Xiyu Ammunition Depot Introduction
We often use the term "copper wall and iron wall" to describe the sturdiness of a house, but the Western Islet Ammunition Depot is a genuine example of a copper wall and iron wall! The Western Islet Ammunition Depot includes the earthen cool ammunition depot and the cave-type ammunition depot, also known as the copper wall and iron wall. It is a rare military structure from the early Japanese occupation and one of the four major ammunition depots established by the Japanese military on Penghu Island. As the name suggests, the Western Islet Ammunition Depot is primarily used to store artillery ammunition. The cave-type ammunition depot consists of both single-chamber and double-chamber dry ammunition storage, which store two different types of gunpowder: smokeless and smoke-producing. The cave ammo depots utilize a double-walled vaulted structure; they first excavate a semicircular cave in the rocky base of the mountain and then stack concrete blocks to form the outer depot, while the inner space is constructed with reinforced concrete. To store smokeless powder, in addition to maintaining constant temperature and humidity, the side walls are lined with copper sheets to effectively isolate electromagnetic pulse waves and moisture. On the other hand, the earthen cool ammunition depot is an above-ground structure with exterior walls made of stacked stone, interior walls made of wooden boards and raised wooden floors for moisture proofing, a steel truss roof structure, and a roof made of cultural tiles, which are blackened tiles. The roof is also equipped with a lightning rod to prevent lightning strikes. Both types of ammunition depots are rare military constructions from the early Japanese occupation in Taiwan, showcasing the architectural techniques of that period, and have been designated as county-level historical sites for restoration and preservation.
