That's been my contention for quite some time, The top level of the elevator shack houses the motors for the elevators and the bottom level is for access to the elevators themselves. only question is is it just the top of the elevator or can you bring the whole car up to that lower level.
from my googling both options are viable. i'm thinking with no service elevator in the building having one or both of the elevators able to reach roof top access for moving equipment would be an option. obviously larger things like the water tanks themselves would have to craned up to the roof when the building was built (no helicopters in the 20's)
Usually there is a grate for a small enclosure within the shaft if it is a machine-less roof. However that could have been built after the fact while upgrading the elevator system. If you look up elevator surfing on Google and on YouTube. You'll notice in some of the videos, when they get to the top floor you will see a hatch or grate in the ceiling. To my understanding these are in more modern structures.
In any building it would still be necessary to have access to the hoist / elevator shaft and I assume that area is located in that room to gain access, most likely via a grate/ hatch and must be possible for a person to fit through that area. I also assume that is what you are referring to. In the second link the original purpose of the group that decided to ride the top of the elevator was to gain access to the roof to watch fireworks. It's common for people who elevator surf to do it to gain access to areas that are otherwise off limits to them.
Either way, if the machine room has access to the elevator shaft then a body could be placed onto the top of the elevator and brought to the roof.
Proper ventilation / cooling equipment for the mechanical equipment is necessary for all elevators and is most likely also in the machine room with a ventilation fan that runs into the shaft.
[ame="http://www.youtube.com/watch?v=tKiztsibvic&feature=youtube_gdata_player"]Otis Gen2 Machine Room-less (MRL) Elevator Surfing - YouTube[/ame]
http://gene.greger-weltin.org/elevator_surfing/
Article on machine rooms
http://www.syska.com/thought/articles.asp?art=424
All you would need to access the top of most elevators is a drop key or a bent piece of metal to gain access. Takes about 10 secs to open. From there , controls are on the top of the elevator that allow you to stop normal access and control the elevator, there's even a light.
[ame="http://www.youtube.com/watch?v=QlSxIcoAyrA&feature=youtube_gdata_player"]HOW TO: ELEVATOR SURFING: picking the outer door interlock - YouTube[/ame]
http://www.capitolfiretraining.com/...ticle&id=100:creating-elevator-drop-key-holes
Would have been great if the Chinese investigators had filmed in the maintenance room but I am supposed to be going with a few others from this forum soon. If the trip happens I'll bring a flashlight and try to enter the maintenance room to look around, possibly film inside the room. Also, curious if the elevator doors allow for drop key access. It's a small round hole at the top corner on the outside of the elevator.
Haven't seen any video of the outside elevator doors on the upper floors and cannot access the Chinese investigator videos on my tablet. Anyone notice a small hole at the top of the elevator door in any of those videos? The elevator appears to be an Otis but not sure which model. Any ideas on the model type?
Can't say I suspect that was how the body was transported to the roof. I can't imagine someone bringing an elevator up to the 14th floor, and then running back up to 15, carrying a body over and riding it to the top to gain access to a roof hatch, but anything is possible I suppose. I just don't see someone taking that risk in the halls though.
Then again, carrying a body up a fire escape is a hell of a risk too