0:00:02 > 0:00:06This programme contains some scenes which some viewers may find upsetting
0:00:06 > 0:00:08Londonderry is famous for a remarkable siege,
0:00:08 > 0:00:13but there is an extraordinary time in the city's more recent past that has been forgotten.
0:00:13 > 0:00:18The years when Derry was at the centre of World War II's longest and most decisive battle...
0:00:19 > 0:00:21..the Battle of the Atlantic.
0:00:22 > 0:00:25To reveal this story, we begin not in the city,
0:00:25 > 0:00:27but on the waters of its coast.
0:00:30 > 0:00:32Out there on the horizon,
0:00:32 > 0:00:34hidden deep beneath the waves,
0:00:34 > 0:00:37lie hundreds of forgotten shipwrecks.
0:00:37 > 0:00:40Together, they tell the story of an extraordinary conflict.
0:00:40 > 0:00:47It lasted nearly six years. 100,000 men died and 4,000 ships were sunk.
0:00:48 > 0:00:52Wrecks from the battle still litter the seabed here,
0:00:52 > 0:00:56lost, forgotten and out of reach... until now.
0:00:57 > 0:01:01One underwater explorer has compiled a unique map.
0:01:01 > 0:01:04It charts the lost wrecks of the Battle of the Atlantic.
0:01:04 > 0:01:09Now, he and a team of expert divers are going in search of them,
0:01:09 > 0:01:11to uncover the lost stories of the battle.
0:01:13 > 0:01:15All the hatches are closed.
0:01:15 > 0:01:18There is an open locker with live ammunition in it.
0:01:19 > 0:01:22What they discover will restore Derry's lost place
0:01:22 > 0:01:24in the history of World War II.
0:01:26 > 0:01:28The Battle of the Atlantic could not have been won
0:01:28 > 0:01:33if the bases on the Foyle had not been available to the Allies.
0:01:33 > 0:01:35This is the object of the search today -
0:01:35 > 0:01:38a top-secret bunker complex, deep beneath the grass here.
0:01:38 > 0:01:42And over 70 years later, the generation who witnessed
0:01:42 > 0:01:48first-hand this extraordinary time in Derry share their experiences.
0:01:48 > 0:01:50When they came into the hospital,
0:01:50 > 0:01:54it was dreadful to see a human being like that.
0:01:54 > 0:01:57All you think about is what the people back home will think
0:01:57 > 0:01:59when they know I'm dead.
0:01:59 > 0:02:03"Bride ship leaves Derry for the US." I really was the first
0:02:03 > 0:02:06GI bride to set foot in America.
0:02:06 > 0:02:11And there was a lot of animosity, because we were stealing their men!
0:02:11 > 0:02:15In this series, we will dive back through history, to uncover
0:02:15 > 0:02:21how victory in the Battle of the Atlantic was forged here, in Derry.
0:02:28 > 0:02:30Britain was at war in Europe
0:02:30 > 0:02:34and increasingly dependent on the United States.
0:02:34 > 0:02:36Without American oil, tanks and guns,
0:02:36 > 0:02:40Britain's war effort would grind to a halt.
0:02:40 > 0:02:43Every week, convoys of cargo ships ferried hundreds of thousands
0:02:43 > 0:02:47of tonnes of supplies from America across the Atlantic to Britain.
0:02:49 > 0:02:53Meanwhile, Nazi Germany sent its U-boat fleet to intercept
0:02:53 > 0:02:54and destroy the convoys.
0:02:55 > 0:02:58'In these bomber-laden ships, eastward bound from Canada
0:02:58 > 0:03:01'and the USA, lies a threat not only to Hitler's
0:03:01 > 0:03:06'campaign against the British Isles, but to his grip on Europe itself.'
0:03:06 > 0:03:09It was the U-boats that made the Battle of the Atlantic
0:03:09 > 0:03:13the longest and certainly one of the bloodiest campaigns of the war.
0:03:13 > 0:03:17But it was from Derry and ports just like it that the fightback began.
0:03:17 > 0:03:18It was from here that the corvettes
0:03:18 > 0:03:21and destroyers set sail to hunt them down.
0:03:24 > 0:03:28Within a year of the start of the war, Germany occupied France.
0:03:28 > 0:03:32It gave their U-boat fleet direct access to the Atlantic
0:03:32 > 0:03:35and to the packed shipping lanes off Northern Ireland.
0:03:35 > 0:03:38The waters off Derry were now a U-boat killing zone,
0:03:38 > 0:03:41where no Allied ship was safe.
0:03:41 > 0:03:43Effectively, their force has been multiplied
0:03:43 > 0:03:45because they can go straight out into the Atlantic.
0:03:45 > 0:03:48The Royal Navy now needs a base that is as far
0:03:48 > 0:03:51west in the British Isles as they can possibly get,
0:03:51 > 0:03:56so the Foyle, the city of Londonderry, and the...what is now
0:03:56 > 0:04:01Londonderry Port at Lisahally become truly critical elements.
0:04:01 > 0:04:04The Battle of the Atlantic could not have been won
0:04:04 > 0:04:08if the bases on the Foyle had not been available to the Allies.
0:04:13 > 0:04:17It wasn't just Britain that was aware of Derry's strategic importance.
0:04:17 > 0:04:20Extraordinary clues, hidden just outside the city,
0:04:20 > 0:04:24show Derry was of huge strategic significance to the Americans,
0:04:24 > 0:04:26even before 1941,
0:04:26 > 0:04:30when Japan's attack on their Pacific bases pushed the US into the war.
0:04:34 > 0:04:37Recently declassified documents discovered in Washington
0:04:37 > 0:04:40reveal that even before the Japanese attack on Pearl Harbor,
0:04:40 > 0:04:44the Americans were already building a vast European military base,
0:04:44 > 0:04:46and they were doing it right here in Derry.
0:04:50 > 0:04:53The United States President, Roosevelt,
0:04:53 > 0:04:55had said that the United States Navy was going to
0:04:55 > 0:04:58help in escorting convoys, and indeed were already doing it.
0:04:58 > 0:05:01They were now going to extend that to the point that they
0:05:01 > 0:05:04were going to escort convoys the full way across the Atlantic
0:05:04 > 0:05:06and they wanted a base on this side of the Atlantic.
0:05:06 > 0:05:12A party of US Navy officers came from London to inspect
0:05:12 > 0:05:16the facilities that were already present in the city
0:05:16 > 0:05:17and along the Foyle.
0:05:17 > 0:05:22In early 1941, almost a year before Pearl Harbor,
0:05:22 > 0:05:26the US Navy chose to build their very own docks on the Foyle.
0:05:26 > 0:05:30Meanwhile, just outside the city, Beech Hill was to be
0:05:30 > 0:05:33the site of a military barracks for hundreds of men.
0:05:33 > 0:05:37This camp was America's first foothold in Europe - Base One.
0:05:39 > 0:05:42But like so many of Derry's wartime stories,
0:05:42 > 0:05:48the clues to this lie hidden. Today, Beech Hill is a luxury hotel.
0:05:48 > 0:05:52But I've come here to see what is left of America's first base.
0:05:53 > 0:05:55The clues are intriguing.
0:05:55 > 0:05:58Slabs of concrete where buildings once stood...
0:06:00 > 0:06:04..a few Nissan huts, the military's iconic prefab,
0:06:04 > 0:06:08and on the far edge of the wood, I find the old perimeter fence,
0:06:08 > 0:06:11still marked Base One.
0:06:11 > 0:06:16When I first heard about this American European base,
0:06:16 > 0:06:19Base One, I was expecting a bit more than sort of overgrown woodland,
0:06:19 > 0:06:22but, sadly, this is all that's left of it.
0:06:24 > 0:06:28US photographs reveal the true scale of Beech Hill.
0:06:28 > 0:06:32They show a four-acre site with over 100 Nissan huts...
0:06:34 > 0:06:36..specially built roads,
0:06:36 > 0:06:38bomb shelters,
0:06:38 > 0:06:40ammunition dumps...
0:06:41 > 0:06:44..and accommodation for hundreds of Marines.
0:06:46 > 0:06:48A full battalion of Marines was created,
0:06:48 > 0:06:51called the First Provisional Battalion, and it was shipped
0:06:51 > 0:06:55across and was barracked here and in Springtown
0:06:55 > 0:06:58and also down at Lisahally.
0:07:00 > 0:07:04Most intriguingly of all, the dates on these documents reveal
0:07:04 > 0:07:09construction of Base One was well under way in July of 1941.
0:07:11 > 0:07:14Five months before the attack on Pearl Harbor in the Pacific,
0:07:14 > 0:07:19the United States was preparing for war in Europe, right here in Derry.
