But the actor's personality sits at odds with the character he creates on screen.
Yes, the drawling voice is all his, but the man himself has a lovely, wicked sense of humour. And he uses his rather melancholy disposition to great comic effect.
For example, when asked how he feels about the hit drama being decanted from Rochdale to Greenock, as part of the BBC's corporate policy, Philip pulls the face of a man who has just been parachuted into a war zone.
"At first, I was very dubious about the move up here," he says, speaking from the film base, set in the former home of Greenock Academy.
"I had this vision of Glasgow from the 50s and 60s, that it would be a really aggressive place that doesn't welcome Englishmen."
He adds, grinning: "And my feeling about the show was 'If it ain't broke, don't fix it.
"It's a very dramatic move to take a successful show and move it to another part of the country."
But when the Kent-based actor came to Scotland he realised his fears were unfounded.
"I haven't seen much of Greenock – we are filming five days a week, 11 hours a day – except the inside of Costa Coffee, where I now have over 4000 points to spend," he says.
"However, I have discovered Glasgow is very cultural place. And one of my hobbies, my passions, is eating out. And I can certainly do that here in some great places.
"As for moving the show north? I reckon the success of the show over the (six) years has been its ability to reinvent itself. And this is another way to keep it fresh."
He adds, smiling; "It's easier to get home more often from Glasgow, flying, than I could from Manchester."
Philip's stint in the hit school-based drama is the latest episode in a highly successful career in which he has played his share of authority figures.
He has played cops so often you imagine he walks the streets watching out for miscreants, appearing in the likes of Coronation Street as a detective, even playing a copper in a Bollywood movie.
"Yes, I've played lots of policemen, but I think the oddest character I have played is a Jewish army chauffeur with a Cambridge degree in a TV series called Perfect Spy."
However, he admits Grantly Budgen would have had no time for the young Philip Martin Brown, the son of a Methodist minister who grew up in Barrow-in-Furness.
"I was the class clown," he admits of his stint at grammar school.
"I was suspended more times than I could remember. And I was caned more than 60 times. Thank goodness for exercise books down the trousers."
But the irony is Philip, who has successfully dealt with epilepsy, not only went on to play a teacher – he is a qualified teacher in real life.
"It's art imitating life," he says. "I got just enough qualifications to scrape into teaching training college.
"However, I had always wanted to become an actor since doing impressions of the teacher, but my parents and teachers tried hard to talk me out of it.
"So when I did 'O' Levels at a further education college I also studied drama."
Teaching helped pay the mortgage, but after joining a local theatre company Philip knew he would always chase the acting dream.
And it has worked out for him, going on to work with legends such as Kenneth Williams in Joe Orton's Loot.
"A fascinating man, so knowledgeable, spiritual and a good director," he says of the late Carry On star. "I really liked him."
His standout moment in acting life was appearing as a crewman in The Bounty, the 1984 film starring Mel Gibson, Daniel Day-Lewis and Anthony Hopkins - and spending 10 weeks in Tahiti.
How was Mel? "Fun to be with. I learned a lot from him," he says.
But what of Tahiti adventures? Working in a tropical paradise surrounded by beautiful semi-naked women?
"It was art imitating life," he says with wide smile on his face.
"We arrived in Tahiti in the sunshine, to this idyllic paradise.
"And, a lot of the cast and crew behaved in the way the mutineers did in the real story, men who had been cooped up for nine months then let loose."
Must have been fascinating to watch, this joining of cultures?
"Oh, it was," he says, grinning. "But my wife flew out for two weeks during the run."
Will his wife be coming to visit in Greenock, lest he be tempted by the sultry beauties of Inverclyde?
"I'm not sure she'll see Greenock and Tahiti as that similar," he says, grinning.
l The new series of Waterloo Road starts on BBC1 this Thursday at 8pm