Curious About Submarines

PODCAST 221: CURIOUS ABOUT SUBMARINES

RELEASE DATE: SUNDAY, DECEMBER 25TH, 2022

D:  HELLO, AND WELCOME BACK TO THE CURIOUS KID PODCAST, AND HAPPY HOLIDAYS TO ALL OUR LISTENERS AROUND THE WORLD.    WHEN YOU THINK OF WAYS TO GET FROM PLACE TO PLACE IN THE WATER, THINGS LIKE BOATS, FERRYS, KAYAKS, AND JET SKIS PROBABLY COME TO MIND.  ALL OF THOSE THINGS GET AROUND BY FLOATING AT THE WATER’S SURFACE.  WE GOT CURIOUS ABOUT BOATS BACK IN EPISODE 158, AND IN THAT EPISODE WE LEARNED  SOMETHING THAT ALWAYS FASCINATED ME SINCE I WAS A CHILD.  WE LEARNED HOW SOMETHING AS MASSIVE AS A CRUISE SHIP CAN FLOAT.  TODAY, WE ARE GOING TO LEARN ABOUT A DIFFERENT WAY TO GET FROM PLACE TO PLACE IN THE OCEAN THAT WORKS VERY DIFFERENTLY BECAUSE THESE AMAZING VEHICLES CAN TRAVEL QUICKLY DEEP UNDER THE SURFACE.    

O:  MAILBAG!

D:  MAILBAG!

“HI THERE, WE ARE WRITING TO YOU TODAY FROM MASSACHUSETTS.  VEYLAN IS 4 YEARS OLD AND HE’S VERY CURIOUS ABOUT SUBMARINES.  HE’S WONDERING - WHAT ARE THEY MADE OF SO THEY DON’T GET RUSTY.  HOW FAST CAN THEY GO?  DO YOU NEED TO GO TO SCHOOL TO DRIVE ONE?

HOPE TO HEAR FROM YOU SOON - WE LOVE YOUR PODCAST!

VEYLAN AND HIS MOM, KATY”

O:  THANKS FOR THE EMAIL, VEYLAN.  WE CAN’T WAIT TO LEARN ALL ABOUT SUBMARINES FOR YOU THIS WEEK AND ANSWER ALL YOUR FANTASTIC QUESTIONS.

D:  ONE OF YOUR QUESTIONS IS EVEN GOING TO BE OUR QUESTION OF THE WEEK.

O:  THE QUESTION OF THE WEEK IS, WHAT IS THE FASTEST SPEED RECORDED BY A SUBMARINE?

D:  WHILE YOU’RE THINKING OF THE ANSWER, LET’S LEARN ALL ABOUT SUBMARINES.  SUBMARINES ARE MILITARY VESSELS, AND THEY HAVE BEEN USED FOR ABOUT 400 YEARS.  

O:  UNTIL SUBMARINES WERE INVENTED, NAVY BATTLES TOOK PLACE ABOVE WATER.  ONCE SUBMARINES POPPED UP, SAILORS BECAME ABLE TO BATTLE UNDERWATER AS WELL.  SAILORS ARE EVEN ABLE TO SPEND MONTHS OR YEARS UNDERWATER IN SUBMARINES.  

D:  WE ARE GOING TO LEARN HOW SUBMARINES ARE ABLE TO GET DEEP DOWN IN THE OCEAN, AND HOW SAILORS CAN SURVIVE IN THE HARSH CONDITIONS OF THE DEEP SEA FOR A VERY LONG TIME IN A SUBMARINE.

O:  IN THE EPISODE ON BOATS, WE LEARNED ALL ABOUT BUOYANCY.  IT’S THE KEY TO HOW BIG BOATS CAN FLOAT ON THE WATER, BUT THINGS MUCH SMALLER AND LIGHTER THAN A BOAT, LIKE A HEAVY BOWLING BALL FOR EXAMPLE, SINK IN THE WATER.   

