Manual are all we use in the freight world, we use the type that have a landing for 2 stair cases on our widebody aircraft. They are heavy and we use our cargo tugs to move them. The single type are a bit lighter but very uncomfortable for anyone with a fear of heights. I would not want to use any manual form of stairs on a widebody aircraft. I believe it would be a bottleneck and I would not want to abuse them in this fashion, the weight they would be exposed to would be far greater. A stair truck is designed for passenger service.