Regarding the blowing up of Round Down Cliff to build the stretch of line from the Abbotscliffe tunnel to the Shakespeare tunnels, which I seem to recall reading was the largest manmade explosion in history up to that time, although it only manifested itself as a dull subterranean rumble:
Here is a print from the Illustrated London News in 1849 regarding the wreck of the East Indiaman "Tigris" which went aground off that stretch of line, which can be seen in the picture. The accompanying text is rather interesting!
The full sized images can be viewed on my fotopic site at:
http://shipsintheportofdover.fotopic.net/c1844530.html