Joint Assault Signal Company (JASCO)


A Joint Assault Signal Company was a joint service unit that provided ship to shore, air to ground communications to coordinate and control Naval Gunfire and Close Air Support to the United States Army. They were composed of specially trained Marines, Sailors and Army officers and enlisted. The Army component was composed of Air Liaison Officers, modern day Forward Air Controllers and enlisted communications technicians. JASCOs were created in the Pacific because of communication clutter, too many small teams to be effective. After the costly invasion of Tarawa the need for centralized command and control of air and naval fire support, utilizing Navy, Marine or Army gunners, spotters and radiomen was seen. Based on the Guadacanal experience of Major General Alexander A. Vandergrift the Joint Assault Signal Companies were formed.

Background

The formation of JASCOs parallels the formation of US Army Pathfinder teams. Because of a lack of foresight a deficiency was recognized and special units formed to correct the deficiency. The Pathfinder teams were formed to solve a problem discovered with the Battle of Sicily. Lacking guidance and control the paratroops were dropped all over the island. They managed to achieve their objectives due to the initiative and leadership of the officers and NCOs and the scattered airdrops made the occupying Germans feel overwhelmed. The German Fallschirmjäger had the same experience during the Battle of Crete; however, Adolf Hitler drew the wrong conclusion and never again committed his paratroops to an airborne operation, despite the great success they had at the Battle of Fort Eben-Emael during the attack on the Maginot Line. By contrast the US Army sought to rectify the problem by creating a special unit, which would jump in ahead of a parachute assault and mark the drop zones, providing terminal air guidance to the drop aircraft. These were Pathfinder units; JASCOs were a similar response to command and control deficiencies noted in the after action reports for The Battle of Guadacanal and the Battle of Tarawa.

Units

The first Joint Assault Signal Company was formed in October 1943 as a battalion-sized unit named the 1st Joint Assault Signal Company attached to the 4th Marine Division, under command of Lieutenant Colonel James G. Bishop Jr, Captain Murrary L. Thompson, Warrant Officer William T. Farrar Jr.
The Navajo code talkers were under their command.
JASCOs did not operate as a single unit, but were composed of 13 detachments supplied to Army and Marine divisions, regiments and battalions. Although JASCO units were first created for the United States Navy to coordinate ship-to-shore communications for naval gunfire and air support operations, they included United States Army personnel, Army pilots and enlisted communication personnel. As the Pacific War advanced the need for more JASCO units was realized, and units were created and attached to Marine divisions. By the time of invasion of the Philippines, the U.S, Army was creating its own JASCO's to support its infantry divisions. These JASCOs were primarily staffed by Army personnel, but had US Navy personnel as well. Each JASCO was divided into a battalion shore and beach party communication section, a shore fire control section, and an air liaison section, with each section further subdivided into teams.

Unit assignments

Each Marine division had their own JASCO as follows:
JASCOs took part in the following Pacific Theater Operations:
US Marine Corp JASCOs
The first JASCO operation involved the 1st JASCO and the capture of the island Roi-Namur, the northern half of the Battle of Kwajalein, Marshall Islands, attached to the 4th Marine Division (United States under command of Major General Holland Smith's V Amphibious Corps. Landing on February 1, the islands were seized and cleared the next day. No JASCO casualties were incurred. The short duration of the battle was, in essence, a live fire training operation, which enabled JASCO to work out some kinks. After the operation, on August 24, 1944 they returned to Hawaii for refitting and training.

Mariana Islands

The next operation was in the Mariana Islands, the capture of Tinian and Saipan. The battle of Saipan lasted from 15 June to 9 July 1944, while the battle of Tinian was from 24 July to 1 August 1944. The battle cost JASCO 4 officers and11 enlisted dead, 6 officers and 9 enlisted wounded, and 5 enlisted MIA. The communications teams of the 1st JASCO were the key to controlling the complex amphibian operation.
On Tinian, Navajo code talkers were used only on a few occasions and proved unsatisfactory due to the time it took to decipher long encrypted communications.

Iwo Jima

Participating JASCOs were:
The after action report for the 1st JASCO was critical of the Army component, stating that while the enlisted personnel were well trained, the officers provided were grounded pilots, and the qualifications of half of them "left much to be desired". The report also indicated a priority need for replacement personnel. There was such a loss of equipment, that the first two months of training back in Hawaii had to be limited to physical training, weapons training, and classroom work.

Okinawa

The following JASCO units took part in the Battle of Okinawa:
Two Army JASCOs supported the Central Pacific. These were:
By the time of the Okinawa landing, the JASCO had improved its communications and transportation capabilities, with new equipment including radio jeeps.
Air Liaison Parties from the Joint Assault Signal Companies attached to each division enabled the smooth functioning of coordinating agencies and front line direction of close air support from carrier aircraft and Tactical Air Force at 10th Army Headquarters.

Africa and Europe

In the African Campaign JASCO units were part of special engineer battalions, performing the same duties with a mix of Army and Naval personnel.
On June 6, 1944 there were three distinct JASCO units storming the beaches of Normandy. They were:
JASCO units were disbanded and their responsibility transferred to the US Navy with the signing of the National Security Act of 1947, at that time the Marine Corps began recreating JASCO capability under the ANGLICO designation. The United States Army created its own JASCO units for the European Theater of Operations. Its function has been incorporated into the Signal Corps.