Construction of the Space Needle

7/21/2019 Construction of the Space Needle

1/23

1

`CHAPTER 1: INTRODUCTION

The Space Needle is a tower in Seattle, Washington and a major landmark of

the Pacific Northwest region of the United States and a symbol of Seattle. Located at

the Seattle Center, it was built for the 1962 World's Fair. The architecture of the

Space Needle is the result of a compromise between designs of two men, Edward E.

Carlson and John Graham, Jr.

The proposed Space Needle had no land on which to be built. Since it was not

financed by the city, land had to be purchased that was within the fairgrounds. The

investors thought that there would be no land available to build a tower and the search

for a site was nearly dead when, in 1961, they discovered a plot, 120 by 120 feet (37

by 37 m), containing switching equipment for the fire and police alarm systems. The

land sold for $75,000. At this point, only one year remained before the World's Fair

would begin.

It was privately built and financed by the "Pentagram Corporation" which

consisted of Bagley Wright, contractor Howard S. Wright, architect John Graham,

Ned Skinner,andNorton Clapp.In 1977 Bagley, Skinner and Clapp sold their interest

to Howard Wright who now controls it under the name of Space Needle Corporation.

With time an issue, the construction team worked around the clock. The top

dome housing the top five levels (including the restaurants and observation deck) was

perfectly balanced so that the restaurant could rotate with the help of one tiny electricmotor, originally 0.8 kilowatts (1.1 hp), later replaced with a 1.1 kilowatts (1.5 hp)

motor. With paint colors named Orbital Olive for the body, Astronaut White for the

legs, Re-entry Red for the saucer, and Galaxy Gold for the roof, the Space Needle was

finished in less than one year.
http://en.wikipedia.org/wiki/Bagley_Wrighthttp://en.wikipedia.org/wiki/Howard_S._Wrighthttp://en.wikipedia.org/wiki/Ned_Skinnerhttp://en.wikipedia.org/wiki/Norton_Clapphttp://en.wikipedia.org/wiki/Norton_Clapphttp://en.wikipedia.org/wiki/Ned_Skinnerhttp://en.wikipedia.org/wiki/Howard_S._Wrighthttp://en.wikipedia.org/wiki/Bagley_Wright


2/23

2

It was completed in April 1962 at a cost of $4.5 million. The last elevator car

was installed the day before the Fair opened on April 21. During the course of the

Fair nearly 20,000 people a day rode the elevators to the Observation Deck. The

20,000 mark was never reached, missed by fewer than 50 people one day. At the timeof construction, it was the tallest building in the West, taking the title from theSmith

Tower across town that had held that title since 1914.

1.1 SPECIALITIES OF SPACE NEEDLE

The Space Needle was built to withstand wind speeds of 200 mph, double the

requirements in the building code of 1962. An earthquake registering 6.8 on the

Richter scalejolted the Needle enough in 2001 for water to slosh out of the toilets in

the restrooms. The Space Needle can escape serious structural damage during

earthquakes of magnitudes below 9. Also made to withstand Category 5 hurricane-

force winds, the Space Needle sways only 1 inch per 10 mph (16 mm per 10 km/h) of

wind speed.

For decades, the "hovering disk" of the Space Needle was home to two

restaurants 500 feet (150 m) above the ground: the Space Needle Restaurant, which

was originally named Eye of the Needle, and Emerald Suite. These were closed in

2000 to make way for SkyCity, a larger restaurant that features Pacific Northwest

cuisine. It rotates 360 degrees in exactly forty-seven minutes. In 1993, the elevators

were replaced with new computerized versions. The new elevators descend at a rate

of 10 miles per hour (4.5 m/s).

