1.
Moveable bridge
–
A moveable bridge, or movable bridge, is a bridge that moves to allow passage for boats or barges. An advantage of making bridges moveable is the lower cost, due to the absence of high piers, the principal disadvantage is that the traffic on the bridge must be halted when it is opened for passages. For seldom-used railroad bridges over busy channels, the bridge may be open and then closed for train passages. For small bridges, bridge movement may be enabled without the need for an engine, some bridges are operated by the users, especially those with a boat, others by a bridgeman, a few remotely using video-cameras and loudspeakers. Generally, the bridges are powered by motors, whether operating winches, gearing. While moveable bridges in their entirety may be long, the length of the moveable portion is restricted by engineering. There are often traffic lights for the road and water traffic, ninety-nine were killed and 100 were injured. Four crewmen, including the engineer and fireman, and 44 passengers died by drowning, september 22,1993 – Mobile, Alabama, US, In heavy fog and low visibility, a disoriented towboat pilot made a wrong turn and entered an un-navigable waterway. The rails kinked but did not break, so no fault was indicated for approaching trains, approximately 8 minutes later, an Amtrak train carrying 220 passengers derailed at the kinked portion of the rails, killing 47 and injuring 103 more. November 23,1996 – Kearny, New Jersey, US, An Amtrak passenger and mail train derailed crossing the Portal Bridge over the Hackensack River. Moveable Bridges in the British Isles NSW moveable bridges
Moveable bridge
–
Madison Street Bridge, a bascule bridge over the Chicago River in Chicago, IL
Moveable bridge
–
Types
2.
Lagos, Portugal
–
Lagos is a municipality at the mouth of Bensafrim River and along the Atlantic Ocean, in the Barlavento region of the Algarve, in southern Portugal. The population in 2011 was 31,049, in an area of 212.99 km², the main town of Lagos has a population of approximately 22,000. Typically, these numbers increase during the months, with the influx of visiting tourists. Yet, Lagos is also a centre of the Portuguese Age of Discovery, frequent home of Henry the Navigator, historical shipyard and, at one time. In 2012, travel website TripAdvisor, classified Lagos as the number 1 travel destination, on a list of 15 destinations on the rise worldwide, Lagos is an ancient maritime town with more than 2000 years of history. The name Lagos comes from a Celtic settlement, derived from the Latin Lacobriga and it became an early settlement of the Carthaginians, who recruited Celtic tribesmen in their war against the Romans. Owing to its important harbour, it was colonized by the Romans and integrated into the Roman province of Lusitania. Quintus Sertorius, a rebellious Roman general, helped by the Lusitanians of Lacobriga, with the fall of Rome, the town of Lagos was occupied in the 6th century by the Visigoths from the Kingdom of Toledo and later by the Byzantines. The Moors arrived in the 8th century from North Africa, renaming the settlement Zawaia and it became part of the much larger coastal region of al-Gharb, which eventually became known as the algarve. The Moors fortified the town with Lagos Castle and established important trade links to Northern Africa from their bases in the Iberian peninsula. In 1174, the local Wāli gave permission for the Christian peoples to construct a dedicated to São João Baptista. Even as King Afonso Henriques advanced to the south, the Christian Reconquista never made it into Algarve and Alentejo, King Sancho I, with the support of Crusader forces used Lagos as a stepping stone to attack the fortress of Alvôr. Zawaia was eventually captured by King Afonso III of Portugal in 1241, from this period on the King began self-styling himself as the King of Portugal and the Algarve, stressing the fact that the Algarve had been annexed into the dominion of the Portuguese. Lagos became an independent jurisdiction under the rule of King Peter I in 1361, King John I assembled his fleet in the harbour of Lagos, before setting sail for the siege and conquest of the city of Ceuta in 1415. This was the first step in opening the Muslim world to medieval Europe, by the 15th century, Lagos became the centre of Portuguese maritime exploration, with ships ordered south to trace the shoreline of Africa in order to find routes to India. Infante Henry the Navigator, third son of King John, lived most of the time in Lagos, from here he directed expeditions to Morocco and to the western coast of Africa with caravels, lateen-rigged ships with excellent seafaring capabilities. The act of rounding the Cape, much like the later rounding of the Cape of Good Hope, when, by 1443, Lançarote had sailed as far as Arguim and brought back 275 Africans, the Portuguese had sufficient slaves to relieve the perpetual handicap of agricultural labour. Over the following decades, news of discoveries and achievements, and ships loaded with spices and it was also the gateway for the first African slaves into post-medieval Europe
Lagos, Portugal
–
Lagos
Lagos, Portugal
–
A medieval painting from the 16th century showing a caravel being provisioned in the port of Lagos
Lagos, Portugal
–
Replica of the caravel Boa Esperança
Lagos, Portugal
–
Lagos's slave market. Built in 1444, it was Europe's first slave market
3.
