Tuesday 20 October 2026
Managing modern port infrastructure requires balancing complex marine engineering, environmental compliance, and round-the-clock commercial shipping operations. Expanding berthing capacity while protecting delicate marine ecosystems presents constant technical challenges for engineering leaders.
Overcoming these operational obstacles demands innovative capital dredging strategies, advanced acoustic monitoring, and deep historical knowledge of coastal dynamics. Port engineering teams must guarantee vessel safety while deploying cutting-edge marine equipment in busy fairways.
Engineers Ireland Amplified Podcast Host Dusty Rhodes sits down with Eamon McElroy, Port Engineer at Dublin Port. With nearly two decades of experience overseeing marine infrastructure, dredging projects, and environmental conservation, Eamon shares invaluable practical insights into managing one of the busiest maritime hubs in Europe.
THINGS WE SPOKE ABOUT
● Scope and scale of maritime trade through Dublin Port
● Historical engineering behind the South and North Bull Walls
● Capital dredging protocols and managing marine environmental compliance
● Operational deployment of the Magnor backhoe dredger
● Practical advice for civil engineers building impactful careers
GUEST DETAILS
Eamon McElroy is the Port Engineer at Dublin Port, where he has led marine infrastructure maintenance, environmental conservation programmes, and major capital dredging projects for nearly twenty years. He holds an honours degree in civil engineering from the University of Dundee and oversees critical environmental initiatives, including tern and black guillemot conservation plans in Dublin Bay.
QUOTES
"I tell people to understand the size and scope of Dublin Port, go into any shop in Ireland, and lift three different items that have been imported. Two of those items came through Dublin Port to give you the scale." - Eamon McElroy
"And what we say in Dublin Port is we guarantee at least one metre of water under the keel." - Eamon McElroy
"The keyword for dredging is production. You don't stop a dredger; you just do not." - Eamon McElroy
TRANSCRIPTION
For your convenience, here is an AI transcription:
Dusty Rhodes 0:03
Right now on Amplified,
Eamon McElroy 0:05
I would be doing interviews for you know certain jobs, and people kind of say, "Well, what's your experience? I could list what I did. That's why I got into Dublin Port. But what do you do? I do this. Okay, we want you. And as I said, I came from a building set. I wasn't wearing a shirt and tie when I went for my interview. I can guarantee you. Hi
Dusty Rhodes 0:25
there. My name is Dusty Rhodes, and you're welcome to Amplified, the Engineers Ireland podcast. Today, we're getting a fascinating glimpse into some of the extraordinary marine engineering above and below the waterline at Dublin Port. In particular, we'll be getting the inside story on the arrival of Magner, the world's largest backhoe dredger, which has a bucket large enough to lift a small two-story house or fill six tipper trucks in a single scoop. To tell us all about it is Port Engineer at Dublin Port, Eamon McElroy. Amon, how are you?
Eamon McElroy 0:59
Very well, Dusty. Thank you.
Dusty Rhodes 1:02
Before we get into the massive projects that you are responsible for and working on, how did you get into engineering? Was it a thing since you were a two-year-old boy, or a parent who forced you into it?
