Comments about technological history, system fractures, and human resilience from James R. Chiles, the author of Inviting Disaster: Lessons from the Edge of Technology (HarperBusiness 2001; paperback 2002) and The God Machine: From Boomerangs to Black Hawks, the Story of the Helicopter (Random House, 2007, paperback 2008)

Monday, October 5, 2015

Crane Down at Masjid al-Haram, September 11

About the crane disaster last month in Makkah (Mecca in its westernized spelling). A Liebherr L-11350 crawler crane tipped backward in a windstorm, killing 109 people in what forensic folks call the laydown zone. The worst area of destruction was where the 100-ton mast and jib dropped on the roof of a very long building on the east side called the Massa. The upper end of the jib crashed onto pedestrian areas on the other side of this building (photo AFP)

When the crawler crane fell over it also came close to destroying a tower crane, a Liebherr 335, also located on the east side of the Massa.

Here's how the roof damage looked: 

The "W"-shaped object above the Massa roof, projecting into it, is where the two jib struts join up with the upper end of the main boom, and the lower end of the jib (see below for a diagram). The jib struts provide a support for the jib. As the crane fell over backward, the two jib struts acted like twin piledrivers, smashing into the third and second floors of the Massa

Here's a link to the only public video I've seen of the crane going down (but I'm sure the Saudis have a lot of CCTV footage):

Here's a diagram of the basic components, before and after:

How big was it? As this crane was rigged (called an SDW arrangement in the manual), the tip of the L-11350's upper structure called the "luffing-fly jib") reached more than 600 feet off the ground. 

It's classed as a super-crane: while not the world's biggest crawler crane, it's close. The lift capacity under ideal conditions is 1,350 metric tons. It's a popular crane for refinery turnarounds and wind-farm projects. 

How long had it been on the plaza? More than three years. It was part of a big Saudi purchase from Liebherr in 2012. 

What was the crane doing there? It had been parked and inactive for some time. Details on usage are fuzzy; given past photos taken by pilgrims and posted online, the crane hadn't gotten much use lately. We're told that it was to be used again after the September 2015 Hajj, as part of ongoing expansion of the Masjid al-Haram and the Massa in particular. Here's a diagram of the location. 

What do the initial reports say? Authorities have been interrogating employees of the contractor, Saudi Binladin Group, which has filed an insurance claim. While this particular windstorm was unusually powerful, the crane manufacturer says it was a mistake to park the crane with its boom at such a high angle (85 degrees), where it could catch the wind. 

What about the cleanup? Because the 2015 Hajj pilgrimage was to begin less than two weeks after the wreck, work went on around the clock. Experts decided structural damage to the plaza at the base of the crane was so severe that the removal of the lower chassis (called the car body) would have to wait until after the Hajj, so this area was screened off from pilgrims. 

The focus was on removing the main boom and derrick mast from above the eastern plaza, and pulling the jib and jib struts off the roof -- and without causing more damage to the Massa, which is heavily used by pilgrims. 

If there's interest I'll post on how a team from Aramco got this done, with advice from heavy-life expert Mammoet, which I mentioned in this post about strand jacks

Sunday, September 20, 2015

DeepDreaming with Ice Photography

Will be posting an infographic on the Sept. 11 Mecca supercrane disaster soon; meantime, on a lighter subject, here's a note on what I'm doing with my stock of macro-ice photos. 

As followers may know from
 my Interstellar fan poster, ice photos taken with a macro lens can have an uncanny aspect, suggesting something not quite of Earth. So when I heard about DreamCeption for IoS, that sounded like something I should check out. 

Sure enough: here's an example of patterns that Dreamception added to one of my ice photos, Fire Cave

That's at low-resolution. Here's a sample of what Dreamception can do at a higher resolution, from a small portion of the upper right of the image:

That's impressive for the consumer market. The processing load must be substantial, which is why it runs in the cloud on supercomputers. 

