Actually, we had three people to get across the river. Tim would eat me if he was left on the same side alone (I said he was Dutch, right? That means he's over 6' tall), and arctic_alpine would eat Tim if they were left alone (she was hungry). We decided that trail mix and granola bars (and Tim's Doritos) were enough for lunch, and that we didn't need to lose someone on the trail, so that was the only way to get across with everyone alive. :)
Or... it could handle up to 400 lbs and we didn't want to risk it with everyone together, but we also didn't want to occupy the tram for that long.