Eamon McElroy 1:14
Bit of both, to be honest. My father was a brickie, and he had his own small kind of concrete production, so mainly focused on cattle slots. As a child, I was sitting up; shouldn't be doing it, sitting on the forklift as my dad was kind of working the weekends and stuff like that. I had my youth. I think my mother had me at 16, working in a concrete factory, driving forklifts, then going out with the trucks, mostly farms, as I said, cattle slots was the main thing. So I had that engineering background in it as such, and that was my kind of keen interest in it as such. So I went and did a honours degree in the University of Dundee, and it basically fell into Dublin Port in 2007 because I was working with an agency, and they said, "Look, they need a civil engineer down at the port for a couple of months. So when I went in, did the interview. I'd actually come from a building site, so everyone else was wearing suits, and I walk in coming from a building site, and they said, "Okay, we want you. They said that was for six months, and that was now 19 years ago. So I've been there ever since. So it wasn't intended. It was just the fact that at the time Dublin Port had its own engineering facility, and there was about 19 people in it, and that was a mixture of civil engineers, mechanical engineers, and electrical engineers. And at that time, Dublin Port would have operated maybe 72 cranes up and down the key walls, and warehouses, and bonded warehouses, and so forth. But the strategy at that time of the CEO at that time was Dublin Port was actually losing money. It wasn't making money. It said it right. Let's get out of warehousing. Let's get out of stevedorein. Let's get rid of the cranes because it would take four men to operate one crane at Dublin Port. So they went towards kind of like a landlord structure. So they own the key walls. They own the infrastructure, they own the henta lands, and they rent that out to and issue stevedore licences to different companies. So that's the competition inside Dublin Port. It's actually the different stevedore companies and ferry companies operating against each other commercially. And then for myself, it was basically even though I'm coming up in 20 years, I've never had the same day twice. I've just never had the same day twice. And jobs, I mean, one of my first jobs, believe it or not, I look after all the crane lifts that are on the key walls. And my first crane lift was actually a replica Viking ship that came up out of Collins Barks. I think it was called the Sea Stallion, and we had to put it in a tandem lift. Over the years, I mean, like it was the maintenance of the marine infrastructure, understanding. So I do do tours to Dublin Port and explain to people because one of the things I don't like is when people see stuff and they don't understand it, and it happened by accident. We were doing I don't know open day with buses with people and from the public going up and down the port, and I actually happened to be there with my family, and as we were going around, was nobody was talking, nobody was explaining what was going on. So I just got up, grabbed the microphone, and I says, "By the way, my name's Evan McRory. I'm the port engineer here. I'll explain to you what you're looking at. So yeah, that's how I ended up there. It's such a dynamic, busy, busy place. As I say to people when I give the tours, I say to people to understand the size and scope of Dublin Port, go into any shop in Ireland, and that's north, south, east, west. Any shop left three different items that have been imported. Two of those items came through Dublin Port to give you the scale. So, on the island of Ireland, 10% of all goods cargo comes in by aeroplane. The other 90% comes in by ship. Of that, Dublin Port does 60% of that 90% So that just kind of shows you the size.
Eamon McElroy 4:50
So my main responsibility is maintenance of all the marine infrastructure, and I look after all the dredging projects as well, so to make sure that when ships are coming into. Dublin Port, they've somewhere to go, and they can safely navigate the navigation channel in and out. And then there's a variety of you know dredging projects that we have to associate with that to kind of keep that going. Then there's the maintenance infrastructure, and then by the by, I don't know how. I'm a civil engineer by trade, but I also head up all the environmental projects within Dublin Port. So I have four turn colonies. We have turn conservation plan. We have Black Gilliamot conservation plan. I work very close with Irish Wheel and Dolphin Group, true dredging projects because of the licences that we have to do the dredging. And then I also work very close with Birdwatch Ireland. Back in I think 2009, we had a planning application to do an infill of 21 hectares, and it was turned down by our board Planola because we didn't have a long-term conservation plan at the time, and we kind of discovered okay, there's no point in going out and fighting with scientists, hire scientists to come in and give you the information. So from that, then we were able to learn through the publication of our master plan, 2012, where we looked at throughput, figuring out because the Dublin population is increasing, cargo volumes were increasing. So, to give an example, in 2025, we did 36 million tonnes of cargo, and we did 1.7 million passengers between the ferries, so that makes us even more busier than Shellen Airport.
Dusty Rhodes 6:25
Can I ask you about because you mentioned that you like being a part-time tour guide?
Eamon McElroy 6:30
Yes.
Dusty Rhodes 6:31
What's your favourite story to tell on the tour?