D:  YOU SHOULD TOTALLY CHECK OUT THAT EPISODE TO LEARN HOW BUOYANCY WORKS, BUT THE GIST OF IT IS THAT A SHIP CAN FLOAT BECAUSE THE WEIGHT OF THE WATER THAT IT DISPLACES, OR TAKES THE PLACE OF, IS EQUAL TO OR GREATER THAN THE WEIGHT OF THE SHIP ITSELF.  

O:  THAT’S WHAT PREVENTS THE FORCE OF GRAVITY FROM BEING STRONG ENOUGH TO PULL A SHIP DOWN TO THE OCEAN FLOOR.  

D:  THE AMAZING FEATURE OF A SUBMARINE THAT ALLOWS IT TO SINK OR SURFACE WHEN IT WANTS TO IS THAT SUBMARINES CAN CONTROL THEIR BUOYANCY.

O:  IF A SUBMARINE NEEDS TO SINK DEEP INTO THE OCEAN, IT’S ABLE TO LOWER IT’S BUOYANCY, AND IF IT WANTS TO SURFACE, IT IS ABLE TO INCREASE IT’S BUOYANCY.  THAT’S A REALLY NEAT TRICK THAT SUBMARINES CAN DO.

D:  IT SURE IS.  AND IT IS ABLE TO PULL THE AMAZING TRICK OFF THANKS TO A PART OF THE SUBMARINE CALLED THE BALLAST TANK.

O:  THE BALLAST TANKS CAN FILL WITH AIR OR WATER, DEPENDING ON THE SITUATION.  IF THE SUBMARINE NEEDS TO FLOAT ON THE SURFACE OF THE WATER, THE BALLAST TANKS ARE FILLED WITH AIR.  THAT ALOWS THE OVERALL DENSITY OF THE SUBMARINE TO BE LOWER THAN THE DENSITY OF THE SURROUNDING WATER.  

D:  ON THE OTHER HAND, IF THE SUBMARINE NEEDS TO DIVE DOWN INTO THE DEPTHS OF THE OCEAN, THE BALLAST TANKS FILL WITH WATER.  THAT ALLOWS THE DENSITY OF THE SUBMARINE TO BE GREATER THAN THE DENSITY OF THE SURROUNDING WATER.  THIS IS CALLED NEGATIVE BUOYANCY, WHICH MEANS THAT THE SUBMARINE NO LONGER HAS THE BUOYANCY NEEDED TO FLOAT.  

O:  COMPRESSED AIR IS STORED ON THE SUBMARINE THAT IS USED TO FILL THE BALLAST TANKS WHEN IT’S TIME FOR THE SUBMARINE TO SURFACE.  

D:  A SUBMARINE ALSO HAS HYDROPLANES, WHICH ARE LIKE WINGS THAT ARE LOCATED ON THE STERN, OR BACKSIDE OF THE SUBMARINE.  THE HYDROPLANES HELP CONTROL THE ANGLE OF THE SUBMARINE AS IT SINKS OR SURFACES.  IN ORDER TO SINK, THE HYDROPLANES ARE ANGLED IN SUCH A WAY THAT ALLOWS WATER TO MOVE OVER THE STERN.  THAT, IN TURN, FORCES THE STERN UPWARD, WHICH ANGLES THE SUBMARINE DOWN.  

O:  WHEN THE SUBMARINE NEEDS TO BALANCE ITSELF IN THE OCEAN, A BALANCE OF AIR AND WATER IS MAINTAINED THAT ALLOWS THE DENSITY OF THE SUBMARINE TO BE EQUAL TO THE DENSITY OF THE SURROUNDING WATER.  WHEN THIS HAPPENS, THE RESULT IS SOMETHING CALLED NEUTRAL BUOYANCY.  

D:  AT NEUTRAL BUOYANCY, THE HYDROPLANES CAN BE LEVELED SO THAT THE SUBMARINE TRAVELS FORWARD, THROUGH THE WATER, WITHOUT GOING UP OR DOWN.  

O:  THERE IS ALSO A TAIL RUDDER THAT TURNS TO MOVE THE SUBMARINE TO THE RIGHT, ALSO CALLED STARBOARD, OR TO THE LEFT, ALSO CALLED PORT.  

