In
military science, a 'blockhouse' is a small, isolated
fort in the form of a single building. It is intended to serve as a defensive strongpoint against any enemy which does not possess
siege equipment or, in modern times,
artillery. If a fortification is intended to protect against such weapons as well, it is more likely to qualify as
castle or, in modern times, a
bunker.
Age of Exploration
Originally blockhouses were often constructed as part of a large plan, to "block" access to vital points in the scheme. But from the
Age of Exploration to the
nineteenth century standard patterns of blockhouses were constructed for defence in frontier areas, particularly
South Africa,
New Zealand,
Canada, and the
United States.
Blockhouses may be made of
masonry where available, but were commonly made from very heavy
timbers, sometimes even
logs arranged in the manner of a
log cabin. They were usually two or even three
floors, with all storeys being provided with
embrasures or loopholes, and the uppermost storey would be roofed. If the structure was of timber, usually the upper storey would project outward from the lower so the upper storey defenders could fire on enemy attacking the lower storey, or perhaps pour water on any fires. When the structure had only one storey, its loopholes were often placed close to the ceiling, with a bench lining the walls inside for defenders to stand on, so that attackers could not easily reach the loopholes.
Blockhouses were normally entered via a sturdy, barred door at ground level. Most blockhouses were roughly square in
plan, but some of the more elaborate ones were
hexagonal or
octagonal, to provide better all-around fire. In some cases, blockhouses became the basis for complete forts, by building a
palisade with the blockhouse at one corner, and possibly a second tower at the opposite corner. Many historical stone blockhouses have survived, and a few timber ones have been restored at historical sites. In New Zealand, a number of one storey timber blockhouses survive from the
Maori Wars, while stone blockhouses from the
Boer War are relatively common in South Africa.
Concrete blockhouses

A pillbox on the East coast of England. Part of the defences that were built during World War II (the railings are a modern addition)
During the First and Second World Wars many types of blockhouses were built, when time allowed usually constructed of reinforced concrete. The major difference between a modern blockhouse and a
bunker is that a bunker is constructed mostly below ground level while a blockhouse is constructed mostly above ground level.
Some blockhouses like those constructed in England in 1940 were built for traditional fortification reasons, often hexagonal in shape and were called '
pillboxes'. Between 20 and 30 thousand were
built in Britain during WWII in preparation for a possible German attack.
In London the
Admiralty Citadel is one of the most sturdy above ground structures built during World War II. It was constructed in 1940–1941 as a bomb-proof operations centre for the Admiralty, with foundations nine metres deep and a concrete roof six metres thick. It too was intended to serve as a strongpoint in defending against the feared invasion.
In Berlin and other cities during
World War II some massive blockhouses were built as air-raid shelters and
anti-aircraft artillery platforms. They were called ''
Hochbunker'' "High Bunkers" and those which functioned as anti-aircraft artillery platforms were also called
Flak Towers. Some were over 6 stories high. Several survive to this day because the cost of demolition would be prohibitive. The Pallasstrasse air-raid shelter
Schöneberg has a post-war block of flats built over the shelter. During the
Cold War the shelter was in use as a NATO foodstore.
[ Lupin Pooter.]
Afghanistan 2006
Blockhouses and
Sangars have become a feature of the 2006 conflict in Afghanistan, being used by the British coalition forces, amongst others, as strong points to control the contested Southern provinces. These positions have served to draw out the Taliban, who have taken to attacking repeatedly in numbers.
See also
★
Battery tower
★
Flak tower
External links
★
[1]:PILLBOX STUDY GROUP: A 300 strong group dedicated to the preservation of pillboxes and anti-invasion defences. A huge website detailing many aspects and locations of PILLBOXES & anti-invasion defences.
★
Royal Engineers Museum: Blockhouses during the Anglo-Boer War (1899–1902)
★
Berlin Air-raid Shelters, Flak Towers and Bunkers
★
Pillboxes
★
Information on Australian World War 2
★
British World War 2 Fortifications
★
Bunker Pictures: Pictures, locations, information about bunkers from WW2 and The Atlantikwall
Image:BH5.jpg|Lacolle Mills Blockhouse