The app's based on earlier work at Google, originally set up so that its artificial-intelligence program, called DeepDream, could recognize elements of photos, say, distinguishing a dog from a doghouse. Turns out that DeepDream can work the other way, superimposing details onto photos in a search for patterns and meaning. Filters such as "afterlife" impose buildings, faces, and all kinds of crazy things on ice photos: 

Using the Dreamception app on an iPad is easy -- just upload an image from your Camera Roll folder, select a filter, hit submit, then save back to the Camera Roll. It's possible to process an image with one filter and then apply another filter to that result. 

After some experimenting, I think the most striking results come that way, from using the filters in series. For higher resolution you may have to break your image into pieces and recombine the Dreamception output with a graphics app, such as one of my faves, ProCreate

ProCreate's layer tool is also a good way to restore some of your original image, in places where Dreamception's patterns don't make sense. That's what I did for the center of Fire Cave

Thursday, August 13, 2015

Summer reading: Quick book reviews

The Martian: Fun read, and reflects an amazing amount of research and thought by the author. The family enjoyed it even more than I did. Many novels have featured marooned individuals, on Mars and elsewhere, but this has a uniquely fast pace as things continue to wrong and then even wronger. I think one reason it's so currently popular is that the plot affirms hopes among the Colonize Mars crowd:  if we could just hurl a few plucky humans to the surface, along with a few hundred tons of supplies, they'd take it from there and make us all proud. 

The Martian is based on an appealing fantasy, but it's not a good basis for a manned space program. In my conversations with astronauts about human vs. robot roles in space, they convinced me that when it comes to distant places like Mars and the moons of Jupiter and Saturn, they'd prefer that robots do the advance work, dig shelters against cosmic rays, and turn up hazards long before the humans touch down. Quite likely, the first astronauts to arrive in the vicinity wouldn't land at all. Rather they'd handle the robots' mission control from orbit. But that's too wonky for fiction. 

Lawrence in Arabia: Many good insights about T.E. Lawrence, the scheming British and French, the Turks, residents of Palestine, and the Saudi tribes. We hear much about what drove T.E. to such heights and such depths. But I found the side stories of other intriguers so prominently mentioned on the jacket -- presented in a parallel thriller style -- as weakly tied to the main story, because those people had little to do with Lawrence's exploits. Are they there for contrast, to show how much Lawrence did and how much they didn't do? I couldn't tell, but it was distracting. I did appreciate the occasional revisionist info correcting fictions in the David Lean motion picture

Time and Again: A classic. A wonderful book, worth reading numerous times. Jack Finney is one of the few time-travel writers to realize that great narration and characters are more important than dropping time-travelers into the Turning Points of History. One of many examples of the latter cliche is The Final Countdown, where the writers dispatch a modern aircraft carrier through a "time storm," conveniently to arrive off Hawaii hours before the attack on Pearl Harbor. Here's the poster:

The Theory That Wouldn't Die: Reading this now: nonfiction about the origin of the Bayes Theorem and why it took more than two centuries to catch hold. Why does an old theory about using prior scenarios and posterior corrections matter? It's proven vital to good decision-making in uncertain and fuzzy situations. If the wreck of Malaysia Airlines MH370 is ever found -- no, make that when it's found -- the use of Bayesian methods is likely to share some of the credit ... as it did with the location of the remains of Air France Flight 447. 

Tianjin blasts: How big, and how did they happen?

Monitoring news of the explosions in the giant port of Tianjin, China. 

We are told that a fire in containerized cargo brought dozens of firefighters to the scene and later led to two explosions, the first about two or three metric tons of TNT-equivalent and the second less than 23 metric tons ... according to the official seismic data.

I looked up the site for the China Earthquakes Networks Centerbut all the information I see posted there is dated and limited to earthquakes. 