0:07:22 > 0:07:24But even before the Americans arrived,
0:07:24 > 0:07:26Derry was in the heat of the action.
0:07:26 > 0:07:30From 1939, British escort ships based in the city were
0:07:30 > 0:07:35fighting off attacks by German U-boats along the Ulster coast.
0:07:35 > 0:07:39Today, wrecks from both sides lie forgotten on the seabed.
0:07:39 > 0:07:42Naval historian Ian Lawler wants to change that.
0:07:43 > 0:07:46We are stepping back into 1940, 1941, 1942 and so on.
0:07:46 > 0:07:49Is that what it feels like when you dive?
0:07:49 > 0:07:51When you're looking at the wreck, you're looking at,
0:07:51 > 0:07:54"What am I seeing with respect to the damage?
0:07:54 > 0:07:56"Is the bow missing, is the stern missing?
0:07:56 > 0:07:58"Can I tell it was a torpedo?"
0:07:58 > 0:08:01You can now start to put a few more pieces in the jigsaw.
0:08:01 > 0:08:06Following years of research, Ian has created a unique map, one that
0:08:06 > 0:08:10he believes charts the lost wrecks of the Battle of the Atlantic.
0:08:12 > 0:08:15We have seabed survey data, we have fishermen's fasts,
0:08:15 > 0:08:19where their nets caught on things, and we have information from diving.
0:08:19 > 0:08:22So what I've done is put it all together on the one chart.
0:08:22 > 0:08:25But while Ian's research has confirmed the locations
0:08:25 > 0:08:29of hundreds of wrecks, he has not yet put names to all of them.
0:08:29 > 0:08:33Each of the red symbols on the chart represents a shipwreck.
0:08:33 > 0:08:35About half of what is here, we don't know what it is.
0:08:35 > 0:08:40Now Ian plans to dive and identify six wrecks on his map,
0:08:40 > 0:08:43which he believes are key to understanding the Battle
0:08:43 > 0:08:47of the Atlantic and the role Derry played in the Allied victory.
0:08:47 > 0:08:50He is joined by a team of Europe's top deep-water divers.
0:08:52 > 0:08:54You can read about it all you want.
0:08:54 > 0:08:57You can read all the textbooks, all the source material,
0:08:57 > 0:09:00but there is nothing like actually going down and seeing what it is.
0:09:02 > 0:09:06Ian and the team will be diving in waters which during the war
0:09:06 > 0:09:10were the checkpoint for the Allies' Atlantic shipping.
0:09:10 > 0:09:11Every Allied escort group,
0:09:11 > 0:09:14every Allied support group that crosses the Atlantic, is going
0:09:14 > 0:09:19to tie up in Derry for refuelling and for a couple
0:09:19 > 0:09:22of days before it heads back out to do more work in the North Atlantic.
0:09:22 > 0:09:26When you realise the Allies moved 85,000 shiploads of cargo
0:09:26 > 0:09:29across the Atlantic and each of those ships
0:09:29 > 0:09:34assembled into perhaps 600 convoys, will be escorted by five or
0:09:34 > 0:09:37six escorts, you get an idea of the scale of what's going on.
0:09:39 > 0:09:42The most common of the warships crowding Lisahally were
0:09:42 > 0:09:45the corvettes. They were tough opponents.
0:09:45 > 0:09:49Of more than 300 built, the U-boats sank just 25,
0:09:49 > 0:09:52only two of which were in Northern Irish waters.
0:09:52 > 0:09:56But Ian believes his map identifies one of them.
0:09:56 > 0:10:00He was tipped off about its location by local skipper Michael McVeigh.
0:10:01 > 0:10:03Found it last October.
0:10:03 > 0:10:05It really is literally sitting at three, four, five,
0:10:05 > 0:10:08six feet off the seabed. Unbelievable.
0:10:08 > 0:10:11It was really, really, really, REALLY lucky to find it.
0:10:13 > 0:10:14Based on the wreck's location,
0:10:14 > 0:10:19Ian has a hunch it is in fact the lost corvette, HMS Hurst Castle.
0:10:20 > 0:10:24Now, for the team's first dive, they are planning to explore it.
0:10:24 > 0:10:27Rich Stevenson is the dive supervisor
0:10:27 > 0:10:30and a deep-water veteran who has dived all over the world.
0:10:30 > 0:10:33He is responsible for the safety of the team.
0:10:33 > 0:10:35Would it be fair to say that when the ship sank,
0:10:35 > 0:10:38she was fighting, potentially?
0:10:38 > 0:10:41Oh, yeah, she was fully armed, absolutely.
0:10:41 > 0:10:45So, it's probably a good assumption that any armaments or explosives
0:10:45 > 0:10:48or missiles, whatever, that we're going to find, could be live?
0:10:48 > 0:10:50- Absolutely.- Yeah.
0:10:50 > 0:10:53So I think we are going to employ a common-sense approach today, guys,
0:10:53 > 0:10:58we are here to video and document, not to interfere and tamper.
0:10:58 > 0:11:01The dive site is 40 miles offshore.
0:11:02 > 0:11:06Using his echo sounder, Michael positions the boat over the wreck.
0:11:07 > 0:11:10It is now 250 feet beneath them.
0:11:10 > 0:11:13At that depth, there is no room for mistakes.
0:11:13 > 0:11:17The number of people in Ireland that can dive to that depth,
0:11:17 > 0:11:19you could count on, well, your fingers and toes.
0:11:19 > 0:11:23It's very, very deep. It's very, very, very dangerous.
0:11:23 > 0:11:24There are no errors allowed.
0:11:26 > 0:11:30You can't say that going underwater isn't risky, because it is,
0:11:30 > 0:11:31because we can't breathe underwater,
0:11:31 > 0:11:35so therefore, the risk has to be managed.
0:11:35 > 0:11:37I want to keep gas toxicity levels down to a minimum.
0:11:37 > 0:11:39Safety is a priority.
0:11:39 > 0:11:43The depth of the water puts you into a situation that is just
0:11:43 > 0:11:45impossible to recover from quickly.
0:11:45 > 0:11:47For three hours, they will rely
0:11:47 > 0:11:50on a precise mix of gases to keep them alive.
0:11:50 > 0:11:53Prepping the kit requires meticulous attention.
0:11:59 > 0:12:03Fully prepped, the dive team drop into the water.
0:12:03 > 0:12:07They are descending over 250 feet into the dark of the Atlantic.
0:12:08 > 0:12:11For 15 minutes, they swim straight down.
0:12:12 > 0:12:16On the seabed, the team has just 20 minutes to explore
0:12:16 > 0:12:17and film the wreck.
0:12:18 > 0:12:21Ian is looking for clues to prove his theory that this is
0:12:21 > 0:12:23the armed corvette Hurst Castle.
0:12:25 > 0:12:30She was 250 feet long and weighed over 1,000 tonnes.
0:12:30 > 0:12:33The Hurst Castle was also armed with a variety of guns,
0:12:33 > 0:12:39depth charges and a mortar. The site could be littered with ammunition.
0:12:39 > 0:12:44We have a fair degree of wariness about poking around in amongst
0:12:44 > 0:12:47Second World War munitions.
0:12:47 > 0:12:48I wouldn't be touching it.
0:12:56 > 0:13:03The entire stern has been destroyed. Only the bow section remains intact.
0:13:08 > 0:13:11With time running out, the team have found nothing to confirm
0:13:11 > 0:13:14Ian's theory that this is the Hurst Castle.
0:13:18 > 0:13:24But then he finds his first clue - piles of decaying explosive shells.
0:13:24 > 0:13:28After 70 years on the seabed, they are still a real risk.
0:13:28 > 0:13:31You wonder what's going to happen next.
0:13:31 > 0:13:34All you can do is hope that you're not around when it happens!
0:13:35 > 0:13:38Ian examines the shells carefully.
0:13:38 > 0:13:41They are important evidence that this was a military vessel.
0:13:43 > 0:13:48Then, with only minutes left on the seabed, he discovers another clue.
0:13:48 > 0:13:49It is the squid mortar,
0:13:49 > 0:13:52a weapon fitted to Second World War corvettes.
0:13:52 > 0:13:56It launched depth charges hundreds of yards in front of the ship
0:13:56 > 0:13:57with deadly accuracy.
0:13:58 > 0:14:03This one is still loaded - a sign the ship went down fighting.
0:14:03 > 0:14:07Now you realise just how big a squid mortar is.
0:14:07 > 0:14:10They look like torpedoes - these things are huge.
0:14:12 > 0:14:15The squid mortar is a major clue this wreck could be
0:14:15 > 0:14:19the Hurst Castle. But the team is out of time.
