0:00:04 > 0:00:07It is an iconic structure and every other bridge fades into
0:00:07 > 0:00:11a little bit of insignificance compared to the size of it.
0:00:11 > 0:00:14MUSIC: It's A Sign Of The Times by Petula Clark
0:00:17 > 0:00:19They wanted to show that we were the best in the world.
0:00:19 > 0:00:22It is really like a pencil line on the horizon.
0:00:22 > 0:00:24It was far ahead of its time.
0:00:24 > 0:00:26# You've changed a lot somehow
0:00:26 > 0:00:29# From the one I used to know... #
0:00:29 > 0:00:32It was magical. I don't think I'd ever been into Bristol
0:00:32 > 0:00:35until after the Severn Bridge did open.
0:00:35 > 0:00:39# And a year ago, I never could have seen it... #
0:00:39 > 0:00:42Back in the day, that was a massive feat of engineering,
0:00:42 > 0:00:44that was a huge deal.
0:00:46 > 0:00:49# Just leave the past behind
0:00:49 > 0:00:52# And maybe only think of how it is today... #
0:00:52 > 0:00:55The Severn influenced almost everything long-span
0:00:55 > 0:00:57that has happened since,
0:00:57 > 0:01:01so the Severn Bridge is remarkable.
0:01:01 > 0:01:03I don't say "was", it IS remarkable.
0:01:03 > 0:01:07# It's a sign of the times
0:01:07 > 0:01:10# It's a sign of the times... #
0:01:10 > 0:01:13Hi, Luke, it's James, the team manager at South West RCC.
0:01:13 > 0:01:18A south-westerly gale buffets the 50-year-old Severn Bridge.
0:01:18 > 0:01:22We're seeing gusts now of about 48mph for the M48 bridge.
0:01:22 > 0:01:24So we just wanted an updated forecast.
0:01:24 > 0:01:26That's great, OK, thank you for that.
0:01:26 > 0:01:30Yep, Dan, can we deploy the crews for the filtering?
0:01:30 > 0:01:33At present, the wind speeds have got up above 46mph.
0:01:33 > 0:01:36That's the point at which we filter high-sided vehicles
0:01:36 > 0:01:39and motorcycles off of the motorway
0:01:39 > 0:01:41as they're highly likely to get blown over.
0:01:41 > 0:01:43If the winds happen to get up to 69mph,
0:01:43 > 0:01:45then we'll close it completely.
0:01:54 > 0:01:56He left that one right till the last second.
0:01:56 > 0:01:57We'll keep an eye on that.
0:01:57 > 0:02:01If that stays up at that kind of speeds for the next 10-15 minutes,
0:02:01 > 0:02:05- then we'll probably need to close it.- Yep.
0:02:05 > 0:02:07It's perhaps only when it's closed
0:02:07 > 0:02:10that we fully appreciate the Severn Bridge.
0:02:10 > 0:02:13Winter gales apart, we zip over in minutes,
0:02:13 > 0:02:16giving little thought to the slender span we're traversing,
0:02:16 > 0:02:18or to how it was built or who maintains it.
0:02:19 > 0:02:21Before 1966, though,
0:02:21 > 0:02:25just as drivers are experiencing this stormy morning,
0:02:25 > 0:02:28crossing between England and Wales was far from plain sailing.
0:02:31 > 0:02:36The world may have been changing - Yuri Gagarin had orbited the Earth,
0:02:36 > 0:02:40but closer to home, the frontier between Beachley near Chepstow
0:02:40 > 0:02:44and Aust on the Bristol side was still a little ferry.
0:02:46 > 0:02:50This film hasn't been shown in public for many years.
0:02:50 > 0:02:53Very choppy. I'm glad I wasn't on board that day.
0:02:56 > 0:03:00Before the bridge, to go to Bristol was really unheard of, wasn't it?
0:03:00 > 0:03:02Because it just seemed so far away.
0:03:02 > 0:03:04- It was out of bounds, really. - It was.
0:03:04 > 0:03:10Going over to Aust was, you know, our overseas holiday!
0:03:10 > 0:03:15Of course, the ferry could only run when the tides were suitable
0:03:15 > 0:03:20at Aust and at Beachley, so a ferry timetable was very important
0:03:20 > 0:03:23when you were planning your trips over.
0:03:23 > 0:03:25Everybody remembers these ferries.
0:03:25 > 0:03:28In the last full year of service, 1965,
0:03:28 > 0:03:31over half a million cars used those ferries.
0:03:31 > 0:03:35They were a vital link between the southwest and South Wales.
0:03:35 > 0:03:37The queue could go two, three miles away,
0:03:37 > 0:03:39so they were really, really long queues.