From the images, and the continually rising death toll in the headlines, I'd be surprised if the total yield was much below 100 tons of TNT equivalent. Damage visible in the daytime (Photo, Beijing Youth Daily):

The ripple effect on the world's supply chain could last longer than hospitalizations, as Tianjin is one of the top export-import hubs for China. From NBCNews, this stack of toppled empty containers:

To the extent other stored goods in the area have been tainted by the alleged chemical releases, there may be a lot of dumping to come.

Not knowing the kind of explosive materials stored there, it's hard to speculate on the chain of events. Some titanic explosions of stored ammonium-nitrate fertilizer have been triggered by fires (for more info, see Inviting Disaster, Chapter 9, but so far we don't know what energetics were being stored here. 

Saturday, May 9, 2015

Tales of the Chopper: "Gunfighter" Emerson in Vietnam, Part 2

This follows my earlier post on Gen. Hank "Gunfighter" Emerson, who died in February. It's excerpted from my book on the social history of helicopters, The God Machine.  Gen. Emerson called me from Montana after my book came out, saying he was interested in writing a book based on his experiences, which I thought a fine idea, so I put him in touch with my agent at William Morris, but as far as I know the project didn't happen. It's a shame because the general was an outstanding tactician and leader. 

                        ==    ==

Col. Hank Emerson returned to Vietnam for his second combat tour in February 1968. He was to command the First Brigade with the 9th Infantry Division (the “Old Reliables”) in the Mekong Delta. The principal mission of the brigade seemed simple: to keep a 16-mile stretch of Highway 4, and its bridges, open for traffic. This highway connected Saigon with the vital rice-growing regions to the south (Image, US Army Corps of Engineers).

A simple mission ... but one that looked close to impossible. The Delta had little in common with the sparsely populated, heavily forested areas of Emerson’s first tour, except for the presence of a die-hard enemy. However successful up north, his Checkerboard tactic wouldn’t work here because it required men to walk long distances without being noticed. The open, rice-paddy terrain made long treks impossible and the many villages and their ever-alert dogs would foil any attempt at stealth. And Checkerboard’s wide-ranging artillery fire would have threatened the closely-packed villages. 

Through 1964 the highway had been safe for traffic, but beginning with the 1965 offensive the Vietcong had frequently been able to blockade it or blow up its bridges. At the time Emerson took charge, helicopter pilots were reporting flocks of little red Vietcong flags across the countryside; once they had been modestly pulled down by day but not any more. For a while armed powerboats along the canals called “riverine forces” had been able to break up enemy concentrations, but then the Vietcong had learned how to ambush the boats with rocket-propelled guns and heavy machine guns. 

“The psychological situation in the Delta was very bad,” the commander of the 9th Infantry Division, Gen. Julian Ewell, told an interviewer later. “I wouldn’t say it was defeatist, but it was tense and very nervous. The troops weren’t quite sure whether they would make it.” Ewell gave Emerson, who was one of three brigade commanders, permission to try something new. 

When Emerson arrived, American infantry tactics in the Delta had mostly been variations on the “sweep,” an ancient tactic for hunting wild animals. At its simplest, the sweep had troops walking in lines across the landscape to flush the enemy from hiding. When and if the enemy appeared, the Americans called in artillery or gunships to kill as many as possible before they scattered. 

Though the sweep sounded intimidating, like hunters closing in on foxes, usually the enemy units remained snug in their bunkers, and if caught outside were usually savvy enough to slip away via tunnels, by waiting for darkness, or by using canals and ditches. “Although you’d occasionally corner someone and beat up on them, often it was a dry hole,” Ewell recalled.

“The old idea wasn’t working,” Emerson told me. “The delta was full of mines, deep mud and paddy dikes, so we couldn’t get around on foot. I said, ‘We’ve got to get airmobile! This is one big LZ!’”

Emerson came up an approach he called the Jitterbug. As with the high-energy swing dance of the 1930s for which it was named, forces carrying out the Jitterbug maneuver tried to be everywhere at once. The concept was to find large groups of enemy soldiers, pry them out of hiding, and then confuse them once in the open so they couldn’t see a way out. It required a sustained, high level of operational tempo.