0:14:19 > 0:14:22They need at least two-and-a-half hours to make a controlled
0:14:22 > 0:14:24ascent to the surface.
0:14:24 > 0:14:28Any faster and nitrogen bubbles could form in their bloodstreams
0:14:28 > 0:14:30and kill them.
0:14:30 > 0:14:33Finally, safely back on board,
0:14:33 > 0:14:36Ian and the team are delighted with what they've discovered.
0:14:36 > 0:14:38I thought we were looking at a winch in front of me,
0:14:38 > 0:14:41because I saw the cogs. Then it was, "Ooh! That's a squid!"
0:14:43 > 0:14:48We got 10 minutes of just excellent footage of that.
0:14:48 > 0:14:51- Really pleased with that. - Yeah, the shot was good.
0:15:01 > 0:15:04On an Atlantic cliff top overlooking the very waters
0:15:04 > 0:15:06the team are diving, Ian's footage will be
0:15:06 > 0:15:09studied by two of the world's leading naval experts.
0:15:10 > 0:15:14Dr Randy Papadopoulos is a historian at the Pentagon,
0:15:14 > 0:15:16specialising in naval strategy.
0:15:17 > 0:15:19Dr Axel Niestle is German
0:15:19 > 0:15:23and a world expert on Second World War U-boats.
0:15:23 > 0:15:27Ian needs their specialist knowledge to confirm his hunch that this
0:15:27 > 0:15:29is the wreck of HMS Hurst Castle.
0:15:31 > 0:15:33For a ship that was sunk so recently,
0:15:33 > 0:15:36it's much more of a jigsaw puzzle than I expected.
0:15:36 > 0:15:39- I'll say!- But then we found this.
0:15:41 > 0:15:43- Well, that's a squid mortar.- Yup.
0:15:48 > 0:15:52- Were there any charges in it? - There is, definitely. It's loaded.
0:15:52 > 0:15:56And here we have a lot of shells, sort of four-inch diameter.
0:15:56 > 0:16:01- And lots of live ammunition in there. - Yes.- Yup.- So you have to be careful.
0:16:05 > 0:16:09Axel and Randy study the footage carefully, then they consult Allied
0:16:09 > 0:16:15naval records, historical documents and plan drawings of possible ships.
0:16:15 > 0:16:18Every detail helps in identifying the wreck.
0:16:18 > 0:16:21Finally, they confirm Ian has made a remarkable discovery.
0:16:21 > 0:16:24The wreck is HMS Hurst Castle.
0:16:24 > 0:16:27One of only two Second World War corvettes
0:16:27 > 0:16:29ever sunk in Northern Irish waters.
0:16:30 > 0:16:33Just talk us through the anatomy of the ship
0:16:33 > 0:16:35and how it relates to what you were able to see.
0:16:35 > 0:16:38She's got radar, she's also got high-frequency direction finding,
0:16:38 > 0:16:42or "Huff-Duff", and most importantly, the squid mortar.
0:16:42 > 0:16:45They are very much the state-of-the-art for that time,
0:16:45 > 0:16:47and that's the key thing.
0:16:47 > 0:16:50Despite their corvette's weaponry, the crew of the Hurst Castle
0:16:50 > 0:16:54were unable to repel a torpedo attack by a German U-boat.
0:16:54 > 0:16:57The enemy submarine landed a direct hit.
0:16:59 > 0:17:03The acoustic homing torpedo would have targeted the loud engines
0:17:03 > 0:17:06of the corvette and essentially would have blown her stern off.
0:17:06 > 0:17:09It was a decisive strike for the Nazi captain, who
0:17:09 > 0:17:14brought his U-boat to within just 20 miles of the Northern Irish coast.
0:17:14 > 0:17:1970 years later, it marks Ian's first success in his mission to map
0:17:19 > 0:17:22the lost wrecks of this forgotten battlefield.
0:17:22 > 0:17:25During the war, all these things are forgotten about,
0:17:25 > 0:17:28they are just incidental, they just happened, that's it.
0:17:28 > 0:17:29The Hurst Castle was sunk.
0:17:29 > 0:17:33So, you know, just a loss in action, that's it.
0:17:33 > 0:17:39But it's generally the divers that start to make the discoveries
0:17:39 > 0:17:42and try and shed light on what happened.
0:17:42 > 0:17:45When you find what you're looking for, that's what makes it,
0:17:45 > 0:17:48that really makes it all worthwhile.
0:17:48 > 0:17:50Because it marks more than just a wreck.
0:17:50 > 0:17:53It marks the position of a war grave,
0:17:53 > 0:17:56where 17 men lost their lives, fighting for freedom.
0:18:02 > 0:18:04For the crews of any escort ship,
0:18:04 > 0:18:09arrival into the protective waters of Lough Foyle meant safety at last.
0:18:09 > 0:18:14You can imagine the crew of a convoy escort that have had a really
0:18:14 > 0:18:17rough time, coming across the Atlantic,
0:18:17 > 0:18:20entering the River Foyle and breathing a huge sigh of relief
0:18:20 > 0:18:23and looking forward to all that Derry could offer them.
0:18:23 > 0:18:26I remember one former convoy escort sailor writing to me
0:18:26 > 0:18:29and saying that the wind seemed to die down
0:18:29 > 0:18:33when he got into the shelter of the lough and then the river.
0:18:33 > 0:18:35The captain on his ship actually
0:18:35 > 0:18:38had "Danny Boy" piped over the loudspeakers.
0:18:40 > 0:18:44On entering Lough Foyle, warships then made their way 20 miles
0:18:44 > 0:18:47upriver to the docks at Lisahally.
0:18:47 > 0:18:51Those war years were the busiest the river has ever seen.
0:18:51 > 0:18:56Every week, 100 escort ships steamed up and down this stretch of water.
0:18:56 > 0:18:58The docks were crammed with vessels,
0:18:58 > 0:19:00all fighting to keep the Atlantic open.
0:19:03 > 0:19:07Derry's safe harbour and westerly location made it the perfect place.
0:19:08 > 0:19:12So, Naval Command took over two key sites in the city -
0:19:12 > 0:19:14Magee College and Ebrington Barracks.
0:19:14 > 0:19:18This was the Allies' anti-U-boat academy.
0:19:18 > 0:19:22It was here that hundreds of escort captains came to learn
0:19:22 > 0:19:25the difficult task of how to hunt down and sink submarines.
0:19:25 > 0:19:28It meant that during the Battle of the Atlantic, the skills taught
0:19:28 > 0:19:32here made this one of the most important naval bases in the UK.
0:19:35 > 0:19:37After every Atlantic mission,
0:19:37 > 0:19:39skippers came here to perfect their skills.
0:19:41 > 0:19:45They role-played against an imaginary enemy, shared tactics
0:19:45 > 0:19:48and were brought up to speed on the latest anti-U-boat weaponry.
0:19:48 > 0:19:50Ebrington Barracks became...
0:19:50 > 0:19:54It had been a backwater before the war, an army base.
0:19:54 > 0:19:58In the course of the war, it is handed over to the Admiralty.
0:19:58 > 0:20:02It becomes an essential part of the whole,
0:20:02 > 0:20:08if you like, network that was the Allied effort to defeat
0:20:08 > 0:20:10the submarines in the Battle of the Atlantic.
0:20:10 > 0:20:13So, a huge amount of resources given over to training
0:20:13 > 0:20:17and honing those skills to try at last to beat the U-boats.
0:20:17 > 0:20:20Very, very much so. I mean, literally as well as being the focal point
0:20:20 > 0:20:25of the battle against the U-boats, the physical battle,
0:20:25 > 0:20:28it was also the focal point in the training of those who were
0:20:28 > 0:20:33taking part in the battle. In fact, there was
0:20:33 > 0:20:36a small flotilla of submarines based in the city as well
0:20:36 > 0:20:40and their job simply was to go out into the Atlantic, play,
0:20:40 > 0:20:44as it were, with the escort groups, act the role of U-boats.
0:20:46 > 0:20:50They involved the air in the exercises as well as the surface
0:20:50 > 0:20:54ships, and of course, you had a training element also
0:20:54 > 0:20:58based in Magee College, where the Royal Navy had its headquarters.
0:20:58 > 0:21:02And it is Magee College that may well hide one of the biggest
0:21:02 > 0:21:05secrets of Derry's wartime story.
0:21:05 > 0:21:08Key to victory in the Battle of the Atlantic was the vast
0:21:08 > 0:21:12logistics of coordinating over 100 armed escort vessels with
0:21:12 > 0:21:16thousands of convoy ships crisscrossing the ocean.
