how do you sing like bruce dickinson

[craigc21]

Hi, just wondering, I sing mostley iron maiden songs, and i can sing up to a high D in full voice, but after a while my throat starts to feel tight and i have to stop, i use my diaphragm with the right breathing, it doesnt hurt and i am compleatly relaxed, i dont get it, can somebody please explain the technique to me. Thank You, there are some links below of Bruce Dickinson singing, can someone tell me the what the technique is and how to do it please i realy need your help on this.

The Trooper
http://www.youtube.com/watch?v=BGPoE3DYlUs

Powerslave
http://www.youtube.com/watch?v=K-sUlvXx ... re=related

Hallowed Be Thy Name Live
http://www.youtube.com/watch?v=U3CaieO5O7U