A successful Jitterbug operation began long before the shooting. It required sifting all available information to divine where an enemy main-force unit might be hiding. Emerson knew the identities of the main-force units in his area, but the location of their hidden heavy weapons and companies at any given time was an ever-changing secret. Learning that location quickly enough to mobilize a large-scale attack relied on village informers, starlight scopes, radar coupled with long-range listening gear, and reports from 12-man reconnaissance patrols that ranged out each night, when the Vietcong were most active. 

In one intelligence-gathering incident, an informer led Emerson’s men to a building at which Vietcong commanders were meeting with a North Vietnamese officer. The men broke down the door, shot most of the men, and took the NVA officer prisoner.

The brigade also experimented with the people sniffer, a laboratory-in-a-crate that fitted into a Huey and detected the presence of ammonia that all encampments emitted. The sniffer worked, but only until the enemy adopted some simple steps to frustrate the equipment. One effective countermeasure was to hang buckets of urine from tree branches.

Once the enemy position was identified with reasonable probability, helicopters moved in and shifted troops at a rapid pace. This frenetic activity was intended to alarm the enemy and persuade them that they were nearly surrounded, which prompted them to bring out their 12.7mm DShK heavy machine guns to use against the helicopters. 

The distinctive green tracer rounds (which looked as big as balloons as they came up to meet helicopter crews) pinpointed the guns’ locations and also indicated the value of the force. The more AA fire the better: heavy fire indicated a main-force unit, and Emerson was out to destroy the biggest forces he could find. If Emerson was satisfied that the enemy was within the Recondos’ grasp, he transmitted the radio signal, “Pile on!” which meant that all infantry units were to move in and create a tight perimeter.

The goal was to get the Vietcong out of shelter and trapped inside a ring about one half-mile across. To block exits via the paddy canals, troops draped concertina wire across the waterways and tossed grenades in the water at frequent intervals to discourage escape. 

Locating the enemy and creating a tight seal sometimes required 72 hours of unceasing activity. When the ring was secure, helicopters dropped bundles of tear gas bombs, particularly along lines of nipapalm trees where bunkers were likely to be concealed. 

Anyone caught in the ring came under a blanket of fire delivered simultaneously by fixed-wing aircraft, helicopter gunships, and artillery. “We had great artillery officers, like Joe Wallace and Bob Dirmeyer,” Emerson told me. “Dirmeyer could figure out how to deliver what I needed and deal it out all at once. We worked out aircraft flight patterns so they wouldn’t get hit by artillery.” 

Called “shooting the doughnut,” Dirmeyer’s intent was to put every howitzer round within the area ringed by American troops, and to keep doing this even as the Americans shrunk the circle by closing in. At intervals the firing would stop so that bullhorns could transmit a call for surrender.

“I hate buzzwords but in this case synergy was the right word – each type of fire protecting the other – and suppressing the AA,” Emerson recalled. “It was synergistic as hell.”

According to a dispatch by Associated Press reporter Peter Arnett -- who was as skeptical of military quackery as any correspondent in Vietnam -- by early 1969 the 9th Infantry Division was a formidable machine of war, even in the northern Mekong Delta, the Vietcong’s once-fearsome stronghold. It was an amazing performance considering that as recently as 1965, the Vietcong main-force units of the Delta were regarded as unbeatable. Arnett did express doubts about whether America’s firepower was leading anywhere productive, but wrote that when it came to dealing out such carnage with the “pile-on” tactic, the draftees of the Old Reliables were masters. 

“The game of hide and seek has honed the Ninth Division into a deadly efficient machine,” Arnett wrote for the Associated Press in April 1968. “One recently captured document from the enemy high command described it as the most dangerous division in the country.” 

