Albert Mathieu-Favier's proposal this project would have featured a ton of ventilation chimneys and the construction of a new (*) island on the Varne Bank.  
A museum commemorating this project contains a rescued Whitaker Machine from a failed 1920s attempt.  Engineers working on an earlier attempt to complete this project happily discovered that the high clay content of the Lower Chalk prevented the need for a lining.  One of the chief opponents of this project was Jonathan Sloggett, who was the chairman of Flexilink.  Albert Mathieu-Favier's proposal this project would have featured a ton of ventilation chimneys and the construction of a new (*) island on the Varne Bank.  The completed version of this project was damaged in a 1996 fire caused by an HGV shuttle.  The Treaty of Canterbury modified national borders to make this project possible.  It is the second longest structure of its kind in the world after one named Seikan that goes underneath Japan's Tsugaru Strait.  For 10 points, name this underwater construction project that linked France and Great Britain.
A museum commemorating this project contains a rescued Whitaker Machine from a failed 1920s attempt.  
The Chunnel [or the Channel Tunnel or Eurotunnel]