Heysen Tunnels Response Plans state that for a confirmed fire in the tunnels an automatic second alarm shall be transmitted (Bridgewater, Aldgate, Upper Sturt & MFS). OIC can request specialist resources from either service, including foam pod/s, State Hazmat, BWC's etc. Also, dispatch should incllude a phone call to the Norwood Traffic Control Centre to see what their monitors show, from which they would likely close the freeway completely.
From past experience on that road dealing with large spillages, they have 25 mins on a rainy day to catch the flow before it hits the Patawolonga, or longer if the waterways aren't full. Now, burning fuel down the catchment presents a whole host of new issues, and may warrant a strike team response from the MFS to follow it through the channels in MFS area & cut it off.