Watch it, Morris, or we'll rip yer bloody arms off

Elizabeth Farrelly
April 16, 2008

Thank God for the Greens. I've often argued that they should stick to green issues, rather than adopting every homeless puppy of a cause they see in the soft-left shop window. But when it comes to their Democracy 4 $ale website we - all of us - have much to thank them for. Not just for keeping the bastards honest when the Opposition lost its bottle (the one with a warm rubber teat they dropped through the cot bars and have been whimpering for ever since). But for concretising an issue whose environmental impact is, as it happens, huge.

Democracy 4 $ale started in 2002, when the retired academic Dr Norman Thompson offered to help the Greens leader Lee Rhiannon on a small research project. About 30 hours' worth, they thought. Six years and thousands of hours later, they have one of the most compelling websites in the country, cataloguing donations to all parties at both state and national level by industry, year, recipient and donor...

read more at the SMH

Drivers on Australia's busiest train line are voicing their alarm about an unprecedented number of dangerous mud holes along the track that have the potential to cause derailments.

One driver, speaking anonymously to ABC's 7.30 Report, has described the main Sydney-to-Melbourne line as "'an accident waiting to happen".

"The odds are there for a train to derail. I'd describe it as absolutely atrocious. I've never seen conditions like it in my 30-odd years on the job," he said.

Rail, Bus and Tram Union spokesman Bob Hayward says the mud is the result of a bungled re-sleepering program carried out by the government-owned Australian Rail Track Corporation (ARTC), which he describes as "a massive misuse of taxpayers' money".

"It was supposed to decrease transit times to make rail more efficient. And it's done the opposite, the total opposite," he said.

The union is calling for an independent inquiry and an audit of the infrastructure program.

http://www.abc.net.au/news/stories/2010/09/27/3023154.htm?section=justin

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Gus: the problem with the lines started (continued) when lines of "tired" hardwood sleepers were replaced with concrete sleepers...

Concrete railway sleepers are stronger and far less affected by weather but they have little give.

A wooden sleeper will slightly crunch under the weight of trains and, doing so, will absorb most of the vibration and spread the downward force on the track ballast. A concrete sleeper will transfer the weight — and all the vibrations — directly onto the track ballast.

The track ballast usually made of small crushed stones that spread the weight and the vibrations onto the subsoil.

In normal circumstances, concrete sleepers would work as well (even better) as hardwood sleepers. But with the amount of rain that has fallen recently, the "extra" vibrations have "liquified" the poor subsoil in places, creating a less than satisfactory and uneven support...

I believe the track engineers are working hard at fixing the problem.

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A fast train can only work on a very stable substrate, very stable special ballast on top supporting some precisely aligned concrete sleepers. From wikipedia...:

LGV construction is similar to that of normal railway lines, but with a few key differences. The radii of curves are larger so that trains can traverse them at higher speeds without increasing the centripetal acceleration felt by passengers. The radii of LGV curves have historically been greater than 4 km (2.5 mi). New lines have minimum radii of 7 km (4.3 mi) to allow for future increases in speed.

Lines used only for high-speed traffic can incorporate steeper gradients than normal. This facilitates the planning of LGVs and reduces their cost of construction. The high power/weight and adhesive weight/total weight ratios of TGVs allow them to climb much steeper grades than conventional trains. The considerable momentum at high speeds also helps to climb these slopes very fast without greatly increasing their energy consumption. The Paris-Sud-Est LGV has grades of up to 3.5% (on the German NBS high-speed line between Cologne and Frankfurt they reach 4%). On a line reserved for high-speed trains it is possible to have greater superelevation (tilt), since all trains are travelling at the same (high) speed and a train stopping on a curve because of a stop signal is a very rare event. Curve radii in high-speed lines have to be large, but increasing the superelevation allows for tighter curves while supporting the same train speed. Allowance for tighter curves can reduce construction costs by reducing the number and/or length of tunnels or viaducts and the volume of earthworks.

Track alignment is more precise than on normal railway lines, and ballast is in a deeper-than-normal profile, resulting in increased load-bearing capacity and track stability. LGV track is anchored by more sleepers or ties per kilometre than normal, and all are made of concrete, either mono- or bi-bloc, the latter consisting of two separate blocks of concrete joined by a steel bar. Heavy rail (UIC 60) is used and the rails themselves are more upright, with an inclination of 1 in 40 as opposed to 1 in 20 on normal lines. Use of continuously welded rails in place of shorter, jointed rails yields a comfortable ride at high speed, without the "clickety-clack" vibrations induced by rail joints.

The points or switches on LGVs are different from those on the lignes classiques. Every LGV set of points incorporates a swingnose crossing (coeur à pointe mobile) or 'moveable point frog' which eliminates the gap in rail support as wheels of a train pass over the 'frog' of conventional points, causing shock and vibration. Eliminating shock and vibration makes the passage of a TGV over an LGV switch imperceptible to passengers, and reduces stresses on wheels and track. In addition, LGV switches permit much higher speeds. Crossover switches on LGV's permit a TGV to move from one track to the adjacent track at 160 km/h (99 mph). At junctions, such as the junction on the TGV Atlantique where the line to Le Mans diverges from the line to Tours, special points designed for higher speeds are installed which permit a diverging speed of 220 km/h (140 mph).

The diameter of tunnels is greater than normally required by the size of the trains, especially at entrances. This limits the effects of air pressure changes, which could be problematic at TGV speeds.