D:  WHEN THE SUBMARINE IS READY TO COME UP, POSITIVE BUOYANCY IS ACHIEVED BY REPLACING THE WATER IN THE BALLAST TANKS WITH AIR.  THE HYDROPLANES ALSO HELP MOVE WATER OVER THE STERN, FORCING THE STERN DOWNWARD, WHICH ANGLES THE SUBMARINE UP TOWARDS THE SURFACE.  THIS CAN BE DONE VERY QUICKLY IN THE EVENT OF AN EMERGENCY, TO GET THE SUBMARINE TO THE SURFACE AS QUICKLY AS POSSIBLE.

O:  NOW THAT WE KNOW HOW SUBMARINES MOVE, LETS LEARN MORE ABOUT HOW PEOPLE ARE ABLE TO SURVIVE IN SUBMARINES FOR A LONG TIME.

D:  THERE ARE THREE MAJOR CONCERNS WHEN IT COMES TO SURVIVING IN A SUBMARINE.  IT’S IMPORTANT TO ENSURE THAT THERE IS GOOD AIR QUALITY, FRESH WATER, AND A COMFORTABLE TEMPERATURE.  THOSE ARE ALL CHALLENGES FOR A SUBMARINE THAT IS HANGING OUT DEEP DOWN IN THE OCEAN.

O:  WE DON’T OFTEN THINK ABOUT IT, BUT THE AIR WE BREATHE HAS A VERY SPECIFIC COMBINATION OF DIFFERENT GASSES.  78% OF THE AIR IS NITROGEN, 21% IS OXYGEN, AND THE REMAINING 1% IS A COMBINATION OF ARGON AND A TEENY TINY AMOUNT OF CARBON DIOXIDE.

D:  WHEN WE BREATHE, OUR BODIES TURN OXYGEN INTO CARBON DIOXIDE.  SO, EVEN THOUGH THE AIR WE BREATHE IN, OR INHALE, HAS ONLY 0.04% CARBON DIOXIDE, THE AIR WE BREATHE OUT, OR EXHALE, IS ABOUT 4.5% CARBON DIOXIDE.  THAT’S A HUGE DIFFERENCE.

O:  THIS MEANS THAT THINGS COULD GET DANGEROUS IF YOU HAVE A BUNCH OF PEOPLE IN A PRETTY SMALL SEALED CONTAINER LIKE A SUBMARINE FOR A LONG TIME.  EVENTUALLY, THE AIR IS GOING TO LOSE OXYGEN AND GAIN CARBON DIOXIDE.  CARBON DIOXIDE BECOMES VERY DANGEROUS WHEN IT STARTS TO BUILD UP.  IF MORE FRESH OXYGEN DOESN’T REPLACE THE CARBON DIOXIDE, PEOPLE WOULD HAVE TROUBLE BREATHING AND SUFFOCATE.

D:  ADDITIONAL OXYGEN IS ADDED TO A SUBMARINE BY TANKS OR BY AN OXYGEN GENERATOR, WHICH IS ABLE TO EXTRACT OXYGEN FROM WATER, BECAUSE WATER HAS OXYGEN IN IT.  

O:  DANGEROUS CARBON DIOXIDE IS REMOVED FROM THE AIR USING SOMETHING CALLED SODA LIME.

D:  SODA LIME IS A COMBINATION OF CALCIUM HYDROXIDE AND SODIUM HYDROXIDE.  

O:  AS FOR OUR SECOND CONCERN, WHICH IS FRESH WATER, SUBMARINES ARE ABLE TO HAVE FRESH WATER BECAUSE OF A MACHINE THAT DISTILLS SEA WATER.  IT IS ABLE TO TURN SEA WATER, WHICH WOULDN’T BE SAFE TO DRINK, INTO FRESH WATER THAT IS DRINKABLE.

