Narrator: CHICAGO --
A CITY SHAPED BY ICE
AT RISK OF MELTING FROM KILLER HEAT WAVES.
[ SIREN WAILS ]
HEAT WAVES KILL MORE THAN HURRICANES AND TORNADOS
AND FLOODS COMBINED.
Narrator: IN THE SUMMER,
TEMPERATURES CAN SOAR TO OVER 100 DEGREES,
AND STORMS THAT FOLLOW...
[ THUNDER CRASHES ]
...THREATEN LIVES WITH FLASH FLOODING.
HOW DOES CHICAGO SURVIVE?
TO FIND OUT, WE WILL STRIP THE CITY
TO REVEAL ITS SECRET INNER WORKINGS
AND EXPOSE THE INGENIOUS TECHNOLOGY
THAT ALLOWED ENGINEERS TO BUILD THIS CITY
ON THE BRINK OF DISASTER.
-- Captions by VITAC -- www.vitac.com
CAPTIONS PAID FOR BY DISCOVERY COMMUNICATIONS
CHICAGO SITS ON THE SHORES OF LAKE MICHIGAN.
IT'S THE THIRD-BIGGEST CITY IN AMERICA...
...AND A CRITICAL BUSINESS AND TRANSPORT HUB.
MORE PLANES AND TRAINS PASS THROUGH CHICAGO EACH YEAR
THAN ANY OTHER U.S. CITY.
BUT CHICAGO IS UNDER THREAT.
BLISTERING HEAT BRINGS THE CITY TO ITS KNEES IN THE SUMMER.
2010 AND 2012
WERE SOME OF THE HOTTEST SUMMERS ON RECORD.
AND IN JULY 1995,
A DEVASTATING HEAT WAVE CRIPPLED THE CITY.
TEMPERATURES HIT 106 DEGREES.
IT'S HOT OUT THERE. YOU KNOW, WALK OUT THERE.
VERY, VERY, VERY HOT.
[ SIREN WAILS ]
Narrator: CITY SERVICES FALTER, AND THE POWER GRID FAILS.
WE'RE EXPERIENCING
AN UNPRECEDENTED HEAT-RELATED DISASTER.
Narrator: 739 PEOPLE DIED.
IT WAS ONE OF THE WORST NATURAL DISASTERS
IN AMERICAN HISTORY.
[ SIREN WAILS ]
BUT EVERY SUMMER IS A POTENTIAL KILLER.
TODAY, ENGINEERS RACE TO HEATPROOF CHICAGO
BY BUILDING HEAT-RESISTANT BRIDGES,
RAILROADS, AND RUNWAYS.
HEATPROOFING SKYSCRAPERS
IS A PARTICULARLY CHALLENGING TASK.
THIS IS THE TALLEST BUILDING IN TOWN,
THE WILLIS TOWER.
IT SOARS MORE THAN 1,700 FEET HIGH
AND HOUSES 11,000 PEOPLE.
NINE COLUMNS OF CONCRETE AND STEEL STAGGERED IN HEIGHT
SUPPORT THE STRUCTURE.
THE CENTRAL TWO COLUMNS HOLD 110 FLOORS.
WITH FEW BUILDINGS TO CAST SHADE AROUND IT,
SUNLIGHT STRIKES THE TOWER ALL DAY LONG...
...TURNING THIS OFFICE IN THE SKY
INTO ONE GIGANTIC GREENHOUSE.
THE WILLIS TOWER'S CHIEF ENGINEER, TOM CRONIN,
BATTLES THE HEAT.
Cronin: WE'RE ON THE WEST EXPOSURE,
AND IF I PUT MY HAND ON THE ALUMINUM,
I CAN'T HOLD IT THERE.
IT'S PROBABLY 130 DEGREES
ON THE ANODIZED BLACK ALUMINUM SKIN OF THE BUILDING
RIGHT NOW.
BECAUSE IT'S SINGLE-PANE,
IT HAS VERY LITTLE INSULATION VALUE TO IT.
THE LONGER THE HEAT STAYS IN FORCE,
THE MORE STRESS IT PUTS ON THE BUILDING EQUIPMENT,
THE SAME WAY IT PUTS STRESS ON HUMANS
IF THEY'RE OUT IN THE HEAT ALL THE TIME.
Narrator: TO WORK OUT HOW TO PROTECT STRUCTURES LIKE THIS
FROM HOT WEATHER,
ENGINEERS MUST FIRST UNDERSTAND HOW HEAT WAVES FORM.
METEOROLOGIST DR. DAVE KRISTOVICH
HAS SPENT HIS CAREER STUDYING THE CITY'S CLIMATE.
Kristovich: HEAT WAVES ARE QUITE COMMON IN THE MIDWEST
AND ARE BASICALLY A TIME PERIOD
OF ANOMALOUSLY WARM TEMPERATURES,
TEMPERATURES WELL ABOVE WHAT'S NORMAL
FOR A CERTAIN AREA FOR A CERTAIN TIME.
Narrator: TODAY, DAVE IS LAUNCHING A WEATHER BALLOON.
IT CARRIES A SPECIAL DEVICE CALLED A RADIOSONDE,
WHICH MEASURES HUMIDITY, TEMPERATURE, AND PRESSURE
IN THE ATMOSPHERE.
Kristovich: HEAT WAVES ARE DRIVEN
BY LARGE-SCALE HIGH-PRESSURE SYSTEMS
THAT DEVELOP OVER A REGION.
RADIOSONDES ARE LAUNCHED
AND USED TO PREDICT FUTURE WEATHER CONDITIONS.
3, 2, 1.
THERE SHE GOES.
Narrator: THE LAND THAT CHICAGO IS BUILT ON
CAUSES THE CITY'S HEAT WAVES.
