▁until ▁September ▁and ▁a ▁bridge ▁col lapsed ▁into ▁it ▁in ▁December . ▁Tra ffic ▁began ▁to ▁switch ▁to ▁the ▁new ▁cut , ▁which ▁was ▁too ▁narrow ▁to ▁allow ▁b arg es ▁to ▁pass ▁one ▁another , ▁and ▁so ▁a ▁programme ▁of ▁w iden ing ▁it , ▁which ▁was ▁completed ▁in ▁September ▁ 1 7 7 7 , ▁was ▁carried ▁out . ▁The ▁channel ▁now ▁ends ▁in ▁L ime house ▁Bas in . ▁ ▁Access ▁to ▁the ▁new ▁navigation , ▁now ▁known ▁as ▁the ▁Lee ▁Navigation , ▁was ▁still ▁by ▁tid al ▁gates ▁at ▁Bow . ▁There ▁had ▁been ▁gates ▁at ▁the ▁site ▁since ▁at ▁least ▁ 1 3 0 7 , ▁as ▁a ▁structure ▁was ▁ere cted ▁by ▁Henry ▁de ▁B edy k ▁during ▁the ▁reign ▁of ▁Edward ▁I ▁of ▁England . ▁The ▁gates ▁were ▁re built ▁in ▁ 1 5 7 3 ▁by ▁the ▁own ers ▁of ▁the ▁t ide ▁mill , ▁but ▁the ▁City ▁of ▁London ▁appointed ▁a ▁survey or ▁to ▁inspect ▁the ▁plans ▁and ▁a ▁committee ▁to ▁over see ▁the ▁work . ▁Document s ▁from ▁ 1 5 8 8 ▁suggest ▁that ▁the ▁gates ▁opened ▁automatically ▁when ▁the ▁incoming ▁t ide ▁reached ▁a ▁level ▁with ▁the ▁river ▁above ▁them . ▁Another ▁re building ▁took ▁place ▁in ▁ 1 7 2 1 , ▁again ▁by ▁the ▁t ide ▁mill ▁own ers , ▁and ▁with ▁the ▁City ▁of ▁London ▁appoint ing ▁a ▁survey or ▁to ▁over see ▁the ▁work . ▁S me aton , ▁in ▁ 1 7 6 6 , ▁suggested