Hundreds of people have turned out at Brisbane's Roma Street Station to ride, photograph and farewell the first leg of the final journey of the famous Sunlander train service.

It was gloomy weather for a gloomy occasion in the city - the beginning of the end for the 61-year-old service, that first started chugging up the Queensland coast in 1953.

Since then, it has made the 31-hour, 1,681-kilometre journey from Brisbane to Cairns up to three times a week.

More than 3.5 million people have dined in its club cars and slumbered in the sleeping carriages.

The trip was once voted Australia's Best Rail Journey and labelled one of the world's top 25 rail journeys by the Society of International Railway Travellers.

This morning, hundreds of passengers packed platform 10 at Roma Street Station for the 9.20am (AEST) departure, but not before being treated to cake and some entertainment to celebrate.

The Sunlander has carried more than 3.5 million people since 1953. ( ABC News: Patrick Williams )

The Sunlander will arrive in Cairns on Monday before beginning the long trip back to Brisbane and into retirement.

It is due back in the city on New Year's Day, giving passengers on board chance to celebrate new beginnings for themselves and rail travel in the state.

Photographers snap up opportunity for one more look

It was not just family and friends there to see passengers off - train enthusiasts and photographers packed the platform for a look at the locomotive.

John Hoyle, who writes for national rail magazine Railway Digest, was at the departure to cover the final journey of the Sunlander.

He said photographers would be out in force along the route, snapping the Sunlander in action as it travels to Cairns and back.

Journalist John Hoyle was covering the departure of the Sunlander for Railway Digest. ( ABC News: Patrick Williams )

"I've been on it many times over the years both as a sleeping car passenger and a sitting passenger. It's always been an interesting train to travel on," Mr Hoyle said.

"It's sad to see it go but few trains last over 60 years with basically the same rolling stock.

"It's amazing its lasted so long."

Mr Hoyle said there were not many trains like the Sunlander left in the world.

"A lot of them have been replaced by high-speed trains or more modern trains ... others have completely disappeared and been replaced by buses and aircraft," he said.

"With the airline deregulation in the 1990s it meant that lot of passengers were lost virtually overnight to long-distance trains.

"But there's a small market that has kept with the train, people on a budget who want to to travel in the sitting cars and people who want to sample the traditional sleeping car and dining cars ... it's a slightly different market, they've stuck with the train."

The sleeping cars will be no more once the Sunlander retires. ( ABC News: Patrick Williams )

Mr Hoyle said Queensland Rail would lose the sleeping car market because the service replacing the Sunlander would not have the traditional sleeping compartments.

"They have rail beds which for many people lack the privacy and security of a traditional sleeping car."

Queensland Omnibus and Coach Society vice president Matt Luchterhand travelled from Jimboomba to get shots at Roma Street Station before racing north to Wooloowin for some more photos as the train passed by.

"I've been a train enthusiast for a little while. I'd been on it 10 years ago with my father and grandparents, we went up to Cairns for a holiday.

Matthew Luchterhand came from Jimboomba to photograph the Sunlander leaving Brisbane. ( ABC News: Patrick Williams )

"It brings back some memories and I wanted to see it off.

"I do like the Sunlander. It will be sad to see it go."

Passengers pack in for one final journey

Train travelling friends Jennifer Purse and Robyn Williams were in no rush to get to Cairns.

In fact, they said, the longer the trip the better when it comes to train travel.

"I've been on one of those fast European trains from the Hague to Paris, it takes three hours and you cross a whole country but it's so fast you can't see it, it's just a blur," Ms Purse said.

"The ones in Australia do a nice speed," Ms Williams said.

The two are well travelled when it comes to trains, having travelled through Canada and across Australia on the Ghan and the Indian Pacific.

The only one left for them was the Sunlander.

The sleeping cars will be no more in Queensland once the Sunlander retires - they will be replaced by railbeds on the Spirit of Queensland. ( ABC News: Patrick Williams )

"It's my birthday, so it's my birthday treat to be on the Sunlander," Ms Purse said.

"I've never been to Cairns so it's just another little train adventure for me.

"You can see so much and it's like you leave the everyday world behind and you're in a little world of your own. Everyone talks to everyone."

Ms Williams said they had dressed up for the occasion because the experience was a part of history.

"We've seen the pictures of the original trip and we decided if it's going to be the last one we better be part of the history," she said.

For Bruce Warrell, riding the Sunlander took him back to his time on board in 1958.

"We took 19 Scouts on the Sunlander to Townsville and up to Magnetic Island," he said.

Colleen Mcintosh has been using the service for 30 years.

"There's some sort of peace when you're in a sleeper and yeah, we're sad to see it go," she said.

Spirit of Queensland steps in to replace Sunlander

The Sunlander will be replaced by the third and final Spirit of Queensland train, part of a newer and faster fleet.

The first service was introduced in October 2013, with the second following a year later.

Each of the new trains can carry 172 passengers.

The train is part of a $200 million project to revitalise long-distance train travel in the state.

"Through this investment we will increase rail services from four to five per week, providing an additional option for customers travelling between Brisbane and Cairns," Assistant Minister for Public Transport Steve Minnikin said.

A look inside of one of the Sunlander's sleeping cars. ( ABC News: Patrick Williams )

"The new fleet is part of our strong plan to revitalise frontline services and support tourism to regional communities."

Sunlander train driver Chris Pianta said the Spirit of Queensland would be much different.

"This train [Sunlander] does 100 kilometres per hour maximum, the new train will do 160 kilometres per hour" he said.

The process has not been without controversy though.

Earlier this month, the state's Auditor-General found that Queensland Rail staff withheld the full cost of replacing the Sunlander train service and had fanciful hopes of it becoming a success.

In Andrew Greaves's scathing 71-page report, he said the project was not value for money and that public servants clouded the facts and were guilty of ill-informed decision making.