0:00:05 > 0:00:08Japan's Bullet Train.
0:00:08 > 0:00:10The world's first high-speed railway.
0:00:12 > 0:00:15Still the most technologically advanced in the world.
0:00:18 > 0:00:21In its life, it's shifted the equivalent
0:00:21 > 0:00:23of the entire population of the Earth,
0:00:23 > 0:00:26at nearly 200 miles an hour.
0:00:28 > 0:00:32The Japanese high-speed train is very different from a normal train.
0:00:32 > 0:00:35You don't just add a more powerful locomotive.
0:00:35 > 0:00:38It doesn't even have a locomotive in the traditional sense.
0:00:38 > 0:00:43A normal train can't stand the stresses of high speeds. You need to redesign it.
0:00:43 > 0:00:47In fact, along the way, you'll need to reinvent the wheel.
0:00:47 > 0:00:50And that called for some surprising engineering connections.
0:00:50 > 0:00:53The Bullet Train wouldn't have been possible without...
0:00:53 > 0:00:55ancient chariot racing.
0:00:55 > 0:00:57Oh, my god!
0:00:58 > 0:01:00'Yes, eat your heart out, Ben Hur!'
0:01:00 > 0:01:01A crowbar...
0:01:03 > 0:01:05..a medieval clock...
0:01:07 > 0:01:09That really IS moving.
0:01:11 > 0:01:14The stopping's going to be uncomfortable, obviously.
0:01:14 > 0:01:16..a 19th-century luxury car...
0:01:17 > 0:01:22My wheels on my train just can't get enough grip to get me moving.
0:01:22 > 0:01:24..and the electric telegraph.
0:01:27 > 0:01:28Any sign of an earthquake?
0:01:28 > 0:01:31- Yeah there's something coming. - Right, quick!
0:01:45 > 0:01:50Japan. A rugged land of volcanic mountains
0:01:50 > 0:01:52and devastating earthquakes.
0:01:54 > 0:01:59Most of the population is squeezed into some of the largest cities on the planet.
0:02:02 > 0:02:06Getting around the country is a challenge.
0:02:06 > 0:02:08Space for roads is restricted.
0:02:08 > 0:02:10And to move all the travellers by air,
0:02:10 > 0:02:14three jumbo jets would have to take off every 5 minutes.
0:02:16 > 0:02:19So, the Japanese chose the train for mass transport.
0:02:24 > 0:02:26They transformed the humble train
0:02:26 > 0:02:29into an iconic and sophisticated engineering marvel.
0:02:44 > 0:02:45This is the N700 bullet train,
0:02:45 > 0:02:49latest in a line of pioneering, high-speed trains.
0:02:49 > 0:02:53Well, it even looks fast, which it is.
0:02:53 > 0:02:58Close on 200 miles an hour, 300 km an hour in regular service.
0:02:58 > 0:03:02But if you think it's all about what happens here, at the pointy end, you'd be wrong.
0:03:02 > 0:03:04It's much more radical than that.
0:03:04 > 0:03:07The whole thing is a system, designed to get up to speed,
0:03:07 > 0:03:10then to corner safely and comfortably,
0:03:10 > 0:03:13even to stop automatically if there's an earthquake.
0:03:13 > 0:03:15It is quite a train.
0:03:17 > 0:03:21How do you turn a normal train into a bullet train?
0:03:25 > 0:03:27It starts with the simplest thing...
0:03:29 > 0:03:30..the shape of the wheels.
0:03:32 > 0:03:35You would think the one place where a wheeled vehicle
0:03:35 > 0:03:39would have no problems at all is a straight piece of track like this.
0:03:39 > 0:03:43I mean, you've got wheels, rails, no bends, what can possibly go wrong?
0:03:43 > 0:03:47In fact, everything can go wrong if the wheels are the wrong shape.
0:03:47 > 0:03:50I mean, it's still round, round is good in a wheel,
0:03:50 > 0:03:54but it's the part that touches the track here, that makes contact,
0:03:54 > 0:03:57that is absolutely critical.
0:03:58 > 0:04:00Without the help of a medieval clock,
0:04:00 > 0:04:04a high-speed train could simply throw itself off the rails.
0:04:06 > 0:04:08No need to take my word for it,
0:04:08 > 0:04:14because I've brought my very own carriage to the Hammond Railways proving ground
0:04:14 > 0:04:17for its inaugural journey, to test its wheels.
0:04:21 > 0:04:24It's not a grand design. It doesn't even have its own power,
0:04:24 > 0:04:27but that doesn't matter, because I've got a powerful winch
0:04:27 > 0:04:32to drag it along this dead straight piece of track at speeds up to 50mph.
0:04:35 > 0:04:40Unfortunately, Hammond Railways don't stretch to basic amenities, like seats.
0:04:42 > 0:04:46That's one of the reasons why I won't be riding on my carriage.
0:04:46 > 0:04:50The other reason is, well, it doesn't have any brakes. I did say it was basic.
0:04:50 > 0:04:56It'll be brought to a complete and probably quite sudden halt by that barrier down there.
0:04:56 > 0:04:58On the plus side, this does have everything we need
0:04:58 > 0:05:02to show just what high-speed train engineers are up against.
0:05:02 > 0:05:05Namely, we've fitted it with these, train-style wheels.
0:05:06 > 0:05:11They're exaggerated, yes, but just like real train wheels, they're conical,
0:05:11 > 0:05:15angled where they rest on the track.
0:05:15 > 0:05:20They might look pretty odd, but according to Paul Allen, an expert in wheel dynamics,
0:05:20 > 0:05:24they'll show clearly what happens to real trains travelling at speed.
0:05:24 > 0:05:30Finally, Hammond Rail is offering a feature never before seen on trains,
0:05:30 > 0:05:32basketballs on poles.
0:05:32 > 0:05:34They'll show how the carriage moves.
0:05:36 > 0:05:38He's revving his V8 muscle car from the 1970s.
0:05:40 > 0:05:42Here he goes.
0:05:53 > 0:05:55As it speeds down the track at about 40 miles an hour,
0:05:55 > 0:05:59the carriage starts rocking from side to side.
0:06:01 > 0:06:04It's called hunting oscillation.
0:06:04 > 0:06:08I can see, is that why the top of these posts are moving side to side?
0:06:08 > 0:06:11Yeah, you can see it hunting a bit now.
0:06:19 > 0:06:23That's not gone at all well for it, has it? That's a bad thing.
0:06:23 > 0:06:26The kind of thing you need to avoid in a real train.
0:06:26 > 0:06:29And this isn't just a problem for Hammond Rail.