On December 31, 1999 (New Year's Eve), a powerful beam of light was

unveiled for the first time. Called the Legacy Light or Skybeam, it is powered by

lamps that total 85 millioncandelas shining skyward from the top of the Space Needle

to honor national holidays and special occasions in Seattle. The concept of this beam

was derived from the official 1962 World's Fair poster, which depicted such a light
http://en.wikipedia.org/wiki/Smith_Towerhttp://en.wikipedia.org/wiki/Smith_Towerhttp://en.wikipedia.org/wiki/Richter_Scalehttp://en.wikipedia.org/wiki/Saffir%E2%80%93Simpson_Hurricane_Scalehttp://en.wikipedia.org/wiki/New_Year%27s_Evehttp://en.wikipedia.org/wiki/Candelahttp://en.wikipedia.org/wiki/Candelahttp://en.wikipedia.org/wiki/New_Year%27s_Evehttp://en.wikipedia.org/wiki/Saffir%E2%80%93Simpson_Hurricane_Scalehttp://en.wikipedia.org/wiki/Richter_Scalehttp://en.wikipedia.org/wiki/Smith_Towerhttp://en.wikipedia.org/wiki/Smith_Tower


3/23

3

source although none was incorporated into the original design. It is somewhat

controversial because of thelight pollution it creates. Originally planned to be turned

on 75 nights per year, it has generally been used less than a dozen times per year. It

did remain lit for eleven days in a row from September 11, 2001, to September 22,2001, in response to theSeptember 11, 2001 attacks.

The same 1962 World's Fair original poster showed a grand spiral entryway

leading to theelevator,but this, too, was omitted from the final building plans. This

stairway was added as part of the Pavilion and Spacebase addition/remodel in June,

2000. The main stairwell (generally emergency access) has 848 steps in all from the

basement to the top of the observation deck. At approximately 605 feet (184 m), the

Space Needle was the tallest building west of theMississippi River at the time it was

built byHoward S. Wright Construction Co., but is now dwarfed by other structures

along the Seattle skyline, among them the Columbia Center, at 967 feet (295 m).

Unlike many other similar structures, such as the CN Tower in Toronto, the Space

Needle is not used for broadcasting purposes.

1.2 ROTATING RESTAURANT

The restaurant could rotate with the help of one tiny electric motor, originally

0.8 kilowatts (1.1 hp), later replaced with a 1.1 kilowatts (1.5 hp) motor. The entire

Space Needle saucer does not rotate, only a 14-foot ring next to the windows rotates

on the SkyCity restaurant level.

1.3 THE ELEVATORS

Two of the Space Needle elevators are high speed and can travel at a rate of 10

mph, or 800 feet per minute. Actual travel time from the ground level to the top-house

is 43 seconds. Under high wind conditions these high-speed passenger elevators are

slowed to 5 mph. The third elevator, primarily used for freight but occasionally used

to carry passengers, only travels at 5 mph, or 400 feet per minute. The Space Needle
http://en.wikipedia.org/wiki/Light_pollutionhttp://en.wikipedia.org/wiki/September_11,_2001_attackshttp://en.wikipedia.org/wiki/Elevatorhttp://en.wikipedia.org/wiki/Mississippi_Riverhttp://en.wikipedia.org/wiki/Howard_S._Wrighthttp://en.wikipedia.org/wiki/Columbia_Centerhttp://en.wikipedia.org/wiki/CN_Towerhttp://en.wikipedia.org/wiki/CN_Towerhttp://en.wikipedia.org/wiki/Columbia_Centerhttp://en.wikipedia.org/wiki/Howard_S._Wrighthttp://en.wikipedia.org/wiki/Mississippi_Riverhttp://en.wikipedia.org/wiki/Elevatorhttp://en.wikipedia.org/wiki/September_11,_2001_attackshttp://en.wikipedia.org/wiki/Light_pollution


4/23

4

elevators weigh 14,000 pounds each with a capacity of 4,500 pounds. The counter-

weight weighs 40 percent more than the elevator fully loaded. Each elevator carries

25 people. Each elevator has seven cables total, even though one cable is strong

enough to hold the entire weight of the elevator. Space Needle elevators are equippedwith a governor brake that would lock the elevator on the tracks in case all seven

cables broke.

1.4 OTHER SPECIALITY

There are 25 lightning rods (24 actual rods plus the tower) on the roof of the

Needle to withstand lightning strikes. The Space Needle can escape serious structural

damage during earthquakes of magnitudes below 9.