Movable bridge
–
A moveable bridge, or movable bridge, is a bridge that moves to allow passage for boats or barges. An advantage of making bridges moveable is the lower cost, due to the absence of high piers, the principal disadvantage is that the traffic on the bridge must be halted when it is opened for passages. For seldom-used railroad bridges over busy channels, the bridge may be open and then closed for train passages. For small bridges, bridge movement may be enabled without the need for an engine, some bridges are operated by the users, especially those with a boat, others by a bridgeman, a few remotely using video-cameras and loudspeakers. Generally, the bridges are powered by motors, whether operating winches, gearing. While moveable bridges in their entirety may be long, the length of the moveable portion is restricted by engineering. There are often traffic lights for the road and water traffic, ninety-nine were killed and 100 were injured. Four crewmen, including the engineer and fireman, and 44 passengers died by drowning, september 22,1993 – Mobile, Alabama, US, In heavy fog and low visibility, a disoriented towboat pilot made a wrong turn and entered an un-navigable waterway. The rails kinked but did not break, so no fault was indicated for approaching trains, approximately 8 minutes later, an Amtrak train carrying 220 passengers derailed at the kinked portion of the rails, killing 47 and injuring 103 more. November 23,1996 – Kearny, New Jersey, US, An Amtrak passenger and mail train derailed crossing the Portal Bridge over the Hackensack River. Moveable Bridges in the British Isles NSW moveable bridges
Movable bridge
–
Madison Street Bridge, a bascule bridge over the Chicago River in Chicago, IL
Movable bridge
–
Types
4.
Castle
–
A castle is a type of fortified structure built in Europe and the Middle East during the Middle Ages by European nobility. Scholars debate the scope of the castle, but usually consider it to be the private fortified residence of a lord or noble. Usage of the term has varied over time and has applied to structures as diverse as hill forts. Over the approximately 900 years that castles were built, they took on a great many forms with different features, although some, such as curtain walls. A European innovation, castles originated in the 9th and 10th centuries, after the fall of the Carolingian Empire resulted in its territory being divided among individual lords and princes. Although their military origins are often emphasised in castle studies, the structures served as centres of administration. Many castles were built from earth and timber, but had their defences replaced later by stone. Early castles often exploited natural defences, lacking features such as towers and arrowslits, in the late 12th and early 13th centuries, a scientific approach to castle defence emerged. This led to the proliferation of towers, with an emphasis on flanking fire, many new castles were polygonal or relied on concentric defence – several stages of defence within each other that could all function at the same time to maximise the castles firepower. These changes in defence have been attributed to a mixture of castle technology from the Crusades, such as concentric fortification, not all the elements of castle architecture were military in nature, so that devices such as moats evolved from their original purpose of defence into symbols of power. Some grand castles had long winding approaches intended to impress and dominate their landscape, while castles continued to be built well into the 16th century, new techniques to deal with improved cannon fire made them uncomfortable and undesirable places to live. As a result, true castles went into decline and were replaced by artillery forts with no role in civil administration, and country houses that were indefensible. From the 18th century onwards, there was a renewed interest in castles with the construction of castles, part of a romantic revival of Gothic architecture. The word castle is derived from the Latin word castellum, which is a diminutive of the word castrum, meaning fortified place. The Old English castel, Old French castel or chastel, French château, Spanish castillo, Italian castello, the word castle was introduced into English shortly before the Norman Conquest to denote this type of building, which was then new to England. In its simplest terms, the definition of a castle accepted amongst academics is a fortified residence. Feudalism was the link between a lord and his vassal where, in return for service and the expectation of loyalty. Castles served a range of purposes, the most important of which were military, administrative, as well as defensive structures, castles were also offensive tools which could be used as a base of operations in enemy territory
Castle
–
The
Alcázar of Segovia in Spain overlooking the city
Castle
–
Bodiam Castle in
East Sussex, England, surrounded by a water-filled
moat
Castle
–
The
Norman "White Tower", the
keep of the
Tower of London, exemplifies all uses of a castle including city defence, a residence, and a place of refuge in times of crisis.
Castle
–
Windsor Castle in England was founded as a fortification during the
Norman Conquest and today is one of the principal official residences of Queen
Elizabeth II.
5.
Fortifications of Malta
–
The fortifications of Malta consist of a number of walled cities, citadels, forts, towers, batteries, redoubts, entrenchments and pillboxes. The earliest known fortifications in Malta are defensive walls built around Bronze Age settlements, the Phoenicians, Romans and Byzantines built a number of defensive walls around important settlements, but very little remains of these survive today. By the late period, the main fortifications on Malta were the capital Mdina, the Cittadella on Gozo, the Castrum Maris. The fortifications of Malta were greatly improved while the islands were ruled by the Order of St. John between 1530 and 1798, the Hospitallers built new bastioned fortifications, such as the fortifications of Birgu and Valletta, and upgraded the medieval defences. Following a brief French occupation, the islands fell under British rule in 1800, between the 1870s and the 1900s a number of polygonal forts and batteries were built around Maltas coastline and along the Great Fault. In the 1930s and 1940s, Fort Campbell, a series of pillboxes and a number of batteries were constructed. Maltas fortifications are considered to be among the best examples of military architecture anywhere in the world, major General Whitworth Porter of the Royal Engineers, called Malta the most powerful artificial fortress in the world in his 1858 book A History of the Fortress of Malta. The first fortifications in Malta were built during the Bronze Age, at least six sites have been identified as possible fortified settlements. The best preserved of these is the village of Borġ in-Nadur, around 1450 BC, the inhabitants of the village built a 4. 5m high D-shaped bastion to bar access to their village. The wall was built facing inland, showing that the living in the village were more afraid of attacks from the land than from the sea. In around 700 BC, the Phoenicians founded and fortified the city of Maleth on one of the highest points of the island, eventually the city was taken over by the Roman Empire and it was renamed Melite. The city was again renamed Medina by the Arabs which led to its present name Mdina, the remains of several round towers have been found in Malta, and they are believed to date back to the late Punic or Roman periods. It is possible that these were used as watchtowers, but some dispute this since their locations do not really make sense in defensive systems. According to Al-Himyarī, when the Arabs captured