, In concluding that two trailers seized in northern Iraq were biological weapons laboratories, the United States rejected Iraqi claims that the vehicles were actually designed for making hydrogen for weather balloons.

But while some have described the Iraqi explanation as far-fetched, the US Army has its own fleet of vehicles designed for precisely the same purpose. They are among the army's more unusual vehicles: a Humvee with a large container and refrigerator-sized generator where a gun or troop transport shell should be.

The AN/TMQ-42 Hydrogen Generator, as it is known, has never been used in combat, and, with plenty of helium – the preferred gas – to keep the army's weather balloons aloft, it is unlikely that it ever will.

But the truck escapes obscurity in becoming a footnote to the debate over Iraq's alleged chemical and biological weapons programs.

The CIA and the Defence Intelligence Agency have described the two seized trailers as “the strongest evidence to date that Iraq was hiding a biological warfare program”. But some analysts involved in the examination of the vehicles reject that conclusion. Inspection has failed to find any traces of anthrax, smallpox, tularemia or any other known pathogens.
One veteran intelligence official in Iraq, who spoke on condition of anonymity, said he is convinced that the seized trailers were indeed designed to produce hydrogen gas to fill weather balloons that were routinely used by Iraq field artillery batteries.

The intelligence official said the trucks did not carry autoclaves or other equipment needed to sterilise laboratory equipment, as would be needed to grow sensitive pathogens used as germ agents.

Weather balloons are used by artillery units to collect atmospheric measurements – including wind speed and relative humidity – that help calculate the trajectory of rockets and cannon fire. The Observer in London recently reported that Britain sold an artillery weather balloon system to Iraq in the late 1980s.

US artillery units generally fill their balloons with helium, a far safer and less combustible gas than hydrogen. But experts said Iraq probably would not have access to helium, a gas that is scarce in most parts of the world.

In their publicly released analysis of the two Iraqi trailers, the CIA and DIA acknowledged that the vehicles could be used to produce hydrogen but dismissed that capability as a convenient cover story. The CIA noted that Iraq never declared the vehicles to UN inspectors, something it would have faced no risk in doing if they were truly for hydrogen production. CIA officials also said the design of the trailers was unnecessarily elaborate and cumbersome for hydrogen production.

Even so, the agencies' report noted that Iraqi officials at the Al Kindi research facility in Mosul, as well as Iraqis interviewed at a company that manufactured components for the vehicles, all said the trailers were built to make hydrogen.

Los Angeles Times