Monday, March 20, 2006

Trussing & Motors

Again, this entry is primarily to build shipping data.
trusses - 12K#
hoists - 5K#

The performance structure consists of 4 29 m. (95') tower structures, joined at the base by a steel i-beam structure and at the top by an aluminum truss structure containing the motor hoist system and catwalks. The overall performance structure, with base, lightning rods and tension cables, will be 120' tall.

Trusses joining the towers wil be 80' spans of composite truss - a 36" tall x 24" wide top truss attached to a 12 x 12 (or 12 x 18) truss below via alum pipe and swivel clamp. By joining the two trusses, load capabilities are increased to 7000# per truss UDL (uniform distributed load).

4 - 80 spans 36 x 24" 6061 truss. 1600# per section, 6400# total
4 - 80 spans 12 x 12" 6061 truss. 640# per section, 2540# total

bracing -
64 - 10' crossbraces - 640' x 1.5#
64 - 14' crossbraces - 896 x 1.5#
256 clamps x 1.5#
total crossbracing weight - 2700#

Trusses and cross-bracing - 11,700#

Split up among the steel containers, trussing should add no additional containers to the performance structure.

CM chain motors may be available in China, although availability is uncertain during the Olympics. Up to 42 hoists are required. Requirements call primarily for 0.5 kg or less in capacity. With 85' chain drops, .5kg hoists will weigh about 100#. Total hoist weight will be approx. 4800# with spares, less cable. Container space will be 6' x 8' stacked 3 cases high. We will bring a total of 48 hoists, with 6 spares. I'll be designing a custom power and control cable distribution system to reduce cable runs. Nearly all hoists will be top mounted, further reducing cabling requirements.

Sunday, March 19, 2006

Tower structure - weight estimates

The following sizes/numbers are for estimation purposes only - primarily as notes for me. The weight limit is 50,000 lbs per container, possibly a bit less. I need to find out road weight limits for China from the port to Beijing, then the road from Beijing to Shanghai.

20' 5' dia bottom section (6000#) with 6 x 6 x 1.5" base (2400#) = 8400# per base
40' 4' mid section (9600#)
40' 3' top section(7200#)
25,200# (11,000 kg) per tower - 2 containers required minimum
towers sleeve together on ground and are then lifted by crane onto base system

Base Sections:
20 x 20 base structure covered with 1" and .5" plate, filled with sand
4 - 20' x 2' 120# I-beam (3/4" web & flange) = 9600#
4 - 20' x 2' 75# channel (6 x 24 x 5/8") = 6000#
1- 20' x 6' x 1" plate = 4800#
2 - 20' x 7' x 3/8" plate = 4200#
steel - 24,600# - total 2 containers required for 4 base sections.

650 cubic ft. sand = 64,000lbs - will fit in each base
total base weight, sand and steel - each = 88,600#

Cross brace beam sections:
Cross braces join each tower base section. Each brace section consists of 2 20" I-beams approximately 48" apart. Beams are joined at the base to smaller 6x4" junior beams, spaced approx. 10' on center. Beams are joined at the top by 1/4" plate. All cable runs thru these beam channels, joined to cable channels built into the bases. A rail system is mounted on 2 of the sections, permitting tracked deployment of heavy machines during the performance.

2 - 60' x 18" x 6" 40# beams = 4800#
6 - 10' x 4' x .25 plate = 2400#
5 - 5' x 6" x 4" 9# beam = 225#

approx. 7500# per section - 30,000# total
filled to 1' would add approx. 100,000 to the base system weight, for a total system weight of 500,000#.

Weight with towers and base system would be approx. 600,000#

Total steel weight is approximately 230,000# - 5 containers minimum.

Extra space in containers will be used for aluminum truss, softgoods and other high volume, low weight items.

Show Site Design for CHINA 2008

The next few posts concern new designs and devices for the proposed performances in Beijing and Shanghai in Summer/Fall 2008. These performances are not fully confirmed yet and have only partial financial sponsorship. We won't have an answer until fall 2006 on our primary sponsorship, but we must begin work regardless. This will be by far the largest installations we have every done.

We will be performing outside in a public square both in Shanghai and Beijing. Neither site location is confirmed, but I am hoping we will be close to the main Olympic Village in Beijing. We are searching for a very large space, at least 100M square - about the size of a city block. This is extremely hard to find in Beijing, especially during the Olympics.

The performances will be free and open to the public. With the current design we can accommodate approximately 20,000 people per performance in a 100M square site (crunched in at 2 people p.s.m.). With 5 weeks of performances and 2 shows per night - 60 performances, we have a potential audience of 1.2 million people in Beijing and a similar sized audience in Shanghai - 2.5 million people. I've also had an inquiry from a Hong Kong company, so a month of performances in Hong Kong is possible in December after Shanghai. With larger sites, a powerful show and excellent marketing, an audience of 4 million is within possibility.

Realistically, we expect an audience of 8000 to 10,000 per show, given the logistics of traffic and transportation and the problems of site management - still an audience of 1.2 million people over the 3 months in Beijing and Shanghai.