Hey, it's me, Destin. Welcome back to
Smarter Every Day. We're right in the
middle of a deep dive here on Smarter Every Day
into nuclear submarines. We're investigating all
these different things about how nuclear
submarines work, and we're trying to learn
very detailed information about each individual thing. Today we're going to
talk about torpedoes, which is fascinating to
me because I've actually been down range from a torpedo
when it's engaged a target. This is me in a
helicopter back in 2018 as the part of my job, which was
a developmental weapons tester. I'm filming the USS Racine
waiting on a Mark 48 torpedo to impact. And when it did,
it was devastating. That was a part of RIMPAC, the
Rim of the Pacific exercise. That activity took place at
what's called the Barking Sands Missile Range Facility. And what's so interesting
about that is they test missiles there, but
they also test torpedoes. If you looked off the coast
of Kauai at any given day, you could see a helicopter
towing a torpedo that it had picked up out in
the ocean after being fired and they did some kind
of weapons development. But here's the deal. Even though torpedoes are super
fascinating and they're modern and they're constantly
being changed, they are very old technology. In fact, they were used to
great effect during World War I. So this technology needed to
fire a torpedo from a submarine is very old, but generally
speaking most people don't know how it works. Today we're literally
going to crawl inside the torpedo tube of a US
nuclear submarine in the Arctic Ocean under the
ice, and we're going to be able to look
around inside this tube and try to understand how
all these things work. All right. Let's do it. Let's go get Smarter Every Day. [THEME MUSIC] That's running down
towards the torpedo room. DESTIN: Torpedo room. That's what I'm talking about. Oh, yeah. MAN: It's a thing. DESTIN: This is the party. And so one of the places
you could have flooding, this is one of the
very few, right. But that's the most
important spaces. DESTIN: Oh, well,
I'll be danged. There we go. And there it is. DESTIN: And there it is. OK. All right. So what we got here is-- Going to touch it. So my name's Alan Howell. I'm the Torpedo Division
Chief Petty Officer here on the USS Toledo. DESTIN: Oh, awesome. Rock and roll. So you're over the torpedoes,
did I understand correctly? Yes, sir. That is correct. DESTIN: OK. So right now where
are the torpedo tubes? So torpedo are forward the
ship on the port and starboard side. So we currently have
four torpedo tubes on the 688 class submarine. Two over here on the starboard
side, two over on the port. So that's what I'm
seeing right there? Yes, sir. DESTIN: OK, and then-- What you're seeing
is the breach doors. DESTIN: And there's
one way over there. ALAN HOWELL: And there's
two more over on that side. DESTIN: Two on that side. Yes, sir. DESTIN: OK. Got it. So what you're seeing
is the breach doors. And when we're done
with this evolution we can open them up
for you, and if you want to crawl down in there
you're more than welcome to. DESTIN: In the torpedo tube? Absolutely. DESTIN: Crap yeah, I do. Yeah. Good. DESTIN: Let's do that. We send our torpedo
men down there once a month for maintenance, so
we dive the tubes every month. So we're in there all the time. DESTIN: I like you already. So you're in. DESTIN: Rock and roll. I'm going to set this
camera up over here. So, well, now I guess it's going
to open that way, isn't it? Can I prop it on this? ALAN HOWELL: Sure. We got a green if you
want to put that on. It's probably going
to be wet down there. So this is-- TM2 Knight. DESTIN: TM2 Knight. What does TM2 mean? That means torpedoman's mate. DESTIN: Torpedoman's mate. Yes, sir. DESTIN: OK cool. And my understanding is
this is a torpedo tube. Yes, sir. DESTIN: And there's a thing
that you're going to let me do. Yes, sir. So we're going to open
up the breach door and let you crawl down inside
and sign your name at the-- or at least try to sign your
name on the muzzle door. DESTIN: This is the standard
door for a torpedo tube, I guess. TM2 KNIGHT: Yes, sir. DESTIN: And it's hydraulically
operated, you said? TM2 KNIGHT: Yes, sir. DESTIN: OK. And this is a torpedo, right? TM2 KNIGHT: Yes, sir. Mark 48 ADCAP. DESTIN: What's ADCAP mean? TM2 KNIGHT: Means
advanced capability. DESTIN: And so this yellow
stripe right here means that is a live torpedo? TM2 KNIGHT: Yes, sir. DESTIN: That's amazing. If you think about
what's going on here, you've got this long torpedo
down in the bottom floor of this submarine. How did it get there? Because we barely have
enough room to move around. OK, so this is Jacob, the
assistant weapons officer. I'm also the diving officer,
so I'm responsible for-- biggest responsibility
is probably rig for dive, which
we'll talk about here. But this is the
command passageway. Naval tradition kind of thing. It's a area where you're
supposed to minimize passage. Only certain people are allowed
regular passage through here. Right here is the
weapon shipping hatch. And it happens to be
the most convenient way to get into the ship, but it's
also the primary means by which we load torpedoes, actually. DESTIN: Really? JACOB: Right now
it's rigged for dive, so I can't just open this
without cabin suppression. But if you were to open this,