0:03:41 > 0:03:43This is where the queues for the ferry used to come,
0:03:43 > 0:03:45all the way along here, do you remember?
0:03:45 > 0:03:47- Oh.- Right the way in front of us.
0:03:47 > 0:03:51Before we went on holiday, Mike would take the car
0:03:51 > 0:03:53with all the cases in and leave it
0:03:53 > 0:03:56so we'd be first or second in the queue.
0:03:56 > 0:03:59- That's what most of the locals actually did, wasn't it?- Yep.
0:03:59 > 0:04:03The non-locals would be stuck at the back.
0:04:03 > 0:04:05This one, the Severn Princess, was the biggest.
0:04:05 > 0:04:08Fully loaded she could carry 19 vehicles,
0:04:08 > 0:04:12but to get 19 cars on, they had to park them so close together,
0:04:12 > 0:04:14you couldn't open the car doors.
0:04:14 > 0:04:17So they're sailing on the most dangerous river in Britain,
0:04:17 > 0:04:20full of cars full of people who couldn't get out.
0:04:20 > 0:04:25My grandfather was the founder of the ferry here at Beachley.
0:04:25 > 0:04:31We used to come down here after school and I had the unenviable job
0:04:31 > 0:04:35of counting the cars and after so many,
0:04:35 > 0:04:39taking a sign to say this will be the last car tonight
0:04:39 > 0:04:42and the look on the fellow's face behind
0:04:42 > 0:04:46who now faced the daunting task of having to go around Gloucester,
0:04:46 > 0:04:48it was... Yeah, it wasn't a pleasant job.
0:04:48 > 0:04:50There's much, much more traffic on the road,
0:04:50 > 0:04:52therefore more demand for the ferries,
0:04:52 > 0:04:56therefore the bridge was inevitable, to be honest.
0:04:56 > 0:04:58Overshadowed by the bridge, look at that.
0:05:04 > 0:05:06This morning, with the help of my colleagues,
0:05:06 > 0:05:09we're going to build a replica of the Severn crossing with you.
0:05:09 > 0:05:13The planned new crossing wasn't going to be just any old bridge.
0:05:13 > 0:05:17So this is Trish, John,
0:05:17 > 0:05:18and my name is Paul.
0:05:18 > 0:05:22I think the engineers and architects wanted to make a statement.
0:05:22 > 0:05:24So one team's going to build from the one side
0:05:24 > 0:05:26and the other team's going to build from the other
0:05:26 > 0:05:29and we'll meet in the middle when we've finished, OK?
0:05:29 > 0:05:32'In those days, they just didn't build something functional -
0:05:32 > 0:05:35'they wanted to show that we were the best in the world.'
0:05:35 > 0:05:38- OK.- Right, nice and gentle.
0:05:38 > 0:05:41'Certain things like the inclined suspenders
0:05:41 > 0:05:44'and this aerodynamically designed deck box,
0:05:44 > 0:05:46'they were pretty cutting-edge.'
0:05:46 > 0:05:49The human instinct to build starts young.
0:05:50 > 0:05:53Taking a hands-on role in the Severn Bridge's design
0:05:53 > 0:05:55was one youthful civil engineer
0:05:55 > 0:05:58fresh out of Bristol University.
0:05:58 > 0:06:00I was in charge -
0:06:00 > 0:06:03it's a job to imagine nowadays -
0:06:03 > 0:06:08but I was in charge of writing the specification for the Severn Bridge
0:06:08 > 0:06:10and I was the only one working on it.
0:06:10 > 0:06:13The basic engineering tool was a slide rule.
0:06:14 > 0:06:17I spent two years
0:06:17 > 0:06:18doing hand calculations.
0:06:18 > 0:06:23It will have two carriageways, two dual carriageways...
0:06:23 > 0:06:25At just under a mile,
0:06:25 > 0:06:30the proposed Severn Bridge was the longest yet designed in the UK.
0:06:30 > 0:06:35So I knew the span and I knew it was going to be a suspension bridge.
0:06:35 > 0:06:39The first port of call was American technology.
0:06:39 > 0:06:42Mike's instinct was to copy specifications
0:06:42 > 0:06:44from New York's George Washington Bridge.
0:06:44 > 0:06:48The Severn Bridge's cable is a similar design.
0:06:48 > 0:06:50However, American concrete road decks
0:06:50 > 0:06:54resting on weighty girders are expensive to construct
0:06:54 > 0:06:57and Mike was asked to look for economies.
0:06:57 > 0:07:01The ultimate objective is to make something which is lighter
0:07:01 > 0:07:03and ultimately cheaper.
