0:00:00 > 0:00:08GUNFIRE MECHANICAL CRANKING
0:00:08 > 0:00:11MISSILES WHINE
0:00:11 > 0:00:13EXPLOSION
0:00:18 > 0:00:22THUNDER RUMBLES LIGHTNING CRACKS
0:00:35 > 0:00:37It is really tough in here.
0:00:37 > 0:00:39You've got to keep your head out of the water.
0:00:39 > 0:00:41My clothes are really dragging me down.
0:00:46 > 0:00:49You can't really see where the waves are coming from.
0:00:52 > 0:00:56This has only been...less than a minute. And I am already in trouble.
0:01:06 > 0:01:10It is not the North Sea, of course, but this sea survival training tank
0:01:10 > 0:01:14in Lowestoft can create some very challenging conditions.
0:01:15 > 0:01:19I'm hoping for an insight into what may have been like to be attacked
0:01:19 > 0:01:22by one of World War I's most effective weapon systems.
0:01:25 > 0:01:30It is difficult not to think of the First World War as just a land war
0:01:30 > 0:01:33that was fought in the battlefields of western Europe and beyond.
0:01:33 > 0:01:35But of course what happened at sea
0:01:35 > 0:01:38was of immense importance to the outcome of the war.
0:01:38 > 0:01:42Britain's mighty naval fleet protected British trade,
0:01:42 > 0:01:46moved troops around, put the squeeze on the enemy economy.
0:01:46 > 0:01:49And of course it was there to prevent invasion.
0:01:49 > 0:01:53However, the might of the Royal Navy was about to be challenged
0:01:53 > 0:01:57by the emerging technology of submarines.
0:01:57 > 0:02:01Underwater weapons that the British Admiralty had only seen as defensive.
0:02:03 > 0:02:08One of the first U-boat attacks was on the 22nd of September 1914.
0:02:08 > 0:02:12Three Royal Navy cruisers, HMS Cressy, Hogue, and Aboukir
0:02:12 > 0:02:15were all sent to the bottom of the North Sea
0:02:15 > 0:02:18within an hour of each other, by a single U-boat.
0:02:19 > 0:02:22It was a devastating attack that made clear
0:02:22 > 0:02:25the Navy had a major problem on its hands.
0:02:26 > 0:02:30After all, the best way to sink a ship is to put a hole in its bottom.
0:02:30 > 0:02:34And that is what U-boat torpedoes were particularly good at.
0:02:34 > 0:02:37Even the thought that there could be a U-boat nearby
0:02:37 > 0:02:42was enough to affect the behaviour of ships on the surface of the sea,
0:02:42 > 0:02:47wary of the dreadful threat that was lurking below.
0:02:47 > 0:02:51However, it wasn't just warships that the U-boats were targeting.
0:02:51 > 0:02:54In 1915, after much deliberation,
0:02:54 > 0:02:57the Germans decided that U-boats should be used
0:02:57 > 0:02:59against all enemy shipping.
0:02:59 > 0:03:02The British were using their surface fleet to blockade Germany,
0:03:02 > 0:03:04to stop them getting vital supplies.
0:03:04 > 0:03:08So why shouldn't they use their underwater fleet
0:03:08 > 0:03:10to target British shipping?
0:03:10 > 0:03:13And so, they declared unrestricted submarine warfare.
0:03:13 > 0:03:17And suddenly anyone, in any British ship, was fair game.
0:03:18 > 0:03:21One of the most controversial casualties
0:03:21 > 0:03:24of unrestricted U-boat warfare was the Lusitania,
0:03:24 > 0:03:28a passenger liner torpedoed in May 1915.
0:03:28 > 0:03:31Causing the loss of over 1000 civilian lives
0:03:31 > 0:03:35as well as tonnes of ammunition bound for Britain.
0:03:35 > 0:03:38The sinking turned political and public opinion in the United States
0:03:38 > 0:03:40against Germany.
0:03:41 > 0:03:43If you were torpedoed and still alive,
0:03:43 > 0:03:47the next inevitable step was to abandon ship.
0:03:47 > 0:03:49In every survivor account I have read
0:03:49 > 0:03:51plans for evacuation just go out the window,
0:03:51 > 0:03:53because anything could happen.
