Sam and Dennis Pegg run a family engineering firm in Aldeburgh. Their workshop in a quiet side street is full of the usual industrial paraphernalia that accompanies such work. It’s a thriving business doing everything from designing and making gates for people’s homes to creating complex components for pumps and water management systems.

The father and son are a quiet, unassuming pair, who just like to get on with their work. There is the usual ribbing and the verbal cut and thrust of a father-son working relationship but there is nothing obvious to suggest that lurking within these two practical men is a creative spark ready to ignite.

Seven years ago there was a propitious meeting which not only changed the nature of their business but forged a new creative collaboration with Suffolk-based artist Maggi Hambling.

The pair freely admit that they didn’t really know who she was or what they were letting themselves in for when she first strolled in through their gates armed with designs and drawings for a giant scallop sculpture, a tribute to the life and work of Benjamin Britten, which was destined for Aldeburgh beach.

Asked for his reactions when he saw the scale of the project Sam says with a wry smile: “I just thought it was just so big, so complex and expensive, that it would never get off the ground, so we wouldn’t have to worry about actually making it. But Maggi got the money organised and I learnt from that day on never to under-estimate her.”

It’s clear that it’s a working relationship based on mutual trust and respect. Maggi has the ideas and the designs but it is the Peggs who have to deal with the physics and create engineering solutions which will allow her works to exist in a 3-D world.

The relationship involves genuine collaboration because while Maggi’s designs are imaginative and engaging, sometimes they need a little help to stay upright as a piece of sculpture.

Dennis says there are days when there is a lot of huffing and puffing on both sides. Maggi says she wants her structure to look exactly as she has drawn it. Dennis and Sam quietly point out that it will either bend, buckle or won’t stand up. Maggi urges them to find a way, the Peggs go off, have a think and come back with a solution that will work if Maggi agrees to a slight change here and there.

It’s the way they have worked together for seven years and it works because both parties trust and respect one another. “There are moments of quietness,” says Sam with a wry smile; “Things I say are needed and things she doesn’t want. We talk it over and we get there in the end.”

Maggi says: “It’s the work that’s important. The Peggs know that. We are all committed to the work.”

Both Maggi and The Peggs are hugely proud of what they achieved with Scallop, since then they have worked closely together on the foundations for Maggi’s huge bronze Big Wave sculpture which is in a private collection in Suffolk and now they have just finished work on a huge, three metre heron sculpture which will not only dominate the centre of Brixton but will also function as a weather vane.

The heron weather vane weighs a quarter of a ton and involves a lot of engineering work to secure it to the roof of the 1930s Prince and Dex building at the junction of Brixton Road and Coldharbour Lane. It is an area earmarked by Lambeth Council as needing improvement. The Peggs have also designed a ballbearing system which will allow the vast structure to move freely in the wind.

Maggi and the father and son team tested it on the back of a truck driving along Aldeburgh sea front. “It worked brilliantly. But there were a lot of nerves before hand because you never quite know until you get it up there,” says Maggi. “We took it past Scallop, so the heron had a sort of fly past you might say,” she laughs.

She says that she originally discovered the Peggs when she was looking for a local firm to construct Scallop. “I was told about this wonderful firm Peggs, who had been working in Aldeburgh for nearly a 100 years. I met them...” she fixes Dennis with a steely gaze: “Quite a silent lot, but they are exquisite craftsmen and a joy and a pleasure to work with.”

Dennis says that they always try and create in steel what Maggi has produced on paper but they do have to collaborate on changes to the initial design as the construction progresses.

“There are certain practicalities which have to be considered and that’s where engineering strength and sense has to meet art in the middle. If you take the weather vane, it’s got to look how Maggi wants it to look but at the same time, it’s got to be strong enough to do the job. It might have a 100 mph gust of wind hit it. So it’s got to be strong enough but then again Maggi wants it to look a certain way and therefore we have to meet in the middle.”

Dennis admits that after a nervous, slightly wary beginning, on both sides, they now have a very good working partnership.

Dennis and Maggi exchange a look. I ask: “Is she a good person to work with?” Dennis answers with a twinkle in his eye: “I think we are good at managing her expectations.”

