Bomb? What bomb?
UPDATES:
Manila Times: Stinky Explosion
Phil. Daily Inquirer: Metro Manila cop chief: ‘Bomb theory hard to sustain’ and Ayala: 'Nothing extraordinary' about G2 basement conditions
GMANews.TV: Ayala Land says PNP theory of methane gas blast unlikely
PDI Editorial: Don’t rush
GMA Photo Gallery: Great Pics Here
(NOTE: Please click on the "Comments" link below to view more and updated details from exchanges with commenters. Some are too long to rewrite here. Thanks - Tongue
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Original Post
Four days after. Nothing conclusive still. No suspects, no arrests. Not even the cause of explosion. They're floating a new spin: Diesel and/or methane probably did it. Aaah...
Diesel or bunker will not ignite, much more explode, without heat and/or high pressure. That is why you don't need to use spark plugs in diesel engines. Diesel engines instead use heaters that raise the air temperature in the combustion chamber. As the injector nozzle sprays atomized fuel into the chamber, the approaching piston increases the pressure in the fast-diminishing free space inside the cylinder. The increasing pressure produces more heat to vaporize the droplets of diesel to mix with the heated air and just as the piston reaches Top Dead Center in the compression stroke, rapid combustion (explosion) takes place in the chamber, the tremendous force pushes the piston down again (power stroke) to rotate the crankshaft one cycle. This are the second and third strokes of your typical four-stroke diesel engine. The other two are the intake and exhaust strokes.
Compression in the manner I described here is very difficult to recreate accidentally. It is a slow process requiring an almost perfectly sealed environment (like the engine's cylinder). That is also why diesel engines are slower than gasoline-fed ones. Compression bears a heavier load on the power components (pistons, rings, rods).
If the diesel tank, which by the way is almost always filled especially in applications such as malls and other establishments frequented by many people, did cause the huge explosion, it should have been blown beyond recognition. Generators used for critical applications such as Glorietta's are typically run with and without load weekly both automatically then manually for about fifteen minutes just to make sure the Genset (engine + alternator/dynamo w/ Auto-start/Auto-shutdown circuits) and the electrical controls (Automatic Transfer Switch, Paralleling Switchgear, etc.) will work in the event a real power interruption (brownout) does occur. It also ensures that the batteries are recharged regularly. Without batteries, generators are worthless. This regular process, called Plant Exercise, makes it imperative that the fuel tank/s are always filled to its upper limits. Meaning very little space for compression and combustion in the tank's upper chamber.
What did the pictures show? A fuel tank standing perfectly by itself, except for a small hole and with a portion of the top cover appearing to me as intentionally pried open. The tank did not appear to have "bloated" or puffed out as it should be if it had exploded from inside. The small hole? It looks to me like it was there all the time. Maybe a vent punched out by maintenance for pressure release. This is necessary especially if the fuel delivery pipes to the engine operate by gravity (think pressurized water tanks vs. gravity tanks).
Or it could have been used as inspection hole to check fuel level either visually or by using a dipstick. Some tanks usually have level indicators using a transparent plastic tubing stretched vertically outside with both ends connected to metal tubes welded at the top and bottom of the tank's side. The level outside is the same inside since liquids seek their own level. But since this type of indication is neither rigid nor durable, at some time maintenance people disable this and use the more reliable dipstick method.
Again, the metal plate that this hole was created in did not look dented in nor puffed out that would have indicated any explosion either coming directly from the top or from the inside, respectively.
I now also remember talking to military officers from the Electronics group called AFPCES some years back who wanted me to design and build diesel tanks thick enough to repel bullets. I was told the NPAs use AFPCES' tanks for target practice (including soldiers climbing their antenna masts) but when I asked how many have died in the explosions, I was told the bullets just punctured the tanks and at worst, it would deprive them of a week's supply of diesel but no explosions. Either I was watching too many cowboy movies at the time or totally ignorant to have asked that.
I need not discuss it if there was fire in the aftermath or if soot or black smoke or blue flame was present because judging from the condition of the tank alone and my discussions regarding diesel combustion, I'm amazed some dorks posing as investigators are still looking at the diesel tank angle.
Those who still are inclined to believe the spin that the blast was caused by diesel or bunker are, well, bonkers!
Now what about the sewage tank angle?