0:03:53 > 0:03:56But at some point you're going to have to jump in.
0:03:56 > 0:04:00At that moment you've got to do everything you can to help people.
0:04:00 > 0:04:03Haven't got any life rings here, but I have got a stool, that might help.
0:04:05 > 0:04:07And I have got a big chair.
0:04:10 > 0:04:13I have got to try to get away from the ship as quickly as possible
0:04:13 > 0:04:16to avoid the suction from the big propellers.
0:04:16 > 0:04:18Right. Here goes.
0:04:34 > 0:04:36It is really tough in here.
0:04:36 > 0:04:39This is all I've got to really keep me warm.
0:04:39 > 0:04:42But it is really pulling me down.
0:04:42 > 0:04:44But I haven't got a life jacket.
0:04:44 > 0:04:47Not everyone had life jackets in World War I.
0:04:47 > 0:04:49I keep swallowing water.
0:04:49 > 0:04:52I have only been in here about 30 seconds. And it is exhausting.
0:04:54 > 0:04:55What I need to do...
0:05:14 > 0:05:17'After the Aboukir and the Hogue had been torpedoed,
0:05:17 > 0:05:20'the crew of the Cressy ripped up as much timber as they could,
0:05:20 > 0:05:24'including bar stools and chairs from the mess, for saving lives,
0:05:24 > 0:05:28'and they threw it into the sea before they themselves were sunk.'
0:05:30 > 0:05:34Even with these chairs, the waves are too big.
0:05:34 > 0:05:36When the weather is like this,
0:05:36 > 0:05:39you've just got to hold on to survive.
0:05:39 > 0:05:43You've got a far greater chance of surviving with other people.
0:05:43 > 0:05:44Go on, then, boys. In you come.
0:05:46 > 0:05:50'Civilian, merchant seaman or Royal Navy officer -
0:05:50 > 0:05:51'it didn't matter.
0:05:51 > 0:05:54'Most of those who didn't go down with the ship would end up
0:05:54 > 0:05:56'adrift in the water.
0:05:56 > 0:05:59'The natural instinct is to group together.'
0:05:59 > 0:06:01Come on then! Over here, guys.
0:06:02 > 0:06:05Stay together. We're going to link arms and make a circle.
0:06:05 > 0:06:07We've got a much...
0:06:07 > 0:06:11much better chance of surviving if we stay together.
0:06:11 > 0:06:13More than anything, it helps you convince each other that you
0:06:13 > 0:06:18actually are going to survive and you can keep an eye on each other.
0:06:18 > 0:06:20We're doing OK but I haven't got a life jacket
0:06:20 > 0:06:22so can you see any more bits of wood?
0:06:22 > 0:06:26Go and get anything that was chucked off the ship that will help. Go.
0:06:31 > 0:06:33What you need to do to start off
0:06:33 > 0:06:36is just to make sure that the wood doesn't float away.
0:06:36 > 0:06:40They'd all hang onto a little bit and hope that the waves ease.
0:06:40 > 0:06:46Your body loses heat 26 times faster in water than it does in the air
0:06:46 > 0:06:49so what you've really got to do is get out of this water
0:06:49 > 0:06:52as quickly as possible.
0:06:52 > 0:06:54Be looking around the horizon for ships.
0:06:55 > 0:06:57The problem is,
0:06:57 > 0:07:00one of the common survival stories from shipwrecks is disappointment
0:07:00 > 0:07:03because they see a ship first and it doesn't rescue them.
0:07:03 > 0:07:08So keep your eyes on the horizon but prepare yourselves to be let down.
0:07:10 > 0:07:14'Fortunately, on that September morning in 1914,
0:07:14 > 0:07:19'there was some help for the crews of the three torpedoed British warships,
0:07:19 > 0:07:23'as nearby trawlers saved almost 800 lives.
0:07:23 > 0:07:27'However, nearly twice as many were lost in the attack.'
0:07:30 > 0:07:32By the end of the war,
0:07:32 > 0:07:36millions of tonnes of shipping had been sunk by U-boats,
0:07:36 > 0:07:37most of its non-naval.
0:07:37 > 0:07:42Most of it, merchant ships and some passenger liners.
