A local Boston television station reported that the $190 MILLION tunnel
video system for the Big Dig has NO footage of the accident that
resulted in a 3 ton slab of concrete landing on a vehicle and killing a
passenger Sunday night.
Could that be true? Maybe. The turnpike authority, under direction of
Matt Amorello, cleared the fallen slab and several others that were also
fallen or precariously dangling extremely quickly before any other
footag or pictures could be taken. Rescuers who were trying in vain to
save the woman who was killed risked their own lives to work while
another 3 ton slab dangled over their heads. Naturally there is no
video or photos of any of this. It's pretty clear that Amorello didn't
want anyone to get the chance to take photos either. The Boston Herald
had a cover photo taken by a passing motorist with his cellphone before
he called 911.
So why could the $190 million camera system not have any pictures?
Amorello said that there was nobody to press the button to record the
The TV station is reporting that apparently the Turnpike Authority spent
$190 million but didn't get the $300,000 digital video recording
Because this so called "Intelligent Highway System" doesn't work now,
nor has it ever worked properly. Many of the cameras throughout the
tunnels are covered with plastic, pointed toward the wall, or otherwise
obviously not working. The system of green/yellow arrows and red Xs
above each lane only partially works in some areas. The variable
message boards inside the tunnels seldom display anything more useful
This lucrative contract was awarded to Honeywell, a company known for
those ubiquitous, round thermostats containing toxic mercury, and who
is also a major defense contractor. It ran way behind schedule, and
went way over budget, largely because of "software problems". As with
other problematic contractors, BigDig officials claimed they were the
only company qualified to complete the job.
Ultimately, the system was still not working, even after everything
else was completed. Officials at the time said that the system of
cameras, sensors and message boards was so important to tunnel safety,
that the opening of the road (and it was this exact section, I believe)
was delayed for weeks until Honeywell could supposedly get it together.
not work. Why should we think that the cameras would work either?
True. Of course even when I've seen lanes with Xs, cars just kept driving
merrily along in that lane. Naturally there didn't appear to be any reason
for the lane to be closed though.
Just about every thermostat manufactured by anyone contained mercury. (The
alternative was bimetallic strips which are nowhere near as precise, and
today digital thermostats have become popular.) But how is that relevant
They do lots of things, including manufacturing jet engines. So?
You know lots of companies have worked on this project that are renowned
for excellent products elsewhere. But on the Big Dig, everything turns to
crap. A very peculiar pattern.
The mercury in thermostats was not used for temperature sensing. The
"classic" Honeywell thermostats used a bimetallic strip curled into a
coil. The two different metals in the strip expand and contract in
response to temperature changes at different rates from each other,
causing a rotation of the coil.
Attached to the coil is a small, sealed glass bulb with two contacts at
one end. There's a small ball of liquid mercury in the glass bulb which
closes the circuit between the contacts when it is tipped towards that
direction. The rotation of the coil happens very slowly as the
temperature changes, but once it reaches a certain point, gravity
causes the mercury to roll to the opposite end of the glass bulb all at
once. This achieves a quick on-off transition that minimizes arcing or
The set point was adjusted by simply rotating the bimetallic coil so
that the transition occured at a different temperature. It was an
elegantly simple, very reliable design which became the industry
standard for residental and commercial use for many years. The
environmental dangers of mercury have become more apparent in recent
times. In service, they pose no hazard, but items like this must be
recycled in a mercury specific program, and not disposed of into
Alternatives to using mercury in thermostats involved some other
mechanical design that would provide a "snap-action" transition from on
to off at the desired temperature. Mercury was only appropriate for low
voltage, low current switching. Any line voltage thermostat would use a
mechanical contact closure. An alternative to using bimetallic strips
is a gas filled bellows which expands and contracts in response to
Other companies besides Honeywell used mercury in their thermostats in
both bimetallic and gas bellows designs, but the mercury was still only
used for switching, and not for temperature sensing. Today, solid state
temperature sensors have made bimetallic and gas bellows designs
obsolete, and other electronic components perform the switching
function instead of mercury.
My reason for mentioning Honeywell thermostats in the first place was
because they're a very common household product that almost everyone's
familiar with. It was an excellent product for it's day (although that
was fifty years ago).
Haven't the dangers or mercury been known for a long time? There is the
Mad Hatter in Alice in Wonderland. Hatters were mad because they were
exposed to mercury vapor in making hats and suffered neurological damage.
The direct exposure to mercury, yes. But people did not think about
what happened when products containing mercury were thrown in the
trash. Mercury pollution from landfills and incinerators is now known
to be a significant problem and only recently have mercury specific
recycling programs been implemented.
My father used mercury when making fillings for teeth. I think I
expressed interest, or maybe he knew it would be interesting, so he
gave me maybe 4 cubic centimeters of it when I was 6, but I have to
admit, I've never found a use for it (except watching it). I think I
got another 4cc when he died 2 years later. I'm 59 now, and have
moved about 6 times, but the mercury has only had to move 4 times in
all these years. I keep saving it for a special occasion. Like
repairing mercury switches, but it was easier to buy another switch,
or use the ones built into car trunk and hood lights.
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