0:06:29 > 0:06:32Real trains have derailed on straight track,
0:06:32 > 0:06:36and the repeated sideways movement can also damage the track itself,
0:06:36 > 0:06:39like this one in Germany.
0:06:39 > 0:06:44Wobbling along a dead straight track is the fault of those cone-shaped wheels.
0:06:44 > 0:06:47So they don't seem like such a good idea.
0:06:47 > 0:06:49Why aren't they flat?
0:06:49 > 0:06:53- The problem with flat wheels is we need to get round a curve.- Yeah.
0:06:53 > 0:06:55So if we try and do that with flat wheels,
0:06:55 > 0:06:58I've got my flat wheel here, if we run it down the track....
0:06:58 > 0:07:00- It works, it doesn't work. - It doesn't work.
0:07:00 > 0:07:02But, we all know train wheels, they're round
0:07:02 > 0:07:06but then they have a flange on them that keeps them in the track.
0:07:07 > 0:07:11Flanges are the metal lips that sit down the side of the tracks.
0:07:11 > 0:07:13We could put flanges on the wheels, but the trouble is
0:07:13 > 0:07:16the wheels would be guided around the curve
0:07:16 > 0:07:18purely on these flanges and they'll wear them out
0:07:18 > 0:07:21and wear the sides of the rails out and it'll all be wrecked.
0:07:21 > 0:07:23- Very quickly.- Very quickly, yes.
0:07:23 > 0:07:26So it's back to those conical wheels.
0:07:27 > 0:07:31Someone clever came along and thought if we put some cone angles,
0:07:31 > 0:07:33we might be able to get this to go round a curve.
0:07:33 > 0:07:36Go on then. Somebody came up with this!
0:07:37 > 0:07:41So it's off, that's where the other one got to...
0:07:41 > 0:07:44and it's just, well it works, clearly.
0:07:44 > 0:07:47- That's just its shape that's sending it round.- Exactly, yes.
0:07:49 > 0:07:55A cone rolling on its side turns in a circle and train wheels use this principle.
0:07:55 > 0:07:57As it goes round a bend, the train is thrown out
0:07:57 > 0:08:00and the outside wheel effectively gets bigger,
0:08:00 > 0:08:03making a sort of cone which turns the train.
0:08:05 > 0:08:09But, because conical wheels can effectively change size,
0:08:09 > 0:08:13they can make trains unstable, even on straight track,
0:08:13 > 0:08:15causing that hunting oscillation we saw,
0:08:15 > 0:08:18especially at bullet-train-type speeds.
0:08:21 > 0:08:23The solution is an engineering compromise.
0:08:23 > 0:08:26What we try and do is get just the right amount of cone angle
0:08:26 > 0:08:29to get us round curves we need to get round, but no more than that.
0:08:29 > 0:08:32So, there will be an optimum amount of slope - cone -
0:08:32 > 0:08:35- for a train that's going to go faster?- Yes.
0:08:35 > 0:08:38Very high speed trains have very low amounts of cone angle,
0:08:38 > 0:08:41or conicity, and slower trains have more conicity.
0:08:43 > 0:08:47So, the slope on a conventional train wheel is flattened for the bullet train.
0:08:47 > 0:08:49The angle is halved.
0:08:53 > 0:08:58Each wheel is precision-machined to the perfect angle.
0:08:58 > 0:09:01And what's good enough for a bullet train
0:09:01 > 0:09:04is good enough for Hammond Rail.
0:09:06 > 0:09:10I'm exchanging my extreme conical wheels for flatter ones.
0:09:11 > 0:09:16I've also added some weight to try and stop it derailing again.
0:09:17 > 0:09:20I admit Hammond Rail doesn't offer a complete service yet.
0:09:20 > 0:09:24No return tickets. You have to push yourself back to the station.
0:09:24 > 0:09:26Inconvenient, but cheap.
0:09:26 > 0:09:27Here he goes.
0:09:34 > 0:09:39So, what we're looking for here is a steady ride.
0:09:39 > 0:09:42Nice ride, no hunting.
0:09:46 > 0:09:50- That's perfectly happy. - That is going quick, actually.
0:09:57 > 0:09:59God, that really IS moving.
0:10:03 > 0:10:05Er, the stopping's going to be uncomfortable, obviously,
0:10:05 > 0:10:08in a real situation.
0:10:08 > 0:10:12The flatter wheels have eliminated hunting oscillation.
0:10:12 > 0:10:15Look how steady the basketball tell-tales are.
0:10:17 > 0:10:20My carriage travelled straight and true on the rails,
0:10:20 > 0:10:22which means it can go really fast.
0:10:23 > 0:10:26But, still, nowhere near as fast as a bullet train.
0:10:26 > 0:10:32For those speeds, the engineers couldn't just rely on flatter wheels to avoid hunting oscillation.
0:10:33 > 0:10:36They needed a two-part solution,
0:10:36 > 0:10:41the second part of which lay at the heart of a medieval clock.
0:10:44 > 0:10:48Before clocks were invented, time was pretty fluid.
0:10:48 > 0:10:51But, medieval monks wanted regular prayer times.
0:10:53 > 0:10:56They needed precise clocks.
0:10:56 > 0:11:01And that particular prayer was answered for them around the middle of the 15th century
0:11:01 > 0:11:03with the invention of a new type of clock.
0:11:03 > 0:11:06The device that transformed clock making, monastic life
0:11:06 > 0:11:10and, ultimately, the bullet train, was this, the coiled spring.
0:11:10 > 0:11:12There's one in here in this clock, as well.
0:11:12 > 0:11:16As you wind it, it coils itself around itself tighter and tighter
0:11:16 > 0:11:19and that's storing energy.
0:11:19 > 0:11:22Then, as it unwinds itself slowly, that energy is released,
0:11:22 > 0:11:24and that energy is used to turn the gears and cogs
0:11:24 > 0:11:27that turn the hands and tell us the time.
0:11:28 > 0:11:31And, with a little bit of tweaking, this horological motor
0:11:31 > 0:11:36would go on to help solve the problem of hunting oscillation on the bullet train.
0:11:38 > 0:11:42Because coiled springs are also good for suspension systems.
0:11:44 > 0:11:48By stretching and squashing, they smooth out bumps in the road,
0:11:48 > 0:11:53as car mechanics discovered in the early 20th century.
0:11:53 > 0:11:56And train engineers adopted the same idea.
0:11:56 > 0:11:59Coiled springs, in fact, are particularly good for trains,
0:11:59 > 0:12:02because they don't just absorb up-and-down motion,
0:12:02 > 0:12:05they also dampen side-to-side rocking.
0:12:05 > 0:12:06On the bullet train,
0:12:06 > 0:12:10coiled springs absorb the energy of the hunting oscillation.
