Voal was the captain in the Imperial Navy who was in command of the Tarkin while it was being built within the Patriim system.
Voal, along with a significant amount of the officers on the Tarkin, desired to get rid of Darth Vader. The reason for this was that they both feared and detested him due to his lack of concern for the lives of those under his command, particularly after Major Kuhru was unsuccessful in his attempt to capture Luke Skywalker.
When Colonel Nord made the choice to activate the ionic cannon located on the Tarkin with the intention of destroying Luke Skywalker and Leia Organa, the superweapon underwent an explosion. The Alliance had sabotaged it, and it self-destructed upon firing. Voal, along with all of the Imperial personnel who were on board, perished.