0:21:16 > 0:21:18You are dealing with an effort, then,
0:21:18 > 0:21:20that perhaps deals with a million people that are trying to
0:21:20 > 0:21:23make sure that the Battle of the Atlantic comes to
0:21:23 > 0:21:25a successful conclusion from the Allied side.
0:21:25 > 0:21:27It is a tremendous undertaking from their perspective,
0:21:27 > 0:21:30arguably one of the largest endeavours ever made by
0:21:30 > 0:21:33human beings in any conflict, then or since.
0:21:34 > 0:21:38At the heart of this massive undertaking was Magee College.
0:21:38 > 0:21:42But the full extent of its role has been shrouded in secrecy.
0:21:42 > 0:21:45Historian Jonny McNee is determined to unearth it.
0:21:45 > 0:21:49He is convinced the college lawns hide a vast, covert command bunker.
0:21:53 > 0:21:54From here, they were controlling
0:21:54 > 0:21:56the convoys coming in from America,
0:21:56 > 0:21:57the convoys going out,
0:21:57 > 0:21:59deciphering codes that they were
0:21:59 > 0:22:02intercepting from the German U-boats and then doing
0:22:02 > 0:22:06the tactics of organising the RAF coastal command airfields.
0:22:06 > 0:22:11Jonny's research indicates the bunker was staffed by Navy brass.
0:22:11 > 0:22:14But throughout the war, their underground headquarters
0:22:14 > 0:22:17remained top-secret to all but a very few.
0:22:18 > 0:22:20It just operated in lone isolation here,
0:22:20 > 0:22:23people were working in buildings on the top of the bunker complex,
0:22:23 > 0:22:26only those of the highest security clearance were allowed to
0:22:26 > 0:22:29go down into the bowels and work underneath it.
0:22:29 > 0:22:31So, bunker life went on here
0:22:31 > 0:22:34and Derry was completely ignorant to its existence.
0:22:34 > 0:22:37During World War II, it was part of a wider command network,
0:22:37 > 0:22:42coordinating the entire operation of the Battle of the Atlantic.
0:22:42 > 0:22:46There was three of these bunker complexes in the United Kingdom,
0:22:46 > 0:22:50one in Whitehall, one in Derby House in Liverpool, and this one here.
0:22:50 > 0:22:53The other two were working out of the basements
0:22:53 > 0:22:54of existing large buildings.
0:22:54 > 0:22:57This has been purpose-built, this is the closest point to the
0:22:57 > 0:23:00actual Battle of the Atlantic proper, as it is being raged.
0:23:00 > 0:23:0370 years later, finding evidence of something
0:23:03 > 0:23:06so top-secret has been tough.
0:23:06 > 0:23:08Jonny has searched military records
0:23:08 > 0:23:11and discovered mention of the bunker in just a handful of documents.
0:23:11 > 0:23:14Looking through any of the records into this,
0:23:14 > 0:23:17you're talking half a dozen pages of information at the most that
0:23:17 > 0:23:20let you know there was something here.
0:23:20 > 0:23:23While the official evidence may be scarce,
0:23:23 > 0:23:27Jonny has located a compelling description from an eyewitness
0:23:27 > 0:23:29and it has given his team of archaeologists
0:23:29 > 0:23:31a starting point for their search.
0:23:33 > 0:23:36All we have is one testimony from a senior Wren who
0:23:36 > 0:23:40worked in the area, who talks about going into the shed,
0:23:40 > 0:23:43down a set of concrete steps, along a warren of corridors
0:23:43 > 0:23:48and into a mapping room, a cipher room, a decoding room,
0:23:48 > 0:23:51so this is the object of the search today.
0:23:53 > 0:23:56The team are using ground penetrating sonar to search
0:23:56 > 0:23:58the area beneath the college lawns.
0:23:58 > 0:24:00And the technology begins to throw up
0:24:00 > 0:24:02enticing clues to Derry's secret past.
0:24:02 > 0:24:06I'm seeing down 10 metres into the ground here,
0:24:06 > 0:24:09so as well as objects in the near surface,
0:24:09 > 0:24:12I'm seeing geology as well, which is quite exciting.
0:24:12 > 0:24:15Alistair quickly picks up readings that suggest
0:24:15 > 0:24:18they could be right over the underground bunker.
0:24:18 > 0:24:20Stop, whoa! Hang on. That's good. That's good.
0:24:20 > 0:24:22A really nice, clear anomaly.
0:24:22 > 0:24:24Even I can see that!
0:24:24 > 0:24:27Starting at a metre, 1.5 metres,
0:24:27 > 0:24:32with a load of interference coming off a significant object.
0:24:32 > 0:24:36Interestingly, just where we went over that bit of rough ground...
0:24:36 > 0:24:41- Yes. So...- ..which quite often is the case.- Just about here, then.
0:24:41 > 0:24:43That's it, starting there.
0:24:43 > 0:24:47Very sparse grass, this is nice, this is soaked, very damp.
0:24:48 > 0:24:52It's a good indication that the bunker may still remain.
0:24:52 > 0:24:55Pictures from the corresponding naval command centre
0:24:55 > 0:24:58in Liverpool give an idea of the potential size
0:24:58 > 0:25:02of the command centre in Derry and the rooms it might have contained.
0:25:05 > 0:25:08Oh, Jonny, this is good. A really nice anomaly.
0:25:08 > 0:25:10Lots of ringing beneath it,
0:25:10 > 0:25:13which is exactly the sort of thing I would see with a hollow or
0:25:13 > 0:25:15a grave, or something of that size.
0:25:15 > 0:25:17Could that be, like, a stairwell entrance,
0:25:17 > 0:25:20- or am I getting too excited? - No, you're not getting too excited.
0:25:20 > 0:25:23- No, like a tunnel.- Right.
0:25:23 > 0:25:26It's a tantalising clue, but Jonny will have to wait
0:25:26 > 0:25:30until excavations can begin to uncover the truth.
0:25:30 > 0:25:32Today's discovery could be only the first in solving
0:25:32 > 0:25:35the mystery of Derry's secret bunker,
0:25:35 > 0:25:37and further proof of the city's role
0:25:37 > 0:25:39at the centre of the Allied Atlantic campaign.
0:25:39 > 0:25:42This would have been the nerve centre for continuing that fight,
0:25:42 > 0:25:44deep beneath the grass here.
0:25:53 > 0:25:57Every week, a growing number of survivors from the convoys,
0:25:57 > 0:26:00many of them badly wounded, were coming ashore.
0:26:00 > 0:26:02For this city especially, it was a dramatic
0:26:02 > 0:26:07illustration of the growing human cost of the Battle of the Atlantic.
0:26:07 > 0:26:11Once the sirens went, we had to come out
0:26:11 > 0:26:16and get to the Waterside Hospital on our bicycles.
0:26:16 > 0:26:19You just couldn't believe it, seeing first-hand, you know,
0:26:19 > 0:26:21what you would hear of on the news.
0:26:22 > 0:26:26Esdale Johnson was 17 when war broke out.
0:26:26 > 0:26:27Like hundreds of teenagers,
0:26:27 > 0:26:30she volunteered for the St John's Ambulance and worked in the
0:26:30 > 0:26:34makeshift hospital set up to deal with casualties as they came ashore.
0:26:36 > 0:26:39There was no difficulty treating the men,
0:26:39 > 0:26:41because they were very brave and very...
0:26:43 > 0:26:45..glad to be ashore.
0:26:45 > 0:26:50They were just glad to be in a hospital, they said there was
0:26:50 > 0:26:53a lot that weren't saved and they were glad to be saved.
0:26:53 > 0:26:56Esdale remembers treating two survivors
0:26:56 > 0:26:59picked up days after a torpedo attack.
0:26:59 > 0:27:01They had been adrift in lifeboats
0:27:01 > 0:27:05and exposed to the worst of the Atlantic's weather.
0:27:05 > 0:27:09They were in a small boat, and they were
0:27:09 > 0:27:15frozen in the shape of a letter L when they came into the hospital.
0:27:15 > 0:27:18We couldn't get them to lie down.
0:27:18 > 0:27:23If you lay on the back, the feet came up, it was very sad.
0:27:26 > 0:27:30I remember, I would be bandaging their feet one day and then
0:27:30 > 0:27:35when I would go back again, I would find, you know, that
0:27:35 > 0:27:39the toes were coming off. I remember that vividly.
0:27:39 > 0:27:41You just couldn't believe it,
0:27:41 > 0:27:46it was dreadful to see a human being like that.
0:27:46 > 0:27:47It was.
0:27:54 > 0:27:58To understand the battle that raged off Derry's coast, Ian and the team
0:27:58 > 0:28:02need to track down the deadly enemy and see it with their own eyes.