0:07:04 > 0:07:06To me, as an engineer,
0:07:06 > 0:07:09being as economical as possible
0:07:09 > 0:07:12with men and materials
0:07:12 > 0:07:14is what it's all about.
0:07:14 > 0:07:18With resources still scarce in post-war Britain,
0:07:18 > 0:07:21and economic necessity being the mother of invention,
0:07:21 > 0:07:26Mike proposed a lightweight, internally stiffened steel road deck
0:07:26 > 0:07:28and as the design was tested,
0:07:28 > 0:07:31so its shape evolved to offer less wind resistance too.
0:07:34 > 0:07:38The huge leap was the fact that it was aerodynamic.
0:07:38 > 0:07:41This was a huge innovation,
0:07:41 > 0:07:45because it was going to be the first of its kind in the world
0:07:45 > 0:07:47and it wasn't just that it was a small one -
0:07:47 > 0:07:49it was a very big bridge.
0:07:49 > 0:07:52Look at that, isn't that beautiful?
0:07:52 > 0:07:56Back in the '60s, John Evans and Jerry Gurney were junior engineers.
0:07:56 > 0:08:00And the view from here emphasises the beauty
0:08:00 > 0:08:02of the suspended structure,
0:08:02 > 0:08:07which is a shallow box deck, more slender, less wind resistance,
0:08:07 > 0:08:09the cables are lighter,
0:08:09 > 0:08:10the towers are lighter,
0:08:10 > 0:08:13the anchorage is lighter, so it's a big benefit.
0:08:13 > 0:08:17It really was a triumph of British engineering
0:08:17 > 0:08:21and everyone is now saying, "We can build bridges like the Brits."
0:08:29 > 0:08:32It was a bridge looking to the future,
0:08:32 > 0:08:34but, typical of the times,
0:08:34 > 0:08:37future traffic levels were woefully underestimated,
0:08:37 > 0:08:40as was the need to actually maintain it.
0:08:43 > 0:08:47Everybody had this idea that steel was good stuff
0:08:47 > 0:08:49and it would last forever.
0:08:49 > 0:08:54But, of course, the structures carry transient loads all the time.
0:08:56 > 0:08:59I think very soon after the bridge was opened, people realised
0:08:59 > 0:09:03that there were maintenance issues that were inherent in the design.
0:09:03 > 0:09:06You tended to hand a bridge over
0:09:06 > 0:09:11and it was deemed that it would carry on more or less forever.
0:09:11 > 0:09:13So quite quickly, things were wearing out,
0:09:13 > 0:09:16which they didn't anticipate in such a new design.
0:09:16 > 0:09:22To put it in context, by the 1970s,
0:09:22 > 0:09:25there were actually pieces dropping off the Golden Gate Bridge
0:09:25 > 0:09:30in America, so maintenance of long-span bridges is
0:09:30 > 0:09:33a very big part of the industry at the moment.
0:09:35 > 0:09:38This crucial need is undertaken by a specialist in-house team.
0:09:41 > 0:09:43We have to inspect this structure,
0:09:43 > 0:09:47so it's not something you can do in a day
0:09:47 > 0:09:50and therefore that's why we've got a team of 30 people,
0:09:50 > 0:09:53inspectors and guys who will actually maintain the bridge
0:09:53 > 0:09:55and keep it going on an ongoing basis.
0:09:56 > 0:09:59Day-to-day inspections involve going out
0:09:59 > 0:10:02and inspecting specific components of the bridge,
0:10:02 > 0:10:05checking for cracks, corrosion,
0:10:05 > 0:10:09paint loss, or anything that might affect the function of the bridge
0:10:09 > 0:10:12and obviously we've got more critical inspections
0:10:12 > 0:10:14that are set at other frequencies.
0:10:15 > 0:10:18But it's not just the outside that needs regular check-ups.
0:10:18 > 0:10:22One such critical inspection is of the steel stiffness
0:10:22 > 0:10:24inside the bridge's revolutionary deck.
0:10:26 > 0:10:31Traffic loadings have quadrupled and loadings have ballooned.
0:10:31 > 0:10:35Back in 1966, the heaviest lorries weighed 20 tonnes.
0:10:35 > 0:10:39Now, the slimline deck boxes are shouldering 44-tonners.
0:10:41 > 0:10:46Inspector Adrian Friendship checks the wells beneath the carriageways.
0:10:46 > 0:10:49There's over 60 miles of them to inspect.
0:10:49 > 0:10:53OK, what I'm carrying out today is an annual inspection.
0:10:53 > 0:10:56What you can probably hear above my head
0:10:56 > 0:11:01is the sound of traffic, cos the deck plate is only 12mm thick.
