Override Firing Mechanism Wheel

A two-foot diameter metal wheel with a spoked design, mounted on a greased central hub embedded in the rocket's control assembly. The wheel's position in the silo requires the Doctor to lean over the exposed mechanism while red smoke billows from the booster behind him. Its turning motion directly governs the override switch Thawn has activated, making it both the focus of the Doctor's desperate intervention and Romana's fear that the action will endanger him.

4 appearances

Appearances in the Narrative

When this object appears and how it's used

4 moments

S16E19 · The Power of Kroll Part 3

Fenner halts station to combat beast

Fenner seizes control of the main flow valve—massive steel wheel requiring multiple hands—demanding it be shut down to stem the flood threatened by the ruptured pipeline. The valve’s central wheel is greased and straining, nearly torn from its sockets, as he fights to override Thawn’s refusal and Dugeen’s hurried technical adjustments.

Before: Functioning within standard operational control, pressure within the primary life-support pipeline steady.

After: Locked in a struggle for closure—either shut by Fenner to contain destruction or left ajar by Thawn to maintain flow.

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S16E19 · The Power of Kroll Part 3

Thawn defies orders to hunt the beast

The massive main flow valve is the focal point of Fenner and Dugeen’s struggle as they attempt to shut it down to halt the flooding caused by the ruptured pipeline. Its heavy wheel is turned with desperate effort while the valve housing shows the strain of the rushing fluids.

Before: Functioning as the primary control for the pipeline, though under visible stress from years of operation.

After: Still being operated under extreme duress; not yet fully closed due to sustained pressure.

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S16E20 · The Power of Kroll Part 4

Doctor risks life to disable rocket

The override firing mechanism's wheel stands central in the Doctor's plan, its turning motion the key to disconnecting Thawn's launch command. Though unseen directly, its presence solely through dialogue propels the entire sequence.

Before: Activated by Thawn, rotating toward launch

After: Position unknown but implied as immediate target for sabotage

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S16E20 · The Power of Kroll Part 4

Doctor and Romana prepare for sacrifice

Though not physically touched here, the override firing mechanism wheel is the stated target of disconnection. Its symbolic presence in the adjacent control assembly and the Doctor’s stated intent to disconnect it drive the entire sequence, turning the abstract control into the deadly fulcrum of their dilemma.

Before: activated by Thawn and exposed on the control assembly inside the silo

After: still activated, but the Doctor’s planned intervention looms as the final gambit

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