Another type of bunker or blockhouse is a little concrete post, partly dug into the ground, which is usually a part of a trench system. Such bunkers give the defending soldiers better protection than the open trench and also include top protection against aerial attack (grenades, mortarshells). The front bunker of a trench system usually includes machine guns or mortars and form a domainant shooting post. The Rear bunkers are usually used as command posts, for storage and as field hospitals to attend to wounded soldiers.
Pillbox
A pillbox on the East coast of England. Part of the defences were built during World War II (the railings are a modern addition)
Dug-in guard posts (with shooting slights) made from concrete are also known as "pillboxes". Some of the pillboxes have camouflage in order to provide the guards better protection and the element of surprise. They may be part of a trench system, or with other pillboxes form an interlocking line of defence by providing covering fire to each other, or they may be placed to guard strategic structures such as bridges and jetties.
Industrial bunker
Typical industrial bunkers include mining sites, food storage areas, dumps for materials, and sometimes living quarters.
The rear bunkers are usually used as command posts or Tactical Operations Center (TOC), for storage and as field hospitals to attend to wounded soldiers.
Bunkers deflect the blast wave from nearby explosions to prevent ear and internal injuries to people sheltering in the bunker.
If a bunker is in a built-up area, it may include water-cooling or an immersion tub and breathing tubes to protect inhabitants from fire storms.
The bunker was the 13th and last of Hitler's Führerhauptquartiere or Fuehrer Headquarters (another was the famous Wolfsschanze).
The bunker was supplied with large quantities of food and other necessities and by all accounts successfully protected its occupants from the relentless and lethal shelling that went on overhead in the closing days of April 1945.
Most of the bunker's remaining occupants left within hours thereafter, trying with varying success to break through the lines of the encircling Red Army, which by this time was only a block or two away in any direction.