Von Fourche wrote:
How exactly were the rockets held in place when they were on their
launch pads during the Gemini and Apollo missions? They simply
didn't sit
on their engines. How did the launch pad hold up so much weight?


Titan IIs sat on four points (longerons) that were on the
base of the first stage fuselage. These points were also
where the engine thrust frame attached to the missile.
You can see the set up in these photos.

"http://www.spectrum.ieee.org/WEBONLY/wonews/apr05/0405napola.html#sb1"
"http://www.geocities.com/titan_2_missile/images/gallery15.jpg"

The launch stand both supported the rocket from below and
held it down during thrust build up before releasing.
Atlas had two hold-down mechanisms that accessed
fittings hidden inside doors on the nacelles. (Watch
an old Atlas launch closely and you'll see the arms
retract and the doors slam shut at liftoff.) Saturn V
had four massive hold down arms. Saturn I had *eight*
arms altogether (four support and four hold-down).

- Ed Kyle