0:12:10 > 0:12:12Stiffer springs absorb more energy,
0:12:12 > 0:12:17so they dampen the sideways movement, so the train can't rock as violently.
0:12:17 > 0:12:19Right, they are actually building trains here,
0:12:19 > 0:12:21so I'll get out of their way.
0:12:24 > 0:12:27Thanks to some punctual monks and clever watchmakers,
0:12:27 > 0:12:30the engineers were able to design a train undercarriage
0:12:30 > 0:12:34that stops it hunting, shaking from side to side at high speeds.
0:12:37 > 0:12:40With flatter wheels, the train rolls so straight
0:12:40 > 0:12:43that it wears an almost perfect line along the rails.
0:12:46 > 0:12:51The machining of the wheels is the beginning of the journey for the bullet train.
0:12:51 > 0:12:55It ends up like this - a brand-new bullet train.
0:12:55 > 0:13:00And, once built, it's ready to take its first high-speed journey.
0:13:09 > 0:13:12I wonder if they've left the keys in...?
0:13:16 > 0:13:21Ha ha! Here it is, the business end.
0:13:21 > 0:13:26I'm guessing... Flat out at, what, close to 200 mph, 300 kph.
0:13:26 > 0:13:30Being a train driver is quite exciting again.
0:13:30 > 0:13:36This might be the workshop but it is actually wired up and ready to go. It'll be driven out of here...
0:13:36 > 0:13:37but not now, not by me.
0:13:43 > 0:13:45Probably just as well they didn't leave the keys.
0:13:47 > 0:13:50But what happens when you do switch the train on?
0:13:52 > 0:13:56To move at all, let alone reach breakneck speeds,
0:13:56 > 0:13:58the bullet train needs power.
0:13:58 > 0:14:02And it gets all the power it needs in the form of electricity
0:14:02 > 0:14:04from overhead lines.
0:14:06 > 0:14:08The connection between the wire
0:14:08 > 0:14:11and the train is this device along here,
0:14:11 > 0:14:12the pantograph.
0:14:12 > 0:14:16So electricity flows in, through those few square centimetres,
0:14:16 > 0:14:19where it touches the wire, and from there, down into the train.
0:14:21 > 0:14:24To feed enough power, engineers faced a choice
0:14:24 > 0:14:27between a faster or a bigger electrical flow.
0:14:27 > 0:14:31Stepping up the voltage, or boosting the current.
0:14:35 > 0:14:38In a lab that looks more like the set of a sci-fi movie,
0:14:38 > 0:14:41Manchester University professor, Ian Cotton,
0:14:41 > 0:14:43shows the demands big currents make.
0:14:43 > 0:14:46So, Ian, talk me through this. I'm guessing
0:14:46 > 0:14:49current is going to go around there somewhere?
0:14:49 > 0:14:51Yes, we have a transformer fresh from the mains
0:14:51 > 0:14:54and in this loop we get a high current.
0:14:54 > 0:14:57All right. Well, fire it up then, is it working now?
0:14:57 > 0:15:00It will do, you'll see the numbers on the ammeter go up
0:15:00 > 0:15:03so we're getting more current flowing through.
0:15:03 > 0:15:05So this is the quantity of amps flowing through here?
0:15:05 > 0:15:08Oh, hang on, look already! This wire is getting hot.
0:15:08 > 0:15:10What's happening?
0:15:10 > 0:15:14High amps - a big current - overload the thin wire.
0:15:17 > 0:15:21It heats it up to the point of complete failure.
0:15:21 > 0:15:24So if you have very, very high currents, you need to use a very big
0:15:24 > 0:15:26piece of metal to let the current flow.
0:15:26 > 0:15:29So we'd need much bigger than this?
0:15:29 > 0:15:33Absolutely, it'd be very, very big and very, very heavy.
0:15:34 > 0:15:37To carry enough current for the bullet train,
0:15:37 > 0:15:40the overhead wires would have to be huge,
0:15:40 > 0:15:43thicker than a man's arm and enormously expensive.
0:15:45 > 0:15:50Totally impractical for train lines that run for hundreds of miles.
0:15:50 > 0:15:54The only other way to give the train the juice it needs
0:15:54 > 0:15:57was to up the flow, the voltage.
0:15:58 > 0:16:02Train lines usually carry 1,500 or 3,000 volts.
0:16:02 > 0:16:04Nowhere near enough for a bullet train.
0:16:04 > 0:16:09So the engineers increased it to 25,000 thousand volts.
0:16:10 > 0:16:14But with such a gigantic voltage, any break in the circuit
0:16:14 > 0:16:19between the wire and pantograph can be catastrophic.
0:16:19 > 0:16:22The pantograph has, well, just one job, really -
0:16:22 > 0:16:24to maintain that contact with the wire overhead.
0:16:24 > 0:16:28But it is quite an important job because lose that contact
0:16:28 > 0:16:32and you lose power, which would be inconvenient.
0:16:33 > 0:16:35Worse, you might damage the train.
0:16:36 > 0:16:39If the pantograph loses contact, it causes an arc.
0:16:41 > 0:16:45In the safety of a high voltage lab an arc looks very pretty.
0:16:47 > 0:16:48Woo! So what are we seeing here?
0:16:48 > 0:16:51This is something called a Jacob's Ladder
0:16:51 > 0:16:55and we're making a high-voltage arc which is travelling up.
0:16:55 > 0:16:59Arcing happens when there's a break in a high-voltage circuit.
0:16:59 > 0:17:02In a Jacob's Ladder, there's a gap in the circuit
0:17:02 > 0:17:03between the two poles.
0:17:03 > 0:17:07The voltage is so high that it turns the gap into plasma,
0:17:07 > 0:17:10super-heated air.
0:17:10 > 0:17:15And plasma is very hot, close to 10,000 degrees C,
0:17:15 > 0:17:17making arcs very dangerous indeed.
0:17:17 > 0:17:20That's arcing that we're looking at?
0:17:20 > 0:17:22Exactly, so that's what would happen
0:17:22 > 0:17:26if the pantograph moved away from the actual wire.
0:17:26 > 0:17:29Arcing does happen on normal trains.
0:17:29 > 0:17:34Here, icy overhead wires are breaking the circuit.
0:17:34 > 0:17:37But the higher the voltage, the more arcing is a problem.
0:17:39 > 0:17:41In this demonstration I'm going to play the pantograph,
0:17:41 > 0:17:46to see what happens to my paper train when the connection is broken.
0:17:46 > 0:17:50So this is a demonstration of the potential bad side of high voltage.
0:17:50 > 0:17:53Yeah, so the copper bar is at high voltage. If you touch that
0:17:53 > 0:17:57- pole to it and move it away, you'll make a high-voltage arc.- OK.
