[Freeciv] Re: suggestion: ships out of cities

[Jules Bean <jules@xxxxxxxxxxxxxxx>]

On Wed, Jun 19, 2002 at 09:17:58PM -0400, Ross W. Wetmore wrote:
> >Not that hard. Requires Ross' ocean patch and an additional int in the
> >unit field denoting the ship's original ocean, that's all. But is it
> >desirable? I always thought of such cities as the equivalent of the Suez
> >Canal, and a very good feature.
> 
> I too like the feature. When you consider the instant road and railroad
> features of cities, instant canals is not really that farfetched. One of
> the first things done around cities is to dredge and channel any water
> features to provide flood protection, recreation and transportation.

Dredging and channeling for irrigation, drinking water and sewage is
one thing. Making a canal which can carry ocean-going ships is another.

> Then again, portage systems were common at many places that didn't go
> for the full canal investment.

Portage an ironclad?  A battleship?

Actually, there is a suggestion that certain ships (the trireme and
possibly another class of small ships) might be allowed to move along
rivers.  If this is implemented, I'd be in favour of small ships being
allowed to cut through cities this way, but not big ones.  The
assumption being that dredging a river/canal to make it navigable to
boat level is low-tech, but installing the massive locks or ship lifts
for real ships is not.

> And with the level of map detail, there is no way to really tell whether
> there are water channels nearly connecting the two, or that can make
> a connection with a little damming effort at some end. Arguing against
> this on the basis of a worst case scenario only is not that productive.

True.  But natural water channels seldom connect distinct oceans. In
prehistory, the Med was not connected to the atlantic at
Gibraltar. When a connection burst through, the ensuing waterfall was
massive, totally non-navigable, and lasted for a century or so until
the water levels equalised, by which time the ensuing erosion had
ensured that Spain and Africa had a pretty substantial body of water
separating them.

Hmm.  When the Med was separated from the atlantic it actually dried
up: http://www.clas.ufl.edu/users/pciesiel/gly3150/med_story.html

Anyhow, the point remains:

Any time that two oceans are connected by a natural waterway of any
size, I would expect the massive tidal flow back and forth down the
channel to eventually widen it well beyond the point that any
premodern culture could build a bridge across it. Similarly, I don't
think any culture without the mastery of steel and concrete required
to build locks which can hold millions of gallons of water could build
a ship canal.

Jules