it swings down that way. You can see that hand wheel
or that lever right there. DESTIN: Right. JACOB: Turn it and it
will swing down that way. You'll see that it's
actually got a cant, and that's so that torpedoes
actually come in like this, and you wonder where
they're going to go. Well, these plates right
here, these deck plates, you take them out and there's
a tray underneath that actually swings downward. Its hinges are on this side. DESTIN: Coming through, captain? No, I'm good. And likewise on
the next deck down, take the deck plates out,
shipping tray hinges downward, goes all the way down
to the torpedo room. And when we load
torpedoes that way. What I think is
fascinating about this is the geometry of
taking this huge torpedo and getting it to
the bottom floor. All this was figured
out way back in the day. Like the first Los
Angeles class submarines were laid down in
the '70s, which means all the decisions those
engineers made back then affect what types of
weapons can be fired now. Now, I couldn't find any
footage of loading torpedoes into a Los Angeles
class submarine. However, I did find footage of
a harpoon missile being loaded. Now, that has the
same geometric form factor as a Mark 48 torpedo. But what's interesting is if
you watch how they do this, it's like a choreographed
dance to get this torpedo down to the bottom floor. So it doesn't matter what
technological advancements you make in the weaponry
itself, for the seeker heads or the guidance or
the fire control. It doesn't matter. You are still constrained
by the physical size of the torpedo tube and how you
can physically lower it down to the bottom deck of the boat. When it comes to actually
inserting the torpedo into the tube, there's either
one of two ways that it's done. Number one, you
could use hydraulics which basically pushes the
round all the way into the tube. Or number two, they can
actually override that and do it with snatch blocks
and muscle power, because snatch
blocks are awesome. What do you call this
contraption here? This is the door of the torpedo? TM2 KNIGHT: That's the
breach ring or breach door for the torpedo tube. DESTIN: OK. And so if I
understand correctly, you're going to open that. And what you would normally
do is you would go inside and you would clean it? Is that right? Yes, sir. DESTIN: OK. And you're going to let me try? Yes, sir. So how do you open this? All right. So first we're going to verify
that everybody's clear of it and there's nothing interfering
with it because it's hydraulics. We're going to go on one. Clear. All right. We're good. Just pull this plug. DESTIN: Wow. Make sure it's latched. And there's the torpedo tube. DESTIN: Oh, it's awesome. OK, I'm going to level with you. This was the moment
in my life where I realized I was
being offered a chance to crawl inside a torpedo
tube in a nuclear submarine. So side note, how the
heck did that happen? But when it comes right
down to the reality of what's about to go down,
how does a torpedo fire? I did not know how a torpedo
leaves the tube of a submarine. No clue. Before we crawl
down in the tube, I want to try to explain
how this thing works so you'll have a better idea
of what we're looking at. This is a model of
a Mark 48 torpedo. Just 3D printed this,
painted it, the whole bit. I'm really proud of it. Anyway, there's something
really cool about this I want you to see. If you look really close
here, on the top of this thing you can see there's this little
tab kind of thing, right? So those little tabs right there
have a very specific purpose. If we open the back
of the torpedo tube, you can see that on top
there's this little Y, and that Y guides that
little tab into the tube so the torpedo will always align
to the correct orientation. Up will always be up. But there's other things
you can do, right? Not only does it give
you radial alignment, but it can give you axial
alignment along the longitude of the tube. I don't know if I'm saying that
right, but I think you get it. So as it goes in, if you have
something that's pushing down inside that little Y slot, as
the torpedo goes forward, boop, it'll bump right there
and it'll stop the torpedo from going any farther. If you have something
on the back of it, that'll keep it from
going backwards. So at that point, you have
constrained the torpedo in six degrees of freedom. Roll pitch, yaw, X, Y, Z. Just
with that little slot and two little lugs on each side. Before we go down
the tube, I want you to understand exactly
how the torpedo launching system works. So the first thing
we do is make sure the locking lugs are in
the correct configuration, and that's that little
tab thing I was explaining would keep the torpedo from
sliding forward and backwards. So the forward
locking lug is going to be in the load
position, which means it's going to be down, but
the back one is going to be up. Next, we open the
breach door and we can slide the torpedo in. Again, we can do that with
hydraulics or, my favorite way, snatch blocks. Once the torpedo is in and the
locking bolt on the torpedo has moved up against the
locking lug in the tube, the aft locking lug
comes down and secures the torpedo in the tube. In case the submarine
pitches up for some reason you don't want it to slide
against the breach door. At this point the breach
door is shut and locked, and now the torpedo is stable