0:17:59 > 0:18:00There we go.
0:18:00 > 0:18:02But when it gets near to things...
0:18:02 > 0:18:05Ah-ha, yeah, straight away that's...
0:18:05 > 0:18:07Do you know, I can see the downside there.
0:18:07 > 0:18:10What's happened is it's set fire to my train, quite badly.
0:18:11 > 0:18:15OK, so it's no surprise that the plasma arc ignites a paper train.
0:18:15 > 0:18:19But it can also damage a real train and its overhead wires.
0:18:26 > 0:18:29To prevent damage that could take whole lines out of action,
0:18:29 > 0:18:33the engineers needed a pantograph that would not lose contact
0:18:33 > 0:18:35with the overhead wire.
0:18:35 > 0:18:39And the key to their solution lies in this...
0:18:39 > 0:18:43This is just a crowbar. Well, a lever.
0:18:43 > 0:18:44And used in the right way,
0:18:44 > 0:18:48it can keep the pantograph pressing against the wire no matter what.
0:18:49 > 0:18:53Which is a good thing, cos you really don't want to mess about
0:18:53 > 0:18:58with dodgy connections and massively powerful electrical supplies.
0:18:59 > 0:19:02Levers are essentially pretty simple devices.
0:19:02 > 0:19:04There's something long, like this,
0:19:04 > 0:19:08that pivots around a fulcrum, like that.
0:19:08 > 0:19:11The longer the lever, the more it can lift.
0:19:11 > 0:19:14So to move something heavy like this anvil,
0:19:14 > 0:19:18I'm going to need a longer lever.
0:19:18 > 0:19:22Yeah, that... That should do the job.
0:19:22 > 0:19:25In place, and well, that's... that's easy.
0:19:25 > 0:19:27It was the Greek scientist, Archimedes,
0:19:27 > 0:19:30who first worked out the significance of the distance
0:19:30 > 0:19:33between fulcrum and where the force acts on a lever.
0:19:33 > 0:19:37He reckoned, famously, that with a long enough lever he could move the Earth.
0:19:37 > 0:19:43Though he would, of course, have needed somewhere to stand to do it.
0:19:43 > 0:19:47The bullet train's unique pantograph acts like a lever, too.
0:19:49 > 0:19:51A spring pulls the pantograph up.
0:19:53 > 0:19:56If the spring contracts, it pulls with less force.
0:19:58 > 0:20:02To compensate, a cunning mechanism automatically lengthens a lever,
0:20:02 > 0:20:03increasing the force.
0:20:06 > 0:20:09The whole thing is a compensatory mechanism
0:20:09 > 0:20:13and the result is a constant pressure against that wire.
0:20:16 > 0:20:19And so far they've been able to keep the trains supplied
0:20:19 > 0:20:23with high-voltage power without frying the pantographs.
0:20:26 > 0:20:31With power on board, the engineers faced their next challenge...
0:20:33 > 0:20:36..how to convert the power to speed.
0:20:36 > 0:20:42And in particular, how to make a train fast from a standing start.
0:20:43 > 0:20:46It needs the right balance of power and grip.
0:20:52 > 0:20:55Making something fast isn't just about making it more powerful,
0:20:55 > 0:20:58you need to consider its weight too. Light is good,
0:20:58 > 0:21:02that's why they don't make fast cars out of lead, you may have noticed.
0:21:02 > 0:21:06But here's a thing - you can make something too light.
0:21:08 > 0:21:10If a vehicle's too light,
0:21:10 > 0:21:14it can't grip the ground enough to get traction,
0:21:14 > 0:21:18which is how things like cars and trains turn engine power into movement.
0:21:18 > 0:21:21Without traction, you're not going anywhere,
0:21:21 > 0:21:24no matter how big your engine.
0:21:24 > 0:21:26To demonstrate, I've created my own train
0:21:26 > 0:21:29and a very slippery track for it to run on.
0:21:52 > 0:21:53Yeah, well, as I think you can see,
0:21:53 > 0:21:58no matter how much power I use, how much oomph I give it - and I'm giving it plenty -
0:21:58 > 0:22:03my wheels on my train just can't get enough grip to get me moving.
0:22:05 > 0:22:09In fact, sometimes the more power I use, the worse it gets.
0:22:11 > 0:22:13My train doesn't have good traction
0:22:13 > 0:22:16because it's too light to grip properly.
0:22:16 > 0:22:18Of course, real trains don't run on skid pans,
0:22:18 > 0:22:23but they too can suffer from not having enough traction.
0:22:23 > 0:22:26One way to improve traction is to increase weight,
0:22:26 > 0:22:29especially if the added weight is over the driven wheels,
0:22:29 > 0:22:33which in the case of this pick-up, is the rear wheels, here at the back.
0:22:33 > 0:22:37All of which means that lot needs to go in there.
0:22:37 > 0:22:39So carry on, I'll be...here.
0:22:43 > 0:22:46Isn't it great when everyone pulls together?
0:22:46 > 0:22:48Team effort.
0:22:50 > 0:22:55There we go, the last bag in place, I did all of that. There.
0:22:55 > 0:22:59Those bags then, the weight right over the driven wheels at the back of the truck.
0:22:59 > 0:23:01Time to test it.
0:23:03 > 0:23:08I, well, OK, we, have added about half a tonne above the rear axle.
0:23:15 > 0:23:16No contest.
0:23:16 > 0:23:20Same skid pan, more weight, better grip, better traction.
0:23:22 > 0:23:29But the last thing you want to do to a train designed for speed is add weight.
0:23:29 > 0:23:35Instead, bullet train engineers found the solution to their traction problems
0:23:35 > 0:23:39in an early luxury racing car, the Lohner-Porsche.
0:23:41 > 0:23:45In 1899, Ferdinand Porsche, yes, that Porsche,
0:23:45 > 0:23:50designed a pioneering car in which each wheel was driven by a separate motor.
0:23:50 > 0:23:52The first four-wheel drive.
0:23:54 > 0:23:57And, as off-roaders the world over know,
0:23:57 > 0:24:00with more driven wheels, you get better traction.
0:24:04 > 0:24:06I'm going to need to modify this vehicle.
0:24:09 > 0:24:13Right, that's done, this truck is now four-wheel drive.
0:24:13 > 0:24:17With more wheels driving, it should grip.
0:24:18 > 0:24:20And it does.
0:24:20 > 0:24:25Making all four wheels driven means better traction, without added weight.
0:24:35 > 0:24:38And the Japanese did exactly the same with the Bullet Train,
0:24:38 > 0:24:43flipping the traditional train around completely.
0:24:43 > 0:24:46Conventional trains use locomotives,
0:24:46 > 0:24:50big, heavy powerhouses that pull or push the other carriages along.
