A tank of whale oil.
Whale oil is primarily stored and utilized in the form of specialized tanks, which power all of Dunwall's technology. Whale oil tanks that are exposed to heat or pressure will explode in a bright, hot flash, and as such, Corvo Attano can throw one of these tanks to serve as an improvised explosive.
Tanks carried by a guard will drop and explode when the guard is taken down, lethally or not, and alert nearby guards. Such guards if taken down non-lethally also have a chance to be killed by said explosion; players are advised to leave such guards alone if attempting a clean run.
Gallery
A glowing whale oil tank powering a tallboy.
Multiple whale oil tanks powering tallboys.
A whale oil tank powering a wall of light.
A guard carrying a whale oil tank.