Eamon McElroy 6:33
My favourite story on the tour is actually the Great South Wall, and I don't think Dublin people understand what it does. It's actually a very very ingenious piece of engineering, and to give you the background of it was because of the dredging projects that I do when we do capital dredging. I'm just going to explain dredging very quickly. So there's maintenance dredging, and basically you're hoovering the carpet. You're just lifting all the silt and sand that comes down the river Lively or comes in with coastal processes. Then you have capital dredging, where you're lowering the level of the carpet, and that's to facilitate bigger ships coming in and out of Dublin. And ships are getting bigger because if you look at Triple E's that do the transocean, you know they're carrying 20,000 TEUs, which is a 20 foot equivalent unit. So when you see a 40 foot trailer, that's too TEU to give you kind of like the the definition of it. Yeah, but basically, I explained to people that 350 years ago there were so many shipwrecks outside Dublin Port. So basically, Dublin Port on the end of the River Liffey, but outside it there was a sandbar called the Dublin Bar, and it reached from the North Bowl Strand to the South Bowl Strand. And at low water, it was only six foot. So that means if I was standing on it at a low tide, I could put my hand up into the air and wave it, and you would see my hand coming out of the water. It caused so many shipwrecks that we had archaeologists, because we have to have archaeologists involved when we're doing capital dredging in case we come across a shipwreck, and basically the archaeologist was able to do some research. He came back to me and reported. He says, "Eamon, between Hoth Head, Dunleary, and East Wall Road, there's up to nearly 1000 shipwrecks recorded. Now he got that from insurance claims, so there might have been one or two shipwrecks, maybe claimed for twice, but they actually passed a law that if you were a ship owner, and these were all wooden ships in the day, they were going back 350 years plus. So Dublin Port was actually the worst port in the British Empire to come in and out of, and ships would have to wait for weeks, if not months, to get the right tidal conditions to get in and out. So going back to my point that ships are getting bigger. Well, in those days, wooden ships were getting bigger as well, and they couldn't get past the sandbar. So they actually said, "That's it. We've had enough. We're going to abandon Dublin as a seaport. We're going to build two new harbours, and we're going to build a canal system from them new harbours back into Dublin City. They built the first harbour in Kingstown, which we now call Dunleary, and the second harbour was to be built in Sutton. So, if you go into the harbour master's office there in Hoth, above his table on on the wall is the plan for the Sutton Harbour. But then a Captain Phillips of the British Admiralty, he came along about 300 years ago, and he goes, "Hang on a second, you know this sandbar because it's a sandbar, you cannot dread to say, you know, you dread the sandbar on a Tuesday. It's back on a Wednesday. So any kid whipping speed digging a hole in a beach and a wave comes in, you know what happens. And the sandbar would keep moving because basically you have the River Liffey, 125 kilometres long, going very fast with a lot of energy, picks up all the silt and sand, hits the sea, drops the silt and sand, so the bar would move because if you had heavy rains in winters, the sandbar would push out towards the sea. If you had drought conditions, the sandbar would pull in towards the city. So they couldn't get rid of it, they couldn't dredge it, they couldn't do anything, and they had that plan. And they got as far as building the Leary Harbour. And then the captain fell off and he says, "Hang on a second, can we not increase the speed of the liffey and use the liffey to do kind of scouring?
Eamon McElroy 10:06
So they experimented with wooden piles, which was called piles, and they started out where pool bag lighthouses today, and went the whole way back to the Dodd River, and it worked. The sandbar went from six foot down to 10 foot, so then they had an awful maintenance issues with the wooden piles because storms knocking them over. So they said, "All right, let's do wooden casings, and they built these wooden casings, replaced the wooden piles with wooden casings, and they filled them with a rock that they got from a quarry. And the rock's black, so if you're walking down the south side of the Great South Wall at low tide, looking around the rock arm, and you might see one of the original wooden piles sticking out, and you also might see little black rocks. So the black rocks came from an area we now call Black Rock. That's where the quarry was. Then the wooden casings were notorious to maintain. So they kind of said, "Look, let's just build a wall, and they started at Pool Bag Lighthouse, and they brought it the whole way back to Dollar, and that was great. Then our famous Captain William Bligh of the Mutiny of the Bounty fame, he came to Dublin in 1800, and he did the first ever accurate bathymetric survey of Dublin Bay. And he was then kind of like had made three suggestions. The first suggestion was the Great South Wall wasn't high enough. So if you ever walking down the Great South Wall and you wonder why it rises at the second part of it as you walk down towards the lighthouse, that's Captain William Blay's recommendation. Your wall's not big enough because the waves are going over the top of it, and they also recommended that the lighthouse be increased in size. So that's not the original pool bag lighthouse that you're looking at. It. If you look up the block work; you'll see the way the blocks change in orientation. That used to be the old height, so that was great. He says, and his third recommendation was to to get the sandbar even lower. You need to build a second wall. You need to build a wall, but his recommendation was that the wall was parallel, so it was nearly like a canal system. And then there was a George Halpin who was a port engineer after that, famous for most of the lighthouses in Ireland. He suggests he says no. What you need is a tidal wall, and you need it to come from Clontharf. So if you ever own the North Bull Wall, you notice half of it is above water, and the other half was kind of at high tide underwater. And the whole ethos there was that all of Colca Estory. Now remember, Dublin Port didn't exist, and it in those days East Wall was the end of the port. If you go onto the south side where St John Rodgerson's Quay is, the quay around the corner is called Britain Key because they were looking at Britain at the time. So all of that area was in the field thereafter. But George Halpin's recommendation was that the whole Talca Estuary would fill up like a big dam, and as the tide came down, the water would be funnelled between the two lighthouses. So they didn't know how far to go out with the North Bull Wall. So what they actually did was they built one half, as I said, above the breakwater was built above, and Bull Island didn't exist at this time. By the way, it was just muddy flats. So they built the wall, and then the tidal bit. They would do a bit, and then measure the speed of the liffey, because they didn't want the liffey being any more than four miles an hour. Because wooden ships would have a nightmare getting up into the harbour, so they built a little bit to measure the speed, built a little bit, measured the speed of the water. When they got to four miles an hour and said, "That's it, build the lighthouse here, and that's why North Bull Lighthouse is built where it's at, and the sandbar eroded. After that, Dublin exploded in commerce and and size and population.