0:11:03 > 0:11:06I'm checking for any rusty lines which are an indication
0:11:06 > 0:11:09that the well has cracked.
0:11:09 > 0:11:11Now, this is just one bay.
0:11:11 > 0:11:15Throughout this bridge, there's over 400 of these bays to inspect.
0:11:15 > 0:11:17It's mainly a local workforce.
0:11:17 > 0:11:21They've grown up around it, worked on it a long time.
0:11:21 > 0:11:23It's just part of their lives in a certain way, you know?
0:11:23 > 0:11:26When people generally come working here,
0:11:26 > 0:11:28the majority generally stay.
0:11:28 > 0:11:31The guys who work here are from both sides of the bridge,
0:11:31 > 0:11:33it's probably a 50/50.
0:11:33 > 0:11:36The Welsh ones are obviously a bit better than the English ones, but...
0:11:36 > 0:11:39I think there's slightly more on the Welsh side,
0:11:39 > 0:11:42so we are a minority here.
0:11:42 > 0:11:46I've been here for 34 years and I'm not the senior guy
0:11:46 > 0:11:50in terms of service by any stretch of imagination.
0:11:50 > 0:11:52I've been here 18 months,
0:11:52 > 0:11:56so I am very much the new girl.
0:11:56 > 0:11:58I came here as a student.
0:11:58 > 0:11:59I had a year out and I spent a year
0:11:59 > 0:12:02with the consultants on the bridge at the time
0:12:02 > 0:12:04and it was nice to come sort of like a full circle
0:12:04 > 0:12:09from being a student and coming back here 25 or so years later
0:12:09 > 0:12:12and some of the people still remember me as a student,
0:12:12 > 0:12:13which is a bit scary!
0:12:16 > 0:12:19Old-timers and newcomers alike,
0:12:19 > 0:12:22there are many challenges for the team to overcome.
0:12:22 > 0:12:25The challenges - the main one is the access.
0:12:25 > 0:12:27We're a bridge, therefore we're above water,
0:12:27 > 0:12:30so everything we do, we have to be mindful of that,
0:12:30 > 0:12:33and we need to gain access to all parts of the bridge,
0:12:33 > 0:12:35so it's not just walking along the deck -
0:12:35 > 0:12:38we have to be able to walk up the cable.
0:12:40 > 0:12:43We have to get underneath the deck as well,
0:12:43 > 0:12:46so we've got gantries so we can inspect underneath the deck.
0:12:46 > 0:12:48Areas where we can't get to with the gantry,
0:12:48 > 0:12:52we will either use specialist access companies to come in,
0:12:52 > 0:12:56or we'll use our own guys who can abseil and inspect it from there.
0:12:56 > 0:13:00And on this section, where a temporary platform was needed,
0:13:00 > 0:13:04the only way to dismantle it is by high-level rope access.
0:13:04 > 0:13:07The problem is working above a marine environment,
0:13:07 > 0:13:11you get a lot of salt in the air which causes corrosion.
0:13:11 > 0:13:14As you can see, on these cross girders,
0:13:14 > 0:13:18there is corrosion there and it was like that all the way across,
0:13:18 > 0:13:23but if you look further out, you can see there is no corrosion,
0:13:23 > 0:13:25cos all that's been painted.
0:13:25 > 0:13:29Corrosion is the main enemy on a steel bridge.
0:13:29 > 0:13:31Not only is it attacking the superstructure,
0:13:31 > 0:13:34it's even invaded the main cable
0:13:34 > 0:13:37from which the whole bridge hangs.
0:13:37 > 0:13:40It's ironic that the feature which I copied,
0:13:40 > 0:13:43what the Americans had done for their cables,
0:13:43 > 0:13:46is in my view the only feature
0:13:46 > 0:13:51which could lead to the ultimate destruction of these bridges...
0:13:52 > 0:13:55..because corrosion is occurring in cables.
0:13:59 > 0:14:03The main cable wasn't really designed to have to be maintained
0:14:03 > 0:14:06and the biggest problem is water getting into that cable,
0:14:06 > 0:14:09which is very, very difficult to prevent.
0:14:09 > 0:14:13So we decided to put in a dehumidification system
0:14:13 > 0:14:16and basically what happens is the dry air
0:14:16 > 0:14:17is pumped into the main cable
0:14:17 > 0:14:19and it takes out any of the dampness
0:14:19 > 0:14:22which therefore gives it a nice, dry condition.
0:14:22 > 0:14:25Moisture has been driven out of the cables this way
0:14:25 > 0:14:30for the last eight years and it's a process that's closely monitored.
