Contour Followers

A canal is still water, and still water is flat and level. So how do you get past hills?

18th century navigation engineers (Navvies) had three options:

Similarly, when the canal reaches a valley, the engineers must:

Each of the solutions has its advantages and disadvantages:

Going around the side of the hill may seem daft to us, but in those days they had no trucks to cart the soil away.  They had horses and carts, but they just couldn’t carry very much, and the roads in 1775 were a joke. Beside that, they actually had to dig less soil. Work it out:

It is about 2 miles from bridge 2J to bridge 7C by road. It is 3.6 miles along the canal towpath. The canal is 1.5m deep and 10m wide. My GPS equipped phone says it is 16m above Mean Sea Level (MSL), and that the Netherton hotel (halfway along the road route is 30m above MSL. Assuming the average height of the road above MSL is 22m, compare the volume actual canal cut to the volume of acanal cut along the road route. Allow 2m for the towpath. (Note: 1 mile = 1.6Km)

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Length of cut = 3.6miles                         = 5.76Km

Depth                                                        = 1.5m

Width                                                        = 10m

Volume = 1.5 x 10 x 5760 m3

                                                                  = 86,400 m3


Length of cut = 2miles                                  = 3.2Km

Average Depth of cut to reach canal level  = 7m

Depth of canal                                               = 1.5m

Total Depth = 1.5m + 7m                             = 8.5m

Width of cut = 10+2m                                   = 12m

Volume = 8.5 x 12 x 3200 m3

                                                                        = ?