Eamon McElroy 13:29
So, as I said to people on the tour, the Great South Wall-I call it the Brawn-but the North Bull Wall is the Brains. Those two walls saved Dublin as a city. People don't understand that or appreciate that. So, next time you're walking on the Great South Wall, look back at the city, and it would have been completely different if it hadn't those two breakwaters to save and protect it. Then, as ships got bigger, we got into mechanical dredging, and that where you're lifting and disposal. So, as I say, that's where I started my first dragon project back in 2007. I'll be doing it every year.
Dusty Rhodes 14:04
Well, listen, let's talk about that to bring us way up to that. I'm just fascinated by that story, and it's so long ago, and it's such big engineering thinking. Do you know what I mean? Like that that they were capable of doing that and figured it out and came up with the solution. Anyway, back to current times. At the moment, the big story in Dublin Port is Birth 18 and Birth 53. Tell me what's the problem with them, and what is the solution?
Eamon McElroy 14:29
Well, Birth 53 is a new rural ferry terminal that we're building on the river. So basically, we have 21 ferry services coming in every day to Dublin Port, and most of those ferries would be ro-ro ferries that would take on cargo and passengers. So what we haven't done before to roll on, roll off is ro-ro, and to facilitate those ships taking on cargo or taking off cargo, we need a roo ramp that the ship can come and drop its ramp. So. Some ships will load up at the stern, and then people will come off at the bow. So berth 53 is a new is part of the master plan, and we call it the MP two master plan number part two. And therefore, we're introducing two new rural ferry terminals onto the river. The problem there then is we have to do capital dredging for those ferries to make sure that. So I've always been told that if a ship runs aground in Dublin Port, and he's going through the Panama Canal six months later, and a plate falls off the galley, that's Dublin Port's fault. Anything ever happens to that ship there ever after, so you never let a ship run aground. And what we say in Dublin Port is we guarantee at least one metre of water under the keel. So when a ship comes into longer berth, we have to have what's called a berthing pocket, and basically, as the tide goes up and down, and that ship is on that quay, it still doesn't run aground. It has this deepened area underneath it. So as the tide goes up and down, plus also ships will, you know, as it being offloaded, there'll be more buoyant, and ballast has to be then transferred around to keep the ship steady. So what we're doing at 53 at the moment is we're doing the capital dredging. That's the lowering off the carpet into new material where we have to kind of build that berthing pocket. So when the ferries come in and out, or any other ship that uses that berth, there's a guaranteed depth of water. Then what happens is, as I said, the River Liffey is 125 kilometres long. We get deposited about 120,000 cubic metres of silt and sand every year, and adults can come in with coastal processes. So that equates to what we do is we use a relative index, which we've agreed with EPA, because our dredged material is a mixture of fine sands, coarse sands, and cobbles. So we use a relative density of 1.65. So 120,000 cubic metres is about roughly 200,000 tonnes of silt and sand have to be removed each year. And what we do there, we dredge it and we take it out to a licenced dump site at the Borford Bank, which is an area that the EPA is designated for us to put all our dread spoils. Unfortunately, dredging material that we have in Dublin port it has no reuse. You can't use it for beach nourishment. You can't make bricks out of it. It's just that type of material that cannot be used. So we have to dump it, and therefore it's deemed to a waste. So to do about 53, we went out to tender, and the tender was won by Bascalis, our Irish dredging company. And basically, it's a three year project, and because it's capital dredging, we're only allowed to dredge during the winter months. So we're not allowed to dredge during the summer months for capital dredging because of all the migrating fish that are going up and down the river, and with it, there's strict conditions within our dumping at sea licence. So, to do any dredging project, we need two licences: one from the EPA, which is a dumping at sea licence, which then allows you to lift that material in the berth, in the basin, in the navigation channels, and take it out to that dump site, which is about five kilometres east of Pulberg Lighthouse. Then you need a foreshore licence. Well, it used to be foreshore. It's now Mara, the Marine Area Regulatory Authority, and your foreshore licence then lets you touch the seabed.