Because the style of such warfare required close-in leadership from all officers, the toll was high. “There were six battalion commanders when I was with First Brigade. Three were killed,” recalled one of Emerson’s battalion commanders, James Lindsay, who retired as a four-star.

“Using this technique in Dienh Tuang Province, Col. Emerson over a period of months, essentially was able to break up every communist battalion in the province,” Ewell said an interview with military historians. Emerson’s men later repeated the achievement in the notoriously dangerous Long An province. 

MACV estimated that Vietcong forces controlled 75% of the villages in Long An as of January 1964, despite the Americans’ use of fortified “strategic hamlets.”

“The only problem with the Jitterbug was that it was so complex that it took a real master to do it well,” Ewell said.

“Jitterbug was most practical with enough helicopters to give combat units a high degree of mobility,” Julian Ewell went on. “Hank’s virtue was bringing tremendous intensity to the mission. He was a fighter and combined a high level of tenacity and speed with the Jitterbug. Hank’s sole purpose in coming to Vietnam was to beat the living stew out of the VC with minimum American casualties.”

“Emerson had a great deal of initiative – higher ups didn’t always like it but he just said screw you, and he set the rules,” Brien Richards, veteran of the early Recondo missions, told me. One of Richards’ proudest possessions is a signed photo from the Gunfighter. 

In the photo, Emerson is wearing a Colt .45-cal. single-action revolver, which he once used to shoot two Vietcong soldiers on the bank of a canal. That gun battle won him a Distinguished Service Cross, but Emerson sounded almost apologetic when I asked him about it: “It was a happenstance of course, I’m not that stupid, but I thought I’d cut ‘em off … It was a rash thing to do.” 

 “As good as a man he was, he had some quirks,” Richards recalled. Emerson acknowledged that on occasion he carried Scotch whiskey in his canteens for “medicinal purposes.”

The Gunfighter’s second tour in Vietnam ended with a bang on August 26, 1968, when a Vietcong gunner launched a rocket propelled grenade at his helicopter as he was returning to headquarters from a visit with one of his battalion commanders. Such projectiles are unguided and the great majority of them miss the aircraft at which they are aimed, but this one blew off the tail boom. 

The Huey nosed down, started spinning, and dropped into a rice paddy. It rolled over and caught on fire. Two men died instantly; four men climbed out; that left one man was trapped in the flames. That was Emerson. Emerson pulled himself loose shortly before the aircraft erupted in a fireball, which followed from the fact that it had landed on an enemy ammunition dump. He was evacuated in a Loach helicopter and treated for burns and a massive infection; Gen. Ben Harrison brought a bottle of whiskey to the hospital and they drank it in two hours. 

Motion pictures often portray the genuine risks that infantry soldiers faced when landing in a “hot LZ” but helicopter travel in Vietnam posed risks to all participants, military and civilian, particularly when Vietcong anti-aircraft weapons improved. Statistically, helicopters were the biggest single killer of the highest-ranking officers: helicopter crashes killed four of eight generals who died in the war, along with one admiral. John Paul Vann, early critic of the war and the subject of the biography Bright Shining Lie, died in a helicopter crash in June 1972. 

Emerson recovered from his crash, but never got back to the war. He had run twelve Jitterbug operations before being shot down for his third and last time. In 1969, while training at Fort Rucker to qualify as a helicopter pilot in preparation for a combat command with the 1st Cavalry, Emerson was pulled out of helicopter school and reassigned to the 82nd Airborne Division, as head of special forces. 

Wednesday, May 6, 2015

Tales of the Chopper: Hank "Gunfighter" Emerson in Vietnam

At the first of the Vietnam War, helicopters commonly provided rapid transit for troops attempting to employ a “cordon and sweep” maneuver to round up the enemy. 

