|Equipment & Vehicles|
|Top Speed:||160 knots|
|Main Operator:||Gordon Tracy|
|Appearances:||Thunderbirds Are Go! (TV Series)|
Thunderbird 4 is International Rescue's technologically advanced submarine, with a maximum operating depth of 30,000 feet. Small, but well equipped, it is used for saving innocent lives all around the globe in water based areas such as oceans and rivers. It is piloted by aquanaut Gordon Tracy.
TB4 is the smallest Thunderbird of them all; this helps grant its immense durability and capacity to explore undersea caves, but it also means it is far from convenient enough for the yellow submarine to go to the danger zone by itself, due to limited range and low speed. Thunderbird 4 is therefore airlifted to the danger zone aboard Module 4, one of the six Modules that makes up the centre of the supersonic Thunderbird 2, but should the latter vehicle be unavailable, Thunderbird 4 can leave Tracy Island alone for a mission that is close enough.
Thunderbird 4 can be entered via an underside hatch, which leads straight to the little cockpit (desinged for Gordon to control, however it has managed to squish three other people into it's small space - presumed standing room only (Deep Search)), and a door at the back where rescued people and equipment can be put. Bright lights emit from the very front of the vehicle, allowing Gordon to see in the deepest and darkest of waters. Thunderbird 4 has many small windows on the sides and underneath the cockpit, and even the backdoor has transparent surfaces, further adding to the freedom of exploration. Thunderbird 4 has a flexible fin and two small engines at the back which allow for surprising speed and agility, even though it is still vital for Thunderbird 2 to carry it wherever it needs to go. Where there's Thunderbird 4, there's usually Thunderbird 2.
Height: 10 feet
Length: 32 feet
Length with arms: 34 feet
Width: 15 feet
Cruising speed: 184 m.p.h
Maximum speed: 287 m.p.h
TB4 has two robotic arms that are tucked away on the underside. They swing out when in use, and Gordon controls them directly while looking through the transparent floor to see what he is doing. The left arm ends with a pincher claw, while the right arm can either end with another claw or a plasma cutter.
Located within the side protrusions are torpedoes used for demolition. They also have homing properties, allowing them to hit home on other machines and vehicles.
These can be found on the lower sides of TB4, close to the Robotic Arms. These harpoons, attached to cables like a grapple gun, can be fired forward quick enough to penetrate rock.
The name given to two evacuation pods contained within the same protrusions that store the torpedoes. Fired from the rear, they float swiftly to the surface of the water upon being released. They are big enough to contain one person each, unless perhaps if that person is too tall and/or fat.
- Main article: Thunderbird 4 (TB2015)/Missions
- This version of Thunderbird 4 became the first Thunderbird to be destroyed in action; it was crushed by the Mechanic's remote-controlled submarine during a rescue mission in Up from the Depths Part 1, although Gordon was able to escape in a new Deep Water Exo-Suit.
- The ship was rebuilt by the time the sub was next needed in Lost Kingdom; in City Under the Sea Gordon tells Kayo he has been in trouble with Brains for destroying Thunderbird 4 before, suggesting that it is not too difficult for the team to rebuild damaged Thunderbirds if required.
- Thunderbird 4 has been the only craft (with exception to the Pods) to have another person besides Gordon control it from the pilot seat, Kayo managing to pull some fancy manoeuvres in the little craft to escape the Mechanic in City Under the Sea.