26,000 YEARS AGO,
THE LAST OF A SERIES OF HUGE GLACIERS
MOVED SOUTH ACROSS NORTH AMERICA...
...FLATTENING THE TERRAIN LIKE A GIANT STEAMROLLER.
AFTER IT RECEDES,
IT LEAVES BEHIND THE MIDWEST'S VAST PLAINS.
THOSE OPEN SPACES NOW POWER CHICAGO'S DEADLY HEAT WAVES.
WITH NO HILLS OR MOUNTAINS TO STIR UP THE WEATHER,
WHEN A HIGH-PRESSURE SYSTEM ROLLS IN,
IT GROWS OUT OF CONTROL,
SWELLING TO FORM A GIANT DOME.
THE SUN HEATS THE AIR TRAPPED INSIDE...
...CAUSING TEMPERATURES IN THE CITY TO SOAR.
THE INSTRUMENTS ON THE BALLOON HELP DAVE DETERMINE
IF A HIGH-PRESSURE SYSTEM IS ON THE HORIZON
BRINGING A HEAT WAVE.
Kristovich: WE'RE RUNNING TEMPERATURES
ABOUT 10-DEGREES "C" COOLER THAN HEAT WAVE CONDITIONS.
NO HEAT WAVE TODAY.
Narrator: EXPERIMENTS LIKE THIS
HELP ENGINEERS WORK OUT JUST HOW HIGH
TEMPERATURES IN THE CITY CAN RISE
AND HOW TO PROPERLY DESIGN BUILDINGS
THAT CAN COPE WITH THE HEAT.
THE WRIGLEY BUILDING OPENED IN 1924.
ENGINEERS COVER ITS EXTERIOR WALLS
WITH MORE THAN 250,000 WHITE-GLAZED TERRA-COTTA TILES
THAT REFLECT THE SUN.
A RIGID STEEL FRAME SUPPORTS THICK CONCRETE WALLS
THAT INSULATE THE BUILDING FROM THE HEAT...
...KEEPING OVER 1,000 WORKERS INSIDE COOL.
TODAY, ENGINEERS HAVE FOUND MORE INGENIOUS WAYS
TO COOL SKYSCRAPERS.
THIS MAY LOOK LIKE AN ORDINARY OFFICE BUILDING.
BUT ITS WALLS CONCEAL AN EXTRAORDINARY SECRET --
A GIANT 2-MILLION-GALLON WATER TANK
100 FEET LONG AND 30 FEET DEEP.
IT CONTAINS A GRID OF 435 MILES OF PIPES.
THE PIPES ARE FILLED
WITH 100,000 GALLONS OF LIQUID COOLANT.
THE COOLANT CREATES 10 MILLION POUNDS OF ICE
ON THE PIPES' OUTER SURFACE EVERY NIGHT.
DURING THE DAY, WARM WASTEWATER FROM THE CITY'S BUILDINGS
FLOODS INTO THE TANK.
THE ICE ON THE PIPES MELTS,
COOLING THE WATER DOWN TO 34 DEGREES.
PUMPS CHANNEL THE CHILLED WATER BACK INTO THE CITY,
PROVIDING ENOUGH A.C.
TO KEEP OVER 11 MILLION SQUARE FEET OF OFFICE SPACE
COOL ON CHICAGO'S HOTTEST DAYS.
DAVE BUMP MAINTAINS THIS CITY REFRIGERATOR
AND FOUR OTHERS IN THE NETWORK.
Bump: YOU CAN SEE THE ICE THROUGH THE PINK WATER.
WE DYE IT PINK
SO THAT ALL OUR PIPES RUNNING THROUGH THE STREETS,
YOU CAN TELL IF IT'S OUR WATER OR THE CITY OF CHICAGO WATER.
YOU CAN SEE THIS HAS 1/4 INCH OF ICE.
THIS HAS A COUPLE INCHES OF ICE ON IT.
THIS IS THE LARGEST DOWNTOWN DISTRICT COOLING SYSTEM
IN THE UNITED STATES.
WE HAVE FIVE PLANTS THAT GO INTO THE SAME SYSTEM.
SO, IF ANYTHING WENT DOWN DUE TO AN ELECTRICAL OUTAGE,
COOLING WOULD STILL BE SUPPLIED TO THE BUILDINGS,
HENCE THE RELIABILITY.
Narrator: TOGETHER, THE CITY'S COOLING PLANTS
FEED 8 MILLION GALLONS OF ICE-COLD WATER
THROUGH 16 MILES OF PIPES.
THEY SUPPLY THE VENTILATION NETWORKS
OF 100 BUILDINGS IN CHICAGO'S DOWNTOWN AREA,
KEEPING THE CITIZENS COOL IN THE DEADLY SUMMER HEAT.
CLEVER ENGINEERING KEEPS CHICAGO'S ICONIC SKYLINE
SAFE FROM THE HEAT.
BUT OTHER KEY PARTS OF THE CITY ARE UNDER THREAT.
CHICAGO'S INDUSTRIES COULD GRIND TO A HALT
IF THEIR RAIL NETWORK MELTS DOWN.
Narrator: CHICAGO IS THE LARGEST RAIL HUB
IN AMERICA.
HALF OF THE COUNTRY'S RAIL FREIGHT,
THAT'S NEARLY A BILLION TONS OF CARGO A YEAR,
PASSES THROUGH THIS CITY.
FOR CHICAGO'S COMMUTERS,
THERE'S THE ELEVATED RAIL NETWORK,
THE "L."
ALMOST 250 BILLION PEOPLE RIDE IT EVERY YEAR.
IT'S A HUGE AND COMPLEX ENGINEERING FEAT.
