wrote in message news:3544a0e8-2b26-4400-ad50-
On May 7, 8:20 pm, "Robert Green" wrote:

stuff snipped

One other point. You've doubtless seen the swath a big tornado cuts. Those
big twisters demolish wooden structures, roofs and all. I still contend
that no amount of bracing or improved roof attachment is going to matter
if
you're a stick-built house in the path of an F3 or greater. It's sayonara
time for that structure as it gets pulverized and dragged into the next
county.

I agree. As I said previously, I can see addition roof connectors helping
in the case where you're near the edge of the tornado path. But if you're
directly in the path, it pretty much destroys the whole structure, roof and
all. I suppose you could find some cases where it could have helped,
where there is a house or two, that for whatever reason was spared.
And if that house had the extra connectors, which is certainly a good
idea for any areas prone to extreme storms, then it could help that
house survive with it's roof intact. But in my view, that's the
exceptional case.

The tornado that scattered the oak trees like pickup sticks lifted a car 12
stories in the air at the U. of Md. and killed the occupants. Then the
tornado followed a path along a small creek bed where it hit the park and
then made a bee-line for a Home Depot/shopping center, destroying all the
large signs and pulling up the edges of the metal roof in the open garden
area. Then the funnel just lifted into the air and it was all over, just
like that. Anything "stick built" that was right in the path was destroyed.
Once the cone becomes filled with debris it becomes a potent destructive
force. IIRC, most victims are killed by the impact of the debris.

It was just a miracle that it followed the creek where there were no houses
for most of its trip through my neighborhood. Now that everyone's got a
video camera in their cell phones there's always someone getting a picture
of a cow, a shed, a car, a tractor's trailer, a roof, a tree, street signs
and all sorts of other airborne debris. Someone even had a still photo of
the car in mid air, sailing over the 9 story dormitory and crashing down
into the parking lot.

The most fascinating pictures I've ever seen of a tornado was from a news
chopper flying above the clouds but still close enough to the funnel to film
down inside the cone. It was filled with lightning flashes and tons of
debris like roof sections, 2 by 4's, trashcans. Then it split into three
tornadoes. I can't seem to find it on YouTube, but I've seen the footage
shown several times on both the Weather Channel and the Discovery Channel.

It's as popular as the footage of the family that climbed under an overpass
and filmed the tornado as it passed directly overhead. That's got to change
your life forever. (-: I've heard authorities say not to seek shelter
there, but it looked like the only place they would have been able to
survive (and did).

As for my only tornado experience (thank God) the destruction lessened
further away from the main track but it was still pretty awesome. Standing
on the highest vantage point I could find a few days later, the entire area
was a sea of blue tarps. Almost every house for a block or two on either
side had major roof or tree damage. Storms like that are exceptionally rare
around here and I suspect not many of the newer houses had good "Florida
code" connections between roof and frame.

I was surprised to learn how many homes have their roofs loosely attached,
although that's changing. I was just as surprised when I learned that the
Bismarck's huge gun turrets were held on by gravity alone and they just fell
off when the ship rolled after sinking. I suppose the designers figured
that the tilt angle required to dislodge the turrets meant that it was "game
over" anyway when that angle was reached.

One thing I found quite interesting is that weeping willows were still
standing (stripped almost completely of leaves, though) while the mighty
oaks were all felled. When you drive through a decimated area you realize
how inadequate TV and newspaper coverage is in communicating the scope of
the damage. I heard that said often about both Katrina and Sandy. Until
you're doing a flyover or a drive through the scope doesn't come across.
Five blocks east and I would have been going to Oz in the middle of a funnel
cloud.

I will agree that it's been proven time and again that good building codes
save lives. Florida's rules about attaching roofs has greatly lessened
damage caused by roofs flying off and then striking other homes and even
people with flying debris. While it's still under investigation, that
recent collapse in Bangladesh probably wouldn't have happened if that
structure had been built better with adherence to building codes and
better
inspection during construction.

I haven't followed this closely, but I heard reports around the time it
happened that said the upper floors were added, perhaps illegally.
That has happened before, I remember a dept store in Japan, for
example, where they just added a floor without properly considering
the additional loads put on the rest of the structure.

Yes, I've read that, too. It's a very common occurrence because each floor
is just like the one below it in most cases so when you're on a roll . . .
Most construction workers aren't really thinking about the extra stress on
the floors below. I read another report today that implied the floors may
have "pancaked" and when the top floor collapsed it overload the floor below
it, etc.

If they went stingy on the rebar, as some reports indicate, it's no
surprise. With so many people killed (700+ at least count) at least a few
of us are likely wearing clothing sewed by some of the victims of the
collapse. If there's anything I hate, it's people who are working hard to
make a living getting killed by negligence or criminal activity. People who
rob pizza couriers should be castrated. I wonder if a threat like that
would make thieving scum think twice? It should.

Overbuilding happened in the very tony Montgomery County, MD and bless their
souls, they forced the builder to remove the extra two stories he had
illegally added to the building and fined him quite heavily because the
extra two floors opened him to dozens of inspection violations. I also
think TPTB wanted to send a very strong message that adding unsanctioned
floors is a big no-no. If IIRC, he even tried to bribe someone on the
county council, deepening his legal troubles. Apparently he got away with
it in the beginning because no one measured building heights because the
planning department thought that permitting services was doing it.
Permitting services did not measure because it believed the planning
department had enforcement authority.

--
Bobby G.