In the late 1970s and early 1980s, Australia’s grain industry was almost entirely regulated and the growers’ co-operative in each state worked closely together. Facing harvests too big for permanent silo storage, the industry went looking for a new “temporary” system. As Wayne Owens, the engineer credited with inventing the modern bunker storage system recalls: “from one of these get togethers came the basic bunker concept. The fundamental design, including shape and basic dimensions, was agreed by all.”
Each state then went its own way, with Western Australia adopted high walls, while the others settled on what became today’s standard. At first there was no purpose-built machinery. South Australia solved that by developing the drive over hopper (DOH) stacker, a dedicated machine that, in Owens’ words, “made the bunker very versatile as they could be moved from site to site at short notice.” The economics quickly became apparent, and serious research followed.
The cover was the sticking point. “With the tarp being the most important part of the bunker, this area came under intense scrutiny,” Owens writes, “as most people just considered it as an ‘off the shelf’ item, which is not the case, they just accepted whatever was on offer, with many costly failures.” Suppliers offered all manner of specifications and colours, but could not substantiate their performance claims.
As the bunker proved itself, the case for covered bunker storage over fixed concrete silos grew stronger: bunkers were cheaper per tonne, quicker to establish and movable, provided the cover could be trusted. Jaylon, working with CBH and the other major grain handlers, was among those making that case. Led by Stephen Lloyd, Jaylon set about designing the cover fabric. In those early years the co-operatives bought standard tarpaulin fabric themselves, with weight, specification and colour varying from state to state. Jaylon helped move the industry off general-purpose tarpaulin fabric and onto fabric customised to the specific demands of the grain-cover application and harsh Australian conditions. Having optimised the base cloth design and coating formulation, Jaylon was able to standardise grain cover fabrics Australia-wide. This lead to enhanced performance, longer service life and reduced grain losses through cover failures. In turn, this encouraged handlers to purchase grain covers based on proven performance, rather than price alone.
Over time, the bunker’s “temporary” tag fell away. As Owens puts it, “the new dedicated machinery and ‘state of the art’ dedicated tarp material slowly transformed the bunker from storage of last resort to front-line preferred storage,” and today bunkers are “predominantly the first & preferred option by everyone,” used by the big handlers and individual farmers alike. The system proved so sound that in 2001 Owens took it abroad, building the first international site in Cyprus and spreading it through the Middle East and Africa.
The lesson from that history is the one Owens still presses: the bunker is simple, but not foolproof. “Stick with the proven parameters, don’t use inferior un-tested materials, take advice from those who have done all the work to make them what they are.” One of those proven parameters, the colour of the cover itself, has its own story, which we turn to next.