July 14th, 2013

piano

Can someone in the media please get this right?

Forgive me, this is going to be long, but this is a situation where the truth matters.

Lac-Megantic, site of a particularly catastrophic rail disaster. The heart of the town was destroyed when an uncrewed freight train -- consisting of 73 tank cars loaded with crude oil, a "buffer car" and five engines -- hit a road crossing and curve posted for 10 mph doing 63 mph. The locomotives and buffer car negotiated the curve; roughly half of the tank cars did not. (I have seen a report indicating that the locomotives rolled to a stop ~800m beyond the crash scene.)

The resultant derailment, oil spill, fire, and explosions (probably BLEVEs) razed Lac-Megantic's central business district and killed approximately 50 people. This happened just past 01:00 on Saturday July 6th, 2013.

Why? The train was parked 7 miles away -- uphill -- in the town of Nantes at around 23:00 hours so that the sole crewman could take his mandated rest period. The Maine Montreal & Atlantic (MMA) railroad executives are now saying that the engineer failed to set all of the 16 handbrakes he claimed to have set, and probably skipped the legally required "securement test" to insure that the brakes could hold the train. Even 16 handbrakes is skimpy and inviting trouble. Railroaders have given differing opinions as to the right number, but Canadian National's guidelines say 40% of the brakes should be set for a train parked on a 1 - 1.5% grade. The track at Nantes has a 1.2% grade down to Lac-Magantic. The general number cited is around 30 hand brakes (ranging from 20 to 40+).

There has been much talk about the role of the Nantes Fire Department, who responded to the parked train after passers-by saw flames (not sparks - I have seen video, it's flames) coming from the lead engine and called 911. Nantes FD arrived, and per the protocol they were trained in by the railroad, shut down the engine and put out the fire. Railroad track workers gave the NFD the all clear, and everyone left. Not long after, the train began to roll down hill on its own...

Here's where the media is just endlessly repeating wrong information initially released by the MMA: The NFD shut down the burning engine, the only one of the five that had been left running "to supply air pressure for the brakes." With the engine stopped, air pressure slowly bled out of the brake system and the air brakes lost their hold on the cars. Air brakes off, not enough hand brakes set = disaster.

This is both right and WRONG. The right part: a train left standing with the air brakes applied will slowly bleed pressure out into the atmosphere, and the brakes will eventually release. The WRONG part: this will happen whether there is a running engine attached, a stopped engine attached, or no engine attached to the train.

Train air brakes are not like truck air brakes. On a truck with no pressure in the air system, springs hold the brake pads to the brake drums (or discs) at each wheel. To release the "spring brakes" air is pumped into the side of the brake cylinders opposite the springs, pushing the pads back from the brake drums. Pressing the brake pedal puts pressurized air into the brake cylinders on the same side as the springs, causing the brake shoes press against the brake drums and stop the truck. To set the parking brake (the "spring brakes"), all air is vented from the brakes and the springs push the brake pads into the brake drums. This is why you hear the PSSSSH of escaping air when a big truck or bus parks.

This system doesn't work on a quarter-mile long train (about what trains were in the 1862 when George Westinghouse invented the modern railroad air brake. The length attenuates pressure and draws out the time it takes to apply the brakes from the front of the train to the back. Westinghouse created a differential pressure system which overcame these problems. Here's how it works.

On a train with no pressure anywhere in the air system, the brakes are released. This is a Good Thing when you are switching cars around in a yard or sorting them with a gravity hump. To get a train ready to roll you must first pressurize the system (70-90 psi on most US railroads). Westinghouse's genius was the "triple valve" - a differential pressure valve that responds to the relative air pressures in the train's main brake pipe vs. the air reservoir on each car. When pressure is higher in the brake pipe than the reservoir, the triple valve lets air into the reservoir and vents the car's brake cylinders to the air. When pressure is equal, the valve goes to a middle position where the brake cylinder vents are closed. When pressure is greater in the reservoir than the main brake pipe (e.g. when the Engineer applies the brakes), the valve goes to its 3rd position - allowing air from the car's reservoir to pressurize the brake cylinders and thus apply the brakes.