0:24:50 > 0:24:53But the bullet train engineers have, kind of, turned that principle on its head
0:24:53 > 0:24:56because the pointy carriages at the front
0:24:56 > 0:25:00and the very back of this train have no engines.
0:25:00 > 0:25:04Instead, all the other carriages do. It's called the multiple unit system
0:25:04 > 0:25:10and on this train, 14 of the 16 carriages have their own motors, in here.
0:25:10 > 0:25:12Each motor drives two wheels,
0:25:12 > 0:25:15so it is, by my reckoning, 112-wheel drive.
0:25:20 > 0:25:22Good traction without the extra weight
0:25:22 > 0:25:26means it can accelerate suitably quickly for a bullet train.
0:25:27 > 0:25:30All thanks to a 19th-century four by four.
0:25:33 > 0:25:38The next challenge for the engineers was how to keep that speed up round corners.
0:25:40 > 0:25:43Cornering too fast is a problem for any vehicle.
0:25:49 > 0:25:50This is Dave.
0:25:53 > 0:25:55He and his motorcycle sidecar
0:25:55 > 0:25:58are going to be the guinea pigs in my new challenge.
0:26:01 > 0:26:04This, by the way, isn't just an awkward-to-get-at refreshment system,
0:26:04 > 0:26:07this water is part of the experiment. It's science. Take it away.
0:26:13 > 0:26:16Can Dave and the drinks complete my slalom course?
0:26:19 > 0:26:22Now we come to the first turn.
0:26:22 > 0:26:23Here we go!
0:26:23 > 0:26:27Dave and I go one way and the drinks go the other.
0:26:29 > 0:26:33I'm going to be thirsty, I mean... Dave!
0:26:33 > 0:26:35That's all my drinks gone!
0:26:35 > 0:26:38No big surprises there, OK, but in the interests of science
0:26:38 > 0:26:40we must dot the I's and cross the T's.
0:26:40 > 0:26:43We all know the feeling, if you've ever been round
0:26:43 > 0:26:46any corner at speed, when you feel you're being pushed to the side.
0:26:46 > 0:26:49It's called centrifugal force, and, basically,
0:26:49 > 0:26:52it's because you, your body as an object,
0:26:52 > 0:26:55wants to carry on going in a straight line, but the car,
0:26:55 > 0:26:57or bike, is pulling you that way.
0:26:57 > 0:27:01So, relative to it, you feel a force throwing you that way.
0:27:05 > 0:27:09And centrifugal force can have deadly consequences.
0:27:11 > 0:27:15In Osaka, in 2005, a commuter train took a bend too fast
0:27:15 > 0:27:17and flew off the tracks.
0:27:22 > 0:27:23107 people died.
0:27:25 > 0:27:29Thankfully, derailment is rare.
0:27:29 > 0:27:34But tight bends and high speeds produce strong centrifugal forces.
0:27:34 > 0:27:39Bullet train engineers didn't want to slow the trains down.
0:27:39 > 0:27:41To get round the problem,
0:27:41 > 0:27:45they turned to some of the very first wheeled vehicles...
0:27:45 > 0:27:47TRUMPETS BLARE
0:27:47 > 0:27:49..chariots.
0:27:51 > 0:27:54Ancient charioteers knew how to corner quickly
0:27:54 > 0:27:58without flying off track and so do their modern counterparts.
0:28:00 > 0:28:03This is a modern chariot, a scurry.
0:28:03 > 0:28:06Jeff Osborne is our Ben Hur.
0:28:06 > 0:28:09And these are his ponies, Zig and Zag.
0:28:09 > 0:28:10So what am I going to do?
0:28:10 > 0:28:14What you're going to do, you're going to keep the cart stable.
0:28:14 > 0:28:17I thought I was just being a passenger? I was going to read a book.
0:28:17 > 0:28:21No, you're not going to read a book. You're going to lean this way and that way.
0:28:21 > 0:28:23- So if I get it wrong? - We'll roll over.
0:28:25 > 0:28:30These modern charioteers race round twisty courses, with lots of cornering.
0:28:31 > 0:28:38And to keep the scurry stable, usually Alison sits on the back and leans into the turns.
0:28:38 > 0:28:42But today, I'm doing it. No pressure then.
0:28:42 > 0:28:44Never let go.
0:28:44 > 0:28:50- If a pony trips, you'll be straight out the back. - Bad. So one, two, lean.
0:28:50 > 0:28:54One, two, lean, and I lean the way into the turn as far as I can?
0:28:54 > 0:28:58If the wheel starts coming off the ground, you lean further.
0:29:00 > 0:29:04So, after that frankly terrifying briefing, we're off.
0:29:04 > 0:29:08This is nice, I like this speed. This is fast enough.
0:29:28 > 0:29:33Leaning into bends reduces the centrifugal force that pushes us outwards.
0:29:35 > 0:29:37This balances the carriage
0:29:37 > 0:29:41and allows Zig and Zag, like their ancient counterparts, to corner faster.
0:29:41 > 0:29:46It's a technique first recorded by ancient Greek author Homer
0:29:46 > 0:29:50in his epic account of the Trojan War - The Iliad.
0:29:50 > 0:29:52Ancient charioteers couldn't possibly have known
0:29:52 > 0:29:55about the Newtonian laws of inertia and centrifugal force.
0:29:55 > 0:29:57How could they? They hadn't been invented yet.
0:29:57 > 0:30:02But somehow they instinctively knew that leaning helps you turn faster.
0:30:04 > 0:30:07I'm sure it looks lovely, but it's really frightening.
0:30:09 > 0:30:12But what about my prototype mobile bar?
0:30:14 > 0:30:16To see if leaning is the key to success,
0:30:16 > 0:30:20I've fired Dave and drafted in Frank.
0:30:20 > 0:30:22So, I am going to try this again.
0:30:22 > 0:30:26I am determined to crack my motorcycle mobile refreshment system solution.
0:30:26 > 0:30:28I'm going to use this, which is a rather different
0:30:28 > 0:30:33motorcycle and sidecar outfit, because this one tilts.
0:30:33 > 0:30:36I'm ready, sir!
0:30:44 > 0:30:48This sidecar tilts instantly and effortlessly as it corners,
0:30:48 > 0:30:51keeping my drinks firmly in place.
0:30:51 > 0:30:52Ha ha!
0:30:52 > 0:30:54That is astonishing!
0:30:54 > 0:30:58Ben Hur was clearly onto something.
0:30:58 > 0:31:03Though I'm pretty sure he never foresaw its impact on mobile refreshment systems.
0:31:07 > 0:31:09Science works! Who'd have thought?!
