On Sun, 02 May 2010 23:44:02 -0500, F. George McDuffee
wrote:

If I understand correctly, the "normal" position of the BOP
is closed, with very considerable force, designed to shear
the normal "string" of drill pipe. The hydraulic
lines/pressure force/hold the BOP open,


Nope..with no pressure, they are open. Add pressure and they close.

Gunner

--

"First Law of Leftist Debate
The more you present a leftist with factual evidence
that is counter to his preconceived world view and the
more difficult it becomes for him to refute it without
losing face the chance of him calling you a racist, bigot,
homophobe approaches infinity.

This is despite the thread you are in having not mentioned
race or sexual preference in any way that is relevant to
the subject." Grey Ghost