Strand Jacks, Pulling for You

One thing that makes the job of freelance writer interesting is the sheer diversity. In the last year I've written about drones, strategic bombers, astronauts vs. automated spacecraft, and crisis teams. Right now I'm working on war alerts, the validity of computer models, and a children's book.

Which brings me to yet another unconnected topic, the strand jack. Back when I worked in construction with my brothers, one tool that we greatly admired was the railroad jack, a heavy duty (and also very heavy) manually-operated jack sturdy enough to lift a bridge beam.

Railroad jacks push; strand jacks pull (more on that below). Here's a big strand jack, from mammoet.com:

(For those who might wonder what heavy riggers do, Mammoet does stuff like this, delivering coking units:)

Now about strand jacks, which will be critical to the success of salvage work coming up at Costa Concordia. First, the big picture, from Corriere Etrusco:

As animated in the Parbuckling Project, salvors will be pulling the cruise ship upright (that is, rotating the ship so that the superstructure moves to the left, in this photo), refloating the ship, and towing it to a drydock for scrapping.

While that may not sound too difficult, it is, for many reasons. And it's why the insurers' cost estimates are now edging $400 million.

Here's one reason for the high cost: Concordia is huge and its hull came to rest sideways on two subsea promontories, one fore and one aft. So that means the midships is sagging. While a gang of strand jacks can move any artificial object that mankind cares to build, however large, they can also tear it apart. If salvors were to just start using them to drag the ship upright, the tension on that unsupported midsection would break the hull in half.

So they've been laying down 20,000 tons of cement grout in big bags, filling in the valley (temporarily) to give the hull a sturdier foundation before the hydraulics do their stuff.

Recently Salvors have started the next phase, attaching big steel boxes called caissons to the port side. These caissons will be filled with water, and then it's time for the strand jacks. Here are a couple of the big blue machines, hanging from a formidable crane hook (Photo, Parbuckling Project):

Setting aside the caissons, here's a Parbuckling Project illustration showing how the strand jacks will be lined up along the port side, working in unison to drag the ship upright. 

The term strand jack comes from the fact that it exerts force on strands, commonly steel cables. Think of how you'd lift a bucket on a rope, hand over hand: one of your hands pulls on the rope, as the other shifts to get a new grip.

It's the same with strand jacks, which use hydraulic grips to pull cables a few inches at a time. Commonly the jacks work in groups under computer control.

Strand jacks are slow but very powerful. In 2004, strand jacks raised a 2,000-ton section of roof at the Wembley Soccer Stadium (Photo, Engineering News-Record):

 

Fertilizer-Plant Explosion in West, Texas

A little about the explosion at West, Texas. A Chemical Safety Board go-team is at the site, along with investigators from the Texas State Chemist . This news report says experts have identified the epicenter of the explosion, but aren't releasing that info yet. Later, we'll get the official word about exactly what exploded and why.

But the center is pretty clear from this photo in the Fort-Worth Star-Telegram, given streaks and the location of debris (Tony Gutierrez, Associated Press):

Note, for example, where the company's big ammonia tank sat (the round yellow foundation at upper right) and where the walls of that tank ended up. A line connecting those two locations leads to the center point of the explosion. While I haven't seen an official diagram of the plant, the epicenter looks like the north end of the dry barn mentioned in some news reports.

Here's a labeled photogram of the blast site, along with an aerial posted on Bing.com from last year. (Kudos to Bing and Pictometry for having recent aerial photographs on line):

We're told that West stored a large quantity of dry ammonium nitrate fertilizer in the dry barn, perhaps 270 tons at times. From a good piece in Chemistry World about ammonium nitrate, here's a snip:

"It is an intriguing feature of ammonium nitrate is that it should not, according to thermodynamics, even exist. It is a compound that contains nitrogen in two forms - surrounded by oxygen in one and by hydrogen in the other. In chemical parlance the nitrogen is, side-by-side, in oxidised and reduced forms. Normally one would expect them to react together, combining to form the more stable dinitrogen, dioxygen and water in a complicated partner swapping process called comproportionation. But in ammonium nitrate, this process does not happen at room temperature, making it a metastable compound, like a lake of water trapped behind a dam. Even if you are careful, ammonium nitrate is an accident waiting to happen."

