What position should the coupler control lever be in between a PA-4 work car and a flat?

The coupler control lever should be in the uncoupled position when a PA-4 work car is connected to a flat. This position ensures that the coupling mechanism is disengaged, allowing for the two vehicles to operate separately and safely.

In this context, the uncoupled position is crucial for maintenance and operations; it prevents accidental engagement while performing tasks such as loading or unloading materials, or when moving between different work tasks. This separation minimizes the risk of unintended movements that could lead to accidents or equipment damage.

A position like 'locked' refers to securing the coupler in a fixed state, but it does not specifically apply to the situation where the vehicles need to be operationally independent. The coupled position would indicate that the vehicles are actively engaged, which contradicts the need for separation in the scenario described. The maintenance position typically relates to work required on the coupler system or other components and does not signify the operational state between a work car and a flat. Hence, the uncoupled position stands out as the appropriate choice for safe and effective operations during inter-vehicle arrangements.