The Construction of Hoover Dam

The Construction of Hoover Dam

Technical problems and Solutions

Technical problems and Solutions

Hoover DamHoover Dam

Lake MeadLake Mead

The DamThe Dam Located on the border between Arizona and Nevada

Blocks the Colorado River

Hoover Dam created Lake Mead behind it

Construction began 1931, initially on the four tunnels used to divert the river away from the building site

Located on the border between Arizona and Nevada

Blocks the Colorado River

Hoover Dam created Lake Mead behind it

Construction began 1931, initially on the four tunnels used to divert the river away from the building site

The DamThe Dam

Construction of the actual dam began 1933

Nothing of this magnitude had ever been attempted before

As a result there were many problems with untested solutions

Construction of the actual dam began 1933

Nothing of this magnitude had ever been attempted before

As a result there were many problems with untested solutions

Site Preparation

Site Preparation River water diverted

This was done using four tunnels, two either side of the canyon

In total the tunnels spanned a length of 16,000 feet (3 miles)

The tunnels were dug out using dynamite

River water diverted

This was done using four tunnels, two either side of the canyon

In total the tunnels spanned a length of 16,000 feet (3 miles)

The tunnels were dug out using dynamite

Site Preparation

Site Preparation Scaling the cliff walls and removing any loose rocks

This work was needed to ensure that when the dam was built it would stay firmly in place and not crumble away at the edges

Scaling the cliff walls and removing any loose rocks

This work was needed to ensure that when the dam was built it would stay firmly in place and not crumble away at the edges

‘High Scalers’‘High

Scalers’ The men who were given the job became known as ‘High Scalers’

The workmen were required to hang from ropes off the edge of the cliff and use jackhammers and dynamite to blast off loose rock

They weighed 44lbs

The men who were given the job became known as ‘High Scalers’

The workmen were required to hang from ropes off the edge of the cliff and use jackhammers and dynamite to blast off loose rock

They weighed 44lbs

High RiskHigh Risk

Many men died from falling tools or slipping and falling off the cliff

As a result the men invented hardhats to stop them getting fractured sculls from falling objects

They did this by filling cloth hats with tar

Many men died from falling tools or slipping and falling off the cliff

As a result the men invented hardhats to stop them getting fractured sculls from falling objects

They did this by filling cloth hats with tar

RescueRescue

A spectaculuar example of the dangers involved is a story of a man who slipped and fell. 25 feet below another worker leapt off the cliff, holding onto his rope, and caught the man’s foot. Another worker pinned the man to the cliff until he could be rescued.

A spectaculuar example of the dangers involved is a story of a man who slipped and fell. 25 feet below another worker leapt off the cliff, holding onto his rope, and caught the man’s foot. Another worker pinned the man to the cliff until he could be rescued.

‘High Scalers’‘High

Scalers’

Construction

Construction

Construction began in 1933

The first problem engineers faced was the sheer amount of concrete needed to build the dam

A site to make concrete was first built upstream and later one was built on the edge of the canyon

Construction began in 1933

The first problem engineers faced was the sheer amount of concrete needed to build the dam

A site to make concrete was first built upstream and later one was built on the edge of the canyon

ProblemsProblems

Another problem faced was the fact that concrete produces heat as it sets. Had the dam been created in one pour, the heat generated would have meant the dam would not have set for 125 years. This would have created cracking and erosion.

Another problem faced was the fact that concrete produces heat as it sets. Had the dam been created in one pour, the heat generated would have meant the dam would not have set for 125 years. This would have created cracking and erosion.

Another solutionAnother solution

A solution was devised by engineers

The dam was to be built with a series of concrete pillars, trapezoidal in shape, joined with interlocking grooves

When set, the blocks were pressure grouted together

A solution was devised by engineers

The dam was to be built with a series of concrete pillars, trapezoidal in shape, joined with interlocking grooves

When set, the blocks were pressure grouted together

Blocks of concreteBlocks of concrete

Problems and

Solutions

Problems and

Solutions Pouring the concrete in separate blocks was only part of the solution to the concrete problem

The dam was in the middle of the desert and the heat was setting the concrete too fast

Pouring the concrete in separate blocks was only part of the solution to the concrete problem

The dam was in the middle of the desert and the heat was setting the concrete too fast

PipesPipes

To solve this problem, a system of pipes was woven throughout the concrete and filled with cold water. This slowed down the setting process

Later the pipes were removed and the holes filled with grout

To solve this problem, a system of pipes was woven throughout the concrete and filled with cold water. This slowed down the setting process

Later the pipes were removed and the holes filled with grout