When heated in a fire, ammonium nitrate doesn't always blow up but it might. If the smoke changes color to some shade of orange, that may mean the material is in a runaway reaction generating oxides of nitrogen. I interviewed a worker at a dynamite plant who once saw fumes from an overheating vat of metriol trinitrate change color in such a fashion, and he ran fast enough and far enough to survive the blast.

And one witness in West mentioned that the smoke from the fire at West Fertilizer changed color shortly before the blast.

Nightmare Range, South Korea

I'm a fan of H.P. Lovecraft. In our POW (plain old world) one doesn't often come across geographical names that measure up to Lovecraftian standards, along the lines of his Mountains of Madness. 

But here's a real one that comes close: Nightmare Range, a target-practice area in far north South Korea. It's just a hop-skip-and-a-ricochet from the DMZ, certainly reachable by shell from the DPRK's dug-in heavy artillery just north of the border.

Here's a map, from a recent naval survey of training sites, with the label for Nightmare Range highlighted at upper left, with its location to the side:

 

 

The border with North Korea is the gray line on the map just above Nightmare Range. On an island in the Yellow Sea south-southwest of Nightmare is Chik Do Range -- see the other label. Chik Do is where US bombers did practice runs last month. So we haven't been as provocative as some commentators are saying; practice bombing runs at Nightmare Range would have pushed tensions up a lot more.

Here's an aerial photo of Nightmare, from the Wikimapia site:  

This obscure location came up briefly during an August 18, 1976, meeting of the Washington Special Action Group (WASAG), a small but very influential foreign-policy advisory group in the Ford Administration and, previously, the Nixon White House.

The subject that day was what to do about a murderous attack in which a squad of North Korean soldiers jumped a small American-ROK team that was attempting to trim a poplar tree for better sightlines between observation posts in the DMZ.

Among the many response concepts bounced around by WASAG (not all of which have been declassified) was having American aircraft do practice bombing runs all the way up to Nightmare Range. That was scrubbed as too provocative, and more modest measures were taken when finishing the tree-trimming two days later ... but with a great deal of firepower waiting just over the nearest hill. Call it armed arboreal diplomacy.

For those interested in knowing more about what North Korea itself called an "ultra-tense" situation, I'm researching it as part of an article on military alerts to be published in Air&Space.

Dances with Lone Wolf: What's a History Channel production like?

Tackling this question raised by my blogpost during the Titanic centennial, on the four corners of a wreck: What's it like to participate in a History production?

The short answers: Fun! Long days!

I've appeared in a dozen-odd shows for History, CBS, and National Geographic, but the production Titanic at 100 that aired last year on the day of the wreck's centennial had a bigger budget (since it was part of an international marketing push for the network) so I'll concentrate on that one. The production company was Lone Wolf Documentary Group of South Portland, Maine.

My bit started in June 2011, when Lone Wolf flew me out to their location for a day of interior shots that would serve as a screen test for History's executive on the project (called the showrunner), and, if acceptable, would be part of the show.

 

The cameras at that setup were digital single-lens-reflex cameras, aka DSLRs, which produce broadcast-quality HD video. The setup also included pro-quality sound gear recording on a separate chip, professional lighting and a miniature dolly to move the camera across the room.

 

The equipment filled the back of a van and to set it up all the way to mic checks required more than an hour. I wore a lavalier mic and wireless set, and there was a sound man wielding a boom and watching the levels. Audio quality is very important!

That was one shooting day.

After History okayed me to be a participant in the virtual hangar segment (along with long-time Titanic experts Ken Marschall and Parks Stephenson), in October I flew back to Maine for two more shooting days. The setups the first day were two more interior shots (one against a green-screen, one at a desk by a window in an old building); an exterior shot where I walked along the harborfront; and an exterior shot as I drove around Portland.

One thing Lone Wolf is good about is feeding the cast! There must be some ex-Navy submariners on the staff. We commentators met one or both directors for breakfast before a shooting day started (thumbs up for Becky's Cafe on the Portland waterfront) and dinner afterward, and lunches for all shooting days were catered.