inside the torpedo tube and ready for use. In the event they actually
want to fire the torpedo, the following
sequence takes place. First of all, you have
to flood the tube. There's a tank full of
water called the WRT, or Water Round Torpedo tank. A valve is open to allow
water to flood the tank, but because there's air in there
that you have to let escape you also have to open a valve up
top that will vent the air out as you fill it up with water. So this venting of the air
back into the submarine is critical because air
is a precious resource. You're a submarine. You're a set volume. Now, it's cool to
move air around in different compartments
in the submarine, but you never let it
go because you only have the air that you
brought with you, especially when you're under the ice. And you don't want to have
to come back to the top, or in this case you can't go
back to the top, and get more. So it's important to
preserve your air. OK, so the water
from the WRT tank is filling up the
torpedo tube itself. And at some point it
completely fills the tube and starts to go up
into the vent line. Up there there's
an electrode that senses the seawater, and
at that point the valve on top and the valve on the
bottom close at the same time and we have a torpedo tube
completely filled with water. When you go to fill up the
torpedo tube with water you can't take water
from off the boat, because if you have
hundreds of gallons of water that you need to fill
that tank suddenly that's like putting thousands
of pounds on the front right corner of your boat which would
cause you to tip like this. So in order to do this they had
this carefully choreographed buoyancy ballet where they
take water that's already on the ship-- in fact,
it's very near the tube-- and they fill the
tube with that. So there's no mass exchange
between off the boat and inside. That way they can carefully trim
everything out and it will stay trimmed throughout the
entire firing sequence. So at this point we
have a torpedo tube that's filled with
water, but the problem is it is at a lower pressure
than outside the boat. Because as you know,
the deeper a submarine goes the higher and higher
the pressures can get. So what we have
to do is equalize the system, and that's the
purpose of this valve right here, the equalizing valve. Once we turn this thing,
the pressure in the tube will now be the same as the
pressure out in the ocean. Now that we have
the same pressure on the inside of
the tube as we do on the outside of
the submarine, we can open the muzzle door because
the forces are equalized. But it's also time to move
what's called the slide valve. The slide valve
is a movable part of the tube that's about
midway down the torpedo that concentrically covers all
these different rectangular ports through which
water can travel. So the slide valve
moves, exposing those rectangular ports,
and now you can dump water into the torpedo tube. At this point we are
completely ready to fire. And when the fire command
comes from fire control back in the control room,
both the locking lugs retract, which frees up the
torpedo to move axially, and pressurized water
from an impulse tank provides a tremendous
amount of pressure in-flow which is then introduced
into the torpedo tube from all those rectangular holes
which were covered by the slide valve, and this additional
water in the tube pushes the torpedo out the
front of the submarine. OK. What I'm about to tell you,
I do not know for a fact. But think about it. We had a huge torpedo in
the tube, and we fired it, and it is no longer
on the submarine. The weight of that
torpedo is gone, which tells me that in order to
maintain balance in the system an ideal torpedo is
probably neutrally buoyant. Anyway, so at this point we
have to return the system to its original state without
gaining or losing mass. How do we do that? OK, so the first thing
we're going to do is we're going to
close the muzzle door and close the slide valve
and then close the equalizing valve. At this point the tube is
now shut off from the ocean. And this is the
other magic trick. How do we get all this
water out of the tube without changing the
weight of the boat? We open this three-way valve
down here at the bottom, and we divert the water from
the tube to the auxiliary tank. But because it's going to
take forever for that to drain and you have to back-fill
that water with air, we might as well
use pressurized air. So we open this
blow valve up top, and we have a
pressurized source of air to force all that water out
down into that aux tank. At this point, when
the tube is dry we close both of
those valves and we are left with a
pressurized torpedo tube. That's unacceptable because
we don't want to waste air. So what we do at this point
is we open the three-way valve on top and we vent that
pressurized air back into the people part
of the submarine. And there you have it. All you have to do is unlock
and open the breach and lower the front locking
lug, and you're ready to load another
torpedo in the tube. That plate right
there that you can see? That's the slide valve there. That's where once the
tube is flooded down, if we would open
that slide valve and there was flow slots inside. So that tank is basically
just a free flooded area, so on the other side of
that valve is water. Where is the valve? TM2 KNIGHT: It's this