Maggi shoots back a good natured-retort: “They try and keep secrets from me but it doesn’t work. I have to keep a close eye on them so the structural considerations are in keeping with the work of art – which is sometimes a battle and a challenge but we manage in the end.”

She concedes that despite her quest for artistic perfection, the Peggs have helped her realise that sometimes her ideas will not work until someone invents a way of creating sky hooks – “So I rely on Dennis and Sam’s engineering skills for my ideas to work. It’s absolutely crucial – otherwise the thing won’t be able to stand there. It’ll bend or collapse. Structure is very important.”

Maggi says that there has been a glorious sense of serendipity which has run through the whole heron project. “The project was commissioned by Lambeth Council who wanted to improve the area opposite the Ritzy Cinema. I conceived of this idea of a heron sculpture to act as a weather vane and would go on top of the Prince and Dex Building which overlooks the whole area.

“After having this idea of a heron – as you know I have always been very keen on herons ever since I first saw one as a young girl at Layham just outside Hadleigh. I was on a walk with my mother when I saw this exotic grey bird and I couldn’t believe it was English. It is so beautiful in flight but really quite comic when it lands or walks about. You see them sitting in a line in Battersea Park and they look like a lot of old judges, very comic. Anyway, herons have been in my work all along, so I conceived this idea for the Brixton heron weather vane and then discovered later that there used to be a heronry on the site. The Brixton fish markets are there and Herne Hill derives its name from heron Hill, so it was all quite remarkable how all the history all fitted together.”

She says that with both industry and public bodies tightening their belts, it was a difficult time for public art. “But, it’s investing in the local economy. Look at Scallop, look at how many visitors it has drawn to Aldeburgh, how much money it has brought into the town – car parks, pubs, restaurants, hotels – it’s all money that goes into the local Aldeburgh economy.”

Maggi’s heron was lowered into position by a huge crane at midnight on Thursday. The sculpture will have one side which will remain relatively dark and the other side will be highly polished which should flash as the wind switches direction alerting passers-by by to the change in the weather.

Sam Pegg says that they work from the maquette rather than from Maggi’s drawings to realise the finished sculpture – although Maggi is involved at every stage, checking and rechecking the work.

It’s a genuine collaboration. “She has her original sketch, which is gospel as far as she is concerned, we then make the maquette which she then approves and then we scale things up from there. We work from the maquette as much as possible. It’s when we make the maquette that we uncover any engineering problems we might have.”

When it comes to the construction of the sculpture, the Peggs do all the cutting, soldering and shaping while Maggi makes sure everything stays true to her vision. Sam laughs: “Every so often she’ll come over, look at what we’re doing and say: ‘Did I ask for that piece to go on there?’ and I’ll go: ‘No, but you need it.’ and she’ll mutter but she’ll agree.”

He said that after working on Scallop nothing surprises them any more. “We learnt a lot making that. We’d never done anything like that before, so we were sort of feeling our way. We didn’t really know what she wanted and what it ended up like was nothing like it was when she first came here. What we finished up with was nothing like the prototype. It changed its form a fair bit. We were working on it for about seven months. Maggi did all the changes to the drawings to make it work – we got there in the end.”

He says size was the biggest challenge with realising the Brixton Heron weather vane. “The challenge is not making a weather vane – we’ve been making weather vanes for a lot of years now – but the sheer scale of it. Even the maquette is large for a weather vane. But the finished sculpture weighs a tremendous quarter of a ton.”

Maggi presented them with an etching of a heron she produced in 1993 and wanted The Peggs to realise it in stainless steel. But not only had it to look like the etching it had to be secure, to move and function as a weather vane.

In the end the heron has taken four months to build – “In the last two months Dennis has been working on it more or less full time. I come in, in an advisory capacity when necessary.

“Maggi’s very much an artist but I think we work very well together. I think she respects what we do and we certainly respect what she does and we all get there in the end.” When they are not building giant-sized scallops and herons for Maggi, the Peggs’ core business is supplying engineering work for the pumping industry and supplying dam gates for the water industry. “So we are used to working on large scale projects.”

Sam says that he always looks forward to Maggi walking through the gates waving some drawings in the air with a new project for them to get stuck into. “I always look forward when comes over with an idea. But next time I hope it doesn’t take as long as Scallop and maybe not as much engineering as the Heron.”