The third shooting day started with driving an hour to the former Brunswick Naval Air Station, where we took over a big building to shoot the “virtual hangar” part of the show. This setup lasted the entire day because it was unusually elaborate for a documentary.

 

Readers probably know about blue-screens or green-screens (aka Chroma-Key), in which TV meteorologists or actors perform in front of a solid color background. It's easy for electronics to remove the background color, so that other images can be inserted behind the talent. The movie Sky Captain and the World of Tomorrow was shot entirely in front of a screen.

But it's no longer necessary to use a green-screen to place people into a digital world, though the alternatives are harder to use. One of those is called difference keying, and it's how Lone Wolf put us in a virtual hangar.

The elements:

1) During each shot, the Red camera began the take by shooting the hangar without us in the frame, and then we walked into the frame.

That way, each shot held a record of what the background looked like, before people arrived and started walking around. We also ended each shot by walking out of the frame.

2) In post-production, computer processing pulled away the hangar background imagery and replaced it with a transparent layer, which left Ken, Parks and me walking around in a void -- like villains in Superman's Phantom Zone. Computers can cut away the background, frame by frame, because we humans were moving around, but the hangar wasn't. That created a difference between us and the background, sufficient for difference-keying. No color difference is necessary, though it doesn't hurt. Here's a video demonstration of difference keying.

3) What to use for the new background? Drawing on imagery of the real hangar, the special effects company in New York built a 3-D model of the interior space, which closely resembled the real hangar (as in, it had pipes, a floor, doors, lights, and a ceiling with girders) but was somewhat bigger so as to fit the Titanic.

4) Our images were composited into the computer-generated hangar, along with the ghostly Titanic.

Why go to all this trouble? To put real humans and a digital ship in the same three-dimensional space. For example, when Ken waved his arms, the special effects guys in post-production could make the hulk spin, shrink, or rise off the floor. When Ken and I were walking around with a flashlight near the hangar door, all we could see was a concrete floor. Digital magic inserted the rusty boilers later.

One more footnote for special effects buffs who have seen the History show. Normally difference-keying requires a camera to be locked down (meaning, the camera doesn't move at all during the take), but Lone Wolf gave the shots a little fluidity, this way:  Whenever the camera moved during a take, it was looking down at us from a height, which silhouetted us against a uniformly gray floor. Such a background is easy to correct, so it was possible to give a little motion to the shot without making difference-keying impossible.

ICD-10 Medical Codes: All the modern mishaps

 It would be a rare person who didn't find something to squeam about (meaning, to act squeamish) when looking over the "ICD-10-CM External Causes of Injuries List" mentioned in this PBS blog.

It's a list for use by those who keep medical records, effective 2014. Some very obscure accidents are coded in ICD-10, like burns from flaming water-skis (see category V91.07) or injuries due to accidental contact with non-poisonous frogs.  We're told ICD-10 makes some medical people squeamish about the extra time it will take to find the right codes next year, compared to today's shorter list.

If you'd like to know more, from Findacode.com here's a draft list of externally-caused injuries, as of late 2012, and here's an addendum with updates.

 

While I support the idea of cataloguing the full range of threats, the list still needs some work. For one, I didn't see a category for burns due to high-oxygen atmospheres. (While the list offers many entries for flammable materials, high-oxygen settings allow stuff to catch fire that normally aren't very flammable but will burn in pure oxygen.) Nor did I see a category covering projectile injuries due to unsecured metal objects near very high magnetic fields.

But in general the list is spine-chillingly thorough, covering hundreds of contingencies that have not yet sent hordes to the emergency room. Such as:

• Spacecraft crashing into each other, causing injury to spacemen and spacewomen: V95.43
• Injuries due to nuclear weapons in armed conflict, aka World War III: Y37.50 through Y37.59
• Injury following contact with flying horses: W31.81 *
• Immersion in cryogenic liquids: W93.11
• Injuries due to falling out of an airplane, eg from an airliner at cruise altitude: V97.0 **

===


* This isn't the danger of being struck by a falling, antique Mobil Oil sign. Apparently it refers to a broader category of accidents in amusement park rides, because W31.81 also covers bumper-car-related injuries.

