Humphrey Pump at the Cobdogla Irrigation & Steam Museum with Lisa McAskill in the Riverland region of South Australia

Head northeast from Adelaide into the Riverland and you quickly realise how local communities like Cobdogla rely on the River Murray. The region is affectionately known as the fruit bowl of South Australia - with thousands of hectares of orchards and vines pumping millions of dollars a year into the state's economy.

From the air you can clearly see how this rich tapestry of green hugs the river channel. But the further you venture from the Murray the more the scene changes - quickly reverting to marginal mallee scrub - just as it was when Europeans settlers first arrived.

But that all changed in the early 1900s with the introduction of irrigation… which saw hundreds of kilometres of open channels and giant pipelines fan out to water newly planted crops.

And that's where "Big Thumper" comes in. When you hear the noise it makes there's no prizes for guessing how it got its name. It's the world's only working Humphrey Pump and is the centrepiece of the Cobdogla Irrigation and Steam Museum.

This is a haven for the 'boys and their toys', even if - like the Humphrey Pump - they are getting on a bit. Named after its English designer, Herbert Alfred Humphrey, Big Thumper is unique. Traditional pumps use a piston or impeller to move water but with the majestic old Humphrey Pump, the force from a controlled explosion of gas propels massive amounts of water from one chamber to another, using engineering principles that were way ahead of their time.

"When it was invented at the turn of the century the internal combustion engines were still in their infancy," said engineer, Barry Mudge. "Few people could understand internal combustion principles yet Humphrey adapted that principle to pump water."

Pretty soon, the massive inlet chamber is full of water and the tense wait begins as the burners are lit and the temperature rises. When there's enough pressure - away she goes with a deafening noise. Each firing pumps about eleven tonnes of water - that's about six million litres an hour enough to water an area about 12 times the square mile of Adelaide.

These days the Humphrey is only fire up on special occasions but when she's in full swing the local school kids get an early minute from class and for bigger "kids at heart" it's a day to reminisce about old times.

"It took two firemen and one engineman to run it,' explained Bob Chamberlain who used to work here. "There were three 8-hour shifts running twenty-four hours a day. It used to burn about eleven and a half tons of wood in twenty-four hours to keep it running."

The amazing Humphrey pump is all part of the fascinating history of irrigation in the Riverland and is on show at the Cobdogla Irrigation and Steam Museum on Park Terrace.

For opening times and the dates for special firings of the Humphrey pump contact the Barmera Visitor Information Centre.

Humphrey Pump Cobdogla Irrigation and Steam Museum
Park Tce
Cogdogla
Contact Barmera Visitor Centre
Phone 8588 2289