Tuesday, November 26, 2013

Space-Age Debris: Aerospace Corporation's Log

Starting up another story on space history -- and ran across this interesting website from Aerospace Corporation, which has been tracking successes and failures from the beginning.

It's a continually updated log of space debris that's come back to Earth, with 65 events to date.

Here's one of the more historic entries:

37.
In July 1969, a small fragment (about 30 cm long) fell on the deck of a German ship in the Atlantic Ocean. Other pieces fell in the water near the ship.Identified as debris from the first stage of the Saturn booster used to launch Apollo 11 on July 16, 1969.

Spherical pressure tanks, like this, are strikingly common:


 
Here's the Aerospace Corporation contact to report any pieces that happen to land near you:

"If you are aware of recovered debris not appearing here, please e-mail a description of the debris, and provide references to supporting evidence, e.g., news articles, government reports, photographs, etc. We will add sufficiently corroborated events to our list. "

Saturday, November 23, 2013

What Directors Want: More about prime-time interviews


After my "Call to Adventure" post about what production companies look for when lining up commentators, this note arrived from another director I've worked with several times:

"There's one thing - in my mind - that separates the good experts from the great experts, from the producer's perspective. The best ones...the ones that we like to go to time and again ... are the ones who understand our audience: the general public.

"What that means really is that the people we have to reach don't have an expertise in the topic we're presenting. They're curious, but really won't understand a lot of the more nuanced and complex aspects of a topic - probably the very things that an expert cares the most about. That's why your comment about this being closer to a 100 level than a 400 level class is spot on.

"So, boiling it down...it's the experts who get that it's okay to make conjectures and basic assumptions, and sometimes intelligent speculation, who are the strongest. Of course, we love when it can be delivered in compact expressions, as opposed to longer expositions filled with caveats."

Friday, November 22, 2013

Wrapping Up: Train Crashes into Parade Float, Midland, TX (2012)



(Photo: Midland Police Department, reproduced in NTSB presentation)

Setting: Grade crossing in Midland, TX.

Time: 4:35 pm, November 15, 2012.

Incident:  A street parade was being held to honor veterans that afternoon, escorted by emergency vehicles that protected the street intersections against cross traffic. The latter portion of the route crossed a busy set of Union Pacific railroad tracks at grade level on South Garfield Street, and ended at an arena on the south side of the tracks (Map, NTSB):


The float was a semi-trailer rig, which was moving along the route with law-enforcement escorts. Its flatbed trailer carried 24 veterans and spouses seated in chairs. Before the crossing gate came down, the rig driver approached the crossing started moving slowly across the tracks, paying particular attention (via a rear-view mirror) to how his passengers were coping with a dip in the road short of the grade crossing.

A Union Pacific freight train (four locomotives pulling 84 loaded cars) approached the crossing at a speed less than allowed (62 mph, speed limit of 70 mph).

The engineer saw the semi starting to cross, applied emergency braking and sounded his air horn, but could not stop in time and hit the rear end of the trailer, pushing it from the intersection. In all, the train required nearly a mile to stop.

The crossing gates and alarms had triggered within the required time, at least 20 seconds in advance. The crossing gate came down on the flatbed.

Original post on Disaster-Wise is here.

Effects: Four float passengers died, and five passengers were seriously injured. Eight other float passengers and a deputy sheriff at the site sustained minor injuries. Seven float passengers suffered no injuries.

Report: The NTSB's findings and a slide presentation are linked here.

Probable cause: In general, a failure to anticipate foreseeable risks and manage them through the permitting process. The truck driver assumed that since law enforcement was protecting the street intersections for the floats, it was also managing risk of collision with the two dozen trains that passed through daily. Another factor was that parade drivers had been passing through red traffic signals already at other intersections, so a red signal at the grade crossing did not raise concerns.

Instead of being alert about the possibility of an approaching train as Midland motorists would be under normal conditions, the driver deferred to law enforcement officials along the route. While at the crossing he focused his attention in his tractor's rear-view mirror, looking at the float passengers and how they were handling a rough part of the road. The train's air horn was also hard to hear given noise along the parade route, including the use of a train-like air horn mounted on the parade's lead vehicle.


Summary from the report:

"The National Transportation Safety Board (NTSB) determines that the probable cause of this collision was the failure of the city of Midland and the parade organizer,“Show of Support, Military Hunt, Inc.” (Show of Support), to identify and mitigate the risks associated with routing a parade through a highway–railroad grade crossing. Contributing to the collision was the lack of traffic signal cues to indicate to law enforcement  that  an approaching train had preempted the normal  highway  traffic signal sequence at the intersection of South Garfield Street and West Front Avenue. Further contributing to the collision was an expectancy of safety on the part of the float  driver, created by the presence  of law enforcement personnel as escorts and for traffic control, leading him to believe that he could turn his attention to his side-view mirrors to monitor the well-being of the parade float occupants as he negotiated a dip in the roadway on approach to the grade crossing."

The city of Midland should have required a permit from the parade organizers, and that permit should have had a section on risk management. No permits had been required for such parades from 2009 through 2012. The problem of trains would have come out in such a plan, given that a grade crossing was going to be used, and that 23 trains pass through the city daily. A good review would have withheld the parade permit until the city saw written permission from Union Pacific, which could have held its trains during the parade.

My Comments: The Midland truck-train crash is a classic example of how presumptions affect perceptions, and can keep people from thinking critically. As part of your risk-management process, gather your team before things get busy; list all the foreseeable problems; and describe how the team is going to detect and handle them.