Shortly afterward, using tactics mostly likely borrowed from Algerian rebels, the North Vietnamese learned how to shoot American helicopters down. Americans tried new tactics and new helicopters. While most air-assault missions failed to find and fix the enemy, there were some units who achieved continuing success before the U.S. began pulling out of Vietnam in early 1969. This came in part by using the new helicopters in new ways, but also by knowing when not to use them. Some of the most valuable lessons came from from the pre-helicopter era.

One such successful commander was Hank “Gunfighter” Emerson, of Milford, Pennsylvania, who as an Army infantry officer organized offensives in the Central Highlands and later the Mekong Delta (Photo, 2nd Bn. of the 502nd). 

Emerson's innovations were not heavily publicized during the war, nor in popular treatments of the war afterward. But the men who served under him had a high opinion of him. I interviewed Gen. Emerson at length for my book, The God Machine. And I'm glad I had that chance, since the Gunfighter died in February.

I first came across references to the Gunfighter's story while reading through transcripts of songs taped during talent shows put on by Army aviators during the war. Many were musical complaints about foolhardy missions, clueless commanders, mechanical malfunctions, and mistakes committed by novice pilots. Some songs took aim at the growing fame of Green Berets, who the writers called “Sneaky Petes.”

Since commanders usually come off badly in any song or skit drafted by combat troops, one song stood out. Titled “Gunslinger,” it referred to a lieutenant colonel named Hank with the 101st Airborne Division. In the song, the colonel’s helicopter is shot down after enemy fire cuts the hydraulic lines. Rather than hunker down for rescue, Hank gathers his men, strikes up a song, and goes out to chase down the Victor Charlie who shot at him. 

The enemy replies with hand grenades but the colonel roars his defiance and is victorious. He opens up two canteens of whiskey and shares them with the troops as they await a lift out.

I never had a better time or met a better gang,” the song concludes, “The night we whooped old Charlie’s ass then partied in Phan Rang.”

The unusual part of all of this is that ‘Hank’ was not a pilot or crew member,” remarked Marty Heuer, a former officer of the 174th Assault Helicopter Company who helped gather the song archive. According to Benjamin Harrison, then a brigade commander in Vietnam with the 101st Airborne, the songwriter clearly was referring to Col. Henry Everett Emerson, known as “Gunfighter” to his men. I located Emerson in Montana.

Emerson’s first brush with the long war in Indochina came in March 1953, as a military aide to Gen. Mark Clark. Dwight Eisenhower had asked Clark to bring back a personal report. Emerson, who by then had experience as a platoon leader and company commander for the 442nd RegimentalCombat Team in Korea, spent hours swapping stories with the officers of the French Expeditionary Corps.

The French described how the Viet Minh were cutting up their truck convoys with ambuscades. “They had the flower of the French Army there,” Emerson told me. “These were Legionnaires, and first rate, but they were having a hell of a time…. Clark sent a letter back, saying ‘This is a morass, we want no part of this.’ And Ike stayed out of it. The terrain was all wrong, and there were long logistics lines.”

By 1965, some strategists believed that helicopters had permanently tipped the scales to give the advantage to Western airmobile forces. They pointed to how U.S. troops brought devastating firepower to bear at the battle of Ia Drang, but such opportunities proved to be rare as the enemy learned and adapted. 

What good was a mechanized force that struck like so many lightning bolts, if the enemy refused to come out and fight fair? Were American forces incapable of driving the enemy out of South Vietnam?

Such questions were timely to then-Army Lt. Col. Hank Emerson. In 1965 Emerson was at the U.S. Army War College at Carlisle, Pennsylvania, preparing for his first tour in Vietnam as a battalion commander for the 101st Airborne Division. Feeling that the standard curriculum would not help him there, he cut classes and burrowed into the library. Emerson read books by Mao Zedong and Vo Nguyen Giap. He read about the French-Indian War and border wars on the American frontier. 

“I was most interested in guerrilla tactics,” Emerson recalled, “where the enemy fights like Indians.” Early in his military career Giap had similarly spent many days reading classic military literature, working out tactics against French and then Japanese occupiers.