THE "L" TRAIN RUNS ON THREE RAILS...
...TWO STABILIZE THE WHEELS
AND ONE TRANSMITS 600 VOLTS OF POWER TO THE TRAIN
THROUGH METAL CONTACTS CALLED SHOES.
THE TRACKS TOWER 23 FEET ABOVE THE ROAD,
SUPPORTED BY A LATTICE OF STEEL TRUSSES...
...HELPING COMMUTERS SHUTTLE ACROSS THE CITY.
UNLIKE MOST CITY METRO SYSTEMS IN AMERICA,
CHICAGO'S "L" RUNS ALMOST ENTIRELY ABOVEGROUND.
THAT LEADS TO PROBLEMS IN THE SUMMER,
WHEN THE TRACKS AND TRAINS ARE COMPLETELY EXPOSED
TO SEARING HEAT FROM THE SUN.
ROSS NEARK IS A THERMAL ENGINEER.
HE USES INFRARED CAMERAS
TO INVESTIGATE THE EFFECT HEAT HAS ON CRITICAL INFRASTRUCTURE.
TODAY, HE'S EXAMINING THE STEEL RAILS.
IT'S A BEAUTIFUL DAY. IT'S 75 DEGREES AND SUNNY.
SUN'S BEEN OUT FOR THE LAST SEVERAL DAYS, LOW HUMIDITY.
THESE RAILS HAVE HAD A CHANCE TO SIT IN THE SUN ALL DAY LONG.
WE'RE ANYWHERE BETWEEN 102, 106, 107 DEGREES.
[ BELL DINGING ]
Narrator: EVEN IN THE SHADE, THE ENTIRE STRUCTURE OF THE "L"
REMAINS MUCH WARMER THAN ITS SURROUNDINGS.
Neark: WE TAKE A QUICK TEMPERATURE.
WE'RE ROUGHLY ABOUT 15 DEGREES HIGHER THAN AMBIENT.
SO, THE STEEL JUST BELOW THE PILINGS
IS AROUND 85 TO 88 DEGREES FAHRENHEIT.
SO, IT IS WARM.
IT'S CONDUCTING THAT SOLAR ENERGY AND TURNING IT INTO HEAT.
NOW, IN A HEAT WAVE,
WHERE WE LOSE THAT ABILITY FOR THINGS TO COOL DOWN,
IT'S CERTAINLY GOING TO PUT GREATER STRESS
ON ALL THE COMPONENTS.
HEAT IS REALLY A MECHANICAL KILLER.
Narrator: HEAT CAUSES THE STEEL RAILS TO EXPAND.
LEFT UNCHECKED, THEY CAN BUCKLE AND WARP.
ENGINEERS CALL THIS PHENOMENON "SUN KINK."
WITH SUMMER TEMPERATURES SOARING WELL ABOVE 100 DEGREES,
SUN KINK IS A HUGE PROBLEM FOR CHICAGO.
HEAT-RELATED DERAILMENT CAN BE DISASTROUS.
IN 2002,
SUN KINK CAUSED THIS AMTRAK TRAIN
HEADING EAST FROM CHICAGO TO WASHINGTON, D.C.
TO DERAIL,
INJURING 95 PEOPLE.
TOOK OUR MEASUREMENTS TODAY ON THE RAIL.
THE ALIGNMENT WAS AS MUCH AS 30 INCHES OUT OF ALIGNMENT.
BECAUSE OF THE HIGH TEMPERATURES THIS SUMMER,
THEY'RE GOING TO PUT A HEAT ORDER ON THE TRACK
FOR ALL TRAINS -- PASSENGER AS WELL AS FREIGHT.
Narrator: BUILDING CRITICAL RAIL NETWORKS LIKE THE "L" ABOVEGROUND
MAY SEEM LIKE AN ODD DECISION GIVEN THE EXTREME SUMMER HEAT.
BUT ENGINEERS DIDN'T HAVE A CHOICE.
20,000 YEARS AGO, AN ICE AGE GRIPPED CHICAGO.
A HUGE GLACIER MOVES OVER THE LAND.
IT RIPS ROCKS FROM THE GROUND
AND GRINDS THEM INTO TINY PIECES.
AS THE GLACIER MELTS,
IT LEAVES BEHIND LAYERS OF SOFT SEDIMENTS AND CLAY...
...ON WHICH CHICAGO STANDS TODAY.
THE SOFT CLAY MAKES DRILLING TUNNELS FOR RAIL LINES
EXTREMELY DIFFICULT,
SO ENGINEERS CONSTRUCTED THE "L" ABOVEGROUND.
AVOIDING RAIL DISASTERS IN CHICAGO
WHEN THE TEMPERATURES SOAR IS CRITICAL.
OPERATORS ENACT SPEED RESTRICTIONS
TO SLOW TRAINS DOWN WHEN THE WEATHER GETS TOO HOT.
ENGINEERS HAVE A MORE RADICAL SOLUTION TO THE PROBLEM.
IT'S CALLED THE WATER TRAIN.
THE TRAIN ONLY EMERGES
WHEN RAIL TEMPERATURES REACH THEIR BREAKING POINT.
ABOVE THE WHEELS,
SPECIAL NOZZLES DOUSE THE STEEL TRACKS AND WOODEN TIES,
COOLING THEM DOWN.
TWO 1,600-GALLON RESERVOIRS QUENCH THE STEEL
AND BRING TEMPERATURES DOWN TO SAFE LEVELS,
KEEPING CHICAGO'S "L" NETWORK ROLLING IN THE SUMMER SUN.
INNOVATIONS LIKE THIS SHOULD KEEP CHICAGO'S TRAINS
RUNNING SMOOTHLY DURING HOT SUMMERS.