5/23

5

CHAPTER 2: CONSTRUCTION PROCESS

The construction was driven by private funds, and finding an appropriate

location proved to be so difficult that the project was just about to be terminated whensuitable ground was finally found, only 13 months before its deadline for the 1962

World Fair.

Due to the condensed construction schedule, the Seattle Space Needles legs

and observation pod had to be prefabricated in several sections and then quickly

erected and secured in place. To offset the top heavy loading, the Space Needles

center of gravity was lowered all the way down to ground level by means ofanchoring the three legs to an oversized solid concrete slab 9 meters (30 ft.) thick,

thus matching the entire weight of the exposed structure above.

The deadline for the World's Fair was barely met as the second elevator arrived

and was installed just one day prior to the grand opening.

Fig. 2.1 Early Space Needle sketches


6/23

6

Artist Edward E. Carlson made the first initial sketches for what the Seattle

Space Needle would later become on a napkin at a coffee house. It later went through

many changes as architect John Graham and associates perfected the "flying saucer"

look.

In 1962, the Space Needle was painted orange, then after 1962 it was painted

white. In 2012 the top of the Space Needle was re-painted orange to celebrate the

Seattle Space Needle's 50th Anniversary.


7/23

7

CHAPTER 3: FOUNDATION

3.1 CONCRETE BASE

The Space Needle started construction in April of 1961. As digging began, the

120-foot by 12-foot (depth 30 feet) hole slowly filled with 5850 tons of concrete and

steel. Anchoring the massive Space Needle, there would be more weight underground

than in the tower itself.

The base is Y-shaped. There is an over-all block of concrete under the

structure, 12 ft. wide with arms 44 ft. long. The base is founded on clay and hardpan.

At the end of each of the three arms is a pedestal rising 18 ft. in height. These three

pedestals serve as the bases for the three sets of two legs each. The base used 2,819

cu. Yd. of concrete and 250 tons of reinforcing steel.

The concrete foundation was specified as a monolithic structure and the

Wright firm marshaled its resources for a single lift pour. The contractors best

concrete men were pulled from other jobs and off-duty policemen were engaged to

handle traffic at the site. Markers were placed on the area around the excavation to

guide the Pioneer Sand & Gravel Co. ready-mix trucks. The trucks hauled up to 300

cu. yd. per hour. The entire pour was made in 11 hours and 45 minutes.


8/23

8

Fig 3.1 Y-base of the foundation

fig 3.2 Reinforcement for the Y-base

The steel legs of the needle are fastened to the pedestals by 72 anchor bolts

which were set in place prior to the pour. The anchor bolts reach 30 feet into

underground concrete.


9/23

9

CHAPTER 4: STEEL CONSTRUCTION

4.1 STEEL STRUCTURE DESIGN

The main part of the Space Needle structure is a truncated triangle tower of

three pairs of steel legs built around a structurally working triangular core. If a circle

were to be drawn through the three pairs of legs at the base its diameter would be 102

ft. Each leg is anchored to the concrete base by 12 ASTM 8625 anchor bolts, 32 ft. 8

in. long and 4 in. diameter. Each bolt weighs a ton. A leg consists of three 36-in.-wide

flanges, welded toe-to-toe in a triangular shape with 1-in. diaphragms on the inside,

up to the 410-ft. level; the leg then has two 36-in.-wide flanges in a triangular shape

up to its top where it connects with the steel ring beam at the base of the upper

structure.

The pairs of columns are spaced at 18 ft. o.c. at the base with each pair sharing

a pedestal that is part of the monolithic concrete foundation. The columns in each pair

taper to 11 ft. o.c. at the waist and then flare out again to a spacing of 30 ft. o.c. at the

ring girder. Each pair has a V4-in. architectural plate at the waist. The waist is only 27ft. in diameter at its narrowest point.

The core is a triangle with blunted corners. Each of the three sides has an

outside elevator with two to be used for passengers exclusively and the third to

service the restaurant part time. The utilities use the center of the core. The two sets of

stairs are built around the inside of the core with one stairway painted red and the

other painted yellow. The core continues upward through the entire upper structure,with the elevator motors housed in the top part of that structure.

