shockwaves:
I agree with your technical explanation regarding the difference between stairways and ladders, but I don’t agree with your reasoning that stairways are safer than ladders.
I don’t believe that stairways on 747s and A380s, for example, are any safer than the ladders proposed in the ABH design. Or, for that matter, escalators aren’t very safe either. It’s true, they are stairways, but they are usually very long; they move; they have pointy, jagged edges; and they are made of hard metallic material. I’m a fit and careful person, and I’ve lost my balance in escalators more than once. In my opinion, they’re much more dangerous than the ladders we propose in the ABH design.
About baggage, passengers—even those traveling in the third tiers—will be able to get their carry on luggage up to their seat before climbing the ladder. This is possible because the design permits for the third tiers to be roughly as high as baggage compartments in conventional airplane cabins are today, which are set at about eye level of an average height male. In fact, this would be even better, because passengers would not have to lift their bags over the unprotected heads of other sitting passengers in order to place them in the baggage compartment.
juslight:
I think that stair design would be an obstruction for the aisles.