Aerial Bridges

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• When  the  Duluth  Ship  Canal  was  cut  through  Minnesota  Point  in  1871,  it  created  an  island  and  an  access  problem  for  anyone  living  on  it.    Eventually  an  Aerial  Transfer  Bridge  was  built  in  1905  and  operated  by  the  City  of  Duluth.    
  The  Aerial  Transfer  Bridge  had  a  gondola  car  that  carried  automobiles,  horses  and  wagons,  and  people  across  the  ship  canal  for  just  a  nickel.    
  The  Aerial  Transfer  Bridge  was  in  operation  for  nearly  25  years.    As  Duluth’s  population  increased,  it  could  not  keep  up  with  demands.    Many  new  bridge  designs  were  brought  forward,  and  the  Aerial  Lift  Bridge  was  selected.  This  design  resulted  in  a  new  bridge  which  retained  many  of  the  structural  features  of  the  old  bridge.  
  During  construction,  actually  remodeling  of  the  transfer  bridge,  the  head  span  was  raised  to  accommodate  the  vertical  lift  span  when  in  the  up  position  to  still  provide  135  feet  of  clearance.    When  the  lift  span  is  down,  there  is  only  15  feet  of  clearance.      New,  taller  towers  were  built  inside  the  old  towers.    The  900  ton  vertical  lift  span  and  concrete  counterweights  are  connected  by  steel  cables  which  have  their  own  counterweights  in  the  form  of  large  chains.    A  bridge  operator’s  control  house  was  built  in  the  center  of  the  lift  span  above  the  deck.  
  Today,  Duluth’s  Aerial  Lift  Bridge  lifts  about  4,500  times  per  year.    There  are  6  bridge  operators  that  keep  the  bridge  ready  24  hours  a  day  during  the  shipping  season  which  runs  from  March  25th  to  January  15th.    
  Artifacts  from  the  old  Aerial  Bridges  are  on  display  in  the  Visitor  Center’s  lower  level.    A  free  fact  sheet  on  Duluth’s  Aerial  Bridges  is  available  at  the  Information  Desk  or  as  a  PDF  download  at  www.LSMMA.com.
  

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