D:  IT HEATS UP THE SEA WATER AND TURNS IT INTO WATER VAPOR.  WHEN IT TURNS INTO WATER VAPOR, THE SALTS ARE REMOVED.  THEN THE WATER IS COOLED IN A COLLECTING TANK, AND FRESH WATER IS WHAT YOU END UP WITH.  THE FRESH WATER IS NEEDED TO COOL THE EQUIPMENT ON THE SUBMARINE THAT HEATS UP FROM LOTS OF USE, AND IT IS USED FOR THE CREW AS WELL, FOR THINGS LIKE COOKING, DRINKING, AND BATHING.  

O:  THE FINAL PIECE TO MAKING SURE THAT PEOPLE CAN SURVIVE IN A SUBMARINE FOR A LONG PERIOD OF TIME IS MAKING SURE THE TEMPERATURE ON THE SUBMARINE IS COMFORTABLE.  THE TEMPERATURE OF THE OCEAN WHERE A SUBMARINE USUALLY HANGS OUT IS ABOUT 39 DEGREES FAHRENHEIT, OR 4 DEGREES CELSIUS.  THAT IS SUPER COLD.  NOBODY WOULD WANT TO BE STUCK IN THOSE TEMPERATURES FOR TOO LONG.  

D:  AND THAT’S WHY THE METAL WITHIN THE SUBMARINE IS ABLE TO CONDUCT HEAT TO THE SURROUNDING WATER.  SUBMARINES RELY ON ELECTRICAL POWER TO KEEP THE INSIDE NICE AND WARM.  THE POWER FOR THE HEATERS USUALLY COME FROM A DIESEL ENGINE, A NUCLEAR REACTOR, OR IN THE CASE OF EMERGENCY, CAN COME FROM BATTERIES AS WELL.     

O:  BEFORE WE ANSWER THE QUESTION OF THE WEEK, THERE IS ANOTHER REALLY IMPORTANT THING WE NEED TO LEARN ABOUT SUBMARINES.  WE NEED TO LEARN HOW THEY KNOW WHERE TO GO.  IF YOU’VE EVER SAILED ON THE OCEAN, YOU MIGHT NOTICE THAT LIGHT ISN’T ABLE TO GET VERY FAR DOWN INTO THE OCEAN WATER.

D:  SO, IF YOU’RE JUST STANDING IN A COUPLE OF FEET OF OCEAN WATER AND SPLASHING AROUND, YOU MAY BE ABLE TO SEE THE OCEAN FLOOR, BUT IF YOUR SAILING OVER DEEP OCEAN WATER, YOU WILL NOTICE THAT IT’S HARD TO SEE MORE THAN A FEW FEET DOWN.  THAT’S BECAUSE LIGHT DOESN’T PENETRATE FAR INTO THE OCEAN.

O:  SO, WHEN SUBMARINES ARE NAVIGATING THROUGH THE OCEAN,  THEY ARE PRACTICALLY BLIND, SO SPECIAL EQUIPMENT IS NEEDED TO HELP THEM.  

D:  ON THE SURFACE, A SUBMARINE CAN USE GPS, THE SAME WAY THAT CARS DO ON LAND.  THE ONLY PROBLEM IS THAT GPS DOESN’T WORK PROPERLY IF A SUBMARINE IS SUBMERGED.  WHEN SUBMERGED, SUBMARINES USE INERTIAL GUIDANCE SYSTEMS TO HELP GUIDE THE WAY.  EVEN THOUGH THE INERTIAL GUIDANCE SYSTEMS ARE HELPFUL, THEY CAN ONLY ENSURE THAT SUBMARINES ARE WITHIN ABOUT 100 FEET OF THEIR INTENDED COURSE.

O:  IN ORDER TO LOCATE A TARGET, SUBMARINES USE SOMETHING CALLED SONAR, WHICH IS REALLY NEAT.  SONAR STANDS FOR SOUND NAVIGATION AND RANGING.  THIS IS HOW IT WORKS.  A SUBMARINE CREATES SOUND WAVES THAT TRAVEL THROUGH THE WATER.  THE WAVES HIT THE TARGET AND RETURN TO THE SUBMARINE.  BY USING THE SPEED OF SOUND IN WATER AND THE TIME IT TAKES FOR THE SOUND WAVES TO TRAVEL TO THE TARGET AND BACK, A SUBMARINE CAN ESTIMATE HOW FAR AWAY A TARGET IS.  