Wednesday, November 20, 2013

Wrapping Up: Deadly CH-47 Crash in Afghanistan, 2011


(Photo of typical Chinook: Sgt. Sean Casey, Army Times)

Date and Incident: August 6, 2011. During a night-time combat mission to drop off a squad near Wardak Province, a CH-47D Chinook with a quick reaction force on board crashed on approach to landing. Original post on Disaster-Wise is here. (Map: Associated Press)

 
Setting: Tangi Valley, Wardak Province. Earlier that day, two helicopters had delivered an assault force of Rangers to capture a Taliban leader said to be in the area. The Rangers encountered opposition. Hearing that more Taliban fighters were joining the battle, American commanders ordered reinforcements.

Two CH-47Ds were dispatched; the lead one would carry the entire "immediate reaction force" of SEALs and other personnel to the battle. The trailing helicopter, which carried only the aircrew, was to orbit nearby to be available if needed.

The lead helicopter was on its final approach at 2:00 am when a group of Taliban fighters fired two or three RPG-7 rocket-propelled grenades in quick succession from a mud-brick building 700 feet from the helicopter.

Though it was night and such missiles are unguided, one warhead struck a blade on the aft rotor system, blowing off the outer ten feet of the blade. This threw the rotor out of balance and caused a rapid chain-reaction failure. Having lost all lift from the rotor, the helicopter dropped vertically into a ravine, crashed, and was engulfed in a fuel-ammunition fire.

Consequences: All 38 Americans and Afghans aboard the Chinook died in the crash. It was the deadliest single incident for American forces in Afghanistan since 2001.

Final report: An executive summary prepared by Gen. Jeffrey Colt for the Central Command is here. Key conclusion:

"The decision to load the IRF onto one CH-47D in order to mitigate risk by minimizing aircraft exposure to ground fire and to mass the assault force was tactically sound. The shoot down was not the result of a baited ambush, but rather the result of the enemy being at a heightened state of alert due to 3 1/2 hours of ongoing coalition air operations concentrated over the northwestern portion of the Tangi Valley."

Lessons:  While acknowledging the rapid operational tempo in this case, the report recommends careful use of reconnaissance aircraft in such situations: the commander should have a recon aircraft available nearby to scout the area for hostile forces, but its use should be timed so that it comes within earshot only shortly before the assault landing is attempted. (To bring the recon aircraft overhead too early might provide warning to nearby fighters that a landing is imminent.)

My comment: Despite some early speculation that the Taliban used a secret weapon, it appears that this was a freakishly accurate shot considering the distance, the unguided missile, the darkness, and that the helicopter was blacked out.

Sunday, November 17, 2013

Filters for Digital Photos: The Chrome Effect

More observations on merging cloud and ice imagery into a single photograph ... here's one assembled with Sketchbook Pro, then tweaked with the "Chrome" Filter from the list of IoS 7 photo apps.


Here's a summary describing the effects of the Chrome filter in Adobe Photoshop: "Renders the image as if it had a polished chrome surface. Highlights are high points, and shadows are low points in the reflecting surface."

The Chrome filter can help when deciding whether a given image is worth the extra expense of a metal print (special inkjet dyes on an polished aluminum plate). Metal printing adds brilliance to the image, if at the expense of realism.


Wrapping Up: In-Flight Skin Failure on Boeing 737, April 2011

Incident: Portion of Boeing 737's upper fuselage skin (about eight by 60 inches) blew out at 34,000 feet during a scheduled flight on April 1, 2011. Original post on Disaster-Wise is here. (Photo, NTSB)
 

Location: Southwest Flight 812 was enroute from Phoenix to Sacramento when a portion of fuselage skin blew out, causing rapid decompression. Airplane made an emergency descent and landed safely at Yuma, AZ.
 
Effects: Two injured: one passenger, one employee. (Due to delay in donning oxygen mask, a flight attendant fell unconscious while standing.)
 
Final report: The NTSB's probable cause report, published September 2013, is linked here.
 
Probable cause: Flaw during manufacturing, causing failure along rivet lines. Forensic examination of the fatigue fracture indicated that the "fuselage crown skin panel" involved had been attached at a Boeing factory, and then removed for rework before the airplane was delivered. Poor joining techniques at the factory during this rework (eg, oversized holes and poor riveting), followed by thousands of pressurization cycles, led to micro-fractures and failure. Due to the passage of time, documentation was no longer available from Boeing to show exactly how, or at which facility (Wichita KS or Renton WA), the error happened.

Lessons: (1) Need for better quality control when rework is done in the factory. (2) Aircrew should don their oxygen masks at the first sign of depressurization, rather than attempting to carry out other emergency duties first. This is because loss of consciousness can come very quickly.

Wrapping up: One57 Crane Mishap, October 2012

In the next couple of months I'll be linking to final reports (if issued) on accidents, mishaps, and disasters mentioned in Disaster-Wise since I started the blog more than three years ago.

Incident: Jib on Favelle Favco M440 crane flipped backwards over the operator's cab during Superstorm Sandy's high winds. I blogged about the One57 crane emergency, most recently here.

Location: A thousand feet above street level, at the construction site of the One57 skyscraper, in midtown Manhattan (photo, AP Wideworld).

Effects: No one was injured, but the need to secure the area blocked access to nearby buildings and tied up traffic for a week.

Final report: None released to the public yet, and given the safe resolution in removing the danger, we probably won't see one on the NYC Department of Buildings website.

Probable cause: Wind caught the jib while it was upwind of the mast, and flipped the big steel frame over the cab. We're told that the crane's controls were set so it would "weather-vane" in the wind, meaning it would pivot so that the jib would always be downwind, but severe turbulence around the building might have neutralized that precaution.