0:14:30 > 0:14:32It's a very grey day here on the Severn Bridge.
0:14:32 > 0:14:35You can hardly see the towers, in fact.
0:14:35 > 0:14:37We've got a couple of jobs we've got to do today.
0:14:37 > 0:14:38We'll go down into the anchorage,
0:14:38 > 0:14:42we've got to go and do a few humidity checks down there.
0:14:42 > 0:14:45HE RADIOS CONTROL ROOM
0:14:47 > 0:14:48'Control receiving.'
0:14:50 > 0:14:54Thanks, Chris. Two inspectors entering Aust anchorage.
0:14:54 > 0:14:56'Thank you. Control standing by.'
0:14:56 > 0:14:59The anchorages, where the cables plunge down
0:14:59 > 0:15:02into massive concrete counterweights,
0:15:02 > 0:15:04literally hold the bridge up.
0:15:05 > 0:15:10A suspension bridge is basically like a washing line
0:15:10 > 0:15:12with two props in it.
0:15:12 > 0:15:16But you also have to anchor the ends back.
0:15:17 > 0:15:22Junior site engineers John and Jerry experienced the difficulties
0:15:22 > 0:15:24of building these vital anchors.
0:15:24 > 0:15:27Of course, the river was such a barrier at that stage
0:15:27 > 0:15:30to anything that we were doing.
0:15:30 > 0:15:33I mean, they were the two distinct sites,
0:15:33 > 0:15:39the Beachley side and the Aust side, and never the twain met.
0:15:39 > 0:15:42The Beachley Anchorage, on the Welsh side, where John worked,
0:15:42 > 0:15:44was constructed onshore.
0:15:44 > 0:15:47However, Jerry worked on the English side,
0:15:47 > 0:15:51where the Aust anchorage and tower were embedded in offshore rocks.
0:15:51 > 0:15:54And it was fascinating building all these things in such
0:15:54 > 0:15:57- a tidal river, with a very big rise and fall.- Certainly.
0:15:57 > 0:16:01Because the tower was built on a rock which only appeared
0:16:01 > 0:16:04above the water at low springs.
0:16:04 > 0:16:08And it was literally only about that far above water level,
0:16:08 > 0:16:10so basically it was a question of nipping out there,
0:16:10 > 0:16:13- taking off the seaweed and putting concrete down.- Right.
0:16:13 > 0:16:16And that was done in many, many stages because you could only
0:16:16 > 0:16:19spare the time to do a little bit of it each time.
0:16:25 > 0:16:29With over 165,000 tonnes of concrete to pour,
0:16:29 > 0:16:36the anchorages took over two years to construct, such is their scale.
0:16:38 > 0:16:42First time I went into the anchorage, I thought, wow,
0:16:42 > 0:16:45it is vast. It is just like a massive huge cave.
0:16:45 > 0:16:50You can hear the echoes, there's a large tent which encases the whole
0:16:50 > 0:16:53of the main cable where it splays out.
0:16:56 > 0:16:59OK, when you're ready with the readings.
0:16:59 > 0:17:02We have temperature 14 degrees C,
0:17:02 > 0:17:07and a humidity reading of 40%.
0:17:07 > 0:17:10Anything under 40% is good.
0:17:10 > 0:17:15Corrosion can't happen under 40%, so that is absolutely fine.
0:17:19 > 0:17:23It's always amazing to think that this bridge is held up by
0:17:23 > 0:17:255mm-diameter strands.
0:17:27 > 0:17:33There are over 8,000 of them but all the same it's still amazing.
0:17:33 > 0:17:39Before these 8,322 wires on each side could be pulled over,
0:17:39 > 0:17:41catwalks were constructed.
0:17:41 > 0:17:43Like giant swinging rope bridges
0:17:43 > 0:17:46tracing the future line of the main cables,
0:17:46 > 0:17:49they provided work platforms for the cable spinning.
0:17:49 > 0:17:54Over six months, day and night, the pulley wheels whirred.
0:17:54 > 0:17:59And for the first time people could walk between Beachley and Aust.
0:17:59 > 0:18:02We used to have to walk the cables on the catwalk
0:18:02 > 0:18:07all the way across in the morning, all the way back at night.
0:18:07 > 0:18:08If you get a bit of a breeze,
0:18:08 > 0:18:10you'd have a job to get your breath,
0:18:10 > 0:18:13because it would take your breath away,
0:18:13 > 0:18:16as you're getting up to the top of the towers. And of course
0:18:16 > 0:18:20when the wind was blowing that hard you had a job to walk.
