ined ▁into ▁a ▁perfectly ▁symmet rical ▁shape ▁to ▁ensure ▁optim um ▁aer od ynamic ▁performance . ▁This ▁was ▁no ▁easy ▁task ▁when ▁manip ulating ▁a ▁bomb ▁cas ing ▁with ▁the ▁size ▁and ▁weight ▁of ▁a ▁T all boy . ▁ ▁The ▁Tor pe x ▁filling ▁was ▁pou red ▁by ▁hand ▁into ▁the ▁base ▁of ▁the ▁u pt urn ed ▁cas ing ▁after ▁mel ting ▁it ▁in ▁" k ett les ". ▁The ▁final ▁stage ▁of ▁explos ive ▁filling ▁required ▁that ▁a ▁one - inch ▁layer ▁of ▁pure ▁T NT ▁be ▁pou red ▁over ▁the ▁Tor pe x ▁filling , ▁followed ▁by ▁se aling ▁the ▁base ▁with ▁a ▁ ▁layer ▁of ▁wood me al - w ax ▁composite ▁with ▁three ▁cyl ind rical ▁re cess es ▁fitted ▁with ▁the ▁explos ive ▁boost ers ▁and ▁into ▁which ▁three ▁chemical ▁time - f uses ▁were ▁inserted ▁when ▁the ▁bomb ▁was ▁finally ▁armed . ▁ ▁T all bo ys ▁were ▁not ▁considered ▁exp end able , ▁and ▁if ▁not ▁used ▁on ▁a ▁ra id ▁were ▁to ▁be ▁brought ▁back ▁to ▁base ▁rather ▁than ▁safely ▁j ett ison ed ▁into ▁the ▁sea . ▁ ▁The ▁value ▁of ▁the ▁weapon ▁offset ▁the ▁additional ▁risk ▁to ▁the ▁air cre w . ▁ ▁Given ▁their ▁high ▁unit ▁cost , ▁T all bo ys ▁were ▁used ▁exclus ively ▁against ▁high - value ▁strateg ic ▁targets ▁that ▁could ▁not ▁be ▁destroyed ▁by ▁other ▁means . ▁When ▁it ▁was ▁found ▁that ▁the ▁Lanc aster ▁could ▁be ▁modified ▁to ▁carry ▁a ▁bomb ▁larger ▁than ▁the