The document discusses several major engineering mistakes throughout history. It describes the collapse of the Tacoma Narrows Bridge in 1940 due to unexpected wind forces. It also discusses the St. Francis Dam failure in 1928, the worst US civil engineering disaster of the 20th century, which was caused by inadequate foundation work. The 20 Fenchurch Street skyscraper in London was criticized for focusing design on aesthetics without considering safety, as its reflective glass caused overheating on nearby streets. The Kinzua Bridge collapsed in 2003 after over 100 years when a tornado struck, highlighting the risks of not properly maintaining and updating old structures. These mistakes provided important lessons that improved engineering safety standards and practices.

1. Engineering
mistakes in the
world
B Y
J A L A T H O T A A N I S H A ,
1 7 W J 1 A 0 1 6 1
C I V I L 1

2. Engineering, mistakes and rectification
Engineering is the action of bringing imagination into reality, modification and development in a
particular area. It is a branch of science and technology concerned with the design, building and
usage of machines or structures.
Design, structural integrity and tolerances are often triple checked and then checked again for
safe measure, but sometimes mistakes are made.
Few of these mistakes can be and have been rectified throughout the history, but some, have
been left unattended too and have been a bad influence on the environment and surroundings.

3. The collapse of TACOMA NARROWS BRIDGE
It was the world’s third longest suspension bridge,
Located in the U.S, state of Washington, that spanned the
Tacoma narrow strait of Puget sound, between Tacoma and
The Kitsap Peninsula.
Moisseff and Frederick Leinhard, which was probably the most
Important theoretical advance in the bridge engineering field of
The decade stating that the stiffness of the main cables would
Absorb up to one half of the static wind pressure pushing a
Suspended structure laterally. This energy would be transmitted
To the anchorages and towers.
Moisseff argued for stiffening the bridge with a set of 8 foot deep
(2.4m) plate girders rather than the 25 foot deep (7.6m) trusses.

4. The collapse of the bridge
was described as
“spectacular”. The failure
of the bridge occurred due
to never-seen-before
twisting movement from
winds at 40 miles per hour.
Planners expected fairly light traffic
volumes, designed with two lanes
and just 12m wide (quite narrow in
comparison to the length). The deck
of the bridge was insufficiently rigid
and moved due to wind, even during
the construction. The bridge was
opened on July 1, 1940 and collapsed
on November 7, the same year.

5. ST. FRANCIS DAM FLOODING
St. Francis dam(1924 – 1926) was
a curved concrete gravity dam to
provide as a storage reservoir for
the Los Angeles Aqueduct system.
Base and crest width were 175
feet and 16 feet. Main structure
had a height of 205 feet and
spanned 700 feet along its
curvilinear crest.

6. Worst American
civil engineering
disaster of the 20th
century.
Modifications were made during
construction and dam’s height was
increased by 20 feet, but the base
width wasn’t changed decreasing the
safety margin of structural stability.
Due to the saturated condition of the
reservoir, the left abutment
foundation rock weakened and
reactivated a large landslide. The
maximum height section tilted and
rotated at the right end, causing
catastrophic failure at both ends.
Failure occurred midnight of March 12-13, 1928.

7. 20 Fenchurch street
The 38 story building is a commercial skyscraper situated
in Fenchurch street, London is 160m tall, nicknamed ‘The
Walkie Talkie’.
The glass on the building, acts as a concave mirror when
sunlight hits directly for 2 to 3 hours each day. The light
gets reflected and shines on the surrounding streets and
vehicles, ending up in increase of temperatures to 91°C to
117°C.

8. Worst new
building in the UK,
2015
THE SUN LIGHT REFLECTED SET A
CARPET ON FIRE, MELTED THE
ROOF OF AN ELECTRIC CAR, ETC.
ALSO, DURING HIGH WINDS, THE
CURRENT EXTERIOR OF THE
TOWER, CREATES A WIND TUNNEL
EFFECT STRONG ENOUGH TO
KNOCK PEDESTRIANS OVER.

9. Kinzua Bridge
It was a railroad trestle that spanned Kinzua Creek in in
McKean County in the U.S. state of Pennsylvania.
The bridge was 301 feet tall and 2,052 feet long with
wrought iron columns known as ‘phoenix columns’.
It was originally built of wrought iron in 1882 and was
billed the “Eighth Wonder of the World”, holding the
record of the tallest railroad bridge in the world for two
years.
In 1900, it was rebuilt using steel to allow it to
accommodate heavier trains.

10. The bolts used to
hold down the
anchor blocks were
from the first bridge.
In 2002, the bridge was closed as the
structure was at risk to high winds
and restoration work began.
A tornado hit on July 21, 2003,
increasing the winds to at least 94
miles per hour, which applied an
800kn lateral force on the bridge,
causing it to collapse.
The century old bridge was destroyed
in less than 30 seconds.

11. Other engineering mistakes.
Leaning tower of Pisa The walkway collapse in the Hyatt Regency Hotel

12. Conclusion
Even though these mistakes
resulted in millions of dollars of
property of damage and loss of
lives, they gave important lessons,
helped in the implementation of
strict safety rules in construction
industry and gave a pathway to
various papers published on
different theories in engineering.