BUT CHICAGO IS MORE THAN JUST A RAIL HUB.
IT ALSO HOSTS AMERICA'S SECOND-BUSIEST AIRPORT,
O'HARE.
A HEAT WAVE HERE CAN LEAD TO A SHUTDOWN
ACROSS THE ENTIRE COUNTRY.
Narrator: CHICAGO O'HARE,
AMERICA'S SECOND-LARGEST AIRPORT.
[ MONITORS BEEPING ]
THREE PLANES TAKE OFF OR LAND HERE
EVERY MINUTE DURING PEAK HOURS,
BUT THE SKIES GRIND TO A HALT WHEN HEAT WAVES STRIKE.
TODAY A $6.6-BILLION PROJECT IS UNDER WAY,
UPGRADING O'HARE'S RUNWAYS AND INFRASTRUCTURE
TO BEAT THE HEAT.
Cantrell: IT'S AN ENORMOUS EFFORT.
THERE ABSOLUTELY IS NO MARGIN FOR ERROR ON A RUNWAY.
ONE OF THE BIGGEST REASONS IS
TO REDUCE THE DEPENDENCIES ON WEATHER-IMPACTED DELAYS.
Narrator: HOT TEMPERATURES CAUSE SIGNIFICANT PROBLEMS
FOR LARGER AIRCRAFT.
Cantrell: SO, HERE'S A FULLY-LOADED 777.
THIS AIRCRAFT NEEDS A LITTLE BIT LONGER RUNWAY THAN MOST
ON WARMER DAYS
BECAUSE OF THE INABILITY TO GAIN LIFT
WITH THE SHORTER-DISTANCE RUNWAYS.
Narrator: IN HOT WEATHER,
AIRCRAFT NEED MORE SPEED TO TAKE OFF.
AS PART OF O'HARE'S UPGRADE,
ENGINEERS ARE CONSTRUCTING A BRAND-NEW RUNWAY.
BUT BUILDING IT WON'T BE EASY.
THE ONLY WAY FOR PILOTS TO TAKE OFF WHEN IT'S EXTREMELY HOT
IS TO BUILD UP MORE SPEED.
AND THAT TAKES A LONGER RUNWAY.
DURING A HEAT WAVE,
A FULLY-LOADED 777 NEEDS UP TO 10% MORE PAVEMENT,
REQUIRING A RUNWAY OVER TWO MILES LONG.
AS PART OF O'HARE'S UPGRADE,
ENGINEERS ARE CONSTRUCTING A BRAND-NEW RUNWAY.
BUT BUILDING IT WON'T BE EASY.
O'HARE'S RUNWAYS NEED TO BE MORE THAN THREE FEET DEEP,
MADE UP OF A SANDWICH OF TOUGH MATERIALS.
ENGINEERS LAY DOWN 18 INCHES OF EXTRA-DURABLE CONCRETE ON TOP.
UNDER IT, THEY CAST 6 INCHES OF ASPHALT.
BELOW THIS,
A POROUS LAYER ALLOWS EXCESS RAINWATER TO DRAIN AWAY.
AT THE VERY BOTTOM,
A FOOT-THICK LAYER OF SOIL INJECTED WITH LIME
KEEPS THE GROUND FROM SUBSIDING.
TOGETHER, THESE LAYERS MAKE O'HARE'S RUNWAYS
SOME OF THE TOUGHEST IN AMERICA.
AT THIS LABORATORY IN RANTOUL, ILLINOIS,
ENGINEERS TEST RUNWAY CONCRETE TO MAKE SURE IT'S TOUGH ENOUGH.
OUTSIDE, DR. JEFF ROESLER AND HIS TEAM
LAY EXPERIMENTAL SECTIONS OF RUNWAY
TO CHECK HOW THE CONCRETE STANDS UP AGAINST THE ELEMENTS.
WE'RE TAKING A CORE OUT OF THIS CONCRETE HERE,
AND WE'LL BE TESTING IT FOR ITS STRENGTH
AND ALSO HOW GOOD
ITS CRACKING-RESISTANT PROPERTIES ARE.
O'HARE'S CONCRETE'S THE HIGHEST QUALITY
BECAUSE OF THE HIGH LOADS THAT GO OVER IT FROM THE AIRCRAFT.
ALSO, THE EXTREME TEMPERATURES
THAT IT WILL SEE DURING ITS LIFE,
SUCH AS HOT TEMPERATURES IN THE SUMMER
AND VERY COLD TEMPERATURES IN THE WINTER.
Narrator: CONCRETE IS A COMBINATION OF CEMENT, SAND,
AND LUMPS OF LIMESTONE CALLED AGGREGATE.
[ CONCRETE POPS ]
Roesler: WHOA!
WOW!
LOOKING PRETTY GOOD.
GOT ALL THE AGGREGATES THERE.
THE GRAY PART IS THE CEMENT AND THE SAND.
THIS IS A VERY DENSE MIX.
THIS WOULD BE A MIX YOU'D PROBABLY FIND AT O'HARE.
I WOULD HAPPILY LAND ON THIS.
Narrator: IT WILL TAKE AROUND 120,000 TONS OF CONCRETE
TO BUILD O'HARE'S NEW RUNWAY.
TODAY, CONSTRUCTION MANAGER RAY GOODING AND HIS TEAM
RACE TO LAY NEARLY A MILE OF CONCRETE TAXIWAYS.
TO MY RIGHT, WE HAVE A CONCRETE THAT WAS POURED TODAY.
AND THEN, OVER HERE ON THE LEFT,
THIS LANE WAS POURED PROBABLY ABOUT 10 DAYS AGO.
APPROXIMATELY TAKES A WHOLE MONTH,
BY DESIGN, FOR IT TO GET ITS STRENGTH.