Wednesday, November 6, 2013

Mountains of Madness: An Avalanche of Fan Fiction and Fan Art

H.P. Lovecraft fans are grim! Grimmer than usual, that is, at news last month that filmmaker Guillermo Del Toro is still unable to move forward with his decades-long desire to bring HPL's classic horror story to film, "At the Mountains of Madness."
 
In a September interview in The Wall Street Journal about a book of his artwork (Cabinet of Curiosities), Del Toro said he didn't include his conceptual sketches for MoM, in case the movie is green-lighted after all.

Meanwhile, devotees fill the vacuum with fan fiction and fan art.

The narrator in Lovecraft's story described the range this way:

I could not help feeling that they were evil things—mountains of madness whose farther slopes looked out over some accursed ultimate abyss. That seething, half-luminous cloud-background … gave appalling reminders of the utter remoteness, separateness, desolation, and aeon-long death of this untrodden and unfathomed austral world.
 

Here's what that description suggests to me:
 
 
(Note for fellow dSLR geeks: the image draws on my endless supply of ice photos. This particular mountain isn't even a molehill -- it's less than two inches high.)

Saturday, November 2, 2013

That Call to Adventure: Participating in TV documentaries


 

Following are thoughts about doing commentary work for TV ... for people curious about it, or who might be getting invitations to participate but who are new to the process. I've participated in fifteen shows on History, National Geographic, and CBS: usually as commentator, once as a series consultant.
  • The fun begins with a note from your agent or a call from an associate producer. He works for a production company that acts as a contractor for the cable channel. The prodco is responsible to a showrunner there.
  • The associate or else a director will want to do an initial phone interview to hear your take on the subject, and will want to see what you've done before on TV. Be patient. You could get a call from an associate producer one day, respond to an urgent request for a phone interview two days later, and then hear nothing for five months. You don't need to remind the production company of your existence by leaving a string of messages. They'll call back if they need you  – know that an associate producer isn't going to forget about some expert he's already interviewed by phone. Sometimes the delay is because the network hasn't made up its mind about which commentators to put on the show.
  • Use the time before shooting to refine your talking points. I work them into sticky notes that go into a loose-leaf notebook, and highlight any key points that I hope to get into the raw footage (of course, they may not get into the show -- see the director's comment below). It's easy to flip through my notebook, brushing up, while waiting for the camera crew. (Photo: DP and director, setting up a shot for Life After People)
  • Trim your observations down to short sentences. Directors are also editors, and they need short, confident, vivid, declaratory statements in the editing bay.
  • Other than for people signed as hosts or series consultants (say, because the shows are based on their books), payment for commentators is per day of actual shooting -- not counting days of travel or preparation. Let's call it less than a thousand dollars a day, sometimes a lot less. In any case the prodco will pick up travel expenses (such as a limo from Newark International to NYC), and you won't go hungry. The days are long but time passes quickly.
  • Crew lunches are a good time to meet the gang and hear about what goes on behind the scenes, and about the latest in sound and audio equipment. It's interesting to watch the process; Titanic at 100 involved a lot of shot-checking during the shoot, because of the elaborate CGI that would interlace with digital footage from the Red camera:

  • I prefer setups that allow me to walk and talk, but that chance doesn't come often. The reasons are efficient use of time and certainty of results.
  • After seeing a rough cut, showrunners deliver the fateful message from the channel called creative notes, as in "add this" and "lose that." It's up to the director and post-production team to keep their blood pressure down and get the show through to picture lock. Commentators don't have to deal with that agonizing phase, except for occasional followup questions.
  • Despite an audience of millions for a prime-time show, don't expect residuals as a commentator, no matter how many times the show is re-broadcast on History or Discovery or whatever. If you're looking for fat residual checks, look elsewhere, like doing ads for the prime time shows! I've heard dazzling stories from helicopter pilots in LA about checks they received after flying in major TV ads.
Also, here's a good reminder about expectations, helpfully sent along by a director who does a lot of work for major cable channels:

“You, the expert community that we're lucky enough to work with, will always be our harshest audience, as you are a master of the field. Often documentary filmmaking for the major doc networks is an exercise in compromise: The full story rarely gets told, and programming ends up being closer to the 100 level course than the 400 level course. My suggestion to those being interviewed is to realize that you're fighting the good fight by piquing interest: Unless you're being interviewed for a Frontline, Nova, or program that has more journalistic aspirations, the majority of the doc networks fill a hybrid role of wanting to educate via entertaining.

"In such a format its hard to go into the kind of deep, detailed content that most experts would wish, but you're still getting your message out there and hopefully coaxing a percentage of the audience to take the next steps in researching the topic via the literature.
 
“So, in general, they should know that if we do our jobs correctly the big picture and intent of the topic will always come through, but often the juicy details that make up that big picture can get lost in the shuffle. From an expert's perspective I completely understand how this could be frustrating if you're not aware of this reality from the beginning of the process. We interview you for an hour or more, and sometimes you could end up in the show for less than a minute! … But unless the story is about you and your work specifically, don't expect the amount of time you're interviewed to translate into time on screen. But do know that your contribution is highly valued!”

Monday, October 28, 2013

Mystery Barge 0010: Larry Page's newest dreamboat?

Still waiting for official news about the four-story mystery barge BAL 0010 that CNET has linked to a Google front ...