0:28:02 > 0:28:04They are on the hunt for a submarine.
0:28:05 > 0:28:09The German U-boat fleet consisted of various types of sub,
0:28:09 > 0:28:12but many shared common features -
0:28:12 > 0:28:14a long, narrow hull,
0:28:14 > 0:28:17a raised central section known as the conning tower,
0:28:17 > 0:28:20periscopes for seeing above the waterline,
0:28:20 > 0:28:23a snorkel, a retractable air intake for the diesel engines,
0:28:23 > 0:28:26and of course, torpedo tubes.
0:28:28 > 0:28:32All these features will help the team to identify today's wreck.
0:28:32 > 0:28:36It's lying in deep water, 30 miles off the coast.
0:28:36 > 0:28:40But with a storm blowing in, the team need a head start
0:28:40 > 0:28:42to get there, and they are setting off before light.
0:28:44 > 0:28:46When they come out of the water,
0:28:46 > 0:28:49it'll be blowing a force 5 to 6, so we'll just need to be careful.
0:28:49 > 0:28:51'There is a small craft warning in operation.
0:28:51 > 0:28:53'South-west winds will reach force 6 during today
0:28:53 > 0:28:56'along Northern Irish coastal waters.'
0:28:56 > 0:28:59The wreck is in 200 feet of water.
0:28:59 > 0:29:01Michael uses sonar to scan the seabed
0:29:01 > 0:29:04and position the boat accurately.
0:29:04 > 0:29:06As the wind picks up, the divers have to make their careful
0:29:06 > 0:29:09preparations in a six-foot swell.
0:29:09 > 0:29:13There's the wreck coming up now, you can see about four metres
0:29:13 > 0:29:16there, the top of the wreck is about 60 metres down.
0:29:21 > 0:29:24Rich briefs the team to keep the dive as short as possible.
0:29:24 > 0:29:26Today isn't the day to be taking risks.
0:29:26 > 0:29:29Let's try and keep it to two-and-a-half hours,
0:29:29 > 0:29:31because we are chasing the weather today, lads, there is
0:29:31 > 0:29:35some bad weather coming in, you can feel it brewing already.
0:29:41 > 0:29:46- OK, guys, the shot's in. - The team drop over the side.
0:29:46 > 0:29:49As they descend, Michael keeps his eye on the weather.
0:29:54 > 0:29:56220 feet beneath him,
0:29:56 > 0:30:00the divers' torches reveal the decaying remains of a German U-boat.
0:30:02 > 0:30:05The wreck is at least 200 feet long.
0:30:05 > 0:30:09The team scours its length, looking for clues as to how it sank.
0:30:10 > 0:30:13The U-boat's hull is largely intact.
0:30:17 > 0:30:21But then they locate an area of huge damage.
0:30:21 > 0:30:25The section in front of the conning tower is barely recognisable.
0:30:25 > 0:30:28The sky periscope is bent flat across the hull.
0:30:31 > 0:30:33Everything points to this U-boat being
0:30:33 > 0:30:35the victim of catastrophic damage.
0:30:37 > 0:30:40Ian discovers a magazine still loaded with bullets.
0:30:46 > 0:30:50All these clues could identify the U-boat and explain why it sank.
0:30:50 > 0:30:54As soon as he is on board, Ian reveals what the team has seen.
0:30:56 > 0:31:01All the hatches are closed. But the conning tower is a mess.
0:31:01 > 0:31:05There is an open locker with live ammunition in it.
0:31:05 > 0:31:08- There is live ammunition? - Absolutely.- You saw it?- Yup.
0:31:08 > 0:31:10There's piles of bullets.
0:31:14 > 0:31:16That's why you're the expert, Ian!
0:31:16 > 0:31:19It's a great result for the team.
0:31:19 > 0:31:23They have discovered vital clues that could identify the U-boat
0:31:23 > 0:31:24and explain why it sank.
0:31:27 > 0:31:32But now, a storm is closing in and after a good day's work,
0:31:32 > 0:31:33they face a grim trip home.
0:31:36 > 0:31:39In the Atlantic in World War II, it was no different.
0:31:39 > 0:31:41The weather could be as vicious as the U-boats.
0:31:44 > 0:31:47Seas like this, and far worse, were typical of those
0:31:47 > 0:31:51experienced by the North Atlantic convoys and their crews.
0:31:54 > 0:31:56Looking at the sea on a day like today,
0:31:56 > 0:31:59you see how it all happened, you can actually put a picture on it.
0:31:59 > 0:32:03It really does make you appreciate the sacrifice these people made
0:32:03 > 0:32:07and just how brutal the war that went off here was.
0:32:07 > 0:32:09You don't just have to contend with that,
0:32:09 > 0:32:12but you're contending with people trying to kill you.
0:32:22 > 0:32:25Back onshore, the team's footage has intrigued naval experts
0:32:25 > 0:32:28Randy Papadopoulos and Axel Niestle.
0:32:28 > 0:32:32Something unusual must have happened to this U-boat.
0:32:32 > 0:32:35- This is the control room periscope. - OK.
0:32:35 > 0:32:38- You can see it's been absolutely flattened...- Yes, yes.
0:32:38 > 0:32:40- ..against the...- Perforated. - But it must have been up
0:32:40 > 0:32:42to be torn off. It would be consistent
0:32:42 > 0:32:45with something driving across the top of the conning tower.
0:32:47 > 0:32:50- And here is the head of the snorkel. - Oh, yes.
0:32:50 > 0:32:52That's right, very distinctive. If the mast is up,
0:32:52 > 0:32:56it means the snorkel was being used to run the submarine's diesel
0:32:56 > 0:32:59engines while she was submerged beneath the surface of the ocean,
0:32:59 > 0:33:02and that means she was operating very shallow
0:33:02 > 0:33:06and was attempting to charge her batteries before going back
0:33:06 > 0:33:07deep and running on batteries alone.
0:33:07 > 0:33:11There was an area where one of the life-raft containers had been ripped off,
0:33:11 > 0:33:13there is a space and they're all missing.
0:33:13 > 0:33:18This is one thing we did not spot on the dive. There.
0:33:18 > 0:33:23- We nearly missed it.- That's the hatch.- And it's open.
0:33:23 > 0:33:25- It's open, yes.- It's open.
0:33:25 > 0:33:27This is not a normal situation,
0:33:27 > 0:33:31because this means it had been used as an emergency exit,
0:33:31 > 0:33:34and this is very interesting
0:33:34 > 0:33:38in explaining the situation which had befallen this boat.
0:33:38 > 0:33:40It is consistent with the boat being rammed
0:33:40 > 0:33:45and being evacuated at a later point of time.
0:33:45 > 0:33:49- Rammed while snorkelling, probably. - That's it.- Yeah.
0:33:49 > 0:33:52This evidence is critical in narrowing down which U-boat
0:33:52 > 0:33:54the team has found.
0:33:54 > 0:33:57And after crosschecking German archives with British
0:33:57 > 0:34:01and Canadian records, Axel and Randy arrive at one conclusion.
0:34:05 > 0:34:09The wreck is U-1003, a German submarine that came to a sudden
0:34:09 > 0:34:11and unexpected end.
0:34:15 > 0:34:16Well, after much deliberation
0:34:16 > 0:34:19and some pretty impressive detective work, you have now
0:34:19 > 0:34:24determined that the wreckage we saw there was that of U-1003 -
0:34:24 > 0:34:28a plan of it here, a classic Type 7 U-boat,
0:34:28 > 0:34:31- the backbone of the Wolfpack Fleet. - That's right.
0:34:31 > 0:34:37Here we have a photograph of the 1003 while on its first patrol.
0:34:37 > 0:34:40You can see the snorkel installation and all that,
0:34:40 > 0:34:43which makes up a late-war Type 7C.
0:34:45 > 0:34:48This made them very capable fighting machines
0:34:48 > 0:34:51and very dangerous to the Allied shipping.
0:34:51 > 0:34:53According to the survivor reports,
0:34:53 > 0:34:58this boat was scuttled about 60 miles north-west of Inishtrahull.
0:34:58 > 0:35:00She's snorkelling very close to the surface
0:35:00 > 0:35:04and is accidentally rammed by a Canadian escort vessel,
0:35:04 > 0:35:06it wrecks her snorkel and her periscopes,
0:35:06 > 0:35:10which makes it much harder for the U-boat to operate.
0:35:10 > 0:35:14The Allies realise, "Well, we've hit something, probably a U-boat,
0:35:14 > 0:35:17"we'd better start depth charging, in fact." And they do.
0:35:17 > 0:35:2014 escort ships rushed to the area,
0:35:20 > 0:35:25dropping depth charges on the injured sub, but U-1003 escapes.
