Fuel

In an operation such as the one just conclued in Iraq, the primary commodity consumed is petroleum mostly diesel and jet fuel. The M1 tank and the helicopters are powered by turbine engines while most of the other other equipment is diesel powered. The Army has eliminated all its gasoline engined equipment in order to simplify fueling logistics. I don't know for sure, but I assume the Marine Corps has done the same. Even so, the amounts of fuel required to move a heavy Division boggles the mind. An M1 doesn't get miles per gallon. It gets gallons per mile and it is not shut down while parked so is always burning fuel. The same is true for most other combat vehicles while the logistics vehicles essentially operate 24/7. The battalions in the Division have organic fuel vehicles (around 2500 gallons per transporter) that provide fuel directly to the battalion's combat vehicles and other equipment. These assets move with the battalion and stay fairly close to the fighting forces. They generally have a one day supply of fuel. (My fuels experience is limited, so if I am wrong on the battalion's basic load, sorry). The battalion's organic assets must be resupplied daily. This is done via a combination of Division Support Command and Corps level fuel resupply tankers (5000 gal). As the supply lines stretch out as they did very quickly in Iraq, the turnaround time on resupply gets longer and longer as the tankers must travel further to get refilled from where ever the fuel is stored.


The soldiers operating the fuels resupply lines work extremely long hours even during exercises since the resupply capability is marginal under ideal conditions and there is no such thing as ideal conditions during anything associated with military operations. Soldiers become exhausted and disoriented. The Army tries to have two people in every truck. This allows some rest, but there is little or no true rest. On top of driving the trucks, the log soldiers provide their own security so it is not like the second person is a commercial driver napping in the "sleeper".

Logistics equipment is the most neglected item in the Army. It is not glamourous and usually has no constituency. Given the choice of another tank or 30 fuel tankers, the Army buys the tank. The trucks hauling fuel in Iraq were fielded in the mid-80s on average. They were and are excellent trucks, but they are old.

Logistics units are the last on the list to get new equipment and the equipment authorization tables provide less communications equipment per soldier than any of the combat arms units get. Combine that with the fact that the log units are moving constantly and not always as units, command and control is very difficult.

In my opinion, it is not by chance that the first POWs of the Iraq war were log soldiers.

A few weeks back, I was asked to write about the logistics units supporting the American Forces around the world. I will attempt do so, but must say upfront that I only have experience with the Army and a very little with the Air Force. I was an Army Logistican for twenty years during which time I worked at least a few weeks in every area of Army logistics. The most important thing I learned was that logistics is all about money and transportation. Given enough of those, there is no logistics problem. But even if I have cubic dollars, transportation remains a problem.

In fact, when we read about SECDEF Rumsfeld's efforts to "transform" the military, the driving factor is transportation. The Army seems to be under the SECDEF's gun the most and that is because the Army is currently structured to fight a war where it has most of its equipment prepositioned in the theater and enough troops to provide security until soldiers from other theaters can arrive to operate the pre-positioned weapons and equipment. The problem with this mode of operation is if the war does not conveniently happen where we have the equipment, it can take months to move it to the theater of operations. In Iraq we saw this with the 4th Infantry Division when Turkey refused to allow transit of the division's personnel and equipment. If you remember, there was talk of it taking weeks for the equipment to transit the Suez and be off-loaded in Kuwait. Given the world political situation, an Army that takes months to get into theater is a luxury we cannot afford.

To transform the Army, the current Chief of Staff set out to make a heavy brigade lighter and more transportable. Tanks are out and wheeled armored personnel carriers are in. Since this is about logistics, I will not talk about the merits of the "Striker" vehicle other than to say is lighter, smaller and more easily transported. A brigade thus equipped can get into theater a lot faster either via air or sea. Once in theater, a "Striker" brigade will consume much less fuel and ammunition tonnage than a brigade equipped with M1s and Bradleys. Usually ammunition and fuel are the tonnage and volumn drivers in supporting a military unit,

In addition to ammunition and fuel, a unit requires food, general supplies and equipment maintenance. When you start adding up all the people it takes to transport and handle all these supplies, the logistics tail can easily exceed the size of the fighting force.