** A few such lucky people have made it to the ER, so I suppose a code is needed. One flight attendant survived after falling 33,000 feet from a DC-9 in 1972. I mention a couple of cases in Inviting Disaster. 

Meteor-Eyes: DSP satellites, a unique resource

This article from the San Diego PBS station about the meteor breakup near Chelyabinsk quotes a planetarium producer saying that fireballs happen "about every day," but most happen in remote areas or over open ocean, and so do not reach the headlines.

It's true that fireballs (bolides, as in glowing chunks) happen almost daily, but not explosions in the kiloton-plus range. 

Here's a Wiki list of significant meteor blasts, some leading to breakups and the touchdown of small meteorites. The list of powerful meteor explosions is considerably bigger than this, but if they happen in places so remote that no one is around to watch them, how do we know?

The answer is that someone is watching all the time, from the other direction: via infrared detectors in space. Perhaps the best known to Pentagon-watchers is an array of geosynchronous satellites under the highly generic name of the Defense Support Program, as in DSP East and DSP West. 

DSP satellites have played rather important roles in the American early-warning system since 1970, such as the ability to detect boost plumes of other countries' intercontinental ballistic missiles (ICBMs) or submarine-launched ballistic missiles (SLBMs). Given how fast such missiles travel (about 30 minutes from their missile fields to our targets), and given the limitations of ground-based radar, DSP information is extremely important to military people who fear a surprise attack (Image, USAF):

 The Russians have their own infrared satellites, Oko.

 Now the Space Based Infrared System is replacing the sturdy old DSP sats. Here's a very interesting article from the Astronomical Society of the Pacific on what unclassified DSP and other missile-watching data told scientists about meteor explosions, covering roughly from 1972 through 1997. Here's a map of the events:

The article explains that this is by no means a complete list because the DOD didn't do a lot of data-preservation in the early years. A meteor explosion over the Marshall Islands in February 1994 (approximately 50-70 kilotons, in two explosions) was the biggest in the publicly released data set.

(Even so, researchers now say the blast on Friday was significantly more powerful than the one in 1994, as in hundreds of kilotons).

So that's what the data suggested as of 1998: on average, every week a rock at least three feet in diameter was exploding in the upper atmosphere. Pretty amazing information, in my mind. 

Unfortunately, the DSP data-spigot has turned off.
 
Geoff Brumfiel noted in 2009 in Nature that meteor researchers suddenly lost access to American space-based infrared data (apparently because the Pentagon didn't want the abilities of the system to be in the public literature, and because SBIRS was soon to go on line).

While USAF sources suggested afterward they might open up the files soon, Geoff's meteor-blast article yesterday in Nature notes that the promised release of new meteor data hasn't happened yet. 

But this week's Siberia blast was so remarkable and unsettling that I predict some DSP and perhaps SBIRS data will come out.

Big Bear Lake: ENG pilots, hovering at the fringe

Viewers may wonder how law enforcement authorities are able to keep news helicopters from peering into the cabin where, allegedly, Christopher Dorner is holed up.

The answer is the Temporary Flight Restriction, which is imposed by the FAA at the request of law enforcement agencies. Here's the link to the TFR now in effect at Big Bear Lake: it covers a radius of five nautical miles, from the ground up to 13,000 feet above sea level. 

 CNN has been featuring aerial footage from the LA sister stations KCAL and KCBS. While researching my helicopter book The God Machine I had the fun of spending some hours with Larry Welk, then a contract news reporter/pilot for KCAL and KCBS, through his company Angel City Air.

At HeliExpo conventions since then, I've also heard what he and fellow electronic news-gathering pilots think about today's TFRs: they regard the FAA as way too liberal in handing them out.

Also note the camera work in this evening's news footage, which is able to reach out for miles from its position over a roadblock and zoom in on a semi unloading an armored car way up in the hills. It's remarkably stable though shot from a hovering helicopter.

Larry termed his helo's camera a "kick-ass" unit when I rode with him, and rightfully so. Even back in 2006 the gyro-stabilized, nose-mounted camera was capable of reading a license plate at a half-mile distance.