0:31:12 > 0:31:15So, the more they lean,
0:31:15 > 0:31:22the less the force pushing outwards on sidecars, chariots and trains.
0:31:22 > 0:31:27To make trains lean, tracks are banked, inclined into the bend.
0:31:29 > 0:31:34And that worked well, for older, slower trains.
0:31:34 > 0:31:40But bullet trains are so fast they need to lean even further into bends.
0:31:40 > 0:31:43Bullet train engineers didn't need to wait
0:31:43 > 0:31:46for reports from uncomfortable passengers to know
0:31:46 > 0:31:50that banking alone isn't enough.
0:31:50 > 0:31:52This simulator can replicate the sensations of the bullet train
0:31:52 > 0:31:56travelling at any speed, on any kind of track.
0:31:59 > 0:32:04Today's experiment - cornering, at nearly 200mph.
0:32:07 > 0:32:11Right now, going in a straight line and I'll admit, I'm completely convinced.
0:32:11 > 0:32:13As far as I'm concerned, I am in a high-speed train.
0:32:13 > 0:32:15And as we go into the bend,
0:32:15 > 0:32:19this has been set up to simulate just a banked track.
0:32:25 > 0:32:27I think, starting to... yep, I can, ooh! Yes!
0:32:27 > 0:32:32Straight away, I can feel that throw me off to the right.
0:32:32 > 0:32:33So banking isn't enough.
0:32:33 > 0:32:35And you can't bank the track any more than this,
0:32:35 > 0:32:39because if you do, well, if a train has to stop on it one day,
0:32:39 > 0:32:40it might fall over.
0:32:45 > 0:32:48Which is where Ben Hur comes to the rescue.
0:32:49 > 0:32:55Computer-controlled airbags under each carriage make the entire bullet train lean.
0:32:55 > 0:33:00As it corners, each section of the N700, the latest bullet train,
0:33:00 > 0:33:06tilts independently at just the right time and by just the right amount.
0:33:06 > 0:33:09On a real bullet train, the effect is quite noticeable.
0:33:09 > 0:33:12Or, in fact, it isn't, and that's kind of the point, isn't it?
0:33:12 > 0:33:15Cos right now, judging by the blur through the windows,
0:33:15 > 0:33:18we're doing the kind of speeds that would present a bit of a problem
0:33:18 > 0:33:21for my tea if there weren't some controlled tilting taking place.
0:33:21 > 0:33:25In fact, I'm so confident, I'm going topless.
0:33:26 > 0:33:30This would be potentially dangerous
0:33:30 > 0:33:32without a very clever train.
0:33:32 > 0:33:35Look at that! It's not going anywhere.
0:33:35 > 0:33:37I wonder if Ben Hur was a tea or a coffee man?
0:33:37 > 0:33:39Nah, coffee, I'm sure of it.
0:33:41 > 0:33:43Thanks to ancient charioteers,
0:33:43 > 0:33:48bullet trains corner 12mph faster, keeping travellers right on time.
0:33:59 > 0:34:04So, bullet trains stay on track. Along straights and around bends.
0:34:04 > 0:34:08As long as the track itself stays in place.
0:34:08 > 0:34:14But you can't bank on that here, as recent events show.
0:34:14 > 0:34:18All trains face a big problem in Japan - earthquakes.
0:34:18 > 0:34:22This is one of the most earthquake-prone lands on the planet,
0:34:22 > 0:34:25and the problem could be much worse at higher speeds,
0:34:25 > 0:34:31because trains and passengers could potentially suffer much greater impacts.
0:34:31 > 0:34:34Equipping their high-speed trains to stay on track through
0:34:34 > 0:34:38an earthquake would be a particular challenge for the engineers.
0:34:42 > 0:34:47Japan is struck by around 900 quakes a year.
0:34:47 > 0:34:53In March 2011, an earthquake measuring nine on the Richter scale,
0:34:53 > 0:34:56the largest ever to hit the country, struck Japan.
0:34:59 > 0:35:02The earthquake's epicentre was 80 miles out to sea
0:35:02 > 0:35:06but it triggered a massive and hugely destructive tsunami.
0:35:09 > 0:35:13To date, more than 25,000 people are dead or missing.
0:35:13 > 0:35:18Earthquakes in Japan pose a real challenge to architects and engineers.
0:35:18 > 0:35:21Of course, the thing that really worries railway engineers
0:35:21 > 0:35:24is the same earthquakes that topple tall buildings
0:35:24 > 0:35:26and rip up roads can derail trains.
0:35:26 > 0:35:29So it's good to know that thanks to the electric telegraph,
0:35:29 > 0:35:33there is a system in place to protect passengers on the bullet train.
0:35:33 > 0:35:39Engineers needed advance warning of earthquakes to slow the trains.
0:35:39 > 0:35:44So they designed the world's very first earthquake warning system.
0:35:46 > 0:35:50The idea was to alert engineers before a quake arrived,
0:35:50 > 0:35:54but in actual practice, this proves to be a problem.
0:35:54 > 0:35:57An earthquake warning system is really only as good
0:35:57 > 0:36:01as the tremor detectors or seismometers.
0:36:06 > 0:36:10To understand the problem, we need an earthquake.
0:36:10 > 0:36:14And back in England, you can wait all day for one to come along.
0:36:15 > 0:36:19But according to earthquake expert, Hugh Hunt, a lake
0:36:19 > 0:36:24and a large weight will replicate the key components of a seismic shock.
0:36:24 > 0:36:26And a precarious tower of blocks
0:36:26 > 0:36:29will play the part of its potential victim.
0:36:29 > 0:36:32Right, Hugh, we've assembled everything you asked for.
0:36:32 > 0:36:36We're in a boat on a small lake and there's a digger with a big weight in it.
0:36:36 > 0:36:37How's this an earthquake?
0:36:37 > 0:36:41We can simulate an earthquake by dropping
0:36:41 > 0:36:43this lump of metal into the water to create a wave.
0:36:43 > 0:36:47And in an earthquake, you've got waves in the ground.
0:36:47 > 0:36:51Hugh has set up a system to warn me of the quake before it strikes,
0:36:51 > 0:36:53so I can try to protect the tower.
0:36:53 > 0:36:56It all depends on this...
0:36:58 > 0:37:01That thing there is a seismometer. It measures motion.
0:37:01 > 0:37:05Hugh's seismometer should detect the quake
0:37:05 > 0:37:07and trigger a warning on his laptop.
0:37:07 > 0:37:10We have an earthquake detection system down there,
0:37:10 > 0:37:13attached to my tower, so it will know when there's an earthquake.
0:37:13 > 0:37:16I'm going to use my earthquake detection system
0:37:16 > 0:37:21to tell you when you have to take action to protect the tower...
