Other readers might not know, so some further background: Spain has a broad-gauge network, but when it built its first high-speed line (opened 1992), in view of later linkup with the Trans-European network (which won't happen till 2009 at the earliest), it was built in normal gauge. But there is an even grander and bolder plan, considered earlier already but more seriously now under PM Zapatero, is to convert the entire network to normal gauge in two-three decades. In the meantime, however, to extend trains beyond the existting high-speed lines, the technology shown in the link was developed. (Since then another Spanish company, CAF developed its own rival system; both have contracts about a few dozen 250 km/h trainsets for Spanish railways.) An English page on the Talgo prototype can be viewed here. *Lunatic*, n. One whose delusions are out of fashion.
Here is some info on the Russian gauge from Wikipedia
In the nineteenth century, Russia chose a broader gauge. It is widely believed that the choice was made for military reasons, to prevent potential invaders from using their rail system. Others point out that no clear standard had emerged by 1842. Engineer Pavel Melnikov hired George Washington Whistler, a prominent American railroad engineer (and father of the artist James McNeill Whistler), to be a consultant on the building of Russia's first major railroad, the Moscow - St. Petersburg line. The selection of 1.5 m gauge was recommended by German and Austrian engineers, it was not the same as the 5 ft (1524 mm) gauge which was in common use in the southern United States at the time. Russia and most of the former Russian Empire, including the Baltic states, Ukraine, Belarus, the Caucasian and Central Asian republics, and Mongolia, have the official Russian measurement of 1520 mm, 4 mm narrower than 5 ft (1524 mm), though rolling stock of both gauges is interchangeable in practice.
Another interesting short article on the history of rail gauges is here.
I've always loved trains!
