The 1st bin is called a B type holds about 15000 tonnes They where inloaded via the roof via a nasty elevator called a country elevator the blokes that used them called them a name similar.
Out loading was by using a clark shovel witch was a bent tin plate that worked of the country elevator.The grain was pushed through a shoot on the side of the bin.
The 2nd bin was a H type held 10000 tonne the base of one is at Ongerup roof removed the system of loading the bin was the same as loading and unlolading the B type B type bins can still be seen around the state Beverly Wubin Jerramungup Pingelly
Conveyors and unloading pits were place on the B types in about the late 60s early 70s.
H type had there end walls removed and loaded by the thrower a machine placed on front of a mls and the grain was spat into the bin.Out loading was done by front end loader.
Some H types had there roofs removed and grain was placed into the H type via the above way.Originally the Roofed removed H type had tin placed onto the grain as a way to protect the grain.This was replaced by the tarping system as use today.
The last H type used to my knollage was at SE Hyden but was removed from use before 2000.
A H type is still used for a museum at Pingruphttp://www.flickr.com/photos/railwayofaustralia/sets/72157622665061298/
Pingrup Modifided H type
I hope this helps Cheers Daryle Ex CBH