Railroads

[Hydromancerx]

Well... I guess the problem is that Hydro Plants are available as soon as you get Electricity.

			<BuildingClass>BUILDINGCLASS_HYDRO_PLANT</BuildingClass>
			<Type>BUILDING_HYDRO_PLANT</Type>
			<PrereqTech>TECH_HYDROELECTRICITY</PrereqTech>

Hydroelectrcity techs comes after Electricity. And the Hyrdo Plants come at Hydroelectricity. I am not sure what you are talking about.

 

[Thunderbrd]

hmm... I wish I could have had my wife save her game at the point she got electricity... she had hydro plants available on the round she reached it. May be something flawed in the xml somewhere... Does the 3 Gorges Dam have the Hydro Electricity prereq?

 

[Hydromancerx]

Does the 3 Gorges Dam have the Hydro Electricity prereq?

Yup. Those are about the only things under that tech.

 

[Thunderbrd]

What are the prereqs for Hydroelectricity? It appears on the tech tree to be right after electricity which seems a bit too early. My wife must've already got hydroelectricity by the time she realized she had electricity access at all. I would suggest moving it to at least to a civil engineering prerequisite.

 

[Hydromancerx]

It appears to be just Electricity. However according to Vokarya's Dates ...

Original Post
1873 - Electricity - Maxwell publishes A Treatise on Electricity and Magnetism
1881 - Hydroelectricity - Schoellkopf Power Station No. 1 at Niagara Falls

Which is why they are so close on the tech tree.

Note that Hydroelectricity originally required Electricity AND Civil Engineering.

But I guess not any more.

1884 - Civil Engineering - Home Insurance Building is first steel-frame tall building

 

[intlidave]

To gain electric energy from water, you need a dynamo.

Quoted from Wikipedia:

The first practical designs for a dynamo were announced independently and simultaneously by Dr. Werner Siemens and Charles Wheatstone. On January 17, 1867, Siemens announced to the Berlin academy a "dynamo-electric machine" (first use of the term) which employed self-powering electromagnetic field coils rather than permanent magnets to create the stator field. On the same day that this invention was announced to the Royal Society Charles Wheatstone read a paper describing a similar design with the difference that in the Siemens design the stator electromagnets were in series with the rotor, but in Wheatstone's design they were in parallel. The use of electromagnets rather than permanent magnets greatly increases the power output of a dynamo and enabled high power generation for the first time. This invention led directly to the first major industrial uses of electricity. For example, in the 1870s Siemens used electromagnetic dynamos to power electric arc furnaces for the production of metals and other materials.

Wikipedia on electricity

Alessandro Volta's battery, or voltaic pile, of 1800, made from alternating layers of zinc and copper, provided scientists with a more reliable source of electrical energy than the electrostatic machines previously used. The recognition of electromagnetism, the unity of electric and magnetic phenomena, is due to Hans Christian Ørsted and André-Marie Ampère in 1819-1820; Michael Faraday invented the electric motor in 1821, and Georg Ohm mathematically analysed the electrical circuit in 1827. Electricity and magnetism (and light) were definitively linked by James Clerk Maxwell, in particular in his "On Physical Lines of Force" in 1861 and 1862.

 

[Il Principe]

I think having hydroelectricity real close to electricity makes sense. Asintlidave said: youneed a dynamo. Once you got that it doesn´t matter how you get that moving. Wind, water, steam ( no matter your heating...), hell maybe slaves.
How about making a weaker, but still power generating watermill like building for hydroelectricity, and having the damms depending on other later techs too, so you can´t build them at once.
I mean converting a watermill into a small power plant seems a pretty logical first step on the way to larger hydroelectric constuctions.