(KPIX 5/CBS San Francisco)

... (is it a retail store for Google glasses? A Loon earth station? An earthquake- and asteroid-proof data center?) ... I favor the latter myself, but am still waiting for a zoomed-in photo of the barge's top deck, which might help hone the guesswork. A data center should have big exhaust stacks for onboard diesel generators.

Meanwhile here's a little information about a certain Google co-founder's superyacht that was moored nearby last week, according to dogged reporting by Daniel Terdiman of CNET (his photo):

 

Larry Page's194-foot steel-hulled boat is named Senses, and as a helicopter-book writer, I'm pleased to note that it has a helipad:


But apparently no hangar. Note to super-yacht owners: if you plan to use your helo other than for flitting around the harbor, tack on a hangar for your fly-baby. Helos don't age well around salt spray.

But many yachts don't spend much time at sea anyway, so perhaps I'm carping.

Occasionally I check the Automated Information System (AIS) for shipping on MarineTraffic to see what boats like Senses are up to, but sadly, AIS appears to be of little help when spotting big shots' big yachts: such vessels are likely to be "out of range" most of the time. I take it that their AIS transponders have been switched off to foil PC-using pirates.

One time that AIS revealed the whereabouts of Paul Allen's mega-super-megayacht Octopus was while it provided global communications during Deepsea Challenger's recovery:


Not to make anyone named Larry jealous, but Octopus has hangar space for two helicopters:
 






Wednesday, October 23, 2013

Before the Fall: Mind that Ladder


Have been cruising around the landscape via Google Maps, and came across this remnant from my past:


The dark diagonal line is the shadow of a radio tower in Ropesville, Texas, that I spent time on and around for a Smithsonian story, hanging with the good ol' tower hands of Strickland Tower Service. It reminded me to post a few safety tips about ladders, which I've been using a lot lately in a repainting job around the house.


While the altitude at the peak of our roof is about 500 feet less than in Ropesville, just about any ladder can be dangerous to one's health. During the days of preparation and painting, several neighbors stopped by to urge me not to fall off.

After I put away the ladder, I looked into why thousands of people fall from ladders every year.

Don't try to save time by stretching sideways or "bumping" the top of ladder sideways. Once the ladder starts sliding, even a little, there's nothing you can do to stop it. Experts say that if your belt buckle is beyond the vertical supports of the ladder (called "stiles," by the way) you're already out of balance.

Aluminum ladders are a fine electrical conductor, and the results of electrocution are terrible to behold, so stay far away from live wires.

A large number of injuries trace to mistakes on the first two rungs. Common reasons: holding something in your hand, tripping on hazards around the base of the ladder, or slipping on wet rungs. Since nearly every ladder-related job requires some tool or container available at the top, use a rope to pull it up.

I recommend the "stabilizer" or "standoff" attachment available at hardware stores. It reduces the chance that the ladder will rotate around one side and dump you off, and it also makes for a more comfortable working distance when painting.

Check the ladder out before you head up, looking for anything out of shape, cracked or bent. Dented stiles are a concern with aluminum ladders, and a fiberglass ladder is in trouble when it starts turning fuzzy at the surface. That means it's losing the resin covering that gives it compressive strength.


Ditch the heavy family-heirloom wooden ladder, particularly if it's painted. Paint holds in moisture and hides rot around the rungs, and I wouldn't trust my life to one.

Check the ground surface against any tendency for the ladder feet to slip. In our neighborhood, one hazard while painting the front of the garage is that all our driveways slope toward the street. Combine a sloping surface with a shiny coat of sealer on the driveway: the feet of the ladder are more likely to slide and drop you on your face.

Planning to lop off some tree branches from a long ladder? Mind the fact that after you saw off that big bough, the remainder of the branch could spring upward a foot or more, freeing the top of the ladder to drop you on the ground.


While I haven't fallen from a ladder (yet), I can think of a few mistakes that could have ended that way. The most embarrassing: While I was putting up decorations at a preview showing of the History series on my disaster book, my brother pointed out that I hadn't locked the braces on the stepladder I was using. Oops!



Monday, October 14, 2013

E-book Covers: A few tools for the DIYers

 For those asking about the mockup cover for a science-fiction e-book that I posted recently on LinkedIn (see final result at bottom) here's a little more detail on the steps. Nothing complicated!

I've mentioned before that one of my hobbies is photography. Living in the North, there's plenty of ice and snow available from November to March, and here are two (out of many) pictures of ice I've taken in the depth of winter:
 
 
They struck me as having a slightly alien quality. So what to do? Given that I used a dSLR at 18 megapixels, cropping is an option, particularly since Kindle caps the image size of an e-book cover. Here's an enlarged snippet of the photo on the left:


It looked like an offworld apartment house to me. First I used Sketchbook's airbrush tool to tune it up, then added the other photo, the swirly one, to make the scene a little more alien.

Many programs for stacking photos are out there, such as GIMP and PhotoShop, but for fun I used Autodesk's SketchBook Pro app on an iPad 3, which at high resolution (1800x2400) offers up to four layers. Using Sketchbook I pasted the swirly image into a blank layer, flipped it horizontally, then slid it behind the apartment house.

On the Sketchbook layer menu, there are four options that determine how the stacked imagery shines through. I used the "Add" option in Sketchbook's layer menu, and the "set transparency" slider control to lighten up the interstellar cloud a bit.

The final step was to export the image via DropBox to OpenOffice's presentation module to add some lettering, and voila, a cover mockup:

 "PHA"? It's NASA-speak for Potentially Hazardous Asteroid. Here's a link to PHA info from NASA, via Google cache, which has been quite handy in these days of government shutdown.
 
