So, what is special about the Goomalling grain storage system? Its shape. It features two giant white domes, affectionately called the Dolly Twins by locals.
Goomalling has been part of the CBH storage and handling system since 1938 and they were upgraded in 1964 using a traditional horizontal storage facility which held 13,900 tonnes. But in 1994, new facilities were built and Goomalling became home to the two domes, which locals called The Dollies. Later, two more domes were added and the name was changed to the Dolly Twins.
Each dome is 39.6m in diameter and 19.8m high with a storage capac
ity of 44,000 tonnes. It’s believed that the unusual grain storage choice was made to maximise the storage capacity on small land (if you can help us with finding out more about why the choice was made, please get in touch!).
Concrete was used to construct the domes and they are 350mm thick at the base, graduating to 125mm at the top. Conveyor belts running in tunnels under the domes allow the for the reclaim of grain, and filling occurs via a conveyor belt only the top.
Other than the footprint size and comparative storage capacity, are there any other advantages of storing in a dome? Turns out, there are.
A concrete dome is extremely strong because of its shape and it is able to more efficiently resist the pressure of the grain load than traditional methods. The dome shape also result s in a cooler environment with less condensation than other storage structures.
Not only is the dome structure better at resisting the pressure of internal loads, it is overall a stronger shape. Unlike traditional silos, it will not fall over if incorrect loaded and they have been known to withstand the impact of natural disasters including tornadoes, hurricanes and earthquakes. This is particularly relevant to Goomalling which does experience seismic activity.
Their structure also makes them safe when it comes to fire. They are highly unlikely to succumb to an approaching fire as their structure makes it difficult for the fire to take hold. In the event of a fire or explosion within the dome, the dome contains the hazard and it is unlikely to spread or impact the surrounding area. Domes are also quite challenging for pests, the steep smooth sides making it difficult for unwelcome visitors to enter the storage facility.
You can view the Goomalling domes from the road, but please remember this is a work site and unauthorised access is not permitted.