A Design to be put on top of the Seattle Space Needle

I received an email recently, inviting me to participate in a contest for creating a design to be put on top of the Seattle Space Needle (read about it in the Wikipedia). Yes, I have a design proposal, but it is not the type that conforms to the template they have given. What they seem be looking for is well-illustrated at http://www.spaceneedle.com/ This site describes the contest and invites everyone to submit a design if they so wish. The deadline is Sept 20, 2012 and the occasion is the 50^thanniversary celebration of the structure. They wish to get the design up on the roof in six months. Let them do it; there will be plenty of room to add the design proposed here at a later date! What follows is a description of the idea that requires able structural designers to convert into a design. I think it will be very exciting for students of structural engineering and architecture to take this up as a project. The use of composites seems to be very necessary for the proposed construction –materials such as carbon fiber reinforced polymer (CFRP). So, there is the associated challenge of using advanced materials in an imaginative manner.

The Concept: Build a prototype of a Space Elevatorto sit atop the Space Needle. It won’t take you to the altitude of geocentric satellites! But it will drive millions of people to think seriously about the concept. Wikipedia mentions Elevator: 2010, a site that describes prizes worth millions of dollars for technological advances in the area. Perhaps some of the readers of this blog posting would come up with ideas to win some of these prizes!

Why Seattle? Seattle is a city with a number of high tech industries including Boeing and Microsoft. In fact, Microsoft is reported to have sponsored the annual Space Elevator Conferences over the last five years (Visit NASA’s Strong tether challenge). Boeing is using advanced materials such as CFRP to build very fuel-efficient planes, such as the 787 Dreamliner. Right next to the Space Needleis the well-known Pacific Science Center. Between them, the Space Needle and the Science Center draw millions of visitors every year.

The Proposal: To design a tower that will weigh a very small fraction of the 9550 ton Space Needle. It would not carry anyone up but will allow an elevator capsule, with its top and bottom shaped like bullet heads, to run up and down to illustrate the idea. And, of course, this tower would not carry any fancy restaurant on top! The capsule would carry multiple video-cameras, images from which would be projected inside a hall resembling an IMAX theatre, at ground level. Visitors to this theatre would experience virtual reality trips into space. A part of the experience would show the panoramic view from the elevator capsule, as it ascends and descends; the rest would be computer graphics and animation. At the top of the tower will be what looks like another elevator capsule. It will be stationary, but onlookers will hopefully get the illusion that it is on its way up!

Questions:

Can we use four or five columns and enclosing circular rings to create the tower? Putting a skin around a tower might increase wind resistance and achieve little, except increased visibility. So, can the tower be built with no skin around it? Can we run the elevator capsule inside the structure? Should it be supported by a cable made of advanced materials, or would it better to have toothed rails supported by which the battery powered elevator could climb? How can we improve the visibility of the structure during day and during night?

How much weight can the roof of the space needle carry? How can a structure be affixed to the space needle, without disturbing its circular symmetry? What would be the weight of the new structure – can it be as light as 10 to 100 tons? How high will it rise above the roof of the space needle? Can we hope for it to be in the range of 400 to 1000 feet? Can it be designed to withstand the 200 mph winds, and the 9.1 magnitude Earthquake that the space needle is said to be designed for? How much would the whole thing cost? What would be a reasonable cap to put on the cost, to reflect financial realities? Would the proposal generate additional revenue for the space needle and the science center? How would the city benefit from the project?

What are the problems the designers have to solve? How would they ensure the safety of the tower and of aircraft, given that Seattle has lots of sea-planes constantly using its lakes?

Finally, why Seattle, and why not another city, forgetting for a moment the value of the space needle as a base? Why not a place thirty miles outside a big city, to draw crowds to a new place where shops and restaurants could be developed, creating jobs?

A couple of answers: Air safety issues are not a distraction. The real space elevator, if and when it is built, will create a massive air safety problem, not to mention the risks created by satellites orbiting at an altitude much lower than the top of the tower! So, why not handle a small-scale air-safety system for starters?

On the issue of making the elevator visually prominent: The trick seems to be in painting the two capsules in a carefully chosen color to contrast against the sky. It would be valuable to have bright lights on the capsules, to ensure their visibility at night. 

I welcome comments and suggestions. I would also welcome an artistically inclined reader contributing an illustration that does not infringe on other peoples’ Copyright. I tried making a collage out of the Wikimedia image of the KCCI tower and the Wikipedia image of the space needle, but gave up because of my limited skills with graphics!

Srinivasan Ramani