0:18:20 > 0:18:22Many a time I went over in the morning
0:18:22 > 0:18:25and I had to go and fetch summat and walk all the way back
0:18:25 > 0:18:27and then all the way back over
0:18:27 > 0:18:29and then all the way back at night, like.
0:18:29 > 0:18:33But you couldn't let everyone get in the same step on there,
0:18:33 > 0:18:35else it starts going like this,
0:18:35 > 0:18:40and if you miss your step, you're coming down as that is coming up
0:18:40 > 0:18:43and your knees buckle up underneath you, yeah.
0:18:43 > 0:18:46Yeah, we used to do it on purpose sometimes!
0:18:48 > 0:18:51Meanwhile, in Chepstow, the novel deck boxes were being
0:18:51 > 0:18:54constructed on the banks of the River Wye.
0:18:55 > 0:18:57For over a year,
0:18:57 > 0:19:00the 88 boxes were painstakingly launched,
0:19:00 > 0:19:02then manoeuvred under the bridge,
0:19:02 > 0:19:07hoisted to road level and attached to the hangers, one by one.
0:19:07 > 0:19:10Commence winching on both, Mac. Over.
0:19:10 > 0:19:11Roger, will do.
0:19:12 > 0:19:17With the hoist of the final box, the bridge structure was complete, and
0:19:17 > 0:19:21steel fixer Viv Rooke and his gang now turned their hands to painting.
0:19:21 > 0:19:24- Stop winching.- Winching stopped.
0:19:24 > 0:19:29Well, they had a gang painting the hangers,
0:19:29 > 0:19:31and it just happened to be in line with the ferry
0:19:31 > 0:19:35and we were pulling the pot of paint up and it got caught,
0:19:35 > 0:19:39and I said to the lads, get out of there and we'll give it a good pull,
0:19:39 > 0:19:41and we ripped all the lining out the pot
0:19:41 > 0:19:46and obviously the paint ran out and it went straight over the top of
0:19:46 > 0:19:48the ferry and the cars. Painted the lot!
0:19:48 > 0:19:51Oh, dear! Yeah...
0:19:51 > 0:19:55I think it cost £3,000 to get the cars done, in them days.
0:19:55 > 0:19:59Well, I had a phone call come up to me to say, "Stop all painting,
0:19:59 > 0:20:03"stop all paint..." Oh, dear.
0:20:03 > 0:20:04Like the rest of the bridge,
0:20:04 > 0:20:08the hangers that support the deck need painting regularly.
0:20:08 > 0:20:11A procedure that is now slightly more sophisticated
0:20:11 > 0:20:13than in Viv's day.
0:20:13 > 0:20:16Over the years we've refined our procedures here,
0:20:16 > 0:20:19we've had bespoke platforms and cradles built.
0:20:19 > 0:20:22Some of them you won't find anywhere else in the world.
0:20:22 > 0:20:26Yeah, what we've got here is just a painting cable for painting the hangers, really.
0:20:26 > 0:20:30This bespoke contraption moves up and down the hangers.
0:20:30 > 0:20:32Well, it's a case of now...go up,
0:20:32 > 0:20:35transfer the wires down to the next location, make sure there's
0:20:35 > 0:20:38no twists and then we'll hang it straight back on there.
0:20:38 > 0:20:40Right, we'd best get some harnesses on.
0:20:40 > 0:20:43That's because moving the cradle pulley
0:20:43 > 0:20:45means Nigel and Johnny walking the cable.
0:20:45 > 0:20:48A mere 400 feet above the river.
0:20:48 > 0:20:52Oh, you've got the top of the cable, yeah, you have got butterflies.
0:20:52 > 0:20:56And I've been working round the construction game for a long time
0:20:56 > 0:20:59and worked at heights and it's not bothered me one bit, you know,
0:20:59 > 0:21:03but that does, when you've got to walk down a cable.
0:21:03 > 0:21:04It is a bit nerve-racking.
0:21:04 > 0:21:07Like you say, it's just the initial going off the top.
0:21:07 > 0:21:09Here we go, then.
0:21:16 > 0:21:19It's a great feeling walking along it.
0:21:19 > 0:21:21I mean, basically the world opens up.
0:21:21 > 0:21:23You just see the cars and the road
0:21:23 > 0:21:26and, you know, the people are so small,
0:21:26 > 0:21:29and you've just got...you feel like you're on top of the world.
0:21:46 > 0:21:52Cradle wires relocated, it's mission accomplished for Nigel and Johnny.
0:21:53 > 0:21:58Now Trevor's on a mission to get that hanger painted.
0:22:09 > 0:22:15Back in 1966, the state opening of the freshly painted Severn Bridge
0:22:15 > 0:22:18was broadcast live to the nation, such was its importance.