Eamon McElroy 18:15
So, the way it works is that the seabed from the high water mark to the core of the earth is owned by the Irish government for 12 nautical miles out to sea, so you need permission to work on that foreshore. So technically, and I say this to people, a child with a bucket and spade needs a foreshore licence. Technically, what we do is then we apply for these licences. Then to take that material out to sea, we have to prove that it's not contaminated. We have to prove there's no environmental harm going to be done with that material, and through that we work closely with the Marine Institute and we do sediment testing. So we'll do an awful lot of surface samples, fibro cores. If you want to go down about a metre depth, especially when you're doing capital dredging, you want to make sure the main problem that Dublin Port has is legacy. If you think about it, I mean there were no environmental laws 50 years ago, or and we had two dry docks. And when ships come into dry docks, they'll paint them with anti-filing paint, and so and then, for example, Alexander Basin East is clean material. We can take it out to sea. We've tested at the Marine Institute. We've proved there's no contamination. Or Alexander Key West is a different kettle of fish because you have two dry docks. You had halls, animal feed, also the Gulen's Jetty, which was for fertiliser, and then you have Tara Mines, which is the lead and zinc mine. I think it's one of the largest ones in Europe and ninth in the world, with all their zinc and lead ore. So there were spillages, and the spillages went into sediments, and that makes them contaminated. So the way the Marine Institute works, that there's class one is clean, can go out to see class two slightly contaminated. You make an. Case we got slightly contaminated material across the hurdle into class one by doing ecotoxicity testing, where you get your sediment and you test it for little worms and you see what the mortality rate is and so forth. But once you prove you can take all that material out to sea, then you get dumped at the sea licence. But then there are so many strict conditions within that licence, like in 2015, there was a Natura 2000 site put over our dump site like an SAC Special Area Conservation with two interests: reefs and harbour porpoises. So basically, we went back to the EPA and said, "Look, what we're doing is you know it's temporary. We're not building a permanent structure at the dump site. We're just dumping silt and sand that we have lifted in the the river, we proved it's not contaminated, and it's a dispersal site. So, within that ABR project and the first master plan, we were deepening our entire navigation channel from 7.9 metres chart datum, and a chart datum is basically what level of water you have at low tide. So, our chart datum at Dublin Port is different than the chart datum at the Port of Cork. Every port has its own chart datum, and that's what we will declare to ships. That's the amount of water you have at low tide. So we were deepening our navigation channel. There was about 6 million tonnes of material had to go out to the dump site, but the dump site is the dispersal site, so all the silt and sands that come in from the river or come in from the ocean or down the river, we dump at the dump site, and then they are picked up by tides and currents and dispersed all over Dublin Bay. That's why we have to prove all the sediment is clean and and is not contaminated. We had taken this question to the EPA, and they said, "No, we have sacrificed that area of seabed for you, and that's the only area of seabed we're going to sacrifice for you. So, even though we'd been using it for 100 years ish, we were still limited to that two by two, you know, four square kilometre area beside the Burford Bank.