0:07:42 > 0:07:45It wasn't enough to win the war for Germany
0:07:45 > 0:07:49but the U-boat war affected the lives of thousands of people
0:07:49 > 0:07:54during the war and it changed forever the nature of warfare at sea.
0:07:57 > 0:08:01I wasn't in that water for a very long but it was really intense
0:08:01 > 0:08:04and very frightening, having the wind and waves
0:08:04 > 0:08:07and the rain continually bashing into your face.
0:08:08 > 0:08:11And this pool's quite warm.
0:08:11 > 0:08:15It must have been horrific out in the North Sea,
0:08:15 > 0:08:19those iron grey waters were absolutely freezing.
0:08:19 > 0:08:23You realise very quickly
0:08:23 > 0:08:25you haven't got much chance at all.
0:08:28 > 0:08:32'In World War I, the sea could be as treacherous as the battlefields
0:08:32 > 0:08:34'of the Western front.'
0:08:36 > 0:08:38SHELL WHISTLES
0:08:38 > 0:08:39EXPLOSION
0:08:51 > 0:08:53In the middle of Salisbury Plain
0:08:53 > 0:08:55and I'm off to meet the Royal Engineers,
0:08:55 > 0:08:59who are on a course to learn to use explosives.
0:09:01 > 0:09:03People have been blowing things up in war
0:09:03 > 0:09:07since gunpowder was invented by the Chinese hundreds of years ago.
0:09:07 > 0:09:11And it's still a really important part of warfare.
0:09:11 > 0:09:14But it's more complex than you might suspect.
0:09:17 > 0:09:20'In World War I, the Royal Engineers were
0:09:20 > 0:09:24'pivotal in the development of new types of explosives.
0:09:24 > 0:09:25'100 years later,
0:09:25 > 0:09:29'and blowing things up is still a vital part of their training.'
0:09:29 > 0:09:32This is a strange-looking thing for an explosive.
0:09:32 > 0:09:33Looks like a case for a snooker cue.
0:09:33 > 0:09:37LAUGHING: No, it's the Bangalore torpedo.
0:09:40 > 0:09:44So, it's primarily used for breaching wire obstacles.
0:09:44 > 0:09:48Em, in one length, so this is one length of Bangalore torpedo,
0:09:48 > 0:09:50you've got approximately two kilos of explosive.
0:09:50 > 0:09:54When the explosive detonates, all the metal casing forms into fragments
0:09:54 > 0:09:57and then that's what cuts the barbed wire.
0:09:57 > 0:09:58We haven't got any razor wire,
0:09:58 > 0:10:01but hopefully it's going to cut this to pieces.
0:10:01 > 0:10:04Yeah, hopefully, it should, er, it should cut this knife rest to pieces.
0:10:04 > 0:10:05It's a pretty powerful explosion.
0:10:05 > 0:10:09'The Bangalore torpedo was developed in India by the British Army
0:10:09 > 0:10:14'in 1912 in order to clear old booby traps.
0:10:14 > 0:10:17'On the Western Front, it was ideal for sliding through barbed wire
0:10:17 > 0:10:20'before smashing it to smithereens.
0:10:21 > 0:10:26'Barbed wire entanglements were a major problem in World War I,
0:10:26 > 0:10:29'presenting a dense and often fatal obstacle
0:10:29 > 0:10:32'to soldiers going over the top on the Western front.
0:10:32 > 0:10:34'It was notoriously difficult to clear.
0:10:34 > 0:10:39'New types of artillery were developed to target the problem
0:10:39 > 0:10:42'and the Bangalore torpedo also proved of great use
0:10:42 > 0:10:45'in breaking up sections of the wire.
0:10:45 > 0:10:49'That's why it's so fascinating to see the Royal Engineers
0:10:49 > 0:10:52'still using it a century later.'
0:10:52 > 0:10:53Firing! Firing now!
0:11:01 > 0:11:04'However, the sheer volume of wire meant that it wasn't until
0:11:04 > 0:11:09'the introduction of tanks in 1916 that the British could really
0:11:09 > 0:11:11'start to clear the battlefields.'
