I can only speak from what I have seen in my Squad and the Uk garrison on the whole and that is:
TK's rip the p### out of TD's for being dirty and in need of a good clean up , and TB's for being "tree dodgers".
TD's rip the p### out of TK's for being Eewok foder and afraid of getting dirty, and TB's for being "tree dodgers".
TB's rip the p### out of both TK's and TD's for their inability to sit down, go up stairs etc.
Basically we will take every oppertunity to belittle the other guy.
However, the UK seems to differ from the US in the way friends interact with each other. Over here it is "de rigueur"
ie expected and the done thing to to rip into your mates as a sign of friendship. In my experience you call an American friend a daft barsteward in general conversation and they are liable to take offense, say it to a Brit and they will smile and call you far worse back safe in the knowledge there is a friendship there.