Eamon McElroy 21:58
But they put really stringent conditions on us when we were doing the 6 million tonnes, so we had four of the most sophisticated monitoring buoys ever to be deployed on the Irish coast, and the company we used was TechWorks, actually based in Dunleary. Charlotte, who runs the company, was explaining they they do weather buoys all over the world, globally, globally, and we had these buoys, and there were so many instruments monitoring. So what we were looking for was turbidity, which is the murkiness of water. We wanted to prove we weren't murky in the waters by dumping the silt and sand. So we would measure turbidity at three different levels: at the top of the water column, middle of the water column, and at the bottom of the water column. And then, because it's an SASC, especially area conservation, we proved there were no reefs at Sasanbar, our bank, and we knew that the biggest population of porpoises in the east coast of Ireland is Dublin Bay. So we had to put in microphones on these boys. So we had palms, which are passive acoustic monitors, which you put on the seabed, tape recorders that will record all the clicks and noise, and they would sit for about three months at a time, and then you would take them up and you replace the batteries and replace the recorder, and then we had sorry, there's Sam's static acoustic monitors, and then we had Palm's passive acoustic monitors, which actually would send a message to a mobile phone saying, "Oh, harbour porpoise has just gone past me. So when we went to the dump site, we had three of these boys in the dump site: north, middle, and south. And then we had a control one out at Scotsman's Bay. So basically, we were measuring turbidity, we were measuring wave height, wave frequency, and also we were all the microphones would be telling us about porpoise activity. Every time we do a dredging project, whether it be maintenance or capital, we must employ two marine mammal observers on board 12-hour shifts, 24-seven monitoring. So when a dredger goes out to a dump site and he's doing a dump, the marine mammal observer must do a watch for 30 minutes to make sure there's no seals or there's no porpoises in the area. Plus, they have the connection to the passive acoustic monitor, which sends a little text message saying, "Oh, there's a porpoise here at the north part of the dump site. So the marine mammal observer could then direct the ship to go to the south side of the dump site and dump the load. And all these are conditions within our permits. So we. we had to deploy those boys from 2017 to about 2021, and it was only during the dredging projects. But I went cap in hand to the CEO and I says, "Look, I don't see the sense of these most sophisticated boys we've ever had sitting two to four months in a warehouse. Why don't we deploy them full time? And he agreed. Now it cost us a lot of money, but the data we gained from that paid back. So I'm going to give you one example: the Beast of the East. If you remember it, all the snow that yes. So were boys because the microphones they were actually mirrored with bungees, and the bungees were in an east-west location because you cannot have a chain rattling beside a micro. Phone, you're not going to hear anything. You're just going to hear chains, and basically, these come in. So we recorded wave heights of eight metres every 10 seconds, five kilometres east of Pullback Lighthouse. Now, as I on tours explain to people, that's equivalent of you driving down a motorway and the wave being bigger than the bridge you're driving under and coming at you every 10 seconds. So Charlotte was telling us that even though they had boys out in the Atlantic and all over the world, said the ones in Dublin Bay had to keep go back and upgrading the armour on the cables.
Eamon McElroy 25:33
We have to upgrade, you know, everything because the sea conditions change so quickly in Dublin Bay, and Beast of East was what we could see, and I remember going to the harbour master, saying who used to be the ex captain of one of the big ferries, and I said, "Did you ever witness big waves in Dublin Bay in your time as being a you know doing the ferry going back? No, and I showed him the data, and he couldn't believe it. He was gobsmacked. He says that was out there.
Dusty Rhodes 25:59
It was named the Beast from the East for a reason, and it was a very exceptional event. But of course, when you're engineering, you are always engineering for exceptional events, not just for the day to day. You know, that's a fascinating look at the port. And for somebody who knows nothing about ports and how they all work, you've explained it so well. Literally, my jaw has dropped several times as you're telling these stories, right? What I'd like to find out about is this new dredging machine, the Magner. Tell me about that.
Eamon McElroy 26:29
