Ladies and Gentlemen the next error....
The infamous “Pull” error can be found in Mark's
WTC7
Mark's claim:
Is "Pull" used by demolitions pros to mean "demolish with explosives?"
No.
I won’t rehash the comment from Silverstein that will follow later.
In this case Mark asks if demolition pros (plural) use the term ‘pull’ to mean “demolish with explosives”. He then cites 3 experts to support the answer of no. Three doesn’t seem to be a proper sample to represent demolition pros,
which I assume Mark means all pros but I won’t focus on that fallacy.
Lets examine other statements in the demolition industry and their use
of the term pull within the context of demolishing a building with
explosives:
"In the demolition industry, a
blaster is usually trying to pull a structure away from adjacent exposures and towards an area large enough to contain the debris." -ImplosionWorld.com
"Jack [Loizeaux] brought a basic knowledge of construction,
engineering, and physics to his new science of implosion. More
important, though, he brought the fascination and conviction of a true
believer. Long before anyone else,
he had faith in the power of
explosives to help gravity do what it wants to do anyway: pull things
down." -University of Georgia
On Sunday, June 10, 2001, the City of Des Moines subcontracted the
implosion of the Younkers Warehouse Building to Controlled Demolition
Incorporated (CDI) from Des Moines and Metro Wrecking and Excavating,
Inc. from Phoenix, Maryland. CDI drilled over 500 holes in the
supporting columns in the building and placed approximately 250 pounds
of explosives. The explosives were detonated with a delay pattern that
started in the southeast corner of the building and proceeded toward the
northwest corner in a matter of seconds. This delay sequence allowed the
explosive charges to detonate fractions of seconds apart; reducing the
noise and vibrations to approximately 25 percent of the allowable levels
before damage would occur to surrounding buildings. This delay allowed
CDI to control the direction that the building would fall and resulted
in the illusion that the building melted.
CDI planned the implosion to
pull the building to the southeast and away from the intersection of SW
9th and Mulberry Streets. The implosion was very successful. -Front
Line/Des Moines, IA
"Not all demolition blast(s) are implosions. The industry often refers
to them as implosions because it is a popular expression. A true
implosion is a case when a structure has been caused to fall inwards on
itself. Smokestacks, towers, bridges and most buildings are not
imploded. They are simply knocked over.
Implosion is used when there is limited area on all sides of a
structure making it impossible to lay them out.
The principles used on an implosion are basically the same whether it
is a true implosion, or if the structure is simply going to be laid out.
The principle tool in an implosion is gravity. The
explosives are used
to weaken and cause the supporting members of the structure to fail,
thus allowing gravity to pull the structure down or over." -Dykon
Blasting Corp.
"Stacey Loizeaux, twenty-six years old, has worked for Controlled
Demolition, an international explosives engineering firm, since the age
of fifteen. She learned the fine art of demolition from her father, Mark
Loizeaux, and her uncle, Doug Loizeaux—president and vice-president of
the company.
NOVA: A common misconception is that you blow buildings up. That's not
really the case, is it?
Stacy Loizeaux: No. The term "implosion" was coined by my grandmother
back in, I guess, the '60s. It's a more descriptive way to explain what
we do than "explosion." There are a series of small explosions, but the
building itself isn't erupting outward.
It's actually being pulled in on
top of itself. What we're really doing is removing specific support
columns within the structure and then cajoling the building in one
direction or another, or straight down.
SL: Well, you just
pull it away,
you peel it off. If you have room in the opposite direction, you just
let the building sort of melt down in that direction and it will
pull
itself completely away from the building. It can be done.
NOVA: What do you look for in an explosive?
SL: Velocity. You have two different types of explosives. You have low
order and high order. A low order explosive is like what they used when
they bombed the Oklahoma City building—that's ANFO, ammonium nitrate
and fuel oil. It's a very slow, heaving explosion. It tends to push more
than it does shatter. The explosive we look for is a shattering
explosive. What we want to do is instantaneously remove the integrity of
the columns or whatever we're working on. That's what we look for in
nitroglycerin or NG-based dynamite. With a steel building, we use
something called a linear shaped charge. It's the same explosive they
use to sever the fuel tank off the Space Shuttle, when they launch.
NOVA: I understand that Controlled Demolition was hired to bring down
the remains of the Oklahoma City Federal Building. Were you out there
for that?
SL: My father and my uncle went out.
NOVA: Do you get a thrill watching a building fall?
SL: Oh sure. I mean you really don't ever lose it. Your perspective
changes. When I first started traveling with my Dad at fifteen, sixteen
years old, I used to be awestruck. But you sort of go from that
awestruck feeling to where you understand how the structure is coming
down and you're watching for certain things—counting the delays or
waiting for a part of the building to kick out or waiting for
it to pull
forward. So it does change, but it's always a rush." -NOVA/PBS (1997)
Demolition of Dangerous Building
"City staff have contacted the property owner by phone to request that
he obtain a
demolition permit and pull down and demolish the building,
however, the owner has demonstrated no desire to cooperate.
2. THAT the
owners are hereby ordered to pull down the building and
remove the resulting debris and the discarded materials from the site
within 14 days of the date from a copy of this Resolution being served
pursuant to Section 324A of the Vancouver Charter.
3. THAT in the event that the owners do not comply with the order set
forth in the preceding paragraph, the City Building Inspector is hereby
ordered and authorized to
pull down the building and remove the resulting debris and discarded material from the site at the cost of the owners and dispose of it by selling to the demolition contractor any
material he may agree to purchase, and delivering the rest to a disposal
site." - Vancouver City Council (01/09/96)
"The preparation of the structure for implosion could have been
approached a number of ways...it was decided that CDI [Controlled
Demolition, Inc.] could effectively
minimize the amount of linear shaped
charge explosives to be used in the structure. By torch-cutting splice
plates on selected upper columns/floors, and utilizing approximately
3,000 feet of steel-core cable on alternate upper floors to help
“pull” the northern and eastern walls away from the fiber optics
cables..." -Controlled Demolition, Inc. (01/23/05)
"Phase 1 continued to fall, helping to
pull Phase 2 in. Phase 2 was
detonated several seconds later and collapsed and fell the same as Phase
1." -Controlled Demolition, Inc. (01/23/05)
It appears that the term
“pull” is used to designate bringing a building down with explosives
and using cables to bring down a building.
So in this case, Mark makes another factual error when trying to state that "pull" is not used to demolish a building with explosives.