Traveling from NY Penn to Baltimore last week my seatmate commented on how she hated going through tunnels. I assured her the tunnels were in great shape despite being opened in 1910. Sometime later her comment got me thinking. In Jill Jonnes fascinating book "Conquering Gotham" I learned that the screw pilings that were designed to support these tunnels on bedrock were never installed. There was also a section which dealt with the tunnels rising and falling with the tide on the Hudson. The questions that came to mind were:
1) How much rise or fall are we talking about - millimeters, Inches?
2) Does the passage of a heavy passenger train cause them to deflect, also?
and
3) Since the tunnels "float" within the silt at the bottom of the river, what kind of device can be used to measure the deflections?
As you can tell, I'm no engineer!
Thanks, Mike
1) How much rise or fall are we talking about - millimeters, Inches?
2) Does the passage of a heavy passenger train cause them to deflect, also?
and
3) Since the tunnels "float" within the silt at the bottom of the river, what kind of device can be used to measure the deflections?
As you can tell, I'm no engineer!
Thanks, Mike