 
 
 

 
 

Wednesday, October 9, 2013

Costa Concordia: Recommended video of VDR data and bridge audio

The ex-master of Costa Concordia, Francesco Schettino, is now on trial in the Court of Grosseto, Italy. 

YouTube offers a variety of reconstructions of the final voyage, but I like this one from Mario Piccinelli, of the University of Brescia. It's an overlay of bridge audio onto navigation and system-status screens. Data came from the VDR (voyage data recorder) system on Concordia.


Note the green bars on the left - that's the status of the watertight doors.

Here's a link to Mario's journal article for Digital Investigation, "Modern ships' Voyage Data Recorders: A forensics perspective on the Costa Concordia shipwreck," about the huge effort that went into extracting and rendering data generated by the ship's instruments. 

Here's a description from the article intro:

“This paper delves into the examination of data found in the VDR from the actual Costa Concordia accident in 2012, and describes the recovery of information useful for the investigation, both by deduction and by reverse engineering of the data, some of which were not even shown by the official replay software."

All that info was supposed to go onto the VDR for storage (the equivalent of the airliner's black box), but the VDR malfunctioned. Fortunately Concordia's data stream went into a temporary storage unit called the accumulator, which investigators recovered in good shape. After extracting the data the team had to make sense of what was showing in the multiple channels - the readouts were not standardized like FDRs and CVRs in airliners. 

The methods should be useful as other investigators have to rebuild data from non-standardized accident data recorders.

Monday, October 7, 2013

Coming Up on 100K

A big thanks to readers and followers! Disaster-Wise is coming up on a hundred thousand views. I started the blog three years ago as a follow-up to lectures on my book Inviting Disaster. It's been a learning experience throughout.
 
And special thanks to:
  • Ian Punnett and Coast to Coast AM for having me on his weekend show a dozen times or more; editors at Air&Space, American Heritage Publishing, and the National Board of Boiler Inspectors who allow me to excerpt from my articles; and to Lone Wolf Productions for their invitation to History Channel's Titanic at 100.
  • Experts who graciously responded to my requests for info behind the headlines, particularly forensic engineers and disaster investigators. (And there's more to come: I just received two technical papers from Dr. Fabio Remondino at FBK Trento about the methodology behind Costa Concordia's underwater survey. I'll post them this week.) 
  • Google, for making Blogger available for free. Blogger is a little klunky for a person who was raised on an iMac, but has great functionality.
  • The wifely one, for putting up with quite a few "Just a minute - I need to post this first" demurrers.
 
 
 

Saturday, October 5, 2013

Gen. Giap: Last of a kind?

News yesterday of Gen. Vo Nguyen Giap's death. News reports have featured his role commanding the Viet Minh forces during the long siege that led to the fall of the French outpost at Dien Bien Phu in 1954. But more than a year before that famous battle was Giap's well-planned ambush that caught the French during the last days of Operation Lorraine. After that, analysts in the West picked Giap out as a commander to watch.

I researched the disastrous end to Operation Lorraine as part of writing The God Machine. Here's an excerpt from my book, which I think illustrates Giap's careful planning:

France, then fighting Communists in Indochina, would have liked to employ transport helicopters in the fight but couldn’t afford the cost. Instead the French Expeditionary Corps had to rely chiefly on the country’s narrow, winding roads for moving troops and supplies. Where the Viet Minh controlled the ground, the cost of highway travel could be very high, such as the calamitous ending to Operation Lorraine.

In October 1952, the French sent 30,000 troops, supported by tanks, deep into enemy territory from the French fortified positions along the de Lattre Line. The mission was to attack Viet Minh supply storage dumps a hundred miles away in the Phu Doan area.

The French expected this would force the Viet Minh to stop attacks elsewhere and perhaps bring their massed army out into the open where French airplanes could attack them. After a few weeks the massive ground raid had reached Phu Doan and located hundreds of tons of arms including much new Soviet equipment. It had not, however, brought Viet Minh divisions out into the open where the French could use World War II tactics.

Having taken the towns Gen. Raoul Salan decided not to hold them any longer; he was now worried that Viet Minh commander Gen. Vo Nguyen Giap might have something in mind for his overextended column, which was 100 miles from the nearest French lines. A trap laid for columns in narrow roads -- where the enemy could not bring its power to bear -- was one of Giap’s trademark moves. In mid-November Salan ordered the men to head for safety but, as he had feared, Giap had his men waiting.

The Viet Minh anticipated that the French in pulling back from Phu Doan must pass through the steep-walled valley at Chan-Muong.  (Map: Orbis Publishing)


Here they built log roadblocks and set up heavy weapons trained on its narrowest point, a bottleneck formed by steep rock walls and manioc fields on either side of the road. On November 17 Viet Minh battalions let a line of tanks pass through mostly unscathed, then attacked the more vulnerable middle of the column. Exploding vehicles in the rear blocked help from tanks which had yet to enter the defile, and exploding vehicles in the front blocked escape in that direction. Mortars and then hand-placed satchel charges destroyed each trapped vehicle. French commanders gathered up their infantry from the confusion and sent them up the slopes to attack the mortar and gun positions. A bayonet charge finally sent the Viet Minh into retreat. The battles continued for another week, until the column reached safety at the de Lattre Line. The cost was 1,200 casualties.

My conclusion after reading about Gen. Giap, and talking to Vietnam vets, is that he didn't throw away his troops' lives as wildly as some have said. And he may find a place in history books as the last "big army" general to foil a superpower.

