Original Item: Only One Available. This is a rare and wonderful example of a WWII Imperial Japanese “Yardstick” Anti-Vehicular Mine, which was ground dug at Ramsey Ravine in Manila Bay, Luzon Island in the Philippines, the location where the Battle of Corregidor took place.

This mine is inert and completely void of any explosive content, making this example in total compliance per the current BATF standards on inert ordnance. It measures approximately 36"L x 3 1/2" x 2". This mine cannot be used as a destructive device and is not available for export.

The Battle of Corregidor, fought on May 5–6, 1942, was the culmination of the Japanese campaign for the conquest of the Commonwealth of the Philippines during World War II.

The fall of Bataan on April 9, 1942, ended all organized opposition by the U.S. Army Forces Far East to the invading Japanese forces on Luzon, in the northern Philippines. The island bastion of Corregidor, with its network of tunnels and formidable array of defensive armaments, along with the fortifications across the entrance to Manila Bay, was the remaining obstacle to the 14th Japanese Imperial Army of Lieutenant General Masaharu Homma. Homma had to take Corregidor, since as long as the island remained in American hands, the Japanese would be denied the use of Manila Bay, the finest natural harbor in the Far East.

The U.S. Army, however, then successfully recaptured the island in 1945.

The type of explosive that would have been found in this mine was 8 identical blocks of picric acid cast in a paper container and then coated with paraffin. Each block was molded on one end to take the fuze so that two blocks placed with the molded ends side-by-side would completely enclose the fuzes.

The mine was originally painted olive drab with a black basecoat, with the interior painted with black lacquer. The designation “FUZE TOP PORTION” would have been found stenciled in red kanji vertically approximately ⅞” tall on one side and “FUZE BOTTOM PORTION” in smaller red characters about ½” tall stenciled on the opposite side. The Naval mark of approval would have been stamped into all the fuzes.

The mine itself is an oval tube formed by two halves of sheet steel welded together with continuous welds down the length and closed at both ends by steel caps held in place by screws. Both end caps are present in this example, as are the retaining screws. One of the end caps has a hole for the safety wire, which was a single wire extending the length of the mine and passed through all of the fuzes. A spring clip held the wire in place. The explosive blocks were flattened on one side and did not completely fill the mine case. The space left between the flat sides of the blocks and the wall of the case accommodated the protruding heads of the fuze and also allowed space for the side of the case to be depressed on the fuze by the passage of a vehicle over the mine.

The fuze consisted of a short, cylindrical body which housed the striker release plunger, the striker housing which contained the striker and striker spring and the gaine. The gaine and the striker housing were identical in external appearance and were screwed into the sides of the cylindrical fuze body in diametrically opposite positions. The striker release plunger was a split pin with an enlarged flat head. It was positioned in the fuze body by a copper shear wire. A second hole 90 degrees from the shear wire hole accommodated the safety wire. The lower end of the plunger was split by a slot with the width increasing on the inner end.

Operation of the mine
After the safety wire was removed and the burying plug was screwed in, the mine was then buried. A vehicle passing over would crush the case and thereby applied enough pressure on the top of the fuze to break the shear wire and depress the striker release plunger. As the enlarged portion of the slot came opposite, the spring loaded striker moved across through the opening and onto the primer cap.

The condition of this example reflects that of an item excavated after spending decades buried in the earth. There are no markings left that can be seen and there are various spots with rot holes. The seam is partially split open which would have been done during the de-milling process.

Not too many of these mines survived during the course of the war and to find one in any condition is a rarity. You do not want to miss out on the opportunity to add a wonderful example of rare Imperial Japanese ordnance to your collection!

Comes ready for display.