N-0000.193.147.1 | Coffer dam previous to pumping, Victoria Bridge, Montreal, QC, 1858

 
Photograph
Coffer dam previous to pumping, Victoria Bridge, Montreal, QC, 1858
William Notman (1826-1891)
1858, 19th century
Silver salts on paper mounted on card - Albumen process
7.3 x 7 cm
Gift of Mr. James Geoffrey Notman
N-0000.193.147.1
© McCord Museum
Description
Keywords:  Architecture (8646) , bridge (558) , Construction (163) , Photograph (77678)
Select Image (Your image selection is empty)

Visitors' comments

Add a comment

Keys to History

Around each site where a pier was to stand, a coffer dam, a sort of watertight caisson, was built. The dam was sealed with clay and the water pumped out. Most coffer dams were built of logs weighted down with stones. They took longer to put in place than did floating dams, but could be left over the winter and were easier to seal. The floating coffer dam, for its part, could be towed away after use, but its success was marred by the difficulty of keeping the water out of the work chamber.