One of the books of special interest to Emerson was Shoot to Kill, by British infantry commander Richard Miers. Miers explained how, beginning in 1951, the British worked out tactics to surround insurgents they called CTs, for “Communist Terrorists," based in the Malayan jungles. Four platoons radiated from a common center. 

As the tactic evolved, the British “Ferret Force” began using helicopters supplied by the Royal Navy to surround and capture insurgents. The helicopter unit was the 848 Squadron, whose feisty motto was acip hoc, Latin for “Take that!”

The British had progressed beyond the truck-minded use of helicopters to employ them in setting up a cordon, or ring, with which to trap insurgent forces in the jungles of Pahang for capture or aerial bombing. Later this would be called vertical envelopment. Guided by the commander in an orbiting helicopter, Westland and Sikorsky helicopters of the 848 Squadron shifted infantry units to surround the enemy, using jungle clearings when possible. 

When the troops needed to make a clearing they slid down on ropes and cut the trees with saws and the head-high grass with parang knives. By 1952 the British under Gerald Templer had insurgent leader Chin Peng on the run, having killed four of his top commanders.

Intrigued by the lessons that the British had worked out during their years in the Malay jungles and rubber plantations, Emerson wrote a term paper on the subject (which is still cited in operations manuals of the 101st Airborne Division, entitled “Can We Out-guerrilla the Communist Guerrillas." (Emerson's paper is not available online as far as I know, but more information can be found in this book on the Army's counter-insurgency doctrine.)

Emerson proposed a set of infantry tactics for Vietnam that evolved from Ferret Force tactics. For one thing, Emerson told me, the Ferret Force’s “weakness was being tied to a base, and the enemy would learn that base pretty soon.” After leaving the War College, Emerson tried out his tactics during field exercises at Fort Pickett and in the Dominican Republic.

In October 1965 Emerson took command of Second Battalion, First Brigade, 502nd Regiment, 101st Airborne Division. The forested north-central region in which he would operate (labeled II Corps and III Corps on American maps) was serving as a slow-motion highway for North Vietnamese invaders who passed through on foot. It was a year of rapidly escalating conflict. Seemingly the entire NVA was migrating toward the rice paddies and cities of the South, ten to fifteen men at a time. He had orders to find and destroy them.

Emerson’s paper laid out an approach he called the Checkerboard. While Checkerboard varied according to terrain, it relied on three basic elements. The first was infantry: three to four rifle companies from his battalion, broken into smaller units. All units kept in touch by radio. There were Recondo squads who served as scouts, and smaller groups that maintained observation posts by which to monitor enemy movement. Typically Emerson’s battalion kept one rifle company in reserve.

The second element was a very limited use of helicopters to move infantrymen around the area of operations. Whenever possible, “We all walked,” said Thomas H. Taylor, one of Emerson’s company commanders. “We didn’t want to insert by helicopter because the NVA would know our location. We’d slip through the jungle and meet at a trail junction or near a rice cache.”

The third element was artillery positioned on hilltops that could lay down a steady stream of shellfire for miles in all directions.

In Emerson's original conception, these elements were to play out across a checkerboard on which U.S. troops would move like game pieces, choosing their own moves to block the movements of NVA forces from north to south. This from the Army's Center for Military History

While in practice Checkerboard did not play out as simply as a sand table exercise, Emerson stuck to his first principles: keep fighting men in the field for as many days as possible, move fast and stealthily, and direct the enemy into well-laid traps rather than blunder into random firefights. Each time upon walking into a new area, the American scouts and observers spent days inspecting the terrain to find paths being used by NVA troops in transit.

Once the patterns and bivouac locations were known, they radioed back to headquarters. If artillery was in order, a request might go: lay down a barrage at 0200 hours on the following enemy areas, but not the adjacent friendly ones.