From what little I know about sewage treatment plants (I designed and installed electrical controls including semi-automation modules for, what do you know? A high-rise 5-star Hotel and a mall complex!), the Laguna Lake Development Authority (LLDA)- if your establishment spills a huge volume of effluent towards the Laguna Lake or any of its tributary rivers, or the DENR - if your sewers lead to floodways or esteros flowing to any of the seas in Luzon, sewage treatment plants (STPs) ARE required by either gov't offices before Environmental and Sanitation Permits are issued, thus construction permits are withheld in their absence. A mall the size of Glorietta, or the whole Makati Commercial Complex or Ayala Center as it is now called, IS required to operate a Sewage Treatment Plant.
Two possibilities, therefore. Either Glorietta has its own or it pumps its sewage into a central STP operated by Ayala Center. If not, then either LLDA or DENR did not do its job here. Or were bribed. In the late nineties, 2 or 3 malls/condos in the Ortigas-Shaw corridor were issued Cease and Desist Orders by LLDA because they were found pumping sewage straight to the city lines. They were heavily fined and closed temporarily until they constructed their own STPs. At least, that's what the papers said.
What does an STP do?
To simplify, it first screens solids out of the influent waste from the mall, breaks down into "digestible" size large sediments like a giant blender with many agitator blades at the bottom of the tank; then pumps all of it into an aeration tank where air produced by big fan blowers is pumped from under the sludge, making aerobic bacteria digest organic waste. The next tanks would separate liquid from the remaining sludge. Liquid undergoes chlorination before the effluent is released to the city sewers while the remaining sludge repeats the process. This is where methane gas is produced. In large quantities, it may be dangerous as 14% methane mixed with oxygen explodes when ignited. Some large STPs use the gas to heat and dissolve the sludge but in this size (Glorietta's) there is not enough methane produced to install a collector-burner stage. Abroad, it is common in city-size STPs but of the 3 private-owned medium-sized STPs I've worked on in the past, I have not seen one with a methane collector-burner stage, much less one that exploded.
It would be stupid likewise that Glorietta, or Ayala for that matter, would maintain a large septic vault holding raw sewage under one of its public buildings. They employ the finest architectural firms in the world to design their projects, any firm of that caliber would definitely not skip the basic requirements in their designs. So will sanitation and safety engineers, too. Even our houses' pozo negros have vent pipes with which to "breathe" out the gas. Further, Methane does not stay stable for long. It breaks down into Hydrogen Sulfide which is a very toxic gas. We haven't heard anyone die of gas poisoning in Glorietta prior to the incident, have we? Instead, what many witnesses and victims smelled was a gunpowder-like odor. Or in one victim's words, "amoy-paputok", which is characteristic of a C4 blast. A explosion caused by methane could be preceded or followed by flames and we haven't heard of any such thing in Glorietta. Let's take a look at the simplified chemical equation of burning methane in ordinary air:
CH4 + 2(O2 + 3.76N2) = 2H2O + CO2 + 2(3.76N2 + energy
where energy may be all or combination of Sound/Heat/Light/Shockwave
It is standard that explosion relief vents are constructed in STPs, more so one under a Generator room. The Generator Room itself, depending on the size and quantity of gensets, may have several exhaust fans to evacuate the hot air around the engines, the cooling system's radiators (or water pipes to the external cooling towers for large installations), and the exhaust mufflers. I will not accept any excuse that the generator room is a totally contained/enclosed one, meaning a sealed vault where the operators can die from fumes inhalation either from the fuel or the engine exhaust. It is therefore safe to conclude that the generator room was well ventilated. Blast waves and shock waves cannot be produced like that as in Glorietta (blasting through the flooring up to the 4th floor) if it was not a sealed container.
Now, a room that has many vents and openings, doors, windows, vents, etc. should have allowed the smell at least of the foul-odored sewage, or methane gas, or hydrogen sulfide (when methane breaks down) and it would have been detected earlier by Ayala personnel or reported by shoppers. Any reports? Nothing I'm sure.
That being the case, and all the foregoing arguments here from my raw experience and stock knowledge, all debunks either the methane or diesel theory or the combination of both.
Here's one link emailed to me, it used 9,000 liters of methane gas (about to fill up a tanker truck) and totally enclosed. Watching the resulting blast, you can estimate that it wont even be sufficient to rip a hole that large through the thick concrete floor slab and even send shock waves up to the building's ceilings. I doubt there was even that amount ( a tanker truck) of methane concentrated in the Glorietta sewage.
DILG's Marius Corpus rattling out that the mixture of of methane and diesel could have caused it, is of course, another attempt at cover-up.
These liars never stop, don't they. I bet the next day it will be spontaneous combustion!
Labels: Bombing, Cover-ups, Glorietta, Terrorism
posted by Tongue's Wrath @ 10/23/2007 11:53:00 AM
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