0:35:25 > 0:35:26She hid on the seabed
0:35:26 > 0:35:30while her crew worked frantically to repair the damage.
0:35:30 > 0:35:34For the commanding officer, it was a fatal test of his nerve.
0:35:34 > 0:35:39The impact of the stress imposed on him, he obviously panicked.
0:35:39 > 0:35:41On the third day after the collision,
0:35:41 > 0:35:45under the constant threat of aerial attack,
0:35:45 > 0:35:47he decided to scuttle the boat,
0:35:47 > 0:35:50in order to save the crew, of course,
0:35:50 > 0:35:54but in the way he did it, he sealed the fate of the crew.
0:35:54 > 0:35:56He did it in the middle of the night,
0:35:56 > 0:36:00he did it under very adverse weather conditions,
0:36:00 > 0:36:03without proper preparation, so setting to the lifeboats
0:36:03 > 0:36:08in the night is not the ideal conditions for saving the crew.
0:36:08 > 0:36:12It's interesting, isn't it, when you look back at these pictures,
0:36:12 > 0:36:15you just have to wonder if any of them did survive?
0:36:15 > 0:36:20In the botched evacuation, 33 German crewmen died.
0:36:20 > 0:36:23The remaining 16 were rescued by an Allied corvette.
0:36:24 > 0:36:29But U-1003 sank beneath the waves, to be forgotten for 70 years.
0:36:35 > 0:36:38As the war against the U-boats intensified,
0:36:38 > 0:36:41so did the ranks of troops in Derry.
0:36:41 > 0:36:47There were 20,000 Royal Navy personnel and 10,000 Canadians.
0:36:47 > 0:36:51But most conspicuously of all, 5,000 Americans.
0:36:51 > 0:36:55What was the reaction of the locals in Derry to this influx?
0:36:55 > 0:36:57First of all, when they came,
0:36:57 > 0:36:59it was one of, "Where are these people from?"
0:36:59 > 0:37:03In fact, some local people actually thought they were women,
0:37:03 > 0:37:05because they were dressed so gaudily.
0:37:05 > 0:37:10And people here tended to dress in a rather staid and old-fashioned
0:37:10 > 0:37:15manner, so suddenly here was Hollywood on their doorsteps.
0:37:15 > 0:37:20The 36,000 troops stationed in Derry doubled the city's population
0:37:20 > 0:37:24and transformed daily life as they fitted in with the locals.
0:37:26 > 0:37:29They worked alongside them in the docks, some even had their
0:37:29 > 0:37:34lives saved in the area's hospitals and on occasion, they fell in love.
0:37:35 > 0:37:38Young Derry women couldn't wait to hit the town to meet
0:37:38 > 0:37:40the handsome foreigners.
0:37:41 > 0:37:44After you came out of the factory during the day, you went home
0:37:44 > 0:37:49and you got yourself all dressed up as best you could,
0:37:49 > 0:37:53California poppy and a fist of powder and lipstick and away you went.
0:37:55 > 0:37:57Derry's dancehalls were the place to head.
0:37:57 > 0:38:00They were full of American sailors, unwinding after
0:38:00 > 0:38:03the stress of crossing the Atlantic and looking for fun.
0:38:05 > 0:38:08You never were a wallflower, you'd always get up and dance,
0:38:08 > 0:38:11even if they couldn't put one foot past the other!
0:38:12 > 0:38:16Local women may have enjoyed dancing with the Yanks, but Derry's
0:38:16 > 0:38:20menfolk found it hard to compete with the Americans' fancy footwork.
0:38:20 > 0:38:24The Americans had their own method of dancing, you know,
0:38:24 > 0:38:27jazz and all this sort of thing.
0:38:27 > 0:38:31And the girls around here seemed to fall for that.
0:38:31 > 0:38:34There was two ways to get to our street,
0:38:34 > 0:38:36and I remember one night,
0:38:36 > 0:38:39I had one at one end of the street and one away down the other end
0:38:39 > 0:38:42of the street, I went to see which was the best looking!
0:38:44 > 0:38:46The Americans took the girl away from you!
0:38:49 > 0:38:53They were great, big, burly fellas with big boots,
0:38:53 > 0:38:56and we were quite excited, really.
0:38:56 > 0:38:58I remember my mum saying,
0:38:58 > 0:39:01"Well, thank goodness Maureen's not old enough to get herself
0:39:01 > 0:39:04"involved with any of these young men!"
0:39:04 > 0:39:07But little did she know!
0:39:07 > 0:39:10The war lasted long enough that I did get involved.
0:39:10 > 0:39:13Can you remember getting that picture taken, honey?
0:39:14 > 0:39:17For Maureen Archibald and Robert Mathis, Derry's role
0:39:17 > 0:39:21in the Battle of the Atlantic was a happy twist of fate -
0:39:21 > 0:39:24one that eventually led to pictures of Maureen being
0:39:24 > 0:39:26printed in newspapers across America.
0:39:28 > 0:39:33Through my job, I met Bob's commanding officer
0:39:33 > 0:39:36and he said to me, "I have a young fellow in my outfit that
0:39:36 > 0:39:41"would like to meet you," so eventually we did get together.
0:39:41 > 0:39:46So, he's not one to go to dances, but I got him out on the floor
0:39:46 > 0:39:49and he didn't do too badly at all, he wasn't too bad.
0:39:49 > 0:39:52He thought he was terrible, but I thought he was pretty good.
0:39:52 > 0:39:56And Maureen was convinced by more than just his dancing.
0:39:56 > 0:39:59Within a year, she agreed to marry him.
0:39:59 > 0:40:03Word of an American falling for a local girl set tongues wagging
0:40:03 > 0:40:07and crowds turned out for her big day.
0:40:07 > 0:40:09I just couldn't believe it.
0:40:09 > 0:40:13It was packed with people who I didn't even know,
0:40:13 > 0:40:17but they had heard there was going to be an American wedding,
0:40:17 > 0:40:19so they all came to the Cathedral that day.
0:40:19 > 0:40:23"A charming wedding was solemnised in Derry Cathedral
0:40:23 > 0:40:27"on Thursday morning, when Miss Maureen Archibald became
0:40:27 > 0:40:32"the wife of Petty Officer Robert Lawrence Mathis, United States Navy."
0:40:33 > 0:40:38Maureen and Bob's wedding made a big splash, and that was just the start.
0:40:38 > 0:40:42When Bob was posted back to the States and Maureen packed
0:40:42 > 0:40:45her bags to go with him, the flurry of headlines continued,
0:40:45 > 0:40:47this time, on both sides of the Atlantic.
0:40:50 > 0:40:52"Bride ship leaves Derry for the US.
0:40:52 > 0:40:56"65 young women bound for the various parts of the United States..."
0:40:56 > 0:40:58When you think of it,
0:40:58 > 0:41:0416 hours' advance notice to get ready to leave your family!
0:41:06 > 0:41:09I didn't realise it at the time, but they came and asked me
0:41:09 > 0:41:14if I would be the one to go off the ship first.
0:41:14 > 0:41:19And I didn't realise what I was up against until I got off the ship.
0:41:19 > 0:41:24Because I actually was, supposedly, and I think I really was,
0:41:24 > 0:41:28the first GI bride to set foot in America.
0:41:28 > 0:41:30Maureen and Bob left New York for his mum's house
0:41:30 > 0:41:33in South Bend, Indiana, but wherever they went,
0:41:33 > 0:41:38America's first GI bride couldn't escape her newfound celebrity.
0:41:38 > 0:41:43All these American women reporters were waiting for me.
0:41:43 > 0:41:46"City's first war bride arrives, smiling."
0:41:46 > 0:41:49They were really throwing questions at me.
0:41:49 > 0:41:55There was a lot of animosity, I would say, from the American girls,
0:41:55 > 0:41:57for stealing their men!
0:42:00 > 0:42:03Throughout the course of the war in Northern Ireland,
0:42:03 > 0:42:071,500 other women stole the hearts of American military men
0:42:07 > 0:42:09and joined their new husbands in the US.
0:42:10 > 0:42:13But it was Maureen who blazed the trail to America,
0:42:13 > 0:42:16where she was known as the first GI bride.
0:42:25 > 0:42:28The dive team's next expedition is to the wreck of a notorious
0:42:28 > 0:42:32German submarine, one that stalked the entire Atlantic,
0:42:32 > 0:42:36but brought tragedy to one family right here in Northern Ireland.
0:42:38 > 0:42:41It's difficult to get lost on a submarine, I think.
0:42:41 > 0:42:43But it's good to have a starting point.
