Fifty-Year History of Movable Bridge Construction - Part I

Part I of this three-paper series reviews the history of movable bridges and follows the development of the construction of this type of structure during the past half century. In recent years, however, there has been a preponderant tendency to build high level fixed bridges to avoid the inconvenience caused by an open drawbridge. As the railroads of the country are rebuilt, there will be large numbers of movable railroad bridges constructed. As existing drawbridges in inner cities become obsolete, many will be rebuilt in kind or with increased vertical and horizontal clearances to minimize delays to ground and waterway transport.