Valve interlock systems for use with railcars

A valve interlock system for use in a railcar, the railcar including a tank and a bottom outlet valve assembly coupled in flow communication with the tank, the tank substantially defining a tank cavity, the bottom outlet valve assembly configured to release product from the tank cavity, the bottom outlet valve assembly including a valve and a valve stem coupled to the valve and extending longitudinally therefrom, said valve interlock system comprising a valve stem rotation restriction subsystem comprising:

• a longitudinally and rotatably translatable body comprising:
• an outer surface extending about a longitudinal axis;
• and
• a rotation restriction device coupled to and extending transversely from said outer surface;
• and
• a collar partially extending about said body, wherein said collar and said rotation restriction device are configured to permit longitudinal translation of said body only while the bottom outlet valve is in a substantially closed position and allow rotational translation of said body only while said body is substantially fully inserted longitudinally.

A railcar comprising:

• a tank substantially defining a tank cavity;
• a bottom outlet valve assembly coupled in flow communication to said tank, said bottom outlet valve assembly configured to release product from said tank cavity, said bottom outlet valve assembly including a valve and a valve stem coupled to said valve and extending longitudinally therefrom;
• and
• a valve interlock system comprising a valve stem locking subsystem comprising:
• a coupling device rotatably coupled to said valve stem, said coupling device defining an engagement slot thereon, said coupling device substantially stationary in the longitudinal direction and rotatably translatable about a longitudinal axis;
• a stationary support member extending toward said valve stem coupling device in a transverse direction substantially perpendicular to the longitudinal direction, said stationary support member defining a cavity proximate said coupling device;
• a locking member at least partially positioned within said cavity, said locking member transversely translatable and complimentary with said engagement slot;
• a biasing device at least partially positioned within said cavity, said biasing device coupled to said locking member and configured to increase an engagement bias as said locking member is transversely translated away from said engagement slot;
• and
• a valve operator assembly configured to rotate said coupling device and said valve stem to open and close said valve, said valve operator assembly comprising a longitudinally and rotatably translatable body configured to regulate the slot engagement bias as a function of a longitudinal position of said body.