Why should Scotland’s longest-serving law firm chief be happy enough about the delays at Queen Street station?

“The disruption points to the fact that our infrastructure is going to be enormously improved in the years ahead,” says Bill Drummond, 18 years and counting at the helm of Scotland’s biggest independent, Brodies. “All the improvements that will flow through will encourage investment and economic activity.”

Brodies recently expanded with a move to smart new offices in Queen Street, and has a staff of 272 there, not far below its 339 in home base Edinburgh.

He says: “Major industries have always had a big stake in Glasgow – environmental, financial services, engineering of course – you can count on these businesses to work extremely hard to grow profitability and build exports and make their facilities better and more effective and more important – as long as we can keep relevant to these organisations there is scope for legal businesses to partner with them.”

The man who was first elected managing partner for a three-year term in 1998, at the age of 39, was re-elected for the sixth time in January, making him probably the longest-serving law firm chief in the UK. He was a board member of the Scottish Council Development and Industry for 10 years and steered its contribution to the independence debate before stepping down early last year.

He is unashamedly optimistic about the prospects for the national economy.

“Boardrooms around the world will have something to do with Scotland in there, private equity funds are looking for good places to invest capital, Scotland is on lots of agendas and we mustn’t hunker down and think there isn’t a lot of potential. Lets make sure the environment we have is attractive for indigenous businesses to continue to grow and invest.”

Under his self-deprecating leadership, the firm has grown from 175 lawyers and staff based at a single office to 639 across four offices in Aberdeen, Edinburgh, Glasgow and Brussels. Turnover has climbed from £8million to £58m and profits from £2.5m to £27m. Brodies is out in front as Scotland’s biggest surviving independent, with no London outpost and no plans for an English marriage of unequals.

“We do a lot more international business from Scotland than people might expect,” Mr Drummond says. “We had lawyers based in Doha for a great chunk of 2015 and 2015 supporting client projects over there, there is a lot that goes on within organisations like ours, helping clients, that very often we can’t talk about.”

He expounds: “Lots of firms have felt that the streets are paved with gold in London and traditionally have gone down and set up London operations, and no doubt those strategies will have been relevant at the time.” But not now, he suggests, in an era when the complexity of projects means specialist lawyers in eight or ten different fields from real estate to tax to planning to litigation will be needed to service a client properly. “Physical proximity is really quite important. You can quickly assemble a whole team and discuss things. It is so important that clients get a seamless service, they are not having to manage multiple different locations.”

As for independence, he says Brodies’ resilience through the crash was down to “concentrating on the bigger picture for our clients operating within Scotland as opposed to being too narrowly focused on sectors or work types”. He adds: “If you are market leader going into a recession you have to make sure you are even further ahead when you emerge from it. We have chosen to keep investing.”

Investment was up nine per cent last year to £30.9m but profits before partner pay-outs were up 14per cent, and the firm had £15m in cash. Turnover is up 57per cent post-recession, and by 12 per cent a year over the past decade – from an organic growth strategy focused on the needs of Scottish clients.

On the loss of independence among rivals, Mr Drummond observes: “It seems to me there has been a lack of self-belief which is unnecessary...I have not observed a massive increase in investment on the part of firms which have rebadged in Scotland often with a London-headquartered firm behind them. In some respects there has been attrition in terms of headcount and local experts.”

But it has thrown up opportunities for lateral hires such as private equity star Doug Crawford who decamped in November from CMS to join Brodies’ corporate and commercial team, which is Band 1-ranked by Chambers and has clients such as Clyde Blowers, Abellio and Ineos.

Technology investment has been critical, including IT platforms allowing smooth alignment with the way services are delivered by lawyers on other continents, and software driving services such as the firm’s Binformed platform of ‘free knowledge’ for clients.

Mr Drummond was born in Ayrshire and schooled in Kirkwall, Nairn and North Berwick as his civil servant father moved locations. He has collected whelks in Orkney, driven taxis in Shetland, and worked on farms and building sites. His star childhood memory is “when I caught my first brown trout, in the burn that feeds Scapa distillery”. Now 56, and appearing to have as fresh an appetite as ever for the role, he fishes for the smartest young graduates.

“When I started doing this job I was effectively FD, human resources director, IT director...now I have to be more strategic because of the scale of the business. When I am standing up speaking to our first-year trainees – we recruited 30-odd new lawyers last year and the same this year - they are investing their future in the organisation, and I am responsible for trying to make it successful for them and their futures.”