0:37:21 > 0:37:22So this is my...?
0:37:22 > 0:37:27That's your earthquake protection system. Ready for an earthquake?
0:37:27 > 0:37:30Yeah. 'So I'm going to ignore the sound of a large weight
0:37:30 > 0:37:34'dropping into the water 20 metres away from me.
0:37:34 > 0:37:38'I won't move until Hugh's warning system detects the quake.'
0:37:38 > 0:37:40Ok, earthquake...go!
0:37:54 > 0:37:55Any sign of an earthquake?
0:37:55 > 0:37:58Yeah, there's something coming there.
0:37:59 > 0:38:01Yeah, you see,
0:38:01 > 0:38:03the thing is...
0:38:03 > 0:38:04You were too slow.
0:38:04 > 0:38:07All you did was say, "There's an earthquake happening."
0:38:07 > 0:38:08You were too slow.
0:38:08 > 0:38:10But there was an earthquake, then it fell over...
0:38:10 > 0:38:11It went red here.
0:38:11 > 0:38:14I had a protection system and I never used it.
0:38:14 > 0:38:16Red means earthquake, Richard. You were just too slow.
0:38:16 > 0:38:19Clearly, what we have there then, is a problem.
0:38:26 > 0:38:30Hugh's system only detects an earthquake when it's arrived.
0:38:30 > 0:38:33Not much advance warning, not much good.
0:38:33 > 0:38:37Luckily for bullet train protection,
0:38:37 > 0:38:40earthquakes aren't quite as sneaky as this.
0:38:40 > 0:38:45They actually announce their arrival with small, fast-moving waves.
0:38:48 > 0:38:53What they discovered a hundred and something years ago, was that there are two waves.
0:38:53 > 0:38:56A primary wave which they called the P-wave
0:38:56 > 0:38:58and a secondary wave, which they called the S-wave.
0:38:58 > 0:39:04The slower S-waves are the destructive ones that topple cities
0:39:04 > 0:39:05and floating towers.
0:39:05 > 0:39:11They're what Hugh's seismometer detected, but too late to be a useful warning.
0:39:11 > 0:39:17The key to advance warning is to detect the faster P-waves.
0:39:17 > 0:39:21But unfortunately, P-waves are much smaller than S-waves.
0:39:21 > 0:39:23You need a more sensitive seismometer.
0:39:24 > 0:39:27And for them, you need electromagnets,
0:39:27 > 0:39:31first used in the electric telegraph way back in 1837.
0:39:34 > 0:39:38This is a working model of a device that quite probably represents
0:39:38 > 0:39:42the first ever use of electricity for, well, anything.
0:39:42 > 0:39:46It's actually a machine used to communicate between railway stations.
0:39:46 > 0:39:49Central to it is electromagnetism.
0:39:51 > 0:39:54Behind the metal needles are coils of wire.
0:39:54 > 0:40:00Passing a current through a coil, turns it into an electromagnet which moves the needle.
0:40:00 > 0:40:05Reversing the current moves the needle in the opposite direction.
0:40:06 > 0:40:10If I pass a current through the coil, the needle moves.
0:40:10 > 0:40:12If I pass the current the other way,
0:40:12 > 0:40:15the polarity switches, the needle moves...the other way.
0:40:15 > 0:40:18All they needed then was a map of letters, and you can point to them
0:40:18 > 0:40:22if I want to spell an H, or an I, or a K.
0:40:22 > 0:40:24If I want to do an E, point both needles.
0:40:24 > 0:40:27It hasn't got all the letters - there are only 20 on here,
0:40:27 > 0:40:30so it's an early form of texting.
0:40:31 > 0:40:37'150 years later, the electric telegraph has made way for mobiles and the internet,
0:40:37 > 0:40:40'but electromagnets are still very useful.'
0:40:44 > 0:40:47This isn't a telegraph machine, obviously - it's a crane,
0:40:47 > 0:40:48quite a big one.
0:40:48 > 0:40:53The important bit is at the business end there, because it's an electromagnet.
0:41:01 > 0:41:02There it goes, doing its thing.
0:41:04 > 0:41:07Basically, this is just a magnet that can be on...
0:41:10 > 0:41:12..or, at the touch of a button, off.
0:41:15 > 0:41:17Suddenly, it's no longer a magnet.
0:41:17 > 0:41:21But it isn't always that simple, because it can be a question of degree -
0:41:21 > 0:41:24it can be powerful or less powerful.
0:41:25 > 0:41:28'You can vary this crane's lifting power.
0:41:30 > 0:41:35'Small current - weak magnet, less lift.
0:41:36 > 0:41:40'Up the current, and you can shift large lumps of metal.
0:41:40 > 0:41:42'But that's not all.
0:41:42 > 0:41:45'You can measure changes in electromagnetism
0:41:45 > 0:41:48'very accurately, and knowing how much force is being used
0:41:48 > 0:41:51'is the key to protecting the bullet train -
0:41:51 > 0:41:54'and, I hope, my tower - from earthquakes.
0:42:01 > 0:42:05'Back on the lake, I'm going to update my earthquake warning system.
0:42:05 > 0:42:09'This time, sensor expert Shawn Goessen is coming aboard
0:42:09 > 0:42:13'with a sophisticated electromagnetic seismometer.'
0:42:17 > 0:42:20So, Shawn, you came aboard bringing your posher piece of kit.
0:42:20 > 0:42:24- What is the difference? This is the real deal? - Yes, it's much more sensitive.
0:42:24 > 0:42:29'Shawn's seismometer uses electromagnets to detect tiny movements,
0:42:29 > 0:42:31'such as the pulses of P-waves.'
0:42:31 > 0:42:35So will you be able to detect these finer P-waves,
0:42:35 > 0:42:37that Hugh singularly failed to do?
0:42:37 > 0:42:38Thanks, Richard(!)
0:42:38 > 0:42:41Well, your warning system consisted of saying,
0:42:41 > 0:42:44"There's an earthquake and everything's fallen over."
0:42:44 > 0:42:47'Shawn's seismometer is so sensitive, it needs to be placed
0:42:47 > 0:42:49'on the stable lake bed.
0:42:50 > 0:42:53If everybody's in the right place, shall we give this a go?
0:42:53 > 0:42:55I promise not to look -
0:42:55 > 0:42:59- I'll just wait until I get a warning from Shawn.- We're both monitoring our systems.- Yeah.
0:42:59 > 0:43:01Are we ready for an earthquake?
0:43:01 > 0:43:04Go!
0:43:08 > 0:43:10OK, Richard.
0:43:12 > 0:43:16OK, I've deployed my system! That IS an early warning! Look at that!
