Your turn
Each lab is one part of the video. Tap, tilt and slide, and see what happens.
Each lab isolates one idea. The hull is a simplified teaching model tuned to the 1912 inquiry findings.
Tap the ship and slide the sliders.
Tap a compartment to flood it. How many can fill before the ship is in trouble?
Flood any compartments. The hull floats with any two flooded, or with the first four.
Tap a box to fill it with water. Does the ship still float?
A simplified model of the hull, tuned to the 1912 British inquiry.
Change the speed. How far does the ship travel in the 37 seconds its first turn took that night?
The inquiry estimated a 37-second turn. At 22 knots that uses up most of the ~450 m gap.
Slide the speed. A slow ship travels less far in the same time.
Distances are distance = speed × 37 s, a simple estimate.
Push the bow down. When does water start to spill over the walls?
Increase the trim by the bow and watch the flooded length grow as water tops each bulkhead.
Tip the front of the ship down. Watch the water spill from box to box!
Tilt angles are exaggerated so the spill-over is easy to see.
Flood compartments from the front. How many does it take? Then try taller walls.
Four forward compartments float; five start the spill-over. Taller bulkheads (to C deck) move the limit.
A simplified model of the hull, tuned to the 1912 British inquiry.
Add lifeboats. How many would it take to give all 2,200 people a seat?
Titanic carried 20 boats for 1,178 people: more than the law then required, but about half of those aboard.
Add more lifeboats until everyone has a seat.
Extra boats are counted at 65 seats each.
The Titanic was a giant ship. It was one of the biggest ships in the world. On its very first trip, on a cold, dark night, it scraped against an iceberg.
The bottom of the ship was split into little boxes, like an ice-cube tray. If water got into one box, the walls kept it there, and the ship still floated.
But the walls were not tall enough. The boxes were open at the top.
The iceberg made thin cracks along the side, and water got into too many boxes at the front. The front of the ship got heavy and tipped down. Then the water spilled over the walls into the next box, and the next, until the ship sank. It was a very sad night.
There were not enough lifeboat seats for everyone. Now passenger ships must carry lifeboat or life-raft seats for everyone on board, and an ice patrol watches the sea for icebergs.
The Titanic sank because an iceberg scraped along its right-hand (starboard) side and opened too many of its watertight compartments at once.3 The ship's hull was divided into 16 compartments by walls called bulkheads.3 It was designed to float with any two of them flooded, and even with the first four flooded.1 The iceberg opened the first five or six.1
With that much water in the front, the bow sank lower and lower. The bulkheads didn't reach all the way up to the top deck, so water rose over the top of each wall and spilled into the next compartment, then the next, like tipping an ice-cube tray that's full of water.13 Nothing could stop it. The pumps couldn't keep up: in the first ten minutes alone, water rose about 14 feet (4 m) above the keel in the front compartments.1
Several things set up the disaster: the ship kept a high speed through an area where it had been warned about ice, not every warning reached the officers on the bridge, and a calm, moonless night made the iceberg very hard to see.34 Then too few lifeboats turned a shipwreck into one of the deadliest disasters at sea.2
The Titanic's safety design was clever. Walls called bulkheads split the hull into 16 compartments, and the watertight doors low down in the engine and boiler rooms could be shut from the bridge.3 If one part of the hull was holed, the water was supposed to stay trapped in that section while the rest of the ship stayed dry and kept it afloat.
But the bulkheads were only watertight up to a certain height. Seven of them stopped at E deck and the rest at D or C deck, all well below the top of the hull. They weren't capped at the top.13 That was fine as long as the ship stayed fairly level. The British inquiry found:
| Compartments flooded | What happens |
|---|---|
| Any 2 | Floats safely |
| Any 3 of the first 4 | Floats, with water staying below the tops of the bulkheads |
| The first 4 | Still floats, though water is above some of the forward bulkheads |
| The first 4 + boiler room 6 (5 in total) | Bow sinks until water flows over the next bulkhead, and then the next: the ship is doomed |
floats with 4 vs sinks with 5
That's why the number of compartments mattered much more than the size of the hole. The inquiry also found that if the bulkhead behind boiler room 5 had been carried up to a higher deck (C deck), the ship would probably have stayed afloat with the damage it actually received.1 Try it in the "Your turn" lab above: turn on "Taller walls".
