Thunderbird 4 is usually launched from Thunderbird 2's Pod 4, which is fitted with a sliding ramp and magnetic clamp craft-retrieval system.
At launch stations, the six pods slide underneath Thunderbird 2 until Pod 4 is in position. Thunderbird 2 settles down on the Pod and clamps tight ready for launch. On arriving at the danger zone, Thunderbird 2 drops the Pod onto the water. During the flight from Tracy Island aquanaut Gordon Tracy has transferred to Thunderbird 4, and operates the Pod door. Thunderbird 4 is launched down the extended slipway.
Upon return from the mission, the rail is further extended into the water beyond the pod door, whereupon Thunderbird 4 is maneuvered to face forward just above it. Thunderbird 4 lowers itself on to the rail, is clamped in position and the rail retracts onto the ramp.
Launch From Dry LandEdit
Thunderbird 4 can also be launched from the edge of a riverbank or lakeside in the same manor as a launch at sea.
If Thunderbird 2 is out of action, or is simply not needed, then Thunderbird 4 can be launched directly from the island in an emergency. Using four vertical thrust hover jets, the craft leaves the Pod and passes through to the main hangar, turning right towards the doors. A small door in the cliff face opens for Thunderbird 4 to proceed down the runway to the shore line, were the runway pier is lowered into the water.
Thunderbirds Are Go (2015)Edit
Of all the launch sequences in the new show, Thunderbird 4's is probably the most 'identical' to its original counterpart, and yet it's been modernized. For example, the pod (or module, as it's now known) is much wider than it's original counterpart, and we actually see TB4 being lifted up into deployment angle (in the original show, we only saw the slide sliding out into the sea).
The door opens, TB4 is lifted into the deployment angle, the slide slides out into the sea, the engines extend and ignite, and TB4 slides down the slide into the sea. Intriguingly, there's never actually any footage of TB4 going into the sea; instead, there's a few shots above the sea of TB4 deploying, we hear the inevitable splash, and then a shot in the sea.