Okay, so part of the Birth 52 project, where we're building the new rural ferry, we went out to tendered for the capital dredging, and Boscalis International were the dredging company that were awarded that contract, but Gallus own a backhoe dredger. The massive types of plant. So there's two main types of dredger that we would use within Dublin Port. The main one would be a trailer suction hopper dredger, which is basically a ship, if you can imagine, with a swimming pool in the middle of it, and then you have a Dyson Hoover to the side, so it's called the drag head. It drops it onto the seabed. It sucks up all the silk sandwich sediment, puts it into the swimming pool area, and then it takes it out to the dump site. And the bottom of the hull opens up and it drops material. So that's a trailer suction dredger hopper. The other one is a backhoe dredger, and the Magnor that has come into Dublin Port, is the world's largest backhoe dredger. Its bucket capacity is 40 cubic metres in one scoop. I was lucky enough to see the manufacturing of it because we were getting our rural ramps manufactured in Holland by a company called Ravestein, and we went over to look at our ramps, and there, sitting on the quay wall, was this massive excavator being constructed? So I was able to go over and actually, you know, can I go and take a look at that? That looks interesting. So it was been manufactured by Ravestein, and they gave me kind of guided tour. But they were explaining like some of the basic dynamics of it. I mean, it's just a monster of a machine to kind of describe it. But yeah, that capacity of 40 cubic metres. So we've brought it into Dublin Port to do very accurate. It's accurate till about 30 centimetres, and they can, as I said, they can do a lot of trimming. So because the trailer suction dredger hopper has that hoover, as I said, at the side of it midships. If the dredger's 95 metres long, you're only ever able to dredge as far as the boat can go. You lose that first half of that ship because the drag head, as it's called, is midships. So to get into the nooks and crannies, you need a backhoe. You need a backhoe dredger to pull that material up. So that's why we have the Magner here at the moment. And then she would feed two split barges, which are just barges that are towed by tugboats, and once they are filled again, they take them out to the dump site and deposit the material there. So that's the Magner we have here at the moment, and and she's currently working on what we call the Dublin Harbour Capital Dredge project, where we're looking at also widening all our berthing pockets because ships are getting so much bigger in Dublin Port that the berthing pockets that we traditionally had, which would be maybe 35 metres wide, are not wide enough. So we now have to widen them more. But the problem we have, as again heritage in Dublin Port, is that we have a mixture of different types of key walls. So traditionally, you would have built a key wall with cofferdams. You put a cofferdam down, and then you'd build, drain out the area behind it, and you would build a granite key wall, which you have from say East Wall Road the whole way into the city. All those key walls would have been built in that formation doing cofferdams And then we had a famous port engineer called Bendham Blood Stoney, and he said, "Well, hang on a second. Why are we doing that? He went and seen it in Southampton, where they made these mass concrete blocks. So basically, he said, "Okay, I'll take that idea and amplify it a bit. So if you're ever down on St John Rodgerson's Quay, you'll see this structure. It looks like a big toilet plunger. It's actually a. Diving bell, and Bindon Bloodstone invented that. The diving bell would be dropped onto the seabed, and men would go into it, and then it was pressurised, and they would could then work on the seabed, levelling it. And Bindon Blood then designed these mass concrete blocks, 350 tonnes, and a shear.
Eamon McElroy 30:18
So if you go into, I think it's Trinity University. They have some of the models implant, but he used mass concrete blocks, set them on the seabed, then you build your key wall on top of it. So that's the first key walls that we would have. Birth 18 to 24 are all mass concrete blocks from building blood stoning. The next formation of key walls is concrete caissons, which are just big floating crates that they build in a dry dock, probably the most famous ones would be the mulberries that they use for the D-Day landings. But the world's first ever concrete casing was built in Dublin Port in 1922, and you can actually see the pathy newsreel of it being launched, and that's when engineers wore top hats and big moustaches out to here. But that was the world's first ever concrete case on Dublin Port. So the key walls then again, seabed was levelled, concrete case was floated out, opened up valves, and that sank into position. Then they filled it full dread spoiled. Then you built your key wall on top of it. The next formation of key wall then is combi walls, where you actually drive sheet piles into the bedrock. The advantage of that is that you can go deeper because if you have a concrete casing or you have a mass concrete block like birth 18, you cannot dredge underneath those, or you undermine them, and the whole key wall will fall into the sea. So you're limited to the depths that you get to. So basically, what we're doing with the Magner is that we are widening our birthing pockets where we can widen, and with new key walls where we have designed them to go lower. You know, we haven't dredged them because we didn't need to dredge them at the time, but they're designed to go deeper. So that's what the Magner is now doing. She's moving up from birth 52. She's finishing there today. I think about 5o'clock. She goes up to Alexander Basin East, and she'll start deepening and widening all those berthing pockets.
