Retractile drawbridge

{{Short description|Type of movable bridge}}

File:Aerial view of Summer Street Bridge, July 1925.jpg in July 1925, showing the tracks for the retractable sections to slide on]]

A retractile drawbridge is a rare type of moveable bridge in which the span is pulled away diagonally on rails. It is a variant of the retractable bridge. Only four examples are known to exist in the United States.{{Cite web|url=https://www.loc.gov/pictures/item/ma1236/|title=Summer Street Retractile Bridge, Spanning Fort Point Channel at Summer Street, Boston, Suffolk County, MA|last=Record|first=Historic American Engineering|website=www.loc.gov|language=en|access-date=2019-03-26}} It is believed to have been invented by T. Willis Pratt in the 1860s.