0:42:43 > 0:42:45If we kind of cross over, so we're not in each other's way.
0:42:45 > 0:42:48The hull probably is going to be lying on its side.
0:42:48 > 0:42:52So we'll just wait and see, it's going to be complete pot luck.
0:42:52 > 0:42:54Skipper Michael is bringing them
0:42:54 > 0:42:5710 miles offshore to the location of the wreck.
0:42:57 > 0:43:00But the currents right now are so strong that making
0:43:00 > 0:43:03the dive will be a challenge.
0:43:03 > 0:43:04The tide is going at about 0.6 knots,
0:43:04 > 0:43:08which makes it hard for the divers with all the stuff they carry,
0:43:08 > 0:43:10they can't really swim more than half a knot.
0:43:10 > 0:43:13For Rich, the strong tides mean timing
0:43:13 > 0:43:17when the divers get in the water is critical.
0:43:17 > 0:43:19We don't want to take unnecessary risks and of course,
0:43:19 > 0:43:21if something goes wrong
0:43:21 > 0:43:24and you've got current compounding that, it can go doubly wrong.
0:43:24 > 0:43:28As soon as the tide slows, Michael grabs his opportunity
0:43:28 > 0:43:30and drops a grapple down to the wreck.
0:43:30 > 0:43:34OK, go ahead. OK, guys.
0:43:36 > 0:43:39And the dive team waste no time in dropping over the side.
0:43:47 > 0:43:51190 feet beneath the surface, there is little light reaching the seabed.
0:43:53 > 0:43:56But the team can make out the wreck of a U-boat.
0:43:56 > 0:43:59In the darkness, Ian manages to take measurements.
0:44:01 > 0:44:05At 24 feet wide and 245 feet long,
0:44:05 > 0:44:08they have found an enormous submarine.
0:44:11 > 0:44:15The team see the telltale shape of the conning tower,
0:44:15 > 0:44:16and its periscope.
0:44:18 > 0:44:21And on the starboard side, they find the snorkel assembly.
0:44:21 > 0:44:24On early model U-boats, once submerged,
0:44:24 > 0:44:27the air supply to the diesel engines was cut off
0:44:27 > 0:44:31and the sub relied instead on slow, battery-powered motors.
0:44:31 > 0:44:35A snorkel was an extendable air intake which allowed the sub
0:44:35 > 0:44:37to use its diesel engine underwater.
0:44:39 > 0:44:42It meant the U-boat could travel faster and with greater stealth.
0:44:45 > 0:44:49A typical U-boat launched torpedoes through tubes in the bow.
0:44:49 > 0:44:53But this wreck has two additional torpedo tubes at the stern.
0:44:53 > 0:44:57This distinctive feature will help identify the submarine.
0:45:05 > 0:45:08Ian carefully guides our two experts through the footage.
0:45:08 > 0:45:10The snorkel, rear torpedo tubes
0:45:10 > 0:45:14and positioning of the periscope mean only one thing.
0:45:14 > 0:45:17All of these suggest a Type 9 U-boat.
0:45:19 > 0:45:21The Type 9s were key to the German Kriegsmarine.
0:45:21 > 0:45:24Over 150 saw active duty.
0:45:25 > 0:45:27But after studying naval records,
0:45:27 > 0:45:31Axel and Randy have narrowed down the possibilities to just one.
0:45:33 > 0:45:39It is another success for the team. They have identified U-155.
0:45:40 > 0:45:44She was a notorious submarine that dealt a tragic blow to one
0:45:44 > 0:45:46family here in Northern Ireland.
0:45:46 > 0:45:49This was one of the real workhorses of the U-boat flotilla,
0:45:49 > 0:45:55and 155 has a very long, and productive, one would say, career.
0:45:58 > 0:46:00U-155 was a devastating opponent.
0:46:00 > 0:46:03Huge diesel tanks gave it enough range to cross the Atlantic
0:46:03 > 0:46:06four times non-stop.
0:46:10 > 0:46:14Meanwhile, its snorkel allowed it to remain submerged for hours on end.
0:46:16 > 0:46:18If you think of a Type 9 U-boat,
0:46:18 > 0:46:20it's built for long-range operations.
0:46:20 > 0:46:24The boats had usually to stay submerged for up to 20 hours
0:46:24 > 0:46:27a day, only surfacing at night to recharge the batteries.
0:46:30 > 0:46:32The crew of U-155 made the most
0:46:32 > 0:46:36of their boat's range, stealth and weaponry.
0:46:36 > 0:46:40From its base in France, it crossed the entire Atlantic,
0:46:40 > 0:46:44using its snorkel to stay submerged nearly the entire time.
0:46:44 > 0:46:47This submarine made it, undetected, all the way to Florida.
0:46:48 > 0:46:51Imagine a U-boat built in Germany, based in France,
0:46:51 > 0:46:53able to operate in the Florida Strait,
0:46:53 > 0:46:57just 40 miles off the coast of southern Florida, that's very,
0:46:57 > 0:47:02very close indeed to the US coast at that time, and really very
0:47:02 > 0:47:05startling, of course, to the American defenders of the area.
0:47:07 > 0:47:14In April 1943, just 40 miles from Key West, U-155 sank two giant
0:47:14 > 0:47:18tankers, bringing the Battle of the Atlantic into America's backyard.
0:47:19 > 0:47:23This deadly sub was one of the Germans' 10 most effective U-boats.
0:47:24 > 0:47:27Throughout its career, it lost only five crew
0:47:27 > 0:47:30and inflicted terrible losses on the Allies.
0:47:32 > 0:47:3726 ships had been sunk and over 900 lives lost at sea.
0:47:37 > 0:47:41Amongst them was that of a naval officer from Ulster.
0:47:41 > 0:47:43He left behind a young widow and a family.
0:47:48 > 0:47:52David Brew had not yet been born when war broke out
0:47:52 > 0:47:54and his father joined the Navy.
0:47:56 > 0:48:00In 1939, he joined the Royal Naval Volunteer Reserve
0:48:00 > 0:48:05and married my mum, and that year, we have a wedding photograph.
0:48:07 > 0:48:11We then have him on HMS Dunvegan Castle,
0:48:11 > 0:48:17with some of his officer colleagues, these are dated 1940.
0:48:20 > 0:48:23David never got to know his father.
0:48:23 > 0:48:25But today, he has a precious keepsake.
0:48:25 > 0:48:29A postcard sent to him by his dad when he was just nine months old.
0:48:32 > 0:48:36In March 1942,
0:48:36 > 0:48:41he posted this postcard
0:48:41 > 0:48:45from New York. It's addressed
0:48:45 > 0:48:49to me, but obviously,
0:48:49 > 0:48:52it's directed at my mum.
0:48:52 > 0:48:55But it says, "Dear David,
0:48:55 > 0:48:59"how would you like to come and live here with me
0:48:59 > 0:49:01"and bring your mother with you?
0:49:03 > 0:49:07"Hope you are being a good boy and taking care of your ma. Daddy."
0:49:11 > 0:49:16It must have been written with some longing, er...
0:49:16 > 0:49:20to be home and to be safe with his family.
0:49:28 > 0:49:31In New York, John Brew joined the crew
0:49:31 > 0:49:34of the aircraft carrier HMS Avenger.
0:49:34 > 0:49:38In the early hours of the morning, HMS Avenger passed through
0:49:38 > 0:49:41the Straits of Gibraltar on her way to Glasgow.
0:49:41 > 0:49:44On board, John Brew would have been looking forward to what
0:49:44 > 0:49:47he hoped would be an uneventful and speedy passage home.
0:49:47 > 0:49:51But they weren't alone. Hidden deep beneath the waves,
0:49:51 > 0:49:56the captain of U-155 already had the convoy in his sights.
0:50:03 > 0:50:08The U-boat ace in command of U-155 was Adolf Cornelius Piening.
0:50:08 > 0:50:11We have an extract from his war diary here,
0:50:11 > 0:50:15which gives a narrative of the actions taken by him.
0:50:15 > 0:50:19When he first spotted the convoy, it was at a distance of five miles.
0:50:19 > 0:50:22So then he closed in, in order to attack.
0:50:22 > 0:50:25And then he fired a total of six torpedoes
0:50:25 > 0:50:29at the targets on the rise.
0:50:31 > 0:50:33Piening's aim was deadly.
0:50:33 > 0:50:37He hit three ships, one torpedo igniting the Avenger's bomb store.
0:50:39 > 0:50:44The massive explosion tore the 9,000-tonne aircraft carrier in two.
0:50:44 > 0:50:48It sank in less than two minutes. Over 500 men were killed.
0:50:48 > 0:50:50One was David's father, John.