The artillery fire was not to destroy the enemy in camp but to roust him. “So the VC would go running down the trail, just like anybody else would,” said Brien Richards, an infantryman for the Second Battalion. “The artillery would keep ‘em moving and they never knew where we were.” 

The Recondos were laying in wait inside “friendly” areas, along the expected path of NVA movement. Emerson’s men had prepared fields of fire. They used grenade launchers and automatic weapons, but the most devastating were Claymore mines, which when detonated, sprayed shrapnel like massed machine guns.

The Claymores were arrayed in L-shaped patterns, and detonated by wire. Employing them required the ambushing squads to allow the enemy’s point-men to walk through the U.S. lines. Taylor says Emerson’s vision came closest to his 1965 paper in an action in War Zone D, appropriately called Operation Checkerboard. In such open country there were no well-defined corridors of foot travel, so the battalion set up a checkerboard of friendly and enemy grid-squares.

In all its variations, the Checkerboard usually worked. According to a combat report in Newsweek, by mid-1966 Emerson’s battalion was beating the enemy on its home field: moving like ghosts, laying ambushes, and hauling rucksacks with maximum ammunition and minimum rations. 

A typical ration was a little canned meat and a few pounds of rice, which lasted one man five days until the next resupply mission by air. “We went out heavily gunned, carrying ammo, ammo and more ammo, then water,” Richards told me.

They stayed totally on the move,” Emerson said of his men. “Instead of me picking out an ambush for them, the decisions were decentralized to the lowest level.”

Helicopters kept Emerson’s men hustling to NVA footpaths all over north-central South Vietnam, from A Shau Valley in the west to Tuy Hoa on the coast. What the helicopters didn’t do was to run the men back to camp for hot food, showers, and beer. According to Jim Gould of the Recondos, the troops stayed in the field for as much as three weeks at a stretch, followed by a three-day break. “Then it’s back out we go,” Gould says. “In the early days we did not have what was known as fire bases. We just traveled around the country: set up an LZ, ran the mission and moved on to another LZ.”

Emerson extended his tour an extra six months, but the Army moved him out of country in October 1966. He began laying plans for a return.

I'll describe Emerson's second tour, and its fiery end in Vietnam's Mekong Delta, in a later post.

Sunday, March 8, 2015

Link to Interim Report on MH370: Just released

new interim investigative report from the Malaysian authorities is worth reading, and not just for the news item about an expired battery on the underwater locator beacon for the plane's Digital Flight Data Recorder. 

It goes far to address my questions about what was in the aircraft's maintenance logs. The report identifies no major open issues prior to the flight, and it was good to see that prior to the fatal flight, Malaysia Airlines had indeed replaced oxygen-supply hoses of the type that may have contributed to a flight-deck fire in a 777 on the ground in Cairo in 2011.

I particularly appreciated the report clearing up a few uncertainties on my satellite phone question. Though a marketing brochure from Malaysia Airlines had advertised satellite phones in business class seating, on this particular 777, those phones could only make seat-to-seat calls. 

The only functional satellite phone mentioned in the report rang to the flight deck when the airline's operations center tried calling, after the fateful turn to the south: 
"Two Ground-to-Air Telephony Calls were placed to the cockpit from the MAS Operations Centre at Airline Operational Communications (AOC) Q10 priority level at 18:39 UTC and at 23:13 UTC, 07 March. Neither of the calls was answered."
Such incoming calls would trigger chimes and lights on the flight deck; but for reasons that remain a profound mystery, nobody picked up the phone. 

For me, I continue to guess that a pressurization failure followed by hypoxia played a big part in this tragedy, along with major problems in the electronics bay that knocked out some communications -- but not quite all the communications, as we now know from the satellite handshakes, and two unanswered calls that rang on the flight deck. 

I check the weekly search reports from the Joint Agency Coordinations Center, and lately we were able to see a sample of what the scanning sonar has sent back during the months-long search, the first phase of which is about half complete. The big boxes in the image are probably containers that fell off a ship.