I've worked it out before, and found that the same machine is in different pods in different episodes. So I was wondering if there was any actual order to the contents of the Pods in Thunderbird 2? e.g. all fire-related machines in a certain pod (like we see in Security hazard when most vehicles are used in fire fighting). There are also a number of episodes where it is suggested they take a certain pod for the mission, suggesting some order. If not, and the pods are just filled with vehicles unique for the mission, then why have multiple pods and not just store the vehicles in the storage area we see in Cry Wolf?
According to the wikipedia article, the only vehicle that seemed to have a permanent association with a pod was Thunderbird 4 - it was always in Pod 4 (and Pod 4 was not used for other vehicles). There are also many more vehicles than pods.
It may well be that the pods had standard equipment loadouts (so Pod 1 had gear that Pod 3 didn't, for example) - but the vehicle varied to fit the mission. That would mean that any particular mission could easily be catered for by selecting one pod and one vehicle.
I did a bit of research and found the following:
- Fire Truck
- Jet-Air Transporter
- Neutralizer Tractor
- Electromagnetic Grabs
High Speed Elevator Cars
Laser Cutter Vehicle
Thunderbird 6 (surely this would be pod 6?)
However, bear in mind this does not take into account all pod vehicles, but all listed here were only ever seen in these pods (e.g. The Mole was seen in many pods, but mainly Pod 5)