Narrator: RAY'S TEAM MUST INSTALL CONCRETE
WITHOUT CREATING ANY BUMPS OR BUBBLES
THAT COULD COMPROMISE ITS STRENGTH.
TO DO THIS,
THEY USE AN INGENIOUS ALL-IN-ONE RUNWAY CONCRETE LAYER,
THE SLIPFORM PAVER.
A CONVEYOR BELT DELIVERS FRESH CONCRETE
TO THE FRONT OF THE MACHINE.
HERE, A HIGH-SPEED DRILL MIXES IT,
AND A VIBRATOR SHAKES OUT ANY AIR BUBBLES
THAT COULD WEAKEN THE STRUCTURE.
A PLUNGER FORCES LUMPS OF LIMESTONE
BELOW THE SURFACE...
...BEFORE IT'S SMOOTHED OUT.
THIS MACHINE CAN PAVE THE LENGTH OF A FOOTBALL FIELD
WITH PERFECT RUNWAY-GRADE CONCRETE
IN UNDER 20 MINUTES.
Gooding: IT IS KIND OF LIKE BAKING A CAKE.
YOU HAVE TO MAKE SURE
THAT ALL THE PROPORTIONS OF YOUR MATERIALS ARE CORRECT.
Narrator: THEY SINK STEEL RODS INTO THE WET CONCRETE EVERY 20 FEET.
THE RODS PREVENT THE CONCRETE FROM BUCKLING IN EXTREME HEAT.
BRUSHING THE TOP LAYER GIVES IT EXTRA GRIP...
...WHILE A SPECIAL COMPOUND HELPS THE CONCRETE SOLIDIFY
OVER 28 DAYS.
THIS IS A 1,500-YARD CONCRETE POUR,
AND THEY'VE GOT ABOUT 1,000 YARDS ON THE GROUND RIGHT NOW.
ACTUALLY, THIS IS ONE OF OUR BETTER DAYS.
IT'S GOING PRETTY SMOOTH.
Narrator: RAY'S TEAM WILL COMPLETE O'HARE'S NEW RUNWAY
WITHIN THE NEXT TWO YEARS.
A BRAND-NEW CONTROL TOWER TALLER THAN THE STATUE OF LIBERTY,
GIVING AIR TRAFFIC CONTROLLERS
A CLEAR VIEW OF THE ENTIRE AIRPORT,
ALLOWING THEM TO MANAGE OVER 1.5 MILLION TAKEOFFS
AND LANDINGS A YEAR.
INNOVATIVE CONCRETE SHOULD KEEP THE CHICAGO AIRPORT OPEN
IN THE MOST EXTREME HEAT.
BUT THERE'S ONE CHALLENGE CONCRETE CAN'T FIX...
...CHICAGO'S MOVABLE BRIDGES.
IN A HEAT WAVE, THEY CAN JAM, DISABLING THE ENTIRE CITY.
Narrator: CHICAGO -- AMERICA'S BIGGEST TRANSPORT HUB.
BUILT ON THE CHICAGO RIVER, ITS HARBOR AND WATERWAYS
ARE OTHER VITAL ROUTES FOR THE CITY.
SPANNING THE RIVER, 18 HISTORIC BRIDGES CAN RISE UP,
ALLOWING BOATS TO PASS UNDERNEATH.
NO OTHER CITY IN THE WORLD HAS MORE MOVEABLE BRIDGES.
THE DOUBLE-DECKED DuSABLE BRIDGE IS ONE OF THE MOST DISTINCTIVE,
AN ENGINEERING WONDER.
ON EACH SIDE,
NINE STEEL PIERS DRIVE 90 FEET INTO THE TOUGH CLAY,
ANCHORING THE BRIDGE.
EACH LEAF OF THE BRIDGE WEIGHS 4,100 TONS.
A 12,000-TON COUNTERWEIGHT HIDDEN INSIDE THE HOLLOW PIER
HELPS RAISE THE DECK.
ONCE RELEASED, IT PIVOTS ON A HUGE AXLE...
...HOISTING MICHIGAN AVENUE INTO THE SKY.
THE DuSABLE MAY BE A PIECE OF PRECISION ENGINEERING,
BUT IT HAS AN ACHILLES' HEEL.
HOT WEATHER CAUSES THE TWO HALVES OF THE BRIDGE TO EXPAND,
FUSING THEM TOGETHER OR PREVENTING THEM FROM CLOSING.
SEARING TEMPERATURES IN JUNE 2012 JAMMED THE BRIDGE,
CAUSING GRIDLOCK ON THE WATERWAYS.
IT TOOK EXTREME MEASURES TO COOL THE BRIDGE DOWN.
THE CHRISTOPHER WHEATLEY --
AN ADVANCED FIREFIGHTING RESCUE BOAT...
...DEPUTY DISTRICT CHIEF RON DORNEKER'S
$8.5-MILLION PRIDE AND JOY.
Dorneker: A FIREBOAT'S ALWAYS NEEDED IN CHICAGO,
ONE OF THE LARGEST HARBOR SYSTEMS IN THE COUNTRY,
THE LARGEST BRIDGE SYSTEM IN THE COUNTRY.
THE BRIDGES ARE MADE OF STEEL,
SO THERE'S GOING TO BE SOME EXPANSION.
SO, WITH THAT EXPANSION,
SOMETIMES THE BRIDGES WON'T CLOSE.
IT JUST CREATES ANOTHER PINCH POINT IN THE CITY FOR TRAFFIC,
AND NOT ONLY FOR TRAFFIC,
BUT THINK ABOUT OUR POLICE AND FIRE SERVICES.
WE WANT TO KEEP ALL THESE AVENUES OPEN.
