Introduction
In 1948, the 2nd Marine Tank Battalion at Camp Lejeune began experimenting converting a Medium Tank M4 to serve as a radio communications hub. The primary goal of this experiment was to provide consolidated communications between Air, Naval, and ground elements from the mobile protection of an armored vehicle. A few years later, the idea would be recreated and expanded upon before being fielded in the Korean War. This 2nd iteration of the USMC communications tank came to be known as the "Porcupine."
Converted from an M4A3(105) HVSS medium tank, the Porcupine served the entire duration of the Korean War — from the landing at Inchon in 1950 to the peace talks at Panmunjom in 1952 and 1953. Throughout the war, it supported the 1st Marines, who coined and adopted the nickname due to its "bristling" appearance thanks to its numerous antennas.
Courtesy of National Archives.
Three Vehicles, One Idea
Although referred to collectively as "Porcupines," the concept evolved through three distinct vehicles over several years.
The 1948 Camp Lejeune Prototype
Though many consider the Porucpine an idea thought up during the Korean War, the concept predates the conflict by two years. In 1948, the 2nd Marine Division at Camp Lejeune took an M4A3(75)W VVSS for experimentation with creating a mobile communications hub variant of the M4 Sherman. Though this vehicle predated the use of the term “Porcupine” it clearly laid the groundwork and began the trend for many of the Porcupine’s unique characteristics.
Courtesy of National Archives.
The vehicle chosen for conversion was an M4A3 75w. This M4A3 appears to be a combat veteran, likely from Iwo Jima or Okinawa. It shows various scarring from Marine field modifications such as fabricated periscope covers and weld scarring from spare track armor. Though it’s conjecture, these features are indicative of modifications commonly done by the USMC 4th Tank Battalion.
The prototype never left Camp Lejeune and was likely reconverted or scrapped. However, the lessons learned directly informed the creation of Y53.
Courtesy of National Archives.
The Porcupine — Y53
The best-documented, and perhaps most well known,Porcupine is the vehicle identified as "Y53." Converted from an M4A3(105) HVSS, this tank had its 105mm howitzer breech and internal gun components removed, though the barrel was left in place — fixed in the travel lock or facing rigidly forward — so it would resemble a standard gun tank from a distance. The turret interior was packed with radio equipment enabling communication with naval vessels, aircraft, infantry units, and artillery batteries simultaneously.
Y53 served with the 1st Marine Division throughout the Korean War, operating as a forward air controller (FAC) and communications relay vehicle. Its movements can be partially traced through the few surviving photographs and unit records.
Vehicle History
Chosin Resivoir
The best-documented, and perhaps most well known,Porcupine is the vehicle identified as "Y53." Converted from an M4A3(105) HVSS, this tank had its 105mm howitzer breech and internal gun components removed, though the barrel was left in place — fixed in the travel lock or facing rigidly forward — so it would resemble a standard gun tank from a distance. The turret interior was packed with radio equipment enabling communication with naval vessels, aircraft, infantry units, and artillery batteries simultaneously.
Y53 served with the 1st Marine Division throughout the Korean War, operating as a forward air controller (FAC) and communications relay vehicle. Its movements can be partially traced through the few surviving photographs and unit records.
After the armistice in July 1953, the fate of Y53 is unknown. It was likely reconverted or scrapped along with other surplus Sherman variants as the Marine Corps transitioned to newer equipment.
Project Porcupine
Following the success of the field-converted Porcupines in Korea, the Marine Corps initiated "Project Porcupine" — a formal program to produce improved communications tanks at Camp Lejeune. A photograph from this period shows a Porcupine under construction with the caption: "New Construction of Mobile Communication Tank. (Project Porcupine)", though the image is undated.
Project Porcupine vehicles represented the most extensive modification of the three variants, reportedly featuring up to eight antennas protruding from the hull sides and engine deck. The project aimed to standardize the conversion process and produce vehicles that could be reliably deployed with Marine tank battalions as organic communications assets.
After-action reports and the final report delivered to the Marine Corps Commandant spoke highly of the Porcupine concept, recommending continued production and usage by the USMC. However, it appears these recommendations were never fully acted upon, likely due to the aging Sherman platform and the adoption of newer tank designs in the post-Korea era.
Loose Ends
How many Porcupines were built?
The number of "Porcupines" built remains a mystery. I've only found one photo that cannot be directly attributed to the three vehicles detailed in this article. The photo taken at Camp Lejeune, as seen below, shows a porcupine under construction, but is undated. With a lack of distinguishing "Porcupine" modifications, identifying this vehicle is near impossible.
Courtesy of National Archives.
All after-action reports, as well as the report on Project Porcupine delivered to the Marine Corps Commandant speak highly of the these communications vehicles and often recommended continued production and usage by the USMC. The lack of photos of additional vehicles implies that these recommendations went unaddressed. This may be due to the aging Sherman tanks, the adoption of newer tanks, or even potentially a lesser need for an armored FAC during an era of "peace" between the Korean War and Vietnam War.
What is near certain, however, is that only one Porcupine served in-theater during the Korean War — that being Y53.
Was there an M46 Porcupine?
Some references online make mention of a Porcupine based on an M46. To this date, I have yet to find any accounts or photographs of this vehicle. If anyone has more information, please reach out to me.
What happened to them?
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Sources
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