There are seven sets of struts m, the tower with the lower two sets (built as

platforms with 12-in. concrete decks. The first strut is at 100 ft. elevation, the second


10/23

10

Fig 4.1 30 feet deep foundation and anchor bolts

Fig 4.2 Erection of the pedestal


11/23

11

at 200 ft., the third at 303 ft. and the next four are built close together in the waist.

The top structure is a five-story steel building.

The first floor is the revolving restaurant, the second is a mezzanine floor, thethird is the broad observation floor, the fourth is the mechanical floor and the fifth

houses the elevator equipment. The restaurant floor is 500 ft. above the ground and

the top of the structure is 53 ft. above that.

The structure is surmounted by a 47-ft. high steel framework for a gas-fired

beacon. (A Seattle wag remarked, Now all we need is a cigar-smoking seagull.) The

restaurant design is a further development of a revolving restaurant that the architect-

engineer had previously designed for the top of an office building in Honolulu.

The Eye of the Needle, as this one is called, is 94 ft. in diameter. It revolves

the full 360 degree in an hour. The only revolving part of this floor is the 14-ft.-wide

outer rim where the diners will be seated. The weight of the entire revolving portion is

carried on radial plate girders cantilevered from the steel box ring girder.

Fig 4.3 Splicing joints for the steel legs


12/23

12

4.2 STEEL CONSTRUCTION

The steel was detailed, fabricated and erected under a sub-contract by Pacific

Car & Foundry co. Structural Steel Division, Seattle. Most of the structural steel wasspecified as U.S. Steel A-36. The fabricating plant started work in May, 1961 and

steel erection started on June 26. The steel was topped out on Dec. 11, exactly on

schedule. Superintendent Paul Collop believes that this is the only major structure for

Century 21 that was completed within the target date.

The main problem, of course, was to contrive a way to hoist the steel as the

structure was carried upward. Collop and some Pacific Car & Foundry engineers with

sharp pencils came up with a derrick that was the first of its kind in the true Century

21 tradition. The contractor took a ring gear and pinion off a wrecked Manitowoc

crane and set them on a triangular 1 steel base with a hydraulic swing ' system.

A cable ran from this platform down through the core to a special hoist on the

ground that was built especially for this job by Washington Machinery Co. and Skagit

Steel. The mast section was 66 ft. high with a 60-ft. Manitowoc boom placed offset at

its base. There were 11 parts of V line on the topping lift and five parts of VB" line on

the main load.

The whip line was a special non-spinning wire rope that was made especially

for this job by Roderick & Bascom. This derrick lifted every pound of structural steel

except for some work that was done at the base by a Mantiowoc 3900 with 120-ft.

boom. The derrick was bolted at the inside corners of the steel core while it did its

work.

As the structure was built upward the derrick was gradually closed in. At

intervals of about 50 ft. a move was necessary. This operation was simple and


13/23

13

required only a little more than a half hour. The whip line was pulled out and run

from the drum to the base of the machinery platform on the derrick.

A 7-to-l lift was achieved by this hook-up: from one side of the platform to ablock fastened on the inside of the core, back to a pulley under the platform, to

opposite side of platform, up to another corner of the core, then down again to the

bottom of the platform, up to the third connection with one core, then to the becket.

When the hoist on the ground had pulled the derrick up to its new position it was

bolted into place and was again ready for work.

A lot of people did a lot of guessing about how the Pacific Car & Foundry

crew proposed to pull the derrick out of the core and lower it to the ground after

completion of the job. Inasmuch as the steel stairs had been constructed below it as it

went up, there was no chance of simply lowering the big rig back down the core

section.

Actually the contractor left out the last flight of stairs immediately below the

restaurant level. When the erection job was done, the crane was lowered down to a

point where the base was about 60 ft. below the restaurant.

Panels of X-bracing were removed from the side of the core leaving an

opening 11 ft. wide and 50 ft. high. The contractor revved up and took out the boom

section, rigged a block just under the ring beam girder and lowered the boom mast

and both sections with its own rigging. A small electric winch at restaurant level was

used to place remaining stairs.