Narrator: WHEN THE DuSABLE BRIDGE REFUSED TO CLOSE,
THE CHRISTOPHER WHEATLEY BLASTED IT WITH WATER,
COOLING THE STEEL DOWN IN MINUTES.
THE VESSEL'S HUGE WATER CANNONS
COULD FILL AN OLYMPIC SWIMMING POOL
IN LESS THAN AN HOUR.
IT'S LIKE POWER THAT YOU CAN'T IMAGINE.
YOU GET TO SHOOT WATER WHERE NO MAN CAN GO.
[ SIREN WAILS ]
MASS MONITOR OPENING.
ALL RIGHT. I'M GONNA THROTTLE UP.
I'M GONNA OPEN UP MY DISCHARGES.
Narrator: THE SECRET TO THE SHIP'S FIREPOWER
ARE INGENIOUS PUMPS.
A PAIR OF THEM, ONE ON EACH SIDE,
SUCK WATER INTO TWO GIANT METAL BOXES CALLED SEA CHESTS.
INSIDE, THE BOAT PRESSURIZES THE WATER...
...AND CHANNELS IT INTO A PIPE THAT LOOPS AROUND THE VESSEL...
FEEDING THE FIREFIGHTING CANNONS...
ONE AT THE BACK AND THREE AT THE FRONT.
TOGETHER, THE CANNONS DOUSE A FIRE OR COOL THE BRIDGE
WITH UP TO 15,000 GALLONS OF WATER A MINUTE.
IT'S A WHAT-IF.
THAT'S WHAT THEY PREPARED FOR WITH THIS BOAT,
SO IT'S READY FOR THAT WHAT-IF IF IT HAPPENS.
Narrator: TODAY CHICAGO'S AGING BRIDGES NEED VITAL ATTENTION.
THE WELLS STREET BRIDGE WAS BUILT IN 1922
AND IS GETTING URGENT REPAIRS.
SONNY HAROMIA AND HIS TEAM
ARE REPLACING ENTIRE SECTIONS OF THE BRIDGE
WITH BRAND-NEW STEEL.
Haromia: SINCE IT WAS INSTALLED,
IT'S NEVER SEEN A MAJOR OVERHAUL LIKE THIS.
NO MATTER HOW MUCH YOU PROTECTIVE-COAT IT,
THE STEEL DETERIORATES, AND IT LOSES ITS STRENGTH.
WE'VE GOT TO GET THIS DONE IN TIME.
IT'S VERY IMPORTANT THAT WE MAKE OUR SCHEDULE.
Narrator: A NEW DECK DESIGN WILL HOPEFULLY STOP IT
FROM JAMMING SHUT IN THE HEAT.
THE PREVIOUS GAP WAS A FINGER-LOCK SYSTEM, SO TO SPEAK,
WHICH CONSISTED OF TWO FINGERS COMBING TOGETHER.
THE NEW CENTER BREAK IS ACTUALLY AN OPEN GAP
TO MAKE SURE IT DOESN'T BIND AND THAT IT OPENS PROPERLY.
IT'S A VERY CRITICAL ELEMENT OF THE DESIGN.
Narrator: WORK IS ONGOING, BUT THE BRIDGE MUST OPEN TOMORROW.
IT IS THE FIRST DAY OF ONE OF CHICAGO'S BIGGEST EVENTS --
THE BOAT RUN.
ALL 18 HISTORIC BRIDGES MUST RISE UP
TO ALLOW SAILBOATS TO PASS THROUGH THE CITY'S HEART.
SONNY'S BRIDGE CAN'T RUIN THE SHOW.
AS LONG AS IT GOES UP AND COMES DOWN, I'LL BE A HAPPY MAN.
[ INDISTINCT CONVERSATION ]
Narrator: THE TEAM REMOVES HEAVY TEMPORARY BOLTS CALLED CENTER LOCKS.
[ BELL DINGING ]
ONE BY ONE,
THE OTHER BRIDGES RISE TO THE OCCASION.
MOMENT OF TRUTH.
Narrator: THE 500-TON LEAF OF THE WELLS STREET BRIDGE
SLOWLY LIFTS.
WE'RE MONEY.
IT'S GOOD?
Narrator: SUCCESS.
YEAH!
Haromia: PRIVILEGE TO WORK ON IT.
EVERYTHING'S GOING GREAT,
AND IT'S REALLY GOOD TO SEE
THE FIRST BOAT RUN OF THE FALL SEASON GO SO SMOOTHLY.
YOU GOT TO TIP YOUR HAT TO THESE GUYS.
Narrator: HEATPROOFING CHICAGO'S BRIDGES, RAIL NETWORK, AND AIRPORT
HELP KEEP THE CITY MOVING.
AND TODAY, ENGINEERS ARE DEVISING
EVEN MORE SURPRISING WAYS TO BATTLE THE HEAT.
THEY'RE TRANSFORMING ROOFTOPS INTO GREEN ZONES
TO COOL THE CITY.
Narrator: HEAT WAVES CAUSE HUGE PROBLEMS IN CHICAGO.
THE WORST IN JULY 1995 KILLED MORE THAN 700 PEOPLE.
HEAT WAVES IN CITIES CAN BE DEADLY
BECAUSE TEMPERATURES DURING THE EVENING REMAIN DANGEROUSLY HIGH.
DURING THE DAY,
THE CONCRETE IN THE BUILDINGS AND ASPHALT ON THE ROADS
ABSORB HEAT FROM THE SUN.
DURING THE NIGHT, THE ROOFS AND ROADS
SLOWLY RELEASE THE WARMTH BACK INTO THE ATMOSPHERE...
...KEEPING NIGHTTIME TEMPERATURES
DANGEROUSLY HIGH.