No. For decades people believed the iceberg tore a gash about 300 feet (90 m) long. Engineers who studied the evidence found there was no such gash. Naval engineers concluded the iceberg bent the steel plates and forced open seams and popped rivets, letting water in through many thin cracks.4 Edward Wilding, one of the ship's designers, estimated at the time that the total opening was less than 12 square feet (about 1.1 m²).4 As the engineers put it: "steel cuts ice, but ice does not cut steel."4
Tests on steel brought up from the wreck in 1991 showed it was more brittle in cold water than modern ship steel, which may have made cracking worse.4
Would a head-on crash have been better? Most experts think the ship would have survived a head-on hit.3 The front of the bow would have been crushed, but a glancing blow along the side opened more compartments than the ship could survive.
No single mistake sank the Titanic. It was a chain of small ones, on a night when conditions were against the crew.
A common story says the captain was chasing a speed record. Historians at Royal Museums Greenwich say there's no evidence for this. The Titanic was built for comfort, not to be the fastest ship on the Atlantic.5
About 2,200 people were on board.35 The Titanic carried 20 lifeboats with room for 1,178 people, which was actually more than the law required at the time.12 That's seats for only about half the people on board. The National Archives says the lack of lifeboats was chief among the reasons given for the enormous loss of life.2
Things got worse because the evacuation was slow and confused. Many passengers didn't believe the ship was in danger at first, and many boats left only partly full. Lifeboat 7, the first to leave, held about 27 people but had room for 65.3 The sea was about −2 °C (28 °F), and most people who ended up in the water died of the cold within a short time.53
About 1,500 people lost their lives: the US Senate inquiry counted 1,517, and the British inquiry 1,490.21 Crew members and third-class passengers, many of them families emigrating to America, suffered the heaviest losses.32 The liner Carpathia, about 58 nautical miles away when it heard the distress call, raced through the ice and arrived after the Titanic had gone. It picked up about 706 survivors from the lifeboats.32
Yes. As the bow filled, the stern rose high out of the water, putting a huge strain on the middle of the ship. At about 2:18 am the lights went out and the hull broke in two.3 Survivors disagreed about this at the time, and the 1912 British inquiry concluded the ship went down in one piece.1 The wreck settled the question when it was found in 1985: it lies in two large pieces, 1,970 feet (about 600 m) apart, with a field of debris between them.4
The wreck lies on the floor of the North Atlantic, about 400 nautical miles (740 km) south of Newfoundland, Canada,3 at a depth of about 3,800 meters (12,500 feet).6 A joint French–American expedition found it on 1 September 1985.5 NOAA scientists have studied how it is breaking down: microbes that feed on iron build icicle-shaped "rusticles" that are slowly eating the ship away.6
Inquiries were held in both countries. The US Senate hearings began on 19 April 1912, just days after the sinking, and heard from 82 witnesses.2 The recommendations changed shipping rules around the world:12
An iceberg scraped along its right side and opened the first five or six of its sixteen compartments. The ship could float with its first four flooded. With more, the bow sank low enough for water to spill over the tops of the walls into the next compartments, one after another, until the ship sank.
About 2 hours and 40 minutes. It hit the iceberg at about 11:40 pm on 14 April 1912 and disappeared at 2:20 am on 15 April.
On the night of 14–15 April 1912, in the North Atlantic Ocean about 400 nautical miles (740 km) south of Newfoundland, Canada, on its first voyage from Southampton to New York.
Probably. Going slower in an area with ice warnings, passing on every warning to the bridge, or taller bulkheads could each have changed the outcome. The 1912 British inquiry blamed the collision on excessive speed and found that a bulkhead carried up to a higher deck might have kept the ship afloat.
No. The old idea of a 300-foot gash is a myth. The iceberg bent steel plates and popped rivets, opening thin cracks along the hull. Engineers estimate the total opening was less than 12 square feet, but it was spread across too many compartments.
About 1,500 of the roughly 2,200 people on board. The US Senate inquiry counted 1,517 and the British inquiry 1,490. About 706 survivors were picked up from the lifeboats by the Carpathia.
About 3,800 meters (12,500 feet) down on the floor of the North Atlantic. It was found in 1985, broken into two main pieces, and is slowly being broken down by iron-eating microbes that form rusticles.