Replacement of the side of the core and construction of the final flights of

stairs were the last jobs to be done by Pacific Car & Foundry. The Space Needle was

fabricated at the firm's shop at First Ave. So. And Hudson St.,with Robert G. Hermon


14/23

14

the plant superintendent. This was a job where engineers, fabricators and erectors

worked as a close-knit team with the engineers keeping on top of the work all the

way. All joints were milled and matched at the shop.

The core was of all welded construction and the columns were all bolted with

432 high tensile steel bolts used for each column splice. The new Ingersoll - Rand

impact wrenches used 750 lb. of torque. The struts were a combination of bolt and

weld. The contractor used a total of 146,000 lb. of welding electrode and 51,000 1-in.

high tensile bolts.

A scaffold was built round the core for the connection work and each leg also

had a scaffold. Sometimes these platforms had to be taken apart and reassembled to

get around an obstruction.

The first piece of steel, which was the connection with the concrete pedestal,

was 14 ft. long and weighed 20 tons. The next, heaviest on the job, was 90 ft. long

and weighed 50 tons; this one was lifted by the Manitowoc and the main derrick.

The erection crew moved to the site on June 15 and the first steel was set on

June 26. The needle was up to its narrowest point by Oct. 15 and to the tops of the

legs by Nov. 25. Topping out of the tower on Dec. 11 completed a job that was

always exactly on the schedule that had been set up before the project was started.


15/23

15

Fig 4.4 Straight into July sky, ground cranes place first leg column beside 120-foot

core


16/23

16

Fig 4.5 Welding unit resting precariously on 100-foot levellines danglingneedle top derrick assists in placing of next leg.

Fig 4.6 A new leg section is a 25-ton


17/23

17

Fig 4.7 Derrick and men in skip, top left, are bringing in a curved section.

Fig 4.8 20-ton section of restaurant ring girder, complete with sunburst vanes and

casual walking planks, rises toward sifted clouds


18/23

18

Fig 4.9 Construction of the sky City Restaurant

Fig 4.10 The rotating 14-foot rim


19/23

19

Fig 4.11The Sky City Restaurant

Fig 4.12 Painting of the steel legs with astronaut white


20/23

20

Fig 4.13 Finished Sunburst vanes

Fig 4.14 Finished Space Needle


21/23

21

4.3 OTHER WORKS

While Collop's crew was erecting the steel, other contractors were also busy.

Otis Elevator Co. installed rails for the three elevators and put in a hoisting car forpersonnel and minor materials. This car jumped around from one set of rails to

another tocon form to the varying conditions of the job. After the steel was in place

the fivestory structure at the top was completed as a restaurant, with this work

jammed into a four-month period. Sub-contractors on the job, in addition to those

already mentioned were: University Plumbing & Heating Co., plumbing and heating;

Fischbach & Moore, Inc., electricity; Western Gear Corp., turntable for restaurant.


22/23

22

CHAPTER 5: CONCLUSION

The space needle is one of the fastest constructed structures. It stands out for

its efficient plan, speed of construction and its unique design. The y-base foundation

was now followed recently in the construction of Burj Dubai. No wonder it created an

awe at that time of construction and after it was completed. Now it has been dwarfed

by many structures around the globe. Yet, the Space Needle retains its value and its

significance.


23/23

23

REFERENCES

1. "Space Needle Fun Facts".Space Needle Official Site. Retrieved 2007-01-12.2. "Seattle holds groundbreaking ceremony for the Space Needle on April 17,

1961".HistoryLink.org. Retrieved 2007-01-12.

3. Bill Speidel, Through the Eye of the Needle, Seattle: Nettle Creek, ISBN09148900402. p. 67.

4. "Needle in the sky".Via Magazine. January 2006.5. "Big beam for Space Needle is protested",Seattle Times,30 November 1999.6. Space Needle Official Site: Fun Facts7. This information is on the cover of a Long Playing vinyl 12 disc called "Bells

On Hi-Fi" catalog number AR-8, produced by Americana Records, of

Sellersville, PA.