giant plate right here. That would slide forward
and uncover the flow slots. DESTIN: Got it. Got it. So this thing moves
forward, and there's holes around the outside
that pushes the torpedo out. TM2 KNIGHT: Yes, sir. The torpedo gets loaded
in all the way down. We flood down the tube. We equalize it with
the sea pressure. And then that slide valve,
once we open the muzzle door, will open, and that
pressure pushes the weapon out of the tube. DESTIN: Got it. OK. Cool. So just crawl down there and
sign my name at the end, right? TM2 KNIGHT: Yes, sir. Am I still rolling? You're still rolling. DESTIN: So what can
I not step on here? TM2 KNIGHT: You don't
want to step on-- DESTIN: Can I step on
the nose of the torpedo? I would step right here-- DESTIN: [LAUGHS] OK, thank you. There's sensitive
stuff in there. OK. Here we go. Put your foot on here. Thank you. [GROANS] Yeah, you couldn't be
claustrophobic and do this, could you? No, sir. DESTIN: So these valves here,
are these little screens? Those are just
strainers to make sure that whenever we drain the
torpedo tube nothing solid gets into the system. DESTIN: Gotcha. So there's seawater on
the other side of this? Yes, sir. DESTIN: That's crazy. So sign my name right here? TM2 KNIGHT: Yes, sir. Anywhere you like. DESTIN: Oh, a lot of
people have done this. It's really, really cold. I guess because we're
in the arctic, huh? Might have something
to do with it. DESTIN: There's no way this
marker is going to work. It's literally ice. Well, there was an attempt. Sometimes that's
all you can ask for. DESTIN: That's all
you can ask for. Let's see if I can see you. That's awesome. You're a really long ways away. About 20 feet. DESTIN: 20 feet? Yes, sir. DESTIN: That's pretty cool. Sweet. Coming back. TM2 KNIGHT: All right. Apparently there's
ice on the door. MAN: Ice? Yeah. [LAUGHS] MAN: [INAUDIBLE]. DESTIN: So is that
a detailed slot? Say again? Oh, yeah. So what you're looking at
right now is the stop bolt. DESTIN: Yeah. TM2 KNIGHT: So when we
load the torpedo in, it's got a little
notch on the top of it. So we load that in, and that
forward one, it is down. So that stops it. DESTIN: Yeah. TM2 KNIGHT: And we roll it so
that the rear one comes down as well, and that locks
the torpedo in place so that it's not going to come
out of the tube with the breach door open. DESTIN: Oh, I see. So it's a can that rolls. Yes, sir. DESTIN: Did you grease it? TM2 KNIGHT: We have greased it. DESTIN: That's awesome. It looks like it's riding
on some type of Teflon or Delrin or something. Yes, sir. That's the sliding surfaces
so that the torpedo has something to slide on
without scratching or damaging it. That was awesome. That was really cool. It was ice. Yeah. DESTIN: Is that normal? That's just the arctic, I guess. Yeah, no. Just being in the arctic
with how cold it is. DESTIN: That's amazing. Well, that's something I
never thought I would do. There was an attempt. There was an attempt. All right. So that sliding down a torpedo
tube on the USS Toledo. Thank you. No problem, sir. DESTIN: Appreciate it. It was freaking
cold is what it was. like ice. MAN: Like real cold, I know. Ice at the end, yeah. I didn't expect that. This video is a part of the
Smarter Every Day deep dive series into nuclear submarines. We're going to study a whole
bunch of different stuff, and I would love it if you would
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like this stuff. Isn't that pretty? Thanks for making me Smarter
Every Day in the comments. I'm Destin. I hope you stay tuned for the
rest of the Smarter Every Day deep dive into submarines. We're going to learn
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like on a submarine? All kinds of stuff like that. Please consider subscribing. There's a lot more to learn. I'm Destin getting
Smarter Every Day. Have a good one. Bye. [MUSIC PLAYING]
Small question on the torpedo launch process. In your graphic at the end of the process, there is more water displayed in the system (right tank) than before. Was a step left out/forgotten? what happens to the extra amount of water? Is it kept in the system as replacement ballast for the weight of the torpedo, or is it flushed out of the sub?
Question here.
When the pressure inside the torpedo tube is equalized. Isn't there more water in the tube than before? How is this dealt with? (It might be an insignificant amount but I'm not sure)
I guess this implies that there would be a small net inflow of water.
I guess the same would hold for the missile system. Although now I think of it. How does the submarine deal with the mass difference after fire. Does it have buancy tanks or something?
Sorry for the chaos of my wording. I might edit it later, but the thought popped up now.
I probably would have closed the hatch on you to mess with you.
I have a question.
If anyone dies in the submarine, is that dead person thrown out through the torpedo tube?
If yes, why?
u/MrPennywhistle Question that kept popping up in my mind - what flashlights were the crew fond of? Saw a couple guys with them on belts and I feel like they would use them pretty consistently. Recommendations?
u/MrPennywhistle Man I gotta know what kind of haircut you've got. It's looking pretty long on the back and short on the sides.
Been waiting for this all week!!
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