0:43:16 > 0:43:18Oh, oh, oh, oh!
0:43:18 > 0:43:19Here comes an earthquake!
0:43:19 > 0:43:24Thanks, Hugh(!) We know there's an earthquake because everything's moving, but it's OK, I think...
0:43:24 > 0:43:28My earthquake protection net has saved the day,
0:43:28 > 0:43:32and it was only able to do so because you could actually warn me
0:43:32 > 0:43:34an earthquake was coming this time,
0:43:34 > 0:43:38rather than you could tell me, "There IS one."
0:43:38 > 0:43:41And it's just the fact that your system
0:43:41 > 0:43:45can detect those finer, smaller, different-frequency waves.
0:43:46 > 0:43:51'Shawn's system alerted me about seven seconds before the quake arrived -
0:43:51 > 0:43:53'an actual advance warning.
0:43:55 > 0:43:58'And seismometers using electromagnets are also sensitive enough
0:43:58 > 0:44:01'to protect the bullet train.
0:44:02 > 0:44:05'The current system is the most sophisticated
0:44:05 > 0:44:07'earthquake warning system in the world.
0:44:10 > 0:44:14'About 70 linked seismometers along the track and nearby
0:44:14 > 0:44:16'map seismic activity.
0:44:16 > 0:44:20'Two seconds after detecting P-waves, power is switched off
0:44:20 > 0:44:24'and any train in the danger zone automatically brakes.
0:44:25 > 0:44:29'For vehicles with a stopping distance of nearly two miles,
0:44:29 > 0:44:30'every second counts.
0:44:32 > 0:44:33SIREN WAILS
0:44:33 > 0:44:37'The March 2011 earthquake destroyed stations, tunnels and bridges
0:44:37 > 0:44:40'up and down the bullet train network.
0:44:40 > 0:44:44'But crucially, not a single bullet train was affected,
0:44:44 > 0:44:47'because the earthquake warning system automatically
0:44:47 > 0:44:49'brought them to a halt -
0:44:49 > 0:44:55'in some cases, 15 seconds before the tremors damaged the tracks.
0:44:55 > 0:44:59'But what happens if there's no time for the brakes to kick in?
0:44:59 > 0:45:01'Seven years earlier, one train was
0:45:01 > 0:45:05'so close to the epicentre of an earthquake, it was derailed -
0:45:05 > 0:45:07'the only time this has ever happened.
0:45:07 > 0:45:12'This prompted engineers to develop a cutting-edge anti-derailment system.
0:45:15 > 0:45:18'This is the bullet train research centre.
0:45:18 > 0:45:22'They don't let just anybody see their pioneering kit,
0:45:22 > 0:45:25'and I'm shadowed at all times.'
0:45:25 > 0:45:27Ah, hello.
0:45:27 > 0:45:29HE SPEAKS JAPANESE
0:45:29 > 0:45:30Yes. Hello.
0:45:30 > 0:45:32HE SPEAKS JAPANESE
0:45:32 > 0:45:34Nice to see you. Right, sit down? OK.
0:45:34 > 0:45:37This is where I'm going to find out all about the place.
0:45:39 > 0:45:44'The engineers were keen to share the complicated earthquake science behind the system,
0:45:44 > 0:45:48'but it's all Greek - well, Japanese - to me.'
0:45:49 > 0:45:50HE SPEAKS JAPANESE
0:45:50 > 0:45:53'Yeah, I should've brought a phrase book there.
0:45:55 > 0:45:57'Fortunately, the lesson has a practical demonstration
0:45:57 > 0:46:01'for underachieving students like me.'
0:46:01 > 0:46:04It's one of those simple but effective solutions.
0:46:04 > 0:46:06They've fitted an extra rail,
0:46:06 > 0:46:10so in the event of a train being caught too close to the epicentre
0:46:10 > 0:46:12of an earthquake for the P-wave system to detect it
0:46:12 > 0:46:14and warn the driver in time to slow it down,
0:46:14 > 0:46:18this is here to keep everything on track.
0:46:22 > 0:46:24'Even when the ground moves violently,
0:46:24 > 0:46:28'the wheels are held in place by the extra rails.
0:46:29 > 0:46:32'As with every part of the Bullet Train,
0:46:32 > 0:46:35'it's been exhaustively tested.'
0:46:35 > 0:46:39To find out if their idea worked, the engineers built themselves...
0:46:39 > 0:46:41Well, it's a model train set.
0:46:41 > 0:46:43Admittedly the track doesn't go very far,
0:46:43 > 0:46:45but then it is built for a very specific purpose.
0:46:45 > 0:46:48This is a one-fifth scale replica of the real thing,
0:46:48 > 0:46:51and it has a feature that probably most model railway enthusiasts
0:46:51 > 0:46:54don't have on their set at home -
0:46:54 > 0:46:55an earthquake simulator.
0:46:57 > 0:47:01'The lip of the wheel sits between the two rails,
0:47:01 > 0:47:06'so even the really violent tremors can't shake this train off track.
0:47:06 > 0:47:09'The special rails are currently being introduced
0:47:09 > 0:47:12along sections of the line.
0:47:15 > 0:47:18'It really is an astonishing train -
0:47:18 > 0:47:22'fast, earthquake-proof,
0:47:22 > 0:47:26'always on time... and beautiful too.
0:47:29 > 0:47:35'Bullet train engineers have moved technology pioneered in Britain 200 years ago
0:47:35 > 0:47:37'into the 21st century.'
0:47:37 > 0:47:42Now, bullet train technology is being exported all over the world -
0:47:42 > 0:47:43even back to Britain.
0:47:43 > 0:47:47The bullet train really has led the way to a new global age of the train.
0:47:47 > 0:47:51China and America are committing to high-speed rail networks.
0:47:51 > 0:47:56And this remarkable, revolutionary train wouldn't have been possible without...
0:47:57 > 0:47:59'..ancient chariot racing...'
0:47:59 > 0:48:01Oh, my God!
0:48:04 > 0:48:05..a crowbar...
0:48:07 > 0:48:08'a medieval clock...'
0:48:10 > 0:48:13God, that really IS moving.
0:48:14 > 0:48:16Stopping will be uncomfortable, obviously.
0:48:16 > 0:48:19'..a 19th-century luxury car...'
0:48:21 > 0:48:25My wheels on my train just can't get enough grip to get me moving.
0:48:25 > 0:48:27'..and the electric telegraph.'
0:48:30 > 0:48:31Any sign of an earthquake?
0:48:31 > 0:48:34Yeah, I think there's something coming now...
0:48:53 > 0:48:55Subtitles by Red Bee Media Ltd
0:48:55 > 0:48:57E-mail subtitling@bbc.co.uk