8. "Californian is Needle's 45 millionth visitor".Seattle Post-Intelligencer. May19, 2007. Retrieved 2007-05-30.

9. Tom Paulson. "Computer glitch put hitch in fireworks". Seattle PostIntelligencer. Retrieved 2008-01-02.

10."Spit and polish for a Seattle icon." Komonews.com. May 15, 2008. AccessedJune 4, 2008.

11."Mid-life crisis? Space Needle gets dye job at 50". 2012-04-17. Retrieved2012-05-08.

12."Cougars Win; Space Needle Will Be Crimson And Gray Apple CupWeekend,".2005-11-15. Retrieved 2012-05-09.

13.McFadden, Kay (2004-05-13)."Condo by condo, Seattle has become a lot like'Frasier'".The Seattle Times. Retrieved 2010-01-23.

14."Lego Architecture: Seattle Space Needle".Lego Architecture.15."Badge and Colors Fact Sheet".Sounders FC Public Relations.16.Space Needle contractors set construction records, Paul Nelson.
http://www.spaceneedle.com/discover/funfacts.htmlhttp://www.historylink.org/essays/output.cfm?file_id=722http://www.historylink.org/essays/output.cfm?file_id=722http://www.historylink.org/essays/output.cfm?file_id=722http://www.historylink.org/essays/output.cfm?file_id=722http://www.viamagazine.com/weekenders/space_needle06.asphttp://en.wikipedia.org/wiki/Seattle_Timeshttp://www.spaceneedle.com/discover/funfacts.htmlhttp://www.seattlepi.com/local/316473_needle20.htmlhttp://www.seattlepi.com/local/345650_fireworks02.htmlhttp://www.komonews.com/news/local/18982744.htmlhttp://www.komonews.com/news/local/18982744.htmlhttp://www.q13fox.com/news/kcpq-space-needle-50th-anniversary-20120417,0,115008.story?hpt=us_bn7http://www.q13fox.com/news/kcpq-space-needle-50th-anniversary-20120417,0,115008.story?hpt=us_bn7http://www.wsucougars.com/genrel/111505aab.htmlhttp://www.wsucougars.com/genrel/111505aab.htmlhttp://www.wsucougars.com/genrel/111505aab.htmlhttp://www.wsucougars.com/genrel/111505aab.htmlhttp://community.seattletimes.nwsource.com/archive/?date=20040513&slug=frasier13http://community.seattletimes.nwsource.com/archive/?date=20040513&slug=frasier13http://www.brickstructures.com/LASeattleSpaceNeedle.htmlhttp://www.brickstructures.com/LASeattleSpaceNeedle.htmlhttp://www.soundersfc.com/News/Articles/2008/04-April/Badge-and-Colors-Fact-Sheet.aspxhttp://www.soundersfc.com/News/Articles/2008/04-April/Badge-and-Colors-Fact-Sheet.aspxhttp://www.soundersfc.com/News/Articles/2008/04-April/Badge-and-Colors-Fact-Sheet.aspxhttp://www.brickstructures.com/LASeattleSpaceNeedle.htmlhttp://community.seattletimes.nwsource.com/archive/?date=20040513&slug=frasier13http://community.seattletimes.nwsource.com/archive/?date=20040513&slug=frasier13http://www.wsucougars.com/genrel/111505aab.htmlhttp://www.wsucougars.com/genrel/111505aab.htmlhttp://www.q13fox.com/news/kcpq-space-needle-50th-anniversary-20120417,0,115008.story?hpt=us_bn7http://www.komonews.com/news/local/18982744.htmlhttp://www.seattlepi.com/local/345650_fireworks02.htmlhttp://www.seattlepi.com/local/316473_needle20.htmlhttp://www.spaceneedle.com/discover/funfacts.htmlhttp://en.wikipedia.org/wiki/Seattle_Timeshttp://www.viamagazine.com/weekenders/space_needle06.asphttp://www.historylink.org/essays/output.cfm?file_id=722http://www.historylink.org/essays/output.cfm?file_id=722http://www.spaceneedle.com/discover/funfacts.html

Documents

Construction of the Space Needle