In future posts I will talk about the missions and challenges of log units in a modern theater of operation.

I haven't posted anything about the war. I don't know anything. I watch TV and read the news. What I know is very similar to what I used to know during a large exercise such as the annual REFORGER exercises in Germany. From where I was, the battle was as remote as the Battle of Gettysburg. I knew that certain units needed fuel, food and ammunition. I knew what was going on in my immediate vicinity. Occasionally I would hear a report of something exciting happening that would have everyone talking. Usually after the exercise, we would learn that it never happened.

I believe the same thing is occurring in Operation Iraqi Freedom. The news media have their imbedded reporters who see a small portion of the battlefield. What we see on TV is one or two pieces from a thousand piece jigsaw puzzle. We cannot possibly know what the whole picture is from the few pieces we see.

I suppose I could write about the logistics units and the problems they face, but I don't think it would be of much use to anyone. I do not feel much like writing about technology at this time so postings will be even lighter than usual until times change.

The Zeus system is on its way to Afghanistan. Sparta built the system using company funds. In 2000, it was one of the "pork" projects we often read about. Congress added about $4 million to the Army's budget request to fund the Zeus and to provide for testing against a variety of landmines. Late in 2002, the Army Vice Chief of Staff was given a demonstration of the Zeus while visiting White Sands Missile Range and ordered it to be deployed to assist in landmine clearing. It will undoubtedly save lives.

The Army requirements system never produced the requirements documents that called for a laser to destroy landmines. A few individuals with foresight and drive kept pecking away until they had a prototype to demonstrate and now the Army's is deploying its first high powered laser.

Thanks to Sparta Corporation.

I have been waiting for ten years for this. It is time to move away from the Cold War deployment structure and on to one that matches our national interests. I think are nearing a "Nixon goes to China" moment.

I am behind on my laser myths writing and ICBMs seem a more appropriate subject this week. Please bear with me because this rambles.

SECDEF Rumsfeld says that North Korea has missiles capable of reaching the west coast of the United States. That should not be a surprise to anyone who follows international events. About four years ago, NK sent a missile over Japan into the Pacific Ocean. At the time, they asserted that they were attempting to launch a satellite. Which is easier, firing a missile a few hundred miles or launching something into orbit?

Let’s go back to the beginning of projectile weapons. Probably someone picked up a rock and threw it at someone or something. From there, men advanced to spears and other thrown projectiles. These depended on the strength of the thrower for distance and force of impact. Some aids were developed to increase the leverage applied to the projectile. These aids essentially allowed the thrower to transmit his muscular energy to the projectile over a longer time interval.

Later some brilliant research and development guy came up with the longbow which allowed stored energy to be released into an arrow. The concentrated energy transmitted to the arrow meant that it flew farther and impacted with more force than any man could produce by throwing a projectile. Again, the key was increasing the time interval in which the shooter applied his muscular strength. Pulling back on the bowstring over time puts energy into the bow that is released very quickly into the arrow.

Later still, someone invented the crossbow. This really increased the time interval for storing energy in the bow and thus provided vastly increased energy levels to the bolt. A really strong man could shoot the longbow great distances, but the crossbow allowed anyone to shoot a hard-hitting bolt. Medieval catapults worked on the same principle; put the energy in slowly and release it quickly.

With the invention of gunpowder, soldiers no longer had to depend on their muscles to send the projectiles across the battlefield. The energy in the gunpowder meant projectiles could go faster, farther and deliver more energy to the target. Early guns were limited in projectile velocity and range by three things: the energy release characteristics of the propellant, the length of the tube (barrel) and the composition of the gun. Muzzle velocity determines the range of the gun. To increase muzzle velocity you can increase the burn rate of the propellant, increase the amount of propellant, decrease the mass of the projectile or lengthen the tube. There are limits to each, but this is a good rule of thumb.

