The value of canals

[couerdelion]

Now that these are going to be easier to make, I thought I might start a little thread on the value of this naval shortcuts. It's all well and good saying that they are good value but does this mean that you settler in the middle of nowhere just for the extra naval mobility? Hopefully, with a little discussion people will reach there own conclusions about whether they are worth the cost of sub-optimal city placement.

I will say little on the subject now other than expressing a gut-feel that these routes are probably overvalued by civvers. I suspect that the real value is little more than as a cost-reducers because there is less need for a large naval force to defend two coastal areas.

[Lord Avalon]

Well, it's situational. You may not be able to build a canal if the land is too wide. OTOH if there's a two-tile isthmus, you don't even need to plant a city.

I think the value is in the amount of time you save cutting through the middle of a continent, rather than having to sail all the way around (especially as land mass increases). Also, before you have ocean-going vessels, you may not be able to sail around a continent if there are closed borders. But you could cut through a canal.

And if you're saving travel time, then you're spreading your religion more quickly, or getting your invasion forces there sooner, etc, etc, etc.

[Blaupanzer]

Plus those little cities can be real income producers with all the ocean squares. A mine or resource nearby helps a lot though.

[Blake]

I think for the most part it's just cute.

[Harrier UK]

Why increase overall city maintainance with a new canal city , when a fort will do it for you.

Great addition in my opinion. I have wanted and asked for a canal feature from the old civ3 days (does anyone still play that old relic. ) . If it is called a fort who cares - the feaure is now there.

[BigFree]

Is this going to be a part of BtS only?

[Harrier UK]

Originally posted by BigFree
Is this going to be a part of BtS only?

Sorry, simple answer - yes.

[MattDoyle]

Originally posted by Harrier UK
Why increase overall city maintainance with a new canal city , when a fort will do it for you.

Great addition in my opinion. I have wanted and asked for a canal feature from the old civ3 days (does anyone still play that old relic. ) . If it is called a fort who cares - the feaure is now there.

In answer to your first question, Cybershy explained in his q/a thread that you can make a 2 square canal with 2 forts, or a 3 square canal with 2 forts with a city in between. So thats why you would increase the overall city maint

[couerdelion]

Well one thing might be to consider a relatively large “channel” of three-band width where the canal can only be formed by a fort-city-fort combination. Since the new rules will make canal-building easier, we might consider all options. But in each case, the consideration has to be

Minimum “cost” of setting up a canal vs Benefit

Of course, the simplest canal might just be a single city of a single fort. So the cheapest cost in this is likely to be the cost of a fort (which I guess to be a worker-build). However, I would be surprised that they would be an occasion where a simple fort-canal would not be located in a position where at least an adjacent city-fort canal might be possible. Since we are looking at a coastal city in this case, it is more than likely that this we have a desirable city spot there anyway.

There are again situation in which city settlement is also tech-dependent. Settling on a real-life panama site would probably be a bad site for most ancient cities because of the health costs. Those cities would probably be marginal cities until the time that you can chop jungle and develop the calendar resources. By contrast, this whole question of “time” benefit is most noticeable in the early game where a work boat explorer can be quite valuable. Not to mention the potential “choke” value of the city itself.

But what really do we mean by time value. Does a religion really spread more quickly when we have a canal? Do we significantly reduce the cost of building an army or the land-based unit costs because we have a canal?

I don’t know about others but I tend to use roads to move my units around resorting to naval transports only when forced to do so. D-Day invasions are quite rare in my games because they are more expensive than the simpler option of making the troops walk. As for religion, missionaries are quick enough on their own so are even less likely to board ship when there is a road to take. On occasion, a medium-sized bay might allow a double-move to speed things up but the time benefit here is almost negligible.

This is not to say that speed does not have its value. We are naturally happy to spend valuable worker time in building roads which make our units faster. This does have a value because units get to the front-line more quickly or move around more quickly. The latter makes our insurance costs cheaper (fewer units to defend territory) while the former means that the costs of capturing other cities is smaller and that we acquire them earlier and can then turn them into profitable cities sooner. But even here, were have to ask ourselves how much we valued the road network for the movement benefit. How much would we actually PAY if we had to buy our roads?

And this is just the land-based movement. Naval movement is far less important in the game so surely extra speed for naval units as even lower value. Even if the nature of the “extra speed” is different because it adds a fixed number of tiles to the movement rather than simply converting everything to ½ or 1/3 movement point, it still all boils down to the fact that I will need fewer naval units to do the job that I need them to do. But it will not be a lot fewer so I am inclined to feel that the cost savings is of the order of a couple of gp/turn and a fixed hammer savings of naval units built.

Overall, I suspect the biggest potential value that we will find from canals is from trade in the early game. Easily linking two oceans we acquire trade routes more quickly on a different coast. In time of war, this alternative route might open up a quite valuable foreign trade route that might otherwise be closed in time of war. Even this benefit it likely to be a short term one that disappears when you have cities on both coasts.

So my general feeling is that canals are a bit of a gimmick. I might decide to create one if the cost is low: I either need just a fort of two or that the city site is not much worse than the next best in the area. But certainly not something that I would go out of my way to generate without more compelling reasons that are nothing to do with the movement of naval units.

[Flhaus]

You mention that the "new rules" make canal building easier. Does this mean that there is a way to build canals in vanilla Civ4?

[couerdelion]

Originally posted by Flhaus
You mention that the "new rules" make canal building easier. Does this mean that there is a way to build canals in vanilla Civ4?

Building a city which on an isthmus with sea routes on either side will allow ships from one side to sail through the city to the other side. This was always possible in vanilla.

[Flhaus]

Originally posted by couerdelion


Building a city which on an isthmus with sea routes on either side will allow ships from one side to sail through the city to the other side. This was always possible in vanilla.

Yes of course. I just never considered this to be an intentional building of a canal. So the short answer is in van, you cannot build a canal across a continent unless it is an isthmus.

[Kekkonen]

If you build a fort-city-fort canal, does the city count as coastal?

[GeoModder]

Originally posted by Kekkonen
If you build a fort-city-fort canal, does the city count as coastal?

Not as far as I know.

[Tattila the Hun]

Considering, how much benefit trading gets from Panama and Suez, there should really be some sort of trade bonus for a channel city... Maybe there is?