Born in Grey County, Ontario, Brockebank moved to Saskatchewan with his parents in 1911 to a homestead near North Battleford.
After returning from service in World War I he established his own farm near Bjorkdale in northeastern Saskatchewan.
When the CCF formed government for the first time following the 1944 provincial election Douglas appointed Brockelbank to Cabinet as Minister of Municipal Affairs.
As Natural Resources minister, Brockelbank oversaw the growth of the potash and oil industries in the province.
He retired at the 1967 general election but remained active with the NDP until his death ten years later.