1
00:00:00,700 --> 00:00:02,360
PROFESSOR: When we
take complex things

2
00:00:02,360 --> 00:00:04,400
and break them into
smaller pieces,

3
00:00:04,400 --> 00:00:06,870
we find out that we know a
lot more about things then

4
00:00:06,870 --> 00:00:07,470
we think.

5
00:00:07,470 --> 00:00:10,470
[MUSIC PLAYING]

6
00:00:19,580 --> 00:00:22,560
Now let's take this box,
ORCA I and create damage

7
00:00:22,560 --> 00:00:24,908
below the waterline which
I've indicated right here.

8
00:00:24,908 --> 00:00:27,298
[MUSIC PLAYING]

9
00:00:38,900 --> 00:00:42,094
As we can see, we've
damaged ORCA I right here.

10
00:00:42,094 --> 00:00:44,790
Now let's put ORCA I in the
water and see what happens.

11
00:00:44,790 --> 00:00:48,790
[MUSIC PLAYING]

12
00:01:04,230 --> 00:01:06,720
[WATER GLUGGING]

13
00:01:10,710 --> 00:01:14,100
The ORCA I sank due to the
weight of the added water.

14
00:01:14,100 --> 00:01:19,520
But what if the ORCA I contained
cargo or oil or even people?

15
00:01:19,520 --> 00:01:23,190
Now let's take ORCA II
and do the same thing.

16
00:01:23,190 --> 00:01:26,136
[MUSIC PLAYING]

17
00:01:41,360 --> 00:01:43,270
So, we can see that
ORCA II did not sink,

18
00:01:43,270 --> 00:01:46,160
although it is sitting at
an angle towards the bow.

19
00:01:46,160 --> 00:01:48,840
So why didn't ORCA II sink?

20
00:01:48,840 --> 00:01:51,090
As easy as it sounds,
this simple demonstration

21
00:01:51,090 --> 00:01:54,946
is essential to the design
of huge, complex ships.

22
00:01:54,946 --> 00:01:57,800
Ships that are responsible
for carrying about 90%

23
00:01:57,800 --> 00:01:59,090
of all our stuff.

24
00:01:59,090 --> 00:02:01,190
As naval architects,
how do we design

25
00:02:01,190 --> 00:02:04,133
ships carrying our stuff to
make it into port safely and not

26
00:02:04,133 --> 00:02:05,301
sink?

27
00:02:05,301 --> 00:02:06,849
Well, why don't we find out?

28
00:02:06,849 --> 00:02:10,132
[MUSIC PLAYING]

29
00:02:17,986 --> 00:02:21,450
Here we have ORCA I and
ORCA II from before.

30
00:02:21,450 --> 00:02:23,040
Although ORCA I
and ORCA II don't

31
00:02:23,040 --> 00:02:24,890
engage in international
trade, they

32
00:02:24,890 --> 00:02:28,166
behave just as a 1,000
foot container ship would.

33
00:02:28,166 --> 00:02:31,740
Now let's take a look into
ORCA I. We can see that there's

34
00:02:31,740 --> 00:02:34,950
nothing in it, it's just a box.

35
00:02:34,950 --> 00:02:38,617
But if we look at
ORCA II we can see

36
00:02:38,617 --> 00:02:40,960
that it's subdivided into
these watertight compartments

37
00:02:40,960 --> 00:02:44,100
by these transverse
watertight bulkheads.

38
00:02:44,100 --> 00:02:46,290
Now what that
means, is if we were

39
00:02:46,290 --> 00:02:48,570
to damage this ship
right here, water

40
00:02:48,570 --> 00:02:50,620
would only flow into
this compartment.

41
00:02:50,620 --> 00:02:53,475
It would not go into this
one, this one, or this one.

42
00:02:53,475 --> 00:02:57,060
That would cause the ship to be
angled or trimmed in the water,

43
00:02:57,060 --> 00:03:00,240
but it would not cause the
ship to sink completely.

44
00:03:00,240 --> 00:03:02,950
We refer to ORCA II
as being subdivided.

45
00:03:02,950 --> 00:03:06,450
And we can see subdivision in
many of these ships' plans.

46
00:03:06,450 --> 00:03:08,060
It is unclear when
subdivision first

47
00:03:08,060 --> 00:03:09,870
started being used in ships.

48
00:03:09,870 --> 00:03:12,741
But accounts of 5th
century Chinese trade ships

49
00:03:12,741 --> 00:03:14,990
indicate that water would
be able to enter the vessel,

50
00:03:14,990 --> 00:03:16,142
without sinking.

51
00:03:16,142 --> 00:03:18,980
So let's find out
why this happens.

52
00:03:18,980 --> 00:03:22,910
Let's imagine a barge divided
into 10 equal compartments.

53
00:03:22,910 --> 00:03:25,610
One of them springs
a leak from damage.

54
00:03:25,610 --> 00:03:28,490
Since the ship is subdivided,
only the first compartment

55
00:03:28,490 --> 00:03:30,590
floods and the ship
remains afloat,

56
00:03:30,590 --> 00:03:33,050
protecting both its
people and cargo.

57
00:03:33,050 --> 00:03:35,360
Although the added water
causes the ship to trim,

58
00:03:35,360 --> 00:03:38,244
it still has enough buoyancy
to return to port for repairs.

59
00:03:38,244 --> 00:03:40,564
[MUSIC PLAYING]

60
00:03:42,420 --> 00:03:44,040
Ships still sink, though.

61
00:03:44,040 --> 00:03:45,810
It's both expensive
and impractical

62
00:03:45,810 --> 00:03:47,707
to try to design
the unsinkable ship,

63
00:03:47,707 --> 00:03:49,290
especially when these
ships will never

64
00:03:49,290 --> 00:03:51,260
see that amount of damage.

65
00:03:51,260 --> 00:03:52,940
That's why as
naval architects we

66
00:03:52,940 --> 00:03:57,520
use computer programs to
help us out with subdivision.

67
00:03:57,520 --> 00:04:00,010
Computers make it easy to
simulate certain damage

68
00:04:00,010 --> 00:04:02,820
cases in practically no time.

69
00:04:02,820 --> 00:04:06,140
With different software, we
can damage certain compartments

70
00:04:06,140 --> 00:04:08,520
and see how the
ship responds to it.

71
00:04:08,520 --> 00:04:10,720
This gives the naval
architect a good idea

72
00:04:10,720 --> 00:04:14,401
of what parts to improve
on the ship, if any.

73
00:04:14,401 --> 00:04:18,050
So even though ships seem
like these intricate, complex

74
00:04:18,050 --> 00:04:20,700
things, they're really
just based on principles

75
00:04:20,700 --> 00:04:21,960
that we all already know.

76
00:04:21,960 --> 00:04:25,610
[MUSIC PLAYING]