It's full steam ahead for two Ashburton traction engine enthusiasts as they gear up for the South Island's biggest machinery event: the fourth and final Wheels at Wanaka.

Richard Bradley and Sarah Crossen, members of the Mid Canterbury Vintage Machinery Club, are eager to return with their engines for what will be the event's last year when it opens its gates this Easter.

“I love the whole hype of it, the excitement of getting out and about and taking the engines out and spending the whole weekend meeting other people," Crossen says.

"It's great to let people see the engines instead of hiding them away in sheds."

Crossen, who is an Ashburton dairy farmer, has a family connection with traction engines.

Her great-great-grandfather was a traction engine contractor, and her grandfather and brother owned engines.

"It's just how we were brought up."

She owns a 1908 Burrell single compound traction engine, which is currently in South Canterbury.

However, with a top speed of just 20 km/h, she won't be driving it to the three-day event. "My brother will be transporting it by truck – it’d be a slow journey otherwise."

Bradley, an electrician by trade, has been giving his 1912 Marshall coal-powered traction engine some much-needed TLC in preparation for the show. "We've done major restoration work over the past 18 months, and now the pressure is on to get it all back together in time for the event," he says.

Bradley said there was an exciting atmosphere of Wheels at Wanaka for anyone interested -not just in traction engines – but cars, trucks, motorbikes and earthmoving machinery.

"There are people bringing machinery from all over the world to the event.

"It's for anything with wheels."

This year, Wheels at Wanaka is putting Caterpillars (CAT) in the spotlight as the brand celebrates its 100th birthday, which is being hailed as the "biggest noisiest birthday party" New Zealand has ever seen.

Event promoter Annabel Roy says organisers encourage anyone with a Cat in their shed to bring it to the three-day event.

"If they have a wee D2 in their shed, bring it along and join the world record attempt for the most Caterpillar machines in a parade," Roy said.

In addition to the world record attempt, the Terra Cat Earthmoving Extravaganza will be back.

Spectators can see vintage and modern machines in action in one of the event's six arenas spread over a 60-acre site.

"The biggest point of difference with Wheels at Wanaka is that you can sit on a hay bale with a hot dog and watch the machines as they move in front of you, which is why it has such an appeal across generations."

With an expected 70,000 attendees this year, organizers encourage vehicle owners to register in advance to avoid long wait times at the gates.

The event includes a tractor pull, snowmobile drag racing, and an Enduro Cross competition, in which off-road motorbikes compete over an obstacle course.

OceanaGold is bringing some heavy-duty mining vehicles, a unique experience for spectators.

"Some of those vehicles never see daylight; they never leave underground.

"So, if you come and see nothing else, see those," Roy said.

The event is a charitable trust, with profits going back to the community.

"We will divvy up the funds across as many community groups as we can and keep the money in Wanaka and the Central Lakes region."

While Wheels at Wanaka will be missed by locals and machinery enthusiasts alike, organisers are determined the final event will be the best to date.

"We want to go out on a high.

"We wanted to go out with a final bang for the fourth and final event," Roy said.

By Claire Inkson