A more detailed view on the happy/sad pin orientation that I briefly mentioned in the pin-locks post. Thanks to Todd from Apex for pointing this out to me. Since I had a hard time wrapping my head around the whole thing I made a few pictures to make sure everyone knows what I’m talking about. The first two pictures show pin and bridle on a packed rig as if you could look through the bridle.
Scenario 1: The pin is “sad” and retainer tab sits on the bottom of the eye of the pin like in the pictures above. When pulling the bridle straight up and away from the container, therefore force is applied in “normal” pull direction the pin will first rotate in the loop and then slide out of the loop.
This works like a charm and required force for both steps to happen should be rather low, of course depending on loop tension. (The term “pin tension” is a little misleading in this context because it normally addresses the force required to pull the pin, since this is the variable part here I go with “loop tension” when I really mean the tension of the loop.)
The force required to pull the bottom pin of my slider down rig (the one in the pictures) in this scenario is approximately 0.25 kg (~0.5 lbs), the pins were fully set.
Scenario 2: The pin is “happy” and retainer tab sits on the bottom of the eye of the pin like in the pictures at the top of this post. When pulling the bridle in “normal” direction, the pin cannot rotate in the loop like in scenario 1 because it’s tip tries to dig into the container, levering against the force applied by the bridle on the eye-end of the pin. So the pin has to turn around the loop before it can start sliding out of it.
The force required to pull the pin increases significantly compared to scenario 1, the pull force measured on same rig as above reached up to 3 kg (~6.5 lbs), therefore around the ten-fold of the first measurements. (Again the pins were fully set.)
At higher airspeeds this is going to be less of an issue due to the increased pull force of the PC (and changing angle of the applied force as soon as you start moving forward / tracking / wingsuiting), but can become a problem if you’re doing short delays where you don’t want to have any hesitations in the opening process.
Scenario 3: The pin is pointing straight up. In this case the pin will turn in the loop to either, a more “sad”- , or a more “happy”- orientation, whichever is closer. From there scenario 1 or 2 applies.
To sum this up. Pin orientation matters! Do a pincheck before you jump, have the pins in a “sad” orientation, and if you’re going for a short delay, prime the pins, and leave your pin protector flap open.