METEOROLOGISTS CALL THIS PROBLEM THE URBAN HEAT ISLAND EFFECT.
GREEN SPACES ARE THE PERFECT SOLUTION
TO CHICAGO'S HEAT PROBLEM
BECAUSE TREES, SHRUBS, AND GRASS RETAIN MOISTURE.
AS THEY RELEASE IT INTO THE ATMOSPHERE,
THEY COOL DOWN THE AIR.
BUT CREATING THEM IN A CROWDED CONCRETE CITY
IS AN ENGINEERING CHALLENGE.
MILLENNIUM PARK, WHICH OPENED IN 2004,
DISPLAYS AN INGENIOUS SOLUTION.
THERE'S MORE TO THIS 24.5-ACRE PARK
THAN MEETS THE EYE.
A MAJOR RAIL HUB SITS 28 FEET BENEATH IT...
...ALONG WITH PARKING FOR 4,000 CARS.
MASSIVE CONCRETE PILLARS SUPPORT ITS HEFTY ROOF,
WHICH IS COVERED IN ALMOST 1.5 MILLION TONS OF SOIL.
IT IS THE LARGEST GREEN ROOF IN THE WORLD,
WHICH PLAYS A CRITICAL ROLE IN KEEPING THE CITY COOL.
TRANSFORMING CONCRETE SPACES INTO GREEN ZONES
IS A HUGE ENGINEERING CHALLENGE.
MAGGIE DALEY PARK IS THE LATEST GREEN ROOF UNDER CONSTRUCTION.
THIS 20-ACRE SITE WILL BOAST
LANDSCAPED LAWNS AND WOODLAND, ROCK-CLIMBING SCULPTURES,
AND ICE SKATING IN WINTER.
Man: SO, THE INTENT, FROM MY UNDERSTANDING,
IS THAT THESE ARE STILL GONNA HAVE THE ONE-INCH GAPS.
THE WATER'S GONNA GO THROUGH IT,
AND IT'S GONNA GO DOWN INTO THE DRAIN.
Powers: THIS IS IT.
THIS IS MY FIRST GREEN ROOF
THAT I'VE INSTALLED TO THIS MAGNITUDE.
WE HAVE A CONVEYOR SYSTEM
THAT IS PLACING STONE ON TOP OF CONCRETE STRUCTURE,
WHICH IS ACTUALLY A PARKING GARAGE.
Narrator: MIKE'S TEAM PILE GRAVEL ONTO THE ROOF FOR DRAINAGE,
ALONG WITH SOIL TO HELP THE PLANTS GROW.
A FLAT PARK IS UNINTERESTING,
BUT BUILDING HILLS ADDS A LOT OF WEIGHT --
TOO MUCH FOR THE GARAGE ROOF TO SUPPORT.
THE WHOLE INTENT OF THE DESIGN
IS TO MINIMIZE THE WEIGHT ON TOP OF THE STRUCTURE.
Narrator: THE SOLUTION IS AN INGENIOUS LIGHTWEIGHT POLYMER
CALLED GEOFOAM.
Eschmeyer: IT'S 100 TIMES LIGHTER THAN SOIL AT ONE POUND PER CUBIC FOOT.
AND ON THIS PROJECT,
THE WEIGHT THAT WE DISPLACE BY REMOVING SOIL
AND REPLACING THAT WITH GEOFOAM
TOTALED 240 MILLION POUNDS.
GEOFOAM COMES IN VERY LARGE BLOCKS,
AND SOMETIMES WE GET A PIECE THAT WE NEED TO CUT DOWN.
SO, BOTH OF US JUST KIND OF LET THE WIRE DO THE CUTTING.
GRAVITY DOES IT AFTER HERE. WE JUST KIND OF GUIDE IT DOWN.
WOW, THAT WAS REALLY, REALLY SIMPLE.
I AM VERY IMPRESSED.
THIS IS SO SIMPLE TO USE.
IF THE REST OF THE PROJECT GOES AS FAST AS CUTTING THIS BLOCK,
WE SHOULD FINISH DEFINITELY ON TIME, IF NOT EARLY.
Narrator: MIKE'S TEAM IS WORKING FAST
TO TRANSFORM THE ROOF.
FIRST, THEY LAY DOWN AN ASPHALT AND RUBBER BASE.
THEN THEY SCULPT GEOFOAM TO FORM THE LANDSCAPE.
THEY TOP IT WITH OVER 200,000 TONS OF SOIL.
THIS CREATES A FERTILE BASE FOR PLANTS
AND MORE THAN 1,000 TREES,
MAKING A BRAND-NEW PARK FOR THE CITY.
IN A YEAR'S TIME, THIS SPACE WILL BE UTILIZED BY THE CITY,
AND KIDS WILL BE PLAYING HERE.
I LOVE DOWNTOWN CHICAGO. I LOVE THE AREA.
I WANT TO GIVE BACK.
IT'S GONNA BE JUST FABULOUS FOR THIS CITY.
Narrator: GREEN SPACES HELP COOL CHICAGO DOWN DURING THE SUMMER,
BUT HEAT WAVES BRING ANOTHER CHALLENGE,
ONE THAT'S HARDER TO CONTROL.
AFTER THE HEAT WAVE COMES STORMS
AND LIFE-THREATENING FLASH FLOODS.
[ THUNDER CRASHES ]
Narrator: WHEN HEAT WAVES BREAK, STORMS FOLLOW.
FOR CHICAGO, AMERICA'S THIRD-LARGEST CITY,
THAT'S A HUGE PROBLEM.
THE CITY FLOODS AFTER ALMOST EVERY DOWNPOUR,
CAUSING MILLIONS OF DOLLARS IN DAMAGE
TO HOMES AND BUSINESSES.
