Pods are are kept loaded and ready for use until a mission requiring the equipment stored in them, is called upon. For facilitating speed of loading, they are kept in Thunderbird 2's hanger. Jeff Tracy decides which pod will be used to facilitate the rescue; sometimes consulting Brains if there are factors to take into account beyond Jeff's knowledge.
The pods fit within the frame of Thunderbird 2 perfectly, to become aerodynamic and integral with the craft; as well as housing Thunderbird 2's undercarriage for the sole purpose of enabling the combined craft and pod to travel from the hanger to the launch pad.
Pods have doors front and back for loading and unloading of equipment and machines. Integrity of the pod design allows them to be used for the carrying and launch of Thunderbird 4, usually in pod No.4, after it has been dropped from a small height on the sea or lake. Pods make up the integrity of the body of Thunderbird 2. All other pods are deposited on land.
Thunderbird 2 sits perched on it's stilts while the pods move on a conveyor beneath the craft until the pre-chosen pod is directly underneath it. The craft then lowers and locks the pod into it's frame.
Once at the rescue site, Thunderbird 2 unlocks the pod and raises up on it's stilts; this enables the machinery to freely exit the large pod door. During operations over water which involve the use of Thunderbird 4, Thunderbird 2 is able to jettison the pod directly into the water, whereupon Thunderbird 4 is released via rail.
After the rescue the equipment is loaded back into the pod where the docking and un-docking process is repeated in reverse order.