THE British army in southern Iraq is having to rely on obsolete radios older than most of its frontline soldiers due to problems with a pounds-2.1bn digital communications system making its operations debut.

The Bowman network is nine years late entering service and cannot be used in Challenger tanks orWarrior infantry carriers because its powerful signals interfere with the vehicles' intercoms and electronics.

While a tank officer using Bowman's secure voice-link could speak to his brigade commander miles away without fear of eavesdropping, he would be unable to pass orders to the gunner or driver within three feet of him, and so Clansman radios are still being used.

Sources from 12 Mechanised Brigade, the core of the UK garrison in Iraq, have told The Herald that Bowman makes their strengthened Land Rovers so top-heavy that they are limited to 40mph to avoid overturning.

The portable infantry version of the radio weighs 15lb, three times as much as its predecessor, and has a history of leaving operators with radiation burns.

One officer said: "The company-level radio set is also so bulky that there is no room in the back of the wagons for anything but it and an operator.

The crew's kit has to be towed behind on a trailer. That slows them down and makes them potentially sitting ducks for insurgents.

"The radio has to be protected from the desert sun, so either soft or hardtop covers have to be in place at all times.

That means we can't have two soldiers standing up in the back of the Rover facing out with theirweapons at the ready to provide vital protection against ambush."

A second added: "It's also not much use tactically when the infantry and armour supporting them are operating on different radio nets. People have been using cellphones to make life simpler."

A third source said: "The infantry version, with its delicate wiring, is not robust enough for the rough-and-tumble of the battlefield and the company-level sets are too heavy for the vehicles meant to carry them. The one plus point so far is its ability to send secure voice communications.

"One would have imagined that, in the age of miniaturisation, someone could come up with something smaller."

The MoD plans to equip 18,000 vehicles with Bowman and have 60,000 soldiers trained in its use by 2007.

A spokesman said last night:

"The feedback we have received from Iraq on Bowman's secure voice communications has been very positive, although there are some issues to be resolved.

"These mainly concern the weight of the equipment, but we remain committed to overcoming technical problems and bringing the system to its full potential."