0:22:18 > 0:22:238th September, 1966, I was at school in Chepstow and they'd
0:22:23 > 0:22:27said to us, "If you go and wave the flag for the Queen in the morning
0:22:27 > 0:22:29"you can have the afternoon off school."
0:22:29 > 0:22:32So it was rammed with schoolkids.
0:22:32 > 0:22:36So I was in the line to shake hands with the Queen.
0:22:36 > 0:22:40Royal car comes up and introduced to all the dignitaries.
0:22:40 > 0:22:45Surprising how many dignitaries there are before they get to the engineers!
0:22:45 > 0:22:49- NEWSREEL:- And next to Her Majesty, Michael Parsons, the resident engineer.
0:22:49 > 0:22:51We saw the Queen.
0:22:51 > 0:22:55- It was a cavalcade, you know, you see them go past. - SHE LAUGHS
0:22:55 > 0:22:58"I've seen the Queen!" But we were there, that was what counted.
0:22:58 > 0:23:01We were there on the day it opened.
0:23:01 > 0:23:06It is with great pleasure that I now declare the Severn Bridge open.
0:23:10 > 0:23:13There was a huge sense of achievement.
0:23:13 > 0:23:19We went there in 1960 and all we had then was ideas in our minds,
0:23:19 > 0:23:23and six years later you've got people travelling back and
0:23:23 > 0:23:28forward daily without really considering what they're
0:23:28 > 0:23:31doing now, they just go.
0:23:31 > 0:23:33It's a bridge, it's done it.
0:23:33 > 0:23:37# It's the pride of the Welsh and the west coast alike
0:23:37 > 0:23:42# It's the Severn Bridge's broad and mighty span... #
0:23:42 > 0:23:46Well, obviously the opening of the bridge was the demise of the ferries.
0:23:46 > 0:23:49On September 8th, 1966 the three ferries pulled under the bridge,
0:23:49 > 0:23:52sounded their hooters, company was wound up.
0:23:52 > 0:23:54I was on the last ferry to come across.
0:23:54 > 0:23:58Ah, it was a sad old day because there was
0:23:58 > 0:24:01a lot of people who did use it were just coming over for the last time,
0:24:01 > 0:24:05like, in their car, and it made you think of it like it was
0:24:05 > 0:24:10something that was going that was a part of the community, really.
0:24:10 > 0:24:1450 years on from that momentous September day and the bridge
0:24:14 > 0:24:17is preparing to mark another milestone.
0:24:17 > 0:24:21One anniversary event is the Severn Bridge Half Marathon,
0:24:21 > 0:24:24top of the agenda at Trish and Paul's daily catch-up.
0:24:24 > 0:24:28Erm, lane closures, we've got those booked in,
0:24:28 > 0:24:32so that will be done in the next week or so.
0:24:32 > 0:24:34OK, and tolls and operations are...
0:24:34 > 0:24:37Tolls, I've got a meeting this week with Gareth.
0:24:37 > 0:24:40Then there's the ongoing concern over corrosion.
0:24:40 > 0:24:43To be sure that the dehumidification system is working
0:24:43 > 0:24:46means opening up the cable.
0:24:46 > 0:24:49Deterioration in its core could spell closure.
0:24:49 > 0:24:54An internal inspection is a major undertaking, and the in-house team
0:24:54 > 0:24:58is supplemented by cable specialists, led by Bev Urbans.
0:24:58 > 0:25:02Right, we're inspecting at eight locations altogether
0:25:02 > 0:25:05- and there's two high-level panel positions.- Yep, OK.
0:25:05 > 0:25:08So the high-level platform that's coming to site
0:25:08 > 0:25:11needs to be lifted in in essentially two halves,
0:25:11 > 0:25:13because one half has to sit on the far side of the cable
0:25:13 > 0:25:15because obviously the hangers are in the way,
0:25:15 > 0:25:18and then the second section fits on the inside.
0:25:18 > 0:25:21- So it sort of joins... - And then joined together.
0:25:21 > 0:25:25- All signed off?- Yeah, so we just want to get this one up and then we get going with the inspections.
0:25:25 > 0:25:28That's the important bit, isn't it? See what's in there.
0:25:28 > 0:25:30Yeah, it will give you all the information that you need.
0:25:30 > 0:25:34So what our consultants and contractors will be doing
0:25:34 > 0:25:37will be they will be wedging open the cable,
0:25:37 > 0:25:41having a look at it to see if there's been any corrosion.
0:25:41 > 0:25:45I hope that the inspection will show that the dehumidification system
0:25:45 > 0:25:49is still working well and that the corrosion has been halted.