[ THUNDER CRASHES ]
TO SOLVE THE PROBLEM,
TODAY'S ENGINEERS ARE BUILDING A MASSIVE NEW NETWORK OF TUNNELS
UP TO 350 FEET BENEATH CHICAGO'S STREETS.
IT'S CALLED THE DEEP TUNNEL PROJECT.
MORE THAN 100 MILES OF TUNNELS
WILL CHANNEL BILLIONS OF GALLONS OF RAINWATER
AWAY FROM THE STREETS TO PREVENT FLOODING.
IT'S THE MOST AMBITIOUS ENGINEERING PROJECT
IN THE CITY'S HISTORY.
ENGINEER KEVIN FITZPATRICK HELPS COORDINATE THE PROJECT.
Fitzpatrick: WE'RE GOING DOWN ABOUT 300 FEET RIGHT NOW.
WE SHOULD BE OKAY. I'VE DONE THIS BEFORE.
I'M NOT SCARED OF HEIGHTS,
BUT I AM SCARED OF DEPTHS, YES.
15 FEET, COMING DOWN.
THAT'S THE BOTTOM.
Narrator: BUILDING JUST THIS SMALL QUARTER-MILE SECTION
COST $150 MILLION,
BUT THE CITY IS AT RISK WITHOUT IT.
Fitzpatrick: IT'S A DIRE PROBLEM,
AND IT'S PLAGUED THE REGION FOR DECADES NOW.
GROWING UP, MY HOUSE WAS FLOODED,
AND IT'S NOT A LOT OF FUN
CLEANING THE CRAP OUT OF YOUR BASEMENT.
Narrator: BUILDING GIANT TUNNELS IS ONLY PART OF THE CHALLENGE.
TO STORE THE EXCESS FLOODWATER,
KEVIN'S TEAM MUST ALSO CONSTRUCT THREE HUGE RESERVOIRS.
WE'RE COMING OUT INTO THE THORNTON QUARRY,
WHICH IS GONNA BE THE SITE OF OUR RESERVOIR.
IT'LL HOLD 7.9 BILLION GALLONS.
IT'S ABSOLUTELY ENORMOUS.
THIS IS ONE OF THE BIGGEST RESERVOIRS
YOU'LL EVER SEE ANYWHERE IN THE WORLD.
Narrator: INCREDIBLY, THIS VAST QUARRY
WAS TOO SMALL TO HOLD ALL THE FLOODWATER.
THE TEAM NEEDS TO MAKE IT SIX TIMES BIGGER.
ABOUT 15 YEARS AGO, WE GOT THE IDEA
WE WOULD LIKE TO USE THIS FOR A RESERVOIR,
AND WE ASKED THE QUARRY OPERATOR TO MINE THE HECK OUT OF IT
SO WE CAN GET THIS THING ONLINE AS SOON AS POSSIBLE.
Narrator: MINING LIMESTONE CALLS FOR EXPLOSIVES,
TONS OF IT.
THIS CAP'S GONNA FIRE THIS TUBE, WHICH FIRES THAT CAP,
WHICH HAS TO FIRE THE NEXT ONE DOWN THE HOLE,
AND THEN SO ON AND SO FORTH.
ERIC ANDERSON LEADS THE QUARRY'S BLAST TEAM.
BEING OUTSIDE IN THE HELMETS AND WORKING WITH THE GUYS
AND BEING ABLE TO MAKE THAT JUDGMENT CALL
OF PUTTING THE EXPLOSIVES IN THE HOLE,
THAT'S THE BEST JOB IN THE WORLD.
I LOVE IT.
HOPE NOTHING BAD HAPPENS.
Narrator: ERIC'S TEAM BORE HOLES 120 FEET DEEP INTO THE CLIFF.
THEN THEY PUMP LIQUID EXPLOSIVE INSIDE...
...TOPPING EACH LAYER WITH GRAVEL.
51 DETONATORS THEN TRIGGER THE 18,500 POUNDS OF EXPLOSIVES
AT SPLIT-SECOND INTERVALS...
...BLASTING THOUSANDS OF TONS OF LIMESTONE INTO RUBBLE.
MAN: Sound the siren, and fire the shot.
[ AIR HORN BLOWS ]
ALL RIGHT. I'M GONNA ARM IT.
PUSH THAT BUTTON FORWARD AND HOLD IT FOR A SECOND.
FIRE IN THE HOLE.
[ SWITCH CLICKS ]
SHOT'S OFF. GIVE THE ALL-CLEAR IN A MINUTE.
WOW!
Narrator: THE EXPLOSION BLASTS OUT NEARLY 35,000 TONS OF ROCK,
EATING 10 FEET INTO THE CLIFF.
WHEN IT OPENS A YEAR FROM NOW,
THIS RESERVOIR WILL HOLD
ALMOST 8 BILLION GALLONS OF STORM WATER,
SAFEGUARDING THE CITY FROM FLOODING.
Anderson: I FEEL PROUD.
I FEEL PROUD TO HAVE SOMETHING TO DO WITH THE RESERVOIR
TO KEEP PEOPLE'S HOMES FROM FLOODING.
WENT PRETTY GOOD, ACTUALLY.
Narrator: CHICAGO -- A CITY AT RISK.
BUT ITS CITIZENS CAN RELY ON INGENIOUS INVENTIONS
HIDDEN BENEATH THE SKIN OF THE CITY
THAT CHILL THEIR HOMES...
COOL THEIR COMMUTE...
AND KEEP THEM DRY WHEN THE HEAVENS OPEN,
BRACING THIS GLEAMING METROPOLIS
FOR WHEN THE NEXT HEAT WAVE STRIKES.