Communications and a Pivotal Engagement on the Darkest Day of the Fleet

(From my interview with Captain (Ret.) VGM Eduardo Cerruti, Section Leader in Communications Company 3):

In the Malvinas, the most secure means of communication were wired systems. However, the signals personnel had to work tirelessly to repair lines that were frequently cut—either by shrapnel from bombardments, by sheep chewing through the cables, or, at times, by soldiers who used the wire to secure items while constructing their positions.

Inevitably, due to the use of HF communications on the islands, basic encryption and decryption systems had to be employed—elementary, to use the word loosely—since the type of cipher used had been originally developed by the British and American armies and was widely known across the world’s militaries. It was based on a five-digit code, and the British, though able to intercept Argentine communications, were not immune from making serious errors themselves.

To illustrate this, Captain (Ret.) Eduardo Cerruti refers to a specific engagement between a detachment of the British 3rd Parachute Battalion and a group of Argentine special forces from the 601 Commando Company. This occurred at the Murrell River bridge, during the night of 6 June and the early hours of 7 June 1982. In their retreat, the British abandoned not only their tents and various field supplies, but also their radio equipment. Most crucially, their radio operator left behind a communications pack containing documents listing frequencies, call signs, and network identifiers (e.g., alarm network, fire support network, logistics network, etc.).

For the Argentine communications personnel—who were trained under the doctrine that a message must be swallowed, destroyed, or burned before falling into enemy hands—this captured material was known as the Instructions for the Use and Operation of Communications (IEFC).

With the British documents now in Argentine hands, each time they tuned into a frequency, they heard voices speaking in English. They tried various channels repeatedly, and each time an English voice came through. Still, there was hesitation: given the professionalism of the British forces, they suspected that their enemies were already aware that the IEFC had been lost and that this could be a case of what is known in electronic warfare as simulative deception.

They continued monitoring the British using a Thompson field radio, which was not designed for electronic warfare. To aid in translation, they requested assistance from Communications Company 10 and were sent two soldiers who spoke English.

Meanwhile, Major Rábago reported the situation to General Menéndez, who authorised the purchase of a radio cassette recorder and several TDK tapes (60- and 90-minute lengths) from Port Stanley. Sergeant Edgardo Dalurzo, a field radio technician, successfully adapted the Thompson radio to the cassette recorder, enabling the team to record British transmissions.

On the morning of 7 June, one of the English-speaking soldiers informed Second Lieutenant Cerruti and other communications officers that the enemy was planning a landing at Bluff Cove (Bahía Agradable) the following day. This information was later confirmed by the second translator, who had received the tape and, after listening to it, corroborated the landing plan—and even added the names Bluff Cove/Fitz Roy.

It is worth emphasising that, using only a standard-issue Thompson field radio, which lacked any specialised electronic warfare capability, and thanks to the intel seized during the Murrell River bridge engagement, Communications Company 3 managed to conduct improvised electronic warfare. The report compiled by its personnel directly supported the Argentine Air Force in planning the successful strike carried out on 8 June 1982, during the British landing at Bluff Cove.

An extraordinary achievement.