Tuesday, April 03, 2007

Zoom!


Britain is a land of great engineers. When Britain pioneered industrialisation in the late 18th and early 19th century, it also developed railroads to meet the growing transportation needs. Harnessing steam to power machinery in the factories and pumps in mines was soon followed by putting steam engines on wheels. The engineer to do that first was Richard Trevithick. In 1804, his high pressure steam engine won a bet as it managed to draw 10 tons of iron, 5 carriages and 70 men on the Cambourne tramlines. This combined two inventions, the iron road used for horse-drawn trams, and the steam engine, that had by the efforts of Watt, Trevithick and others now became powerful and portable enough to be mounted on wheels. And the bet proved crucial, at least in hindsight. It showed that a mounted engine could be used to draw loads, using only the traction that results of the weight on the carriage.

25 years later, a much better known locomotive was born. Robert Stevenson's Rocket wasn't the first locomotive, but it was the one that shaped the design of all subsequent steam engines, by introducing a number of new solutions. With its multitubular construction, the engine was much more efficient in drawing heat from the fire to the water in the boiler. Stevenson also pioneered (if didn't invent it) the blastpipe, or releasing the exhaust steam from the engine's cylinders into the smokebox below the chimney, thus creating a draft in the furnace, and making the fire burn better and hotter.

When Britons are good at something, they keep doing it. They still hold the world land speed record for steam-powered, railed vehicles. From Trevithick's 5 miles per hour, the record was pushed to 125 miles per hour by the "Mallard" in 1938.

As steam engines were substituted by more efficient and faster combustion engines, and later with electric motors, British engineers no longer ruled the game. While every steam locomotive, even those by the Americans that occasionally held world records was just an improvement of Stevenson's technology, the other power sources were developed elsewhere. Diesel engines were of course developed by the German Rudolf Diesel (although Brits claim an earlier invention, but Diesel was first to file for patent), and the early speed records with this source of power were held by Germans. Exceeding 127 miles per hour already in 1936, the record of railed vehicles was irrevocably taken away from steam power.

Britons of course didn't leave things to rest, and reclaimed the diesel-title and still hold the official world record of 147.88 mph (or 238 km/h), made in 1987, although both Russians and Spanish claim to have exceeded those speeds in their trials.

But, nobody really cares as The Game has moved on again. While diesel is still widely used for powering trains, it is feed for the workhorses, not the thoroughbreds. Electricity-powered locomotives had been pioneered as early as in the first years of the 20th century, and the Germans had broken the world railed vehicles speed record by a test unit in 1903, exceeding 206 km/h, a speed that has never been reached by a steam engine. Electric trains remained a curiosity, until trams started to get their horses replaced by electric engines, railroads started to get electricity to them, and by 1950's, the race for the fastest electric train was on again.

This time Germans faced the opposition of the French, and the latter have now taken over the title of speed kings. The latest in the long list of achievements was today's world speed record by a conventional train, whopping 574.7 km/h (357.18 mph) with a train that had two engines and 3 passenger carriages.

This experimentation definitely helps the engineers to push the envelope, and advances in this field will soon be reflected in the actual timetables as faster train connections. After today's speedtest, the top speed of the TGV service between Paris and Strasbourg will be lifted from 300 to 320 kilometres per hour.

So, where's Japan in all this? Well, they are one step ahead, as usual with technology. Their bullet train services use trains that are slightly slower than the TGV, but have in the course of the last few years managed to clock some world records in the series for trains in commercial use. It's one thing to build a train that goes zoom, but another set of problems need to be solved to use the zoom to haul passengers from one place to another, according to schedules, among other traffic. And while TGV-speed testing is directly relevant to their service, what the Japanese are up with at the moment, has lately been put to proper use in China. That's MAGLEV.

Trevithick showed that as long as your engine is heavy enough, you can get enough traction between the iron wheels of your train and the iron rails on the ground to pull the weight of the payload. As speeds get higher, though, this friction becomes a nuisance. it holds you back. Luckily you can get rid of friction nowadays. Just use some supercooled magnets and levitate the damn thing. The patent for MAGLEV trains was granted in Germany, as early as 1941. There was a maglev train in Birmingham airport for 11 years, operating between the airport and railway station in 1984-1995. Most first instances of this technology have been for demonstrations, show purposes and running at very low speeds. Some other instances have been made just for testing or are short-lived due to the high expenses and limited benefits compared to conventional technology.

So, while the French have the railed vehicle speed record, Japanese hold the maglev-record. Their JR-Maglev goes 581 km/h, or 361 mph, a speed that the TGV almost reached today. The fastest commercial raillink is in Shanghai China. Using maglev technology, the airport express reaches 431 km/h or 245.5 mph. The probalem with maglev is of course the cost and the fact that you can't run other trains on the maglev tracks. The beauty of TGV and other high speed conventional trains is that you can use the expensive track for slower transport when the speed-freaks are not out. But as you need special track for special speeds anyway, and as the maglev technology has become more available, there are now many plans to open services in Europe. Plans of London - Glasgow maglev line have been made, and also a link between Glasgow and Edinburgh has been proposed. In Germany there are plans, and in Japan the JR hasn't spent billions just to play with the things, either.

Oh, where are the Americans in all this? Well, they made a different sport of the rail speed records altogether. Rather than faffing about with diesel engines or electricity, they bolted a rocket engine into a sled, laid some tracks across a desert in New Mexico, fired away and gained a record of land vehicles with the speed of 10 430 km/h or about Mach 9. Sorted.

(Pic: AFP / BBC)

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