ed ▁to ▁firm ▁rock ▁by ▁the ▁use ▁of ▁a ▁grab ▁type ▁exc av ator ▁working ▁within ; ▁the ▁exc av ated ▁face ▁was ▁kept ▁under ▁water . ▁ ▁In ▁ 1 8 9 8 ▁the ▁bridge ▁was ▁re construct ed ▁and ▁w iden ed ▁for ▁quad ru ple ▁track ; ▁com pressed ▁air ▁exc av ation ▁for ▁ 1 3 - foot ▁( 4   m ) ▁diameter ▁steel ▁pi ers ▁were ▁used . ▁The ▁structure ▁consists ▁of ▁two ▁variable ▁depth ▁continuous ▁g ird ers . ▁The ▁visible ▁sp and rel ▁b rac ed ▁arch es ▁are ▁not ▁primary ▁struct ural ▁members . ▁There ▁is ▁a ▁decor ative ▁cast - ir on ▁cor nice ▁and ▁par ap et , ▁and ▁to wers ▁and ▁half ▁tur rets ▁in ▁red ▁sand stone . ▁The ▁work ▁cost ▁£ 6 7 , 9 7 0 . ▁It ▁is ▁a ▁listed ▁building , ▁category ▁B . ▁ ▁References ▁ ▁External ▁links ▁ ▁Video ▁foot age ▁of ▁the ▁City ▁Union ▁Bridge ▁ ▁Category : B rid ges ▁in ▁Glasgow ▁Category : B rid ges ▁across ▁the ▁River ▁C ly de ▁Category : B rid ges ▁completed ▁in ▁ 1 8 9 9 ▁Category : 1 8 9 9 ▁establish ments ▁in ▁Scotland ▁Category : R ail way ▁brid ges ▁in ▁Scotland ▁Category : Category ▁B ▁listed ▁buildings ▁in ▁Glasgow ▁Category : List ed ▁brid ges ▁in ▁Scotland ▁Category : G orb als <0x0A> </s> ▁Om ega ▁Township ▁is ▁a ▁town ship ▁in ▁O ' B rien ▁County , ▁Iowa