▁top ▁providing ▁views ▁across ▁the ▁har bour ▁and ▁city . ▁The ▁south - western ▁p yl on ▁is ▁used ▁by ▁the ▁New ▁South ▁Wales ▁Ro ads ▁and ▁Tra ffic ▁Author ity ▁( R TA ) ▁to ▁support ▁its ▁C CT V ▁cam eras ▁over looking ▁the ▁bridge ▁and ▁the ▁roads ▁around ▁that ▁area . ▁The ▁two ▁p yl ons ▁on ▁the ▁north ▁shore ▁include ▁vent ing ▁chim ne ys ▁for ▁f umes ▁from ▁the ▁Sydney ▁Har bour ▁T unnel , ▁with ▁the ▁base ▁of ▁the ▁southern ▁p yl on ▁containing ▁the ▁R MS ▁maintenance ▁shed ▁for ▁the ▁bridge , ▁and ▁the ▁base ▁of ▁the ▁northern ▁p yl on ▁containing ▁the ▁traffic ▁management ▁shed ▁for ▁to w ▁tr uck s ▁and ▁safety ▁vehicles ▁used ▁on ▁the ▁bridge . ▁ ▁In ▁ 1 9 4 2 ▁the ▁p yl ons ▁were ▁modified ▁to ▁include ▁par ap ets ▁and ▁anti - air craft ▁guns ▁designed ▁to ▁assist ▁in ▁both ▁Australia ' s ▁defence ▁and ▁general ▁war ▁effort . ▁The ▁top ▁level ▁of ▁stone work ▁was ▁never ▁removed . ▁ ▁History ▁ ▁Early ▁propos als ▁ ▁There ▁had ▁been ▁plans ▁to ▁build ▁a ▁bridge ▁as ▁early ▁as ▁ 1 8 1 5 , ▁when ▁conv ict ▁and ▁noted ▁architect ▁Francis ▁Green way ▁re put edly ▁proposed ▁to ▁Governor ▁L ach lan ▁Mac qu arie ▁that ▁a ▁bridge ▁be ▁built ▁from ▁the ▁northern ▁to ▁the ▁southern ▁shore ▁of ▁the ▁har bour . ▁In ▁ 1 8 2 5 , ▁Green way ▁wrote ▁a ▁letter ▁to ▁the ▁then ▁"