The Terran Tanks have a very large capacity of attack range ,damage and also splash damage when they are in siege mode.This splash ability can be used for another purpose,to determine and  kill hidden Dark Templars when you do not have Scanner or Science Vessel technology in a multiplayer game.But here again the micro usage is very important and you can sacrifice 2 SCVs for this determination.When the Dark Templars strike your base, you must firstly keep your mineral field from this attack,then  locate your siege tank in the range of the Dark Templar strike point and send there an SCV.So when the SCV is attacked by Dark Templar, order your Tank to attack to your own SCV, the splash damage will harm the hidden Dark Templar,if your SCV dies before the death of the enemy Dark Templar, send the second SCV and repeat the same process but remember, this tactic consumes your focus and it may isolate you from other jobs like making more Tanks or etc.. so your APM must be really high to absorb this focus consumption.