Tuesday's column on the latest Amtrak crash provoked a flood of addenda and corrections from railroad enthusiasts. Reader Charles Crawford points out that welded rails not only provide a smoother ride, but also reduce wheel wear and enable greater speeds. All the small gaps on older jointed tracks sap velocity, much in the same way road ruts slow cars.
Emmit Pickett blames the Amtrak accident on the demise of cabooses, the California condor of the railroad world. A freight train passed over the flawed rail 45 minutes prior to this week's accident and noted no hazard. He says that track monitoring was once the job of caboose-borne spotters. Another Slate-reading train buff points out that what Explainer called a "heat kink"—a sun-baked bend in the tracks—is more formally known as a "sun kink" or a "thermal misalignment."
Whenever a train derails, Explainer's mailbag runneth over with the question "Why don't trains have seat belts?" (The latest version came from reader Jane Gunnell.) The Federal Railroad Administration, which conducts crash tests at a research facility in Pueblo, Colo., believes there "is insufficient evidence that clearly demonstrates that safety would be improved by seat belts." An organization called Transportation Involves Everybody disputes that conclusion, and in April it sent a letter to Transportation Secretary Norman Mineta demanding that all passenger trains offer seat belts. Given Amtrak's solvency problems, however, retrofitting its entire fleet to satisfy TIE is probably a low priority. (Explainer has previously mused upon the dearth of seat belts on school buses.)
An earlier Explainer on asteroids, which detailed how scientists calculate the odds a celestial boulder will strike the Earth, attracted a query from a reader: "How can you say that improved knowledge of the asteroid's position and velocity will probably lengthen the odds against its hitting the Earth, rather than shorten them?"
Here's a slightly simplified explanation: Imagine our galactic neighborhood as a two-dimensional line 10 million feet across. Our planet is in the center, with a diameter of 100 feet, and a potentially catastrophic asteroid is a dart whose tip width is 1 inch. (Yes, these are exaggerated size ratios. Please bear with Explainer for a moment.) On a fixed date, astronomers know that an asteroid is going to hit somewhere on that line. But without good positional data, they have zero idea as to where. It could be anywhere on the line, including anywhere in the "bull's-eye." As more is known about the asteroid, they get a much better idea of its location on the fateful date. And given the Earth's relative smallness on the galactic line, chances are it won't be hitting us. In fact, NASA's Jet Propulsion Laboratory removed the latest scare, asteroid 2002 NT7, from its list of impact risks Thursday after gathering more accurate positional data.
Finally, reader Joe Cobb asks, "Does expelled Rep. James Traficant get his congressional pension, or did he lose it when he got expelled? How much would his pension be?"
Only a treason conviction can prevent a formermember of Congress from collecting his or her pension. Traficant was convicted of multiple felonies and booted from the House, but he wasn't charged with treason, so he gets his money. According to the National Taxpayers Union, Traficant's pension will start at $37,120 per year, a sum that will increase annually due to cost-of-living adjustments. Based on actuarial tables, which put the 61-year-old Traficant's life expectancy at 83 years, the NTU estimates he will rake in nearly $1.2 million during his lifetime.