OFF' position signifies that there is no power being supplied to the traction motors. This is crucial for safety and operational integrity. When the circuit breaker is cut out, it disconnects the electrical supply necessary for the traction motors to function, effectively ensuring that the train cannot move. This safety mechanism is essential during maintenance or any situation where power to the traction system should be halted, preventing unexpected train movement that could endanger workers or compromise safety protocols.

The other options do not accurately describe the status of the circuit when it is in the 'OFF' position. For instance, a train being ready to move would require traction power to be engaged, which is not the case here. Similarly, while passenger doors might be locked or safety systems engaged, these functions are independent of the control cut-out circuit breaker’s status. Thus, understanding the implications of a circuit breaker in the 'OFF' position is vital for ensuring safe operations on the train.