D:  THERE ARE ANIMALS THAT USE SIMILAR STRATEGIES TO IDENTIFY HOW FAR AWAY TARGETS ARE.  WE’VE EVEN DISCUSSED SOME OF THEM ON THIS PODCAST IN THEIR VERY OWN EPISODES, LIKE BATS, DOLPHINS, AND WHALES.  ALRIGHT OLIVIA, IT’S IMPORTANT TO KNOW HOW TO NAVIGATE THROUGH THE OCEAN WATER BECAUSE SUBMARINES ARE CAPABLE OF MOVING REALLY FAST.  WHAT IS THE FASTEST SPEED EVER RECORDED FOR A SUBMARINE?

O:  THE SOVIET SUBMARINE K-222 REACHED A SPEED OF 44.7 KNOTS, WHICH COMES OUT TO BE 51.4 MILES PER HOUR, OR 82.8 KILOMETERS PER HOUR.  THAT IS RIDICULOUSLY FAST FOR A VEHICLE MOVING DEEP INSIDE THE OCEAN.  MOST SUBMARINES DON’T TRAVEL NEARLY THAT FAST.  

D:  WE ALSO WANT TO BE SURE TO ANSWER VEYLAN’S SUBMARINE QUESTIONS BEFORE WE GO.  HE WANTED TO KNOW WHAT SUBMARINES ARE MADE OF AND HOW SOMEONE WOULD LEARN HOW TO DRIVE ONE.  

O:  SUBMARINES ARE MADE FROM VERY STURDY METALS TO MAKE SURE THAT THE SUBMARINE CAN HOLD UP IN THE OCEAN WATER.  METALS LIKE STEEL, COPPER, ALUMINUM, AND BRASS ARE OFTEN USED IN THEIR CONSTRUCTION.

D:  IN ORDER TO LEARN HOW TO DRIVE A SUBMARINE, THERE ARE PROFESSIONAL SUBMARINE PILOT COURSES THAT CAN BE TAKEN.  DEPENDING ON HOW DETAILED YOU WANT TO GET, THE COURSES CAN LAST ANYWHERE FROM A FEW DAYS TO A FEW WEEKS.  WELL, THAT’S A WRAP FOR THIS WEEK’S EPISODE.

O:  221 - SUBMARINES.

D:  GREAT JOB OLIVIA, AND GREAT JOB VEYLAN FOR THE DEEP DIVING EPISODE TOPIC SUGGESTION.  LET’S THANK SOME AMAZING LISTENERS OF THE PODCAST.

O:  A BIG THANKS TO OUR NEWEST PATREON SUPPORTERS, JACK C., AND KUYPER AND HOBSON.

D:  THANK YOU FOR SUPPORTING THE PODCAST.  WE CAN’T DO IT WITHOUT ALL THE LOVE WE GET FROM OUR PATREON SUPPORTERS.

WE ALSO WANT TO THANK USERNAME MIA THE SCIENTIST FOR THE 5 STAR REVIEW.  IT SAYS “GOOD”.

O:  IS THAT ALL IT SAYS?

D:  THAT’S IT.  IT JUST SAYS GOOD, AND WE CAN’T THANK MIA ENOUGH FOR LEAVING THAT 5 STAR REVIEW FOR US.  EVEN A SIMPLE ONE WORD REVIEW IS SO HELPFUL, AND IT LET’S NEW PEOPLE DISCOVER THE PODCAST.  JOIN US NEXT WEEK, WHEN WE WILL GET CURIOUS ABOUT LAWS FOR LISTENERS IN AKRON, OHIO FOR EPISODE NUMBER 222.  AS ALWAYS, THANK YOU SO MUCH FOR LISTENING AND GETTING CURIOUS WITH US.