Problems arise quickly when you improve propellants or increase the amounts used. More and faster burning propellants raise chamber pressures and can result in catastrophic failure of the tube. In other words, it blows up. Exploding guns are an occupational hazard for artillerymen. The number of rounds fired through modern artillery tubes is recorded to ensure that dangerously worn tubes are removed from service.

Lengthening the tube also results in greater muzzle velocities as more of the energy from the burning propellant is imparted to the projectile before it leaves the tube. The maximum velocity of a gun projectile is achieved at or near the end of the barrel. There is a limit to how long an artillery tube can be made before it becomes so unwieldy that it is impractical as anything other than a stationary weapon system. Also, higher velocities in the tube result in faster breakdown of the tube itself. There are artillery rounds that have rocket motors at their base. These rocket-assisted projectiles (RAP) increase the range of tube artillery but sacrifice lethal payload capacity. Accelleration forces on tube artillery projectiles can be in the thousands of Gs meaning that the projectile and any cargo must be extremely rugged to withstand the loads. This ruggedness means less mass can be devoted to the kill mechanism.

Rocket artillery such as the US Multiple Launch Rocket System (MLRS) solves the muzzle velocity limited range problem. Just as the crossbow and longbow allowed for longer time intervals to put energy into the arrows, rocket propellants can burn slower and longer and put energy into the rocket projectile over a longer time interval. G-forces are lower, the projectile can be made less rugged and the kill mechanism more lethal for a given caliber. Ranges can be longer because more energy can be applied to the projectile.

Each type of artillery round is a ballistic missile in that once the propellant burns out, three forces determine the impact point: velocity at burnout, air drag and gravity. The altitude, vertical attack angle and velocity at burnout determine how quickly gravity will bring it back to earth. If the velocity is high enough, the projectile can achieve Earth orbit. If not, it falls to earth short of orbit.

The North Koreans said that they were trying to launch an orbiting satellite. By definition, an orbit is a lap around the Earth. An intercontinental ballistic missile does not have to go around the Earth only a few thousand miles. It requires much more energy to launch a satellite into orbit than it does to send a similar mass payload from Asia to North America. If you can do the first, you can do the second.

Get yourself a small nuclear weapon and a decent launch vehicle and you are a contender.

High Energy Laser Myths

This will take several postings.

Opponents of the High Energy Laser (HEL) development community have a list of reasons that HEL will never work. It is a list of the reasons given by critics who question spending defense funds in an area they consider futile. A reason that almost always appears is that defense against HEL weapons is as easy as painting weapons to reflect the laser energy.

That seems intuitively obvious. We all see our reflection in mirrors and we understand that the reflection is merely light returned to our eyes because the mirror is coated with something that does not let the light pass through. This is a case where intuition turns out to be wrong. Theoretically, you could coat and polish a warhead or weapons platform to reflect the laser energy and in fact, that is exactly what is done on the optics that collect, shape and direct the laser beam in an HEL system. Until the mid-1990s, those optics were cooled using high flow-rate liquid coolant systems. Think of those cooling systems as really big automobile radiators. Hundreds of gallons of coolant were required to keep the optics system from burning up when the HEL hit it. Even then a small flaw in the optic could result in a hot spot and blowout of the optic. A cooled optic could cost millions of dollars to produce and polishing and recoating ran hundreds of thousands. In the mid-1990s, uncooled optics became available. These cost an order of magnitude less than similar sized cooled optics, but still cost tens of thousands for even the smallest. The coating and polishing of the optic is a costly, high-precision job.

Another aspect of HEL optics is that the reflective coating is designed for a particular wavelength. The optic that works well for a deuterium-fluorine HEL works less well for a hydrogen-fluorine HEL. More energy is absorbed by the optic and less reflected when the coating is not optimized for the wavelength. In fact, a coating may enhance the energy adsorption of an HEL beam rather than reflecting it.

So theoretically, weapons platforms and projectiles could be coated and polished to reflect laser beams, but it would be very expensive to do so and it would only be effective if you know the exact characteristics of the laser you are defending against.