0:11:18 > 0:11:22That was a much bigger explosion than I was expecting
0:11:22 > 0:11:25and the sort of steel-crossed structure that was
0:11:25 > 0:11:29sitting on top of it was sent cartwheeling across Salisbury Plain.
0:11:34 > 0:11:38It's been just shattered by the aluminium casing
0:11:38 > 0:11:40which went around the explosives in the torpedo.
0:11:40 > 0:11:43You can see how it's shattered into tiny fragments, which has then
0:11:43 > 0:11:47cut the steel at one, two, three, four, five...
0:11:47 > 0:11:51All the way along here, so if you imagined razor wire,
0:11:51 > 0:11:54or barbed wire, being above the torpedo, you can see quite clearly
0:11:54 > 0:11:58how these fragments would have just cut the wire and cleared the way.
0:11:59 > 0:12:03'After World War I, the Royal Engineers continues to develop
0:12:03 > 0:12:08'the use of explosives, using increasingly sophisticated devices.
0:12:09 > 0:12:12'Yet, the type of targets they are trained to blow up today
0:12:12 > 0:12:16'would also have been common targets for explosives a century ago...
0:12:22 > 0:12:24'..such as taking out bridges...
0:12:27 > 0:12:29'..or smashing through concrete bunkers.
0:12:42 > 0:12:47'Today, the biggest charge is being used to blast out a huge crater...'
0:12:47 > 0:12:49Firing! Firing now!
0:12:51 > 0:12:55'..big enough to block off a road and impede enemy traffic.'
0:12:59 > 0:13:00That was amazing.
0:13:00 > 0:13:05There was a huge column of chalk and mud fired up into the air.
0:13:06 > 0:13:10I can feel a really powerful shock wave come through these walls
0:13:10 > 0:13:12and this is two feet thick of concrete
0:13:12 > 0:13:16and we're a good long way away from the explosion,
0:13:16 > 0:13:18but you could really feel it come through the walls.
0:13:18 > 0:13:20And being up on Salisbury Plain's amazing
0:13:20 > 0:13:23because you've got waist-high grass all around the range
0:13:23 > 0:13:25and you could see the effects of the blast
0:13:25 > 0:13:27flatten the grass in all directions.
0:13:27 > 0:13:30And I think, more than anything else, that really makes you
0:13:30 > 0:13:34appreciate the awesome power of the explosives that they're using.
0:13:39 > 0:13:40Whoa!
0:13:40 > 0:13:42HE LAUGHS
0:13:42 > 0:13:44It's an enormous crater!
0:13:45 > 0:13:49It would take several men several hours to dig up
0:13:49 > 0:13:52something like this, but it happened just like that.
0:13:52 > 0:13:56'In World War I, the Royal Engineers had specialist tunnelling units
0:13:56 > 0:13:59'to lay down charges beneath enemy trenches
0:13:59 > 0:14:05'and on 1st July 1916, the first day of the Battle of the Somme,
0:14:05 > 0:14:08'they were behind one of the biggest explosions in modern warfare
0:14:08 > 0:14:12'when over 25,000 kilos of explosives were used
0:14:12 > 0:14:15'in a blast against the German front-line.
0:14:15 > 0:14:19'The resulting shock waves were felt hundreds of miles away.
0:14:20 > 0:14:24'Not that the Engineers' work was restricted to destroying things.
0:14:24 > 0:14:26'Towards the end of the war,
0:14:26 > 0:14:31'its units played a vital role in assisting the British advance.
0:14:31 > 0:14:33'Their work included road and rail repairs
0:14:33 > 0:14:36'and bridging rivers and canals.
0:14:38 > 0:14:42'Watching these Royal Engineers training to use explosives
0:14:42 > 0:14:45'for combat zones such as Afghanistan is a real reminder
0:14:45 > 0:14:51'how, in many respects, World War I saw the birth of modern warfare.
0:14:51 > 0:14:54'New problems required new solutions,
0:14:54 > 0:14:58'providing the foundations for much of the military's operations today.'
0:15:11 > 0:15:13MACHINE-GUN FIRE
0:15:16 > 0:15:18SHELL WHISTLES OVERHEAD
0:15:18 > 0:15:21PLANE FLIES OVERHEAD, EXPLOSION
0:15:28 > 0:15:31MILITARY DRUMMING