One means a vote against the carry over. Two means a vote for the carry over. All people decide then expose their vote simultaneously. The first phase is a non-binding vote held before any discussion so we can see which way people are leaning. Next we have a round of discussion.
People can argue for their preference, and listen to other's.
Andrew says some good words about the positive aspects of committing to a challenging route. Then there is a binding vote. We decide to carry the packs up to the ridge, then discussion the carry over again. All this discussion has eaten up a lot of time and I'm beginning to worry about our pace. Steep snow traverse from the pass.