0:25:49 > 0:25:51Fingers crossed.
0:25:51 > 0:25:55Opening up the cable means closing a lane on the bridge
0:25:55 > 0:25:57and that's 50% less capacity.
0:25:57 > 0:25:59'OK, stop the traffic now, please.'
0:25:59 > 0:26:02All lanes, hold your traffic, please, hold your traffic.
0:26:02 > 0:26:06With the only open lane clogged, the traffic is held back
0:26:06 > 0:26:09at the Aust tolls until the bottleneck has cleared.
0:26:09 > 0:26:12My job is basically to deal with any complaints on the plaza
0:26:12 > 0:26:16with the customers, deal with the breakdowns, deal with the incidents.
0:26:16 > 0:26:19Because we've got this one lane restriction whilst the cables are being inspected,
0:26:19 > 0:26:22I have to make sure that traffic goes through as safely and efficiently as we can.
0:26:22 > 0:26:24I understand the frustrations of the passengers.
0:26:24 > 0:26:26HORN BLARES
0:26:26 > 0:26:28Someone's happy.
0:26:29 > 0:26:32I will try and deal with it and get them on their way as quickly
0:26:32 > 0:26:33and efficiently as we can.
0:26:33 > 0:26:37And then hopefully it will get back to some kind of normality.
0:26:38 > 0:26:42- 'OK, let it go. Thanks, mate.' - Thank you, let them go.
0:26:47 > 0:26:50Right, and that's over and done with.
0:26:50 > 0:26:55Present-day delays are of course in aid of the bridge's long-term future.
0:26:55 > 0:26:57High above the Severn,
0:26:57 > 0:26:59the cable's core is ready for inspection.
0:26:59 > 0:27:03We're heading up to look at one of the grooves that's been opened.
0:27:03 > 0:27:07There's, you know, a bit of trepidation.
0:27:07 > 0:27:10Approaching 400 feet up, in the confines of the gantry,
0:27:10 > 0:27:14the cable is unwrapped and wedged apart.
0:27:14 > 0:27:16Well, that's not bad for 50 years.
0:27:16 > 0:27:18These are the individual wires
0:27:18 > 0:27:21that have carried over 300 million vehicles.
0:27:21 > 0:27:23We're very encouraged.
0:27:23 > 0:27:25You can see some corrosion on the outer wires,
0:27:25 > 0:27:27whereas within the groove very little corrosion,
0:27:27 > 0:27:29and it's good, it's very good.
0:27:29 > 0:27:32The dehumidification has halted the corrosion.
0:27:32 > 0:27:36We wanted to hope for the best and now the results coming in
0:27:36 > 0:27:40show that the corrosion of the wires hasn't deteriorated any more,
0:27:40 > 0:27:44so you feel sort of relieved, obviously, that the bridge is
0:27:44 > 0:27:47standing strong and it will be here for many's a year to come.
0:27:47 > 0:27:50Ten days shy of its 50th birthday
0:27:50 > 0:27:53and there's a party atmosphere on the bridge.
0:27:53 > 0:27:54STARTING PISTOL
0:27:56 > 0:27:58I don't like to get too soppy,
0:27:58 > 0:28:01and it's not my baby or anything like that, but as a structure
0:28:01 > 0:28:05there's not many things in the country that come close to it,
0:28:05 > 0:28:10and I'm proud to say to people that I work on it and that I've
0:28:10 > 0:28:11helped to keep it tiptop.
0:28:11 > 0:28:13Well done, keep it up!
0:28:13 > 0:28:17The Severn Bridge is very special for me.
0:28:17 > 0:28:22Over the years people have said, "When they build the second crossing they'll close the first one,"
0:28:22 > 0:28:25but as far as I'm concerned there's no chance of that happening.
0:28:25 > 0:28:30There are bridges all over the world and they're all...descendants,
0:28:30 > 0:28:33shall I say, of the Severn Bridge.
0:28:33 > 0:28:35A lot of it's down to the people who work here,
0:28:35 > 0:28:40and I always say that they're not just guys who maintain the bridge,
0:28:40 > 0:28:43they're sort of curators, and they absolutely love this structure,
0:28:43 > 0:28:47and it's nice that I'm part of that family that look after it,
0:28:47 > 0:28:49and I feel it really is a family.
0:28:49 > 0:28:54# So raise a cheer, raise a cheer for the great Severn Bridge
0:28:54 > 0:28:58# And the men who have raised her on high
0:28:58 > 0:29:02# Many times, many times had we wondered at the tide
0:29:02 > 0:29:07# Now its wild racing currents we defy. #