Activating the emergency brake on a train vents all air from the brake pipe ensuring a high differential between pipe and reservoir and ensuring a strong, full brake application.

Now this gets us back to the right and WRONG. A train left standing with the air brakes set will slowly leak air out of the brake cylinders. These are rough-and-tumble industrial devices, not space shuttle components: they leak. Eventually there will be too little air pressure left in the car reservoirs and brake cylinders to effectively hold the brakes.

As explained above ("To get a train ready to roll..."), the only way to (re)charge the air reservoirs on the train cars is for the Engineer to release the brakes by putting more pressure into the main brake pipe than there is in the reservoirs. FYI, in railroading, making multiple quick brake applications without allowing time for the system to recharge is a newbie mistake called pissing away your air.

Having an engine running ensures only one thing: that the locomotives' air supply reservoirs will be fully charged, enabling the crew to charge the train brake line faster and get going faster than if there was no pressure anywhere in the system. It does nothing to recharge the pressure in the car reservoirs.

So, shutting down the burning engine had NOTHING AT ALL to do with the inevitable leakage of air from the brake cylinders and the resulting runaway train. Handbrakes are the only guaranteed way to hold a train still for any length of time. When a (possibly fatigued) engineer (took a possible short cut to get to bed quicker and) fails to set enough brakes to hold 31,000,000 lbs of crude oil and its train parked on a slope, disaster happens.

Can someone please get an Engineer (either type - train driver or degreed professional) on the air to call BULLSHIT on MMA's excutives? Please?
driveline

Daring to go where whiteboys fear to tread

I am not an apologist for George Zimmerman. Given the pattern of burglaries in his neighborhood, the man was justifiably suspicious of Trayvon Martin (and that is the subject of this post). BUT he made an utterly bone-headed decision when he disobeyed the Police dispatcher's instructions and started following young Mr. Martin on foot, thereby putting the two of them on a collision-course for conflict and disaster.

It would be nice to think that you can dress however you want, go where ever you want, and be left alone. It just isn't so. Not here in mostly white suburban Glastonbury, not in mostly black and Latino Hartford, and not in Sanford Florida.

Let me give you an example. I'm a friendly guy; I apparently look friendly enough and radiate this aura of trustworthiness so that people have always stopped me and asked for directions -- black, white, hispanic -- didn't matter. Then I got a buzzcut (#2 on the sides, cut really short on top). I have noticed that, now as a walk down the street about 1 in 4 people of color give me the hairy eyeball. Just by cutting my hair short I have gone from being Mr. Trustworthy and approachable, to a guy who apparently looks like an agent of THE MAN to some blacks and Latinos.

Here's my point: any young man, wearing a hoodie, with his face obscured by the hood looks like a hoodlum. Period, full stop. I see a couple white boys in Glastonbury with their hoodies on and hoods up slouching along the sidewalk and I immediately feel that prickle of raised alertness and suspicion. White boys, in Glastonbury. Now make it a young black man, in a hoodie, in the dark, in a neighborhood that has had a rash of break-ins perpetrated by young black men.

Here's my advice, to all young people, but especially young black men: LOOSE THE HOOD. Criminals, since the dawn of time, have covered their faces. Don't look like a criminal. If your head is cold, or wet, or you're having a bad hair day, wear a hat. A baseball cap or a fedora or a pork pie hat, not a knit cap pulled down low over your eyes.

I would love to go to work in jeans and a t-shirt every day. Can't do it. I'd get my head handed to me. My sister once got tailed by staff all through an expensive "gift shoppe" because she walked in wearing her landscaper work clothes. They thought she was going to shoplift. Trayvon Martin got tailed by a nervous citizen watch volunteer because he looked like he didn't fit the model of an honest resident, but instead looked like he fit the model of a criminal.

In an ideal world you could wear whatever you wanted where ever you wanted and it would be OK. This isn't an ideal world. Loose the hood - don't loose your life.