Golden Gate Bridge

Golden Gate Bridge

1.

Introduction

:

The Golden Gate Bridge is a suspension

bridge spanning the Golden

Gate, the opening of the San Francisco Bay into the Pacific Ocean. As part of both U.S. Route

101 and California State Route 1, it connects the city of San Francisco on the northern tip

of

the

San

Francisco

Peninsula

to

Marin

County.

The

Golden

Gate

Bridge

was

the

longest

suspension bridge span in the world when it was completed in 1937, and has become one of

the most internationally recognized

symbols

of San Francisco,

California, and of the United

States.

2.

History

2.1

Ferry service:

Before the bridge was built, the only practical short route between San

Francisco and what is now Marin County was by boat across a section of San Francisco Bay.

Ferry

service

began

as

early

as

1820,

with

regularly

scheduled

service

beginning

in

the

1840s

for

purposes

of

transporting

water to

San

Francisco.

The

Sausalito

Land

and

Ferry

Company service, launched in 1867, eventually became the Golden Gate Ferry Company, a

Southern

Pacific

Railroad

subsidiary,

the

largest

ferry

operation

in

the

world

by

the

late

for

railroad

passengers

and

customers

only,

Southern

Pacific‘s

automobile

ferries became

very

profitable and

important to the regional economy. The ferry crossing

between

the

Hyde

Street

Pier

in

San

Francisco

and

Sausalito

in

Marin

County

took

approximately 20 minutes and cost US$$1.00 per vehicle, a price later reduced to compete

with

the

new

bridge.

The

trip

from

the

San Francisco Ferry Building

took

27

minutes.

Many

wanted

to

build

a

bridge

to

connect

San

Francisco

to

Marin

County.

San

Francisco

was the largest American city still served primarily by ferry boats. Because it did not have a

permanent

link

with

communities

around

the

bay,

the

city's

growth

rate

was

below

the

national

average.

Many

experts

said

that

a

bridge

couldn’t

be

built

across

the

6,700

ft

(2,042

m)

strait.

It

had

strong,

swirling

tides

and

currents,

with

water

500

ft

(150

m)

in

depth at the center of the channel, and frequent strong winds. Experts

said that ferocious

winds and blinding fogs would prevent construction and operation.

2.2

Conception:

Although the idea of a bridge spanning the Golden Gate was not new, the

proposal

that

eventually

took

place

was

made

in

a

1916

San Francisco Bulletin

article

by

former engineering student James Wilkins. San Francisco's City Engineer estimated the cost

at

$$100

million,

impractical

for

the

time, and

fielded

the

question

to

bridge

engineers

of

whether

it

could

be

built

for

less.

One

who

responded,

Joseph Strauss

, was

an

ambitious

but dreamy engineer and poet who had, for his

graduate thesis

, designed a 55-mile (89 km)

long railroad bridge across the

Bering Strait

.At the time, Strauss

had completed some 400

drawbridges

—

most

of

which

were

inland

—

and

nothing

on

the

scale

of

the

new

project.

Strauss's initial drawings were for a massive

cantilever

on each side of the strait, connected

by

a

central

suspension

segment,

which

Strauss

promised

could

be

built

for

$$17

million.

Local authorities agreed to proceed only on the assurance that Strauss alter the design and

accept input

from

several consulting project experts.[

citation needed

]

A

suspension-bridge

design was considered the most practical, because of recent advances in

metallurgy

.Strauss

spent more than a

decade drumming

up support

in Northern

California. The bridge faced

opposition, including litigation, from many

sources. The

Department of War

was concerned

that

the

bridge

would

interfere

with

ship

traffic;

the

navy

feared

that

a

ship

collision

or

sabotage

to

the

bridge

could

block

the

entrance

to

one

of

its

main

harbors.

Unions

demanded guarantees that local workers would be favored for construction jobs.

2.3

Finance:

The

Golden Gate

Bridge and

Highway District

,

authorized

by

an

act

of

the

California Legislature

, was incorporated in 1928 as the official entity to

design, construct,

and

finance

the

Golden

Gate

Bridge.

However

,

after

the

Wall Street Crash of 1929

,

the

District

was

unable

to

raise

the

construction

funds,

so

it

lobbied

for

a

$$30

million

bond

measure

. The bonds were approved in November 1930, by votes in the counties affected by

the bridge. The construction budget at the time of approval was $$27 million. However, the

District was unable to sell the bonds until 1932, when

Amadeo Giannini

, the founder of San

Francisco

–

based

Bank of America

, agreed on behalf

of

his bank to

buy the entire issue

in

order to help the local economy.

2.4

Opening

festivities:

The

bridge-opening

celebration

began

on

May

27,

1937

and

lasted for one week. The day before vehicle traffic was allowed, 200,000 people crossed by

foot and roller skate. On opening day, Mayor Angelo Rossi and other officials rode the ferry

to Marin, then crossed the bridge in a motorcade past three ceremonial

a

blockade

of

beauty

queens

who

required

Joseph

Strauss

to

present

the

bridge

to

the

Highway District before allowing him to pass. An official song,

Golden Gate

on

the

Golden

Gate

Bridge

entitled

Mighty

Task

is

done.

The

next

day,

President

Roosevelt pushed a button in Washington, D.C. signaling the official start of vehicle traffic

over the Bridge at noon. When the celebration got out of hand, the SFPD had a small riot in

the

uptown

Polk

Gulch

area.

Weeks

of

civil

and

cultural

activities

called

Fiesta

followed. A statue of Strauss was moved in 1955 to a site near the bridge.

3.

Design and Construction

3.1

Designer:

Joseph Strauss, Alvin Mauro, Charles Rhys Evans, Leon Moisafe.

3.2

Structure:

The weight of the roadway is hung from two cables that pass through the two

main towers and are fixed in concrete at each end. Each cable is made of 27,572 strands of

wire.

There

are

80,000

miles

(129,000 km)

of

wire

in

the

main

cables.

The

bridge

has