Catastrophic
Engineering Failure Study Guide
Ford Pinto - Gas
Tank liable to rupture in a rear-end collision. Engineers knew about the problem, but Iacocca studied the problem and could
maximize profits by settling the lawsuits for wrongful death rather than fix the cars ($11.00).
Hartford Civic Center – Long span arena roof collapsed from
snow load one hour after the end of a basketball game (16,000 people). Luckily the building was empty. Building trusses were
deflecting 8”, only 3” had been projected, engineer said no problem.
Quebec Bridge - (1st Collapse) 8 million pounds heavier than planned, beams ¼” off at joint, and
visibly deflecting. Engineer said keep building. Cantilever section collapsed. (2nd Collapse) Temporary rocker
arm snapped while lifting the final middle section into place.
Yarmouth Bridge - Clown in rowboat passing under the bridge caused the spectators to run from one side to the other;
the structure slipped laterally off of its foundation.
I35W Mississippi Highway Bridge – Gusset plates
were undersized, rush hour traffic and closed lanes.
Challenger Shuttle
– O-ring in booster rocket brittle from being frozen, it allowed gasses to leak out and ignite. NASA launched as soon
as temperature rose above freezing.
Tay Rail Bridge – Cast Iron plates supporting wrought iron rods cracked when gale-force winds hit the bridge
and a train crossing it. Cast Iron does not perform well in tension, especially brittle when cold. Pins tore through the plates.
Columbia Shuttle – Main Tank foam insulation broke off during launch and punched a hole in the reinforced
carbon carbon leading edge of the wing. Hot gasses entered the wing during reentry and caused structural failure.
Texas A&M Bonfire – Center pole could not support
the loading of the entire bonfire. Also, some wire clamps may have slipped, causing the structure to be unbalanced. Killed
the students building it.
Leaning Tower of Pisa – Poor soil conditions, allowed uneven settling of the foundation. Solved by removing soil
from the higher side.
Tacoma Narrows Bridge – Harmonic Oscillation shook the bridge apart. A low wind (45 mph) caused a frequency wave of 1.5’
in the structure which grew until the bridge failed.
Hyatt Regency Catwalk
– Instead of a single rod, multiple rods were used to suspend catwalks. A bending moment and shear were created. Structure
did not meet code in any case.
Apollo 1 –
Short ignited oxygen environment, extensive use of flammable materials. No way to open hatch from exterior, needed a wrench
to open from the inside.
Silver Bridge – Designed for model T’s (1400 LBS), but cars now weighed 4000 LBS. Also trucks could
now weigh 60,000lbs, but limited to 18,000 when designed. A hidden flaw in an eye bar caused the collapse.
St. Francis Dam
– Dam made taller without widening the base. Extra water pressure ruptured the base. Also poor soil conditions.
Charles DeGaule
Terminal – Advanced structure with insufficient factor of safety, combined with marginal building materials and excessive
expansion and contraction caused the steel supports to punch through the concrete shell.
United Flight 811
– Boeing 747-122 cargo door could open in midair due to electrical problem. Also, door pins could still close, even
though damaged, and could appear closed even when only partially engaged. Door blew out over Atlantic, sucked out several rows of people.
Concorde –
Supersonic Jet crashes because tire blows out on a piece of metal which fell off another plane. Tire debris impacted the wing,
and the shockwave ruptured the gas tank. Gas ignited, one engine dies from lack of fuel. Last engine flames out from turbulence
caused by the fire.
Titanic –
Watertight compartments were open on top. Once enough compartments were breached the water could keep on flooding over the
tops. Also, they flooded faster because the air could be displaced out the top of the compartments.
Apollo 13 –
Oxygen tank exploded, Command Module lost power and oxygen. Crew used the LM as a lifeboat, and returned to earth. Created
extra CO2 filters using duct tape and report covers, set course to earth by hand control of the rockets and by eye (no computer).
Boston Molasses Tank – Molasses tank was built of cast iron. Brittle, does badly in tension. ½”
plates of the tank ruptured under the pressure of the molasses. Wall of molasses swept through the neighborhood.
Sample
Question:
What were these
structures, what went wrong with them, and why did it happen (what was the engineering error)?
1.
Hyatt Hotel Catwalk
2.
Columbia Shuttle
3.
Tacoma Narrows Bridge
4.
Ford Pinto
5.
I35W Bridge
6.
Boston Molasses Tank
