Has anybody out there written a performance specification for lifting criteria (NOT the device ,hoist, crane etc) like:
Restrictions on access;
Available staging areas for helicopters if used
Required load capabilities;
Restrictions on roof access and loading etc.
I’m building one for a strange little project - put a 80,000 lb window washing crane on a roof platform 30x60 feet in size; 750 feet in the air surrounded by a larger roof of all glass; in a crowded downtown; add 8 columns to the interior of the upper most two stories, occupied throughout construction by a high priced tenant (to keep it from collapsing the roof)
Im going to look at crane and hoist specs and start removing the device specific stuff and concentrate on the performance
You might ask the suppliers of the equipment for help - Trachtel presented a good lunch ‘n’ learn.
Hopefully Tractel will be bidding the window washing telescoping crane — but HOW to get the equipment on top of the roof is the issue and the window washing companies DONT know or want to do that. We are talking to helecopter companies and to derrick crane companies and we don’t care who does it just that they accomplish the task.
Once when replacing an AHU in a building with no access save through a window that overlooked a courtyard, we used a helicopter. One attempt had to abort because of the winds. Be sure to add something about weather permitting…
Wow, Mark!! If this is one of your little projects, what is a big one? …750 feet must be 50+ stories. How did they build it in the first place? …cranes?
My first two recommendations are: (1) as you say, keep the spex a performance type, and (2) hire the very best clerk-of-the-works you can get. This kind of a project will most likely generate more flaps than a flag in a hurricane.
Several years ago I worked on a similar project scenario on the Naval Medical Library in Bethesda Maryland which was only 10+ stories but had to either place a crane thru the roof of the cafeteria and/or create access holes through the roof for use by helicopters. IIRC, the very heavy equipment was capable of being broken down into small components which were reassembled at the Penthouse level. We ended up replacing one of the elevators with a large capacity freight elevator. This wont help with your major structural members but will help with the other construction materials. Also, it will stay in place for continued and future use. It might be worth running the numbers.
Marc,
This sounds like the kind of project where the owner should conduct a qualifications-based contractor selection process first, then work with them about the best means and methods to get the project done. I’m not sure that I’d want to be in the position of designing the method of access.
John, those were pretty much the first words out of my mouth followed by such phrases as design-build and, time and materials but, (wait for it) this job “shall be” design-bid-build because for all its complexity it is below the cost threshold for gc/cm (cm/gc) in this state.
Remember architecture is mostly creative stealing.. I mean..uh..honoring those who have published before us.
Anyway, I’m going to start with a couple of temp facilities sections I have and a section on lifting equipment I web searched from an oil company.