0:50:52 > 0:50:55This is the telegram my mum received.
0:50:55 > 0:51:02"Deeply regret to inform you that your husband, John Sydney Brew RNVR,
0:51:02 > 0:51:09"has been reported missing, presumed killed, on war service, stop.
0:51:09 > 0:51:15"Letter follows." That's, um, that's the deadly...the deadly message.
0:51:19 > 0:51:22Many, many more such telegrams were sent out
0:51:22 > 0:51:24to devastated families of Atlantic crewmen.
0:51:24 > 0:51:28The battle claimed the lives of 70,000 Allied sailors
0:51:28 > 0:51:30just like John Sydney Brew.
0:51:35 > 0:51:39As the intensity of the battle grew, so did Derry's involvement.
0:51:39 > 0:51:44By 1941, the city's docks were the cornerstone of the Allied defence,
0:51:44 > 0:51:47with 50 escort ships based on the Foyle.
0:51:50 > 0:51:54The city was now a clear target for Hitler's Luftwaffe.
0:51:57 > 0:52:00I don't know what time of night it was, I had gone to bed.
0:52:01 > 0:52:05And then I suddenly heard the siren going.
0:52:06 > 0:52:09We were so used to it, we didn't pay any attention to it,
0:52:09 > 0:52:12until we heard the drone of the aeroplane.
0:52:12 > 0:52:16We were very familiar with the drone of British aeroplanes,
0:52:16 > 0:52:17but I recognised this one was different.
0:52:17 > 0:52:21German bombers were now in the skies over Derry.
0:52:21 > 0:52:24After months of drills and false alarms,
0:52:24 > 0:52:28volunteers rushed to man the defences for real.
0:52:29 > 0:52:34I was about 15 or 16 years of age at the time, and I had joined
0:52:34 > 0:52:39the air raid precautions, and I ran down Dunfield to get to the post.
0:52:39 > 0:52:42I seemed to be on my own, I don't remember anybody there,
0:52:42 > 0:52:46but by that, the anti-aircraft guns on Corrody Hill,
0:52:46 > 0:52:49the high ground across the river here, they opened up.
0:52:51 > 0:52:55Suddenly, there were two terrible explosions.
0:52:55 > 0:52:57And a blue light flashed through the room.
0:53:00 > 0:53:02The ceilings all came down, the windows came in,
0:53:02 > 0:53:04everything was in darkness,
0:53:04 > 0:53:07I followed my mother downstairs, it was all broken glass,
0:53:07 > 0:53:12I was screaming, I remember that, I went down to the living room,
0:53:12 > 0:53:16there was no windows left, what was there was all twisted and turned.
0:53:16 > 0:53:21I was just sat there and everything was so quiet, very, very quiet.
0:53:23 > 0:53:26The German mines had fallen directly on Messines Park,
0:53:26 > 0:53:29a residential street to the north-east of the city,
0:53:29 > 0:53:32where the houses were full of frightened families.
0:53:32 > 0:53:34The rescue crews scrambled into action.
0:53:37 > 0:53:39When we heard the bombing,
0:53:39 > 0:53:42then we rushed in our ambulance
0:53:42 > 0:53:45down to the area
0:53:45 > 0:53:49and found that the house was pretty well wrecked.
0:53:49 > 0:53:52A horrific scene awaited them.
0:53:52 > 0:53:55An entire street corner had been destroyed.
0:53:55 > 0:53:57That was quite a sight.
0:53:57 > 0:54:01Arms and legs sticking out of the rubble.
0:54:01 > 0:54:03A girl was blown out of her own bed
0:54:03 > 0:54:06and had arrived in a field in front of her house.
0:54:06 > 0:54:10In the hospitals, nurses were waiting to receive the wounded.
0:54:10 > 0:54:16You certainly got your eyes opened, you know, as to what a bomb could do.
0:54:16 > 0:54:22I remember this poor woman with all the holes in her.
0:54:22 > 0:54:24I didn't expect that.
0:54:24 > 0:54:26But it must have been shrapnel.
0:54:28 > 0:54:35Oh, it was an awful time for the locals around Messines Park.
0:54:45 > 0:54:49The German bombs tore through six houses, completely destroying them.
0:54:49 > 0:54:52It was an unexpected attack in the middle of the night
0:54:52 > 0:54:56and it caught families completely unaware in their beds.
0:54:56 > 0:54:5914 people on that one street corner were killed.
0:55:04 > 0:55:07Many believe the German bomber was lost and that it dropped
0:55:07 > 0:55:10its load, believing it was over Belfast or Liverpool.
0:55:13 > 0:55:15But historian Richard Doherty
0:55:15 > 0:55:18has uncovered evidence to prove otherwise.
0:55:18 > 0:55:2515th April 1941, a lone bomber drops its payload over the city.
0:55:25 > 0:55:27Some people have regarded that as a rogue,
0:55:27 > 0:55:31as a mistake on the part of the Germans. But you are not so sure?
0:55:31 > 0:55:35There is a myth that the raid was by a bomber that lost its way.
0:55:35 > 0:55:40It wasn't, it was clearly targeted. This was a planned attack.
0:55:40 > 0:55:43Richard has discovered German reconnaissance photographs,
0:55:43 > 0:55:45taken high above the city.
0:55:46 > 0:55:50On them are clearly marked the city's strategic targets.
0:55:51 > 0:55:54It shows us the shipyard at Pennyburn,
0:55:54 > 0:55:58it shows us barrage balloons, anti-aircraft guns,
0:55:58 > 0:56:04the flak site out here, for example, anti-aircraft site at Corrody Hill.
0:56:04 > 0:56:07It shows Ebrington Barracks quite clearly,
0:56:07 > 0:56:09the bridge, it marks the railway stations
0:56:09 > 0:56:11and the railway goods yards.
0:56:11 > 0:56:15Literally everything that is of military value is marked.
0:56:15 > 0:56:20They didn't send reconnaissance aircraft over for nothing.
0:56:20 > 0:56:23So, there was a clear target in mind that night?
0:56:23 > 0:56:28The clear target was the Navy dockyard at Pennyburn,
0:56:28 > 0:56:30which is marked here as number eight by the Germans.
0:56:32 > 0:56:35Despite the extensive German reconnaissance from the skies
0:56:35 > 0:56:38over Derry, on the night of the actual attack,
0:56:38 > 0:56:41their bomber made a fateful miscalculation.
0:56:41 > 0:56:43They were aiming for the dockyard.
0:56:43 > 0:56:47They were aiming for the dockyard here, but the mines actually
0:56:47 > 0:56:51landed, the one which caused most destruction, here at Messines Park.
0:56:51 > 0:56:55The bombs that they dropped were not actually bombs, they were mines.
0:56:55 > 0:56:59They were intended to explode in the air above the ground,
0:56:59 > 0:57:03blast downwards and flatten it. And we saw the horrible effects
0:57:03 > 0:57:05of those on the houses of Messines Park.
0:57:07 > 0:57:11The cost of that German mistake can be counted in Derry City Cemetery.
0:57:11 > 0:57:1514 dead men, women and children,
0:57:15 > 0:57:18killed as they slept in their beds at night.
0:57:18 > 0:57:21Their names are a tragic reminder of the price Derry paid
0:57:21 > 0:57:25for joining the fight against the U-boat.
0:57:25 > 0:57:28But it was a fight that had to be won.
0:57:28 > 0:57:30Throughout 1941, Britain's war effort was
0:57:30 > 0:57:35still in peril as German submarines continued to hammer Allied shipping.
0:57:37 > 0:57:39The U-boats seemed unstoppable.
0:57:39 > 0:57:42An Allied victory in the Battle of the Atlantic was
0:57:42 > 0:57:47far from certain, but the Allies had one more trick up their sleeves,
0:57:47 > 0:57:51one that would turn the entire tide of the campaign in their favour.
0:57:53 > 0:57:56Next time, Derry helps the Allies to victory
0:57:56 > 0:57:58by helping them into the air...
0:57:58 > 0:58:01Basically, the U-boats daren't operate on the surface any more.
0:58:01 > 0:58:06..and the children of heroes relive their parents' bravery...
0:58:06 > 0:58:10- Down a bit. Up a bit. - Dangerous job, that is!
0:58:10 > 0:58:12Mum must have been nervous and anxious about him
0:58:12 > 0:58:13all the time he was away.
0:58:13 > 0:58:18..while the dive team set out to find Hitler's deadliest U-boat.
0:58:18 > 0:58:22You see just how deep and how big the hull of the submarine is,
0:58:22 > 0:58:25I mean, it's amazing to see. It's just something else.
0:58:44 > 0:58:47Subtitles by Red Bee Media Ltd