Dusty Rhodes 32:06
What kind of engineering thoughts are going through your head? Because if you have such a massive machine as doing such big work, there is all kind of precautions that you have to take in considerations just on an engineering side of things. What's going through your head as the Magner is moving along and doing this work, key
Eamon McElroy 32:23
word for dredging is production. You don't stop a dredger; you just do not. The costs implemented. If I was to stop a dredger for one day, you're talking between 50 to 70,000. So you do not stop these vessels. So therefore, you have to do an awful lot of programming. You have to do an awful lot of communication. Like when I do my dredging meetings, and you know, during this project, we do them really daily. We're sitting with the harbour office. We're sitting with the environmental team. We're sitting with the project managers of the dredging company, and everybody around that table has a very important role to play, because not alone are you doing that under licencing? You have very strict licences, which are audited by the EPA, who have the authority to come in and stop you. Then you have all the port traffic. So Dublin Port had just under 8000 ship arrivals, I think, last year. So there's a ship coming in and out of Dublin Port nearly every 20 minutes. If you do it on average, you now have one of the world's biggest backhoe excavation, right in the
Dusty Rhodes 33:22
middle of it,
Eamon McElroy 33:22
right in the middle of it, which positions itself by dropping spud legs into the seabed and fixes itself so the barge can then be pulled up beside it. So we actually just had that meeting this morning with the harbour office. We're looking at you know what traffic's coming in and out. So there's an awful lot of planning has to be put in place. Then I have two archaeologists full time on board, looking to see if we're pulling up any Viking ships. I then have two full time marine mammal observers on board, doing making sure that we are clear of any seals. Now we do never get harbour porpoises coming in past the breakwaters; very rare, but we do get seals who are curious and will come in. And what do you guys? So the marine mammal observers were on board. The archaeologists are on board. Then all the reporting to the EPA, which is very strict, you have to show where every scoop comes from, and you have to show where every scoop went to, and you have to prove that you're always within the boundaries of your dredging plan drawings. So all of that takes place to make sure that you do not stop that machine once it starts.
Dusty Rhodes 34:25
You're blowing my mind today, Eamon. I have to be honest with it. No, it's it's fantastic. If an engineer is listening, okay, and I've got a couple of different engineers in mind on this. Okay, number one is somebody an engineer is sitting in their job, and I go, God, this is boring. I'd love to do something exciting, like what Eamon is doing, or maybe you've got somebody who's in college at the moment, or kind of just starting off in their career, and they're listening to what you're doing. Now they may not want to do port, but they want to do big, exciting projects like you do. Your story has gone from driving around a forklift as a kid and kind of going, "Well, hey, this is fun, and now like you're. Managing the biggest port in the country. What advice would you give? What have you learned on your journey that you would say to somebody younger coming up behind you that might help their career?
Eamon McElroy 35:11
I always like the fact if anybody ever asks, "What do you do? I say, "I'm a civil engineer by trade, and they go, "What does that mean? I go, "Well, I solve problems. I just solve problems. Whatever the problem is, I take a look at it, and I kind of say, "What's the best solution for that? And if it's in civil engineering, I mean, I fell into the port, even though my second placement ever was building a rural ferry terminal up in the Orkney Islands, where we used to see a change in the weather. Instead of the rain coming horizontally from the right, it came horizontally from the left, so I would say to anybody, go get the experience. Don't be afraid. Don't be afraid to travel. Go try and get in with some company and get you know get a bit of experience because experience really does pay a dividend. I would be doing interviews for you know certain jobs and people who kind of say, "What's your experience? I could list what I did, and they kind of said that's why I got into Dublin Port. But what do you do? I do this. Okay, we want you. And as I said, I came from a building set. I wasn't wearing a shirt and tie. When I went for my interview, I can guarantee you. That's basically it. You know, and get your qualifications. Like I had to up my ante because I would be working in building sets, and people say, oh, you're not qualified like me. Well, I'll go get your qualifications in, and I got my honours degree. And I would say, yeah, definitely look at you know there are certain aspects. Some people might want to do more design and work in consultancy. I never really went into consultancy side of things. I preferred to be on the ground looking at stuff, but yeah, no, definitely look and try and get as much placement experience you can while you're at college. You know, gain that experience. Now, my pay at the beginning, when I was working in the Orkney Islands, the chain boy got more money than I did. Do you know what I mean? When I was doing all the setting out for a rural terminal, but you have to live with that, and then when eventually you do go on, and you will find find something that you're interested in as well. Like I say to you, I've never had the same day twice at Dublin Port, and that's you know that's great. You know, there's no boredom.
Dusty Rhodes 37:13
Eamon, I can't even begin to tell you what a joy it's been to speaking to you. You have told me things about, and you know I'm a Dubliner and I pass the port and it's like yeah yeah whatever wow talk about a new appreciation for it you know and then just the size of the work that you're dealing with and the engineering solutions that you're coming up with and then the history of the engineering solutions there it's mind boggling I've so so enjoyed the conversation. If you've enjoyed the conversation as well, and you'd like to find out more about Eamon McIlroy's work and the work at Dublin Port and ongoing engineering development, you can check out the Dublin Port website, and we'll include a link for that in the description area of this podcast. But for now, Eamon McIlroy, Port engineer at Dublin Port. Thank you so much for joining us.
Eamon McElroy 38:00
Thank you.
Dusty Rhodes 38:01
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