Friday, October 4, 2013

Gravity: Raising space-debris awareness ... perhaps a tiny bit too much

Eager to see Gravity this weekend, which is getting extraordinarily good reviews (98% on the Tomato-Meter, at this writing).

One of the trailers:


While space debris is unlikely to arrive in such pestilential swarms as the movie shows, and probably wouldn't be visible to the eye as it approached (see excerpt from my article below -- the closing speeds are too fast), whoever researched the Gravity script did get some important principles correct. And in any case the movie (particularly in 3-D) apparently does an amazing job of giving the viewer the sense of being up there, and out there.

Setting aside exaggeration for effect, the writers are correct that the biggest threat to manned spacecraft in low earth orbit (particularly the ISS) is man-made debris. It's also worth noting that NASA regarded servicing the Hubble Space Telescope with the Shuttle rather risky (at least after the Columbia loss) because the shuttle had no easily accessible safe haven. The Hubble is in a much higher orbit than the space station.

Here's a link to a NASA report on dangers from space debris.

Following is the introduction from my 1999 space-debris article for Smithsonian on space debris. Coincidentally, that research brought me nose-to-nose with Columbia.

     =  =  =  =  =

ANYBODY WHO BELIEVES THAT SPACE IS AS empty as it looks in the movies should spend a few hours with Justin Kerr of NASA and Ronnie Bernhard of Lockheed Martin. It's June and both scientists have flown in from Houston to inspect the orbiter Columbia, which sits in Bay 3 at the Kennedy Space Center's Orbiter Processing Facility. I'm stretched out on an aluminum work platform by Columbia's windshield, under strict orders not to drop pens or notebooks or wedding rings that might damage the fragile tiles below.

Kerr hunkers down to my left and crawls through a playhouse-size aluminum entryway, emerging onto a catwalk with a nice view of Columbia's spacious payload bay. He grasps a lab notebook and a sampling kit, including a chopstick, a bamboo skewer and an orange stick. He directs my attention to a pair of tiny dark craters, each about twice the size of a sharp pencil tip, bored into a white metal frame that holds up one of the spacecraft's antennas. Kerr uses a bamboo stick and tape to gather up the smoky residue from each of the craters. He wraps up the tape and each stick to preserve the soot for microscopic scrutiny.

A shout comes from a platform one level beneath us: others on the NASA debris team have found another impact crater, this time on the right payload door. As we head down, I learn that NASA has logged io6 significant hits on Columbia from this single mission, most of them caused by unwanted man-made particles in orbit. (On most missions, minor damage means that at least one outer layer of window glass is replaced.) Bernhard is crouched under the open door, craning awkwardly to look straight overhead at the white insulated surface with a magnifying glass. He suggests I take a look. Through the tear I see goldish-brown felt that's been singed by the impact; on the white surface of the door smoky soot trails off one side.

These particular craters look pretty small to me, and I ask Bernhard if tiny but fast particles mean much. Yes, indeed, he says.

During a mission in 1995, Columbia took a hit in a payload door that made a gash almost an inch across. If that piece had crossed into the payload bay and punched a big enough hole in the cooling system there, Houston controllers would have ordered the ship back to Earth immediately. One reason it didn't hit at a bad spot was that the NASA debris squad had predicted the risk beforehand, based on earlier shuttle flights, and suggested keeping one payload door partially closed to help shield the payload bay. Bernhard says that, from the metals found in the crater, the culprit on that mission was probably a fragment of circuit board. Where it came from nobody could say, but an explosion is likely. Space has seen its share of silent blasts, some of them quite recently; in 1996 a Pegasus rocket exploded due to a fuel-tank explosion and propelled into orbit at least 700 pieces more than four inches across.

Science writers of the 1950s vividly described the risks to future spacefarers from rocky micrometeoroids near Earth, but the prognosticators missed the boat on what has turned out as a bigger deal, safety-wise. Near Earth, artificial meteoroids now pose a greater risk than the natural stuff. Over the decades humanity has gone Saturn one better by putting up not just a ring but a spherical shell of glittery objects around the planet. It's a layer of camera lens caps, spent rocket boosters, bolts, nuts, buckets of garbage, and countless flecks of dislodged paint and particles of solid fuel from booster rockets.

Even full-sized spacecraft that can be tracked reliably with radar have begun to cross paths, causing encounters that while rare are positively alarming. During his four-month stay on the Mir space station, astronaut Mike Foale received three warnings of approaching space traffic. In the last incident, an obsolete American satellite called MSTI-2 passed less than a thousand meters from Mir.

At the request of Russian controllers, Foale interrupted his exercise-bike workout to join the cosmonauts in the Soyuz (a Russian spacecraft that can return the cosmonauts to Earth) for a few minutes as a safety measure in case Mir was punctured. "We always looked outside [during the close passes] to spot them and it was inevitably futile," he says now. "Imagine trying to see a small dot ten kilometers away over your left shoulder, and a second later it's right next to you, and another second later it's ten kilometers over your right shoulder."



Wednesday, September 18, 2013

Howl of the Rena: Updated link from Maritime NZ

Back by popular demand, perhaps because people are thinking of how to use it for Halloween, here's the updated web address with the eerie howl recorded two years ago inside the wreck of the containership Rena as waves tore it apart on a reef offshore New Zealand. There's a spine-tingling shriek starting 34 seconds in.


I haven't heard audio recorded from inside Concordia (hydrophone or microphone) as the strand jacks pulled it upright. I'm sure it was noisy inside. Does anyone know of a link?

FYI on the status of Rena: the bow is gone, but the stern is mostly intact and sunk on the reef, and the highest section is within 30 feet of the surface.

Sunday, September 15, 2013

One Risk in Parbuckling the Costa Concordia: Crushing the corner

A good animation is here from Crowley Maritime, which owns Titan Salvage.
 
Using snapshots from that film, which is a head-on view of the ship in which the starboard, or right side is on the left of the image, I labeled the major parts mentioned in this post.

This diagram may help explain some risks that salvors off Giglio will be managing tomorrow (if the weather holds), when they'll have to keep a close eye on concentrations of stress in the hull as it rotates under pull from the parbuckling cables and later the weight of the sponsons. The salvors have been pretty clear that things will bend and break during the process ... hopefully not the bigger things.
 
I'm guessing one risk they'll be watching will be a temporary concentration of weight on the starboard edge of the hull (see yellow arrow, below). The concern is weight of steel not fully offset by displacement in water: that's hull, fittings and the new sponsons, which will be mostly out of the water at that point.


Ship designers sometimes call this area of the hull, where horizontal plating meets vertical plating, the "turn of the bilges." It's the location of a stabilizing fin called the bilge strake, depending on vessel details. Here's a diagram from bestshippingnews.com -- see the highlighted yellow portion.
 
 
Recall that no seagoing cranes will be attempting to hold the weight of the hull off the seafloor. That's the nature of parbuckling: the structure has to hold up while a lateral, rolling force is applied.
 
But the good news is that a world-class crew is on the job. Wreckmaster for Titan-Micoperi is Nick Sloane of South Africa, who came to this job from the wreck of the Rena off Tuaranga, NZ, which I've covered in a series of posts including this one.

Saturday, September 14, 2013

Parbuckling on the Costa Concordia: Historical Origins

You've probably seen the term parbuckling in connection with the Concordia work, as on The Parbuckling Project website. The website is partly correct in its description of early parbuckling as a way to roll heavy casks uphill.

That was one meaning in 1800, but “parbuckling” goes back earlier, and concerns artillery instead. Parbuckling was a way to haul heavy cannon from the base of a hill to the top, say when building a new fortification. Relocating heavy wheeled cannons across rough landscape proved such a problem during the Seven Years War in Canada that the Royal Artillery added rough-ground rigging to its curriculum for new cannoneers, and set up obstacle courses to train them.

As an example, a common parbuckling job for artillerymen was to remove the gun tube from its carriage (which can be done without a major effort by tilting the carriage forward until the muzzle is on the ground), then rolling the tube uphill, using ropes, blocks, and wooden runners. The carriage was brought up separately, on its wheels.
  
While it may seem that the gun crew could have saved some trouble and used whatever wheeled carriage the gun came with, when it came to the bigger guns, those carriages were only usable on a level, hard surface. Otherwise the carriages were top-heavy and the wheels dug in. If dragged across rough and steep ground, the carriage and mounted gun would likely mire or tip over on a slope, rolling over and freeing the tube's trunnions from their mounts, at which point the cliche “loose cannon” takes on real meaning.

So it was best to pull the gun tube from the carriage at the start of the operation and roll it along the ground, using parbuckle ropes, then remount it at the destination. For very heavy tubes, the gun crews laid wooden rails along the ground to ease the job.

Parbuckling is one of many ingenious rigging methods worked out by combat engineers through the centuries. Many are still in use, such as the gin pole I saw used by tower workers when I visited a tower-building job for Smithsonian.

Friday, September 13, 2013

Costa Concordia: Ready for the big pull

Readers of Disaster-Wise may know that I'm a fan of heavy rigging and the related work of collapse rescue, because such projects demand ingenuity, practical knowledge, and nerve. Through the years my writing research has taken me to rigging sites including collapse scenes, tunnels, towers, and derailments.

Photo: Parbuckling Project
 
In the heavy-rigging news this week: almost 20 months after Costa Concordia blundered onto the rocks off the island of Giglio, Italy, drowning at least 32 people, Italy's Civil Protection Department has given the Titan-Micoperi joint venture permission to pull the Costa Concordia upright, which (if the ship holds together) will allow a row of steel flotation boxes called sponsons, welded to the sides and bow like water wings, to ease it off the seabed so that tugs can haul it to a breaker's yard.

Weather permitting, the job of setting Concordia upright could start on Monday morning, September 16, local time. It will take the better part of a day to execute. Rest assured that hundreds of media reps will be watching from land, sea and air, so you won't miss anything.

The salvors will use computer-controlled strand jacks, wire rope, and sponsons to roll the ship very slowly from its capsized position. Right now it's laying on the starboard side, 65 degrees off vertical. If the parbuckling works as intended, the ship will come to rest in one piece, grounded but now upright on a temporarily leveled seafloor. (The leveling work was done with big bags of cement grout and giant steel frames, all of which will be pulled out later. Only anchor holes will be left in the reef, we are told.)

The groundwork should help keep the ship from breaking in half, as it would surely do without the leveling job, since the hull came to rest on two underwater promontories.

Here's my summary of the parbuckling plan. It will need three moving forces:  a row of flotation tanks welded to the port side of the ship that will serve as a downward force when flooded, and two sets of tension rigging on opposite sides of the ship. (By "rigging” I mean the full set of blocks, wire ropes, chains, anchors, and computer-controlled strand jacks.)

Here's a strand jack:


Now for the moving machines.

1) Parbuckle rigging: These are visible as a set of cables on the portside, the side facing the open sea. They will haul the ship upright most of the way, until weight from the flotation tanks (aka sponsons) take over. Specifically, strand jacks mounted on the sponsons will slowly take up cables whose other ends are anchored to underwater steel frames that make up the temporary seabed foundation.


2) Holdback rigging. This will keep tension on the bottom of the hull. Strand jacks will be visible on anchor towers on the starboard side. (Starboard is the side facing the seashore.) The main job of the holdback rigging is to keep tension on the hull nice and even, and to keep the ship from sliding across the temporary seabed, destroying the underwater platforms, and then rolling down the slope in reaction to the pull from the parbuckling cables.

3) Flotation tanks on the starboard side. These will flood to provide seawater ballast at the time of the parbuckling. (Later, for the tow to salvage, they will be pumped out and provide buoyancy for the flooded hull.) Apparently this ballast is necessary to bring the hull down to the seabed, because the ship's compartments will still have some buoyancy as the parbuckling begins.

There are several risks associated with this work, and I'll go into that in another post.

Saturday, September 7, 2013

Visiting the B-2 Bomber Wing: A look at weapons loading


For those curious about the nuts and bolts of weapons that might be employed over Syria if the US intervenes, following is information I gleaned during a recent visit to Whiteman AFB at Knob Noster, MO, for Air&Space/Smithsonian Magazine.

The article as printed in August, "Stealth Bomber Elite," is here; this is bonus material.


(USAF / Senior Airman Nick Wilson )

Having heard of the sophisticated rotary launcher available to B-2 mission planners, I had the mistaken idea that such a high-tech bomber must take on its cargo automatically: perhaps a launcher preloaded with munitions elsewhere in the base, then hustled to the aircraft on a trailer and plugged into a B-2 bomb bay a half-dozen bombs at a time … fast and easy, like ramming a clip into the 9mm pistol issued to pilots before each combat mission.

Time with a bomb-loading crew in Whiteman AFB's Weapons Load Trainer straightened me out: While machines substitute for some of the muscle-power, it's very much a hands-on task, from bomb assembly in the weapons depot to loading the plane behind the closed doors of a dock. That goes for the 30,000-pound Massive Ordnance Penetrator to the smallest, a 500-pounder: all are individually loaded.

Conventional bombs can go on board with no more than tail fins and fuses, or they can be enlightened with JDAM guidance packages. The JDAM unit (short for Joint Direct Attack Munition) relies on satellite signals and inertial navigation to steer the bomb with swiveling tail fins and strakes. Because each JDAM-guided bomb is individually cabled to the plane's targeting computer, the crew can reassign targets over enemy territory. Boeing recently announced manufacture of the 250,000th JDAM kit.

On display when I visited the training facility, which is about the size of a high-school gymnasium, were a full range of conventional bombs. That included green-painted free-fallers, and gray glide bombs with wings that swung out, along with a powered version like a small cruise missile. All were practice models, for loaders to use during initial training and recertification.

The demonstration that morning featured a 5,000-pound bunker buster called the EGBU-28: taking it from its perch on a trailer and loading it into a practice version of the B-2, which featured a rotary launcher in the right bay and Smart Bomb Racks in the left.

According to the pair of sergeants giving me the tour, the combination of GPS and inertial guidance on this bomb's JDAM kit would be accurate enough to put the first bomb in the top of a steel drum, then a second bomb in the hole made by the first.

The loaders had a diesel-powered truck with a hydraulic arm designed for bomb loading, a rugged and bulky remote control, hand tools, and a checklist with grease pencil. And a good deal of elbow grease, as shown by the first job: moving the bomb-bay door from a vertical position and pinning it back so that it's out of the way, against the wing.

The green bomb was long and slim, with a rod-like nose.
(USAF / Airman First Class Shelby Orozco)

The driver edged the loading arm under the bomb's midpoint, then raised and rotate it to line up with the truck's direction of travel. A few turns of the steering wheel and it was lined up under the left-hand bomb bay. Each step was called out and repeated. Watched carefully by an airman on an orange ladder wearing a headlamp, the lift arm edged around obstructions to snug the bomb against an open slot on the rotary launcher, called a station.

For a brief moment, as the loading crew released temporary fastenings in preparation for shifting the deadweight to the aircraft, the 2 ½ ton bomb lay neatly balanced on the tip of the loading arm. Now it was time to make all connections and verify that nothing would come loose: a sway brace to hold it in place, a data cable to provide updates from the aircraft, and an explosive cartridge to separate the mechanical fastenings during the run. Loading the bomb took about five minutes. After each bomb goes aboard, a control panel at the stairway to the cockpit activates hydraulic power that swivels the launcher to take on the next weapon.

While the noncoms had good words for the efficacy of this particular bunker-buster, what I didn't expect was their enthusiasm for a lowly 500-pound non-bunker GBU-38 bomb with a MK-82 warhead ... if JDAM-equipped. The B-2 can haul 80 of these in the Smart Bomb Rack, totaling 20 tons, compared to a maximum of 16 one-ton bombs using both rotary launchers.

“With these you can destroy all the facilities on an airfield and leave the daycare center standing,” said one of the non-coms. Because a 500-pound bomb can demolish most targets as well as a one-ton bomb can, having such a big swarm of bombs in the belly might allow a single B-2 trip to take the place of three, or even four, B-2 sorties carrying one-ton bombs. Hard or buried targets could be left for a separate mission carrying bunker-busters.

That's if people and computers can rise to the opportunity without errors along the way. The 80-bomb load hasn't yet been tried in wartime, even in the most recent engagement, the 2011 attack on Libyan airfields. There's a risk that, along with the more sophisticated situational-awareness tools now available to the pilots, the extra capability could over-tax pilots and mission planners back at Whiteman.