MLG DEPARTS ON DISPLACED THRESHOLD AND BLOWS OVER; BREAKS BARRICADES.

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AFTER CALLING FOR TAXI WE WERE CLRED TO TAXI TO RWY 8 FOR DEP. LBB GND ASKED IF WE WERE FAMILIAR WITH THE DISPLACED THRESHOLD ON RWY 8. I RESPONDED BY SAYING YES WE ARE; BUT THINKING THAT WAS A WASTED XMISSION AS WE'RE DEPARTING NOT LNDG. A DISPLACED THRESHOLD DOESN'T APPLY TO US. WE TAXIED TO RWY 8 VIA 'F' AND 'M'; CONTACTED TWR AND WERE CLRED FOR DEP. BEING HVY AND FACED WITH A SHORTENED RWY THE CAPT POSITIONED THE ACFT TO TAKE ADVANTAGE OF ALL THE AVAILABLE RWY. AFTER A NORMAL DEP WE WERE TOLD ABOUT BLOWING OVER AND BREAKING SOME BARRICADES. WE CONTINUED TO OUR DEST AND UPON AN UNEVENTFUL ARR CALLED LBB TWR. DURING OUR CONVERSATION WITH THEM WE FOUND OUT THAT WE WERE THE 3RD ACFT TO DO THAT TODAY. SOUNDS LIKE A COM PROB. IN THE DEFINITION OF A DISPLACED THRESHOLD IT STATES SEE THRESHOLD. THE DEFINITION OF THRESHOLD IS 'THE BEGINNING OF THAT PORTION OF RWY USABLE FOR LNDG.' WHICH MEANS YOU CAN USE IT FOR DEP (I.E.; TAXI AND TKOF) BUT NOT FOR LNDG. WHAT SHOULD BE USED IS A DISPLACED TKOF POINT. SAME AS USED ON RWY 1L AT SFO. WE CONTACTED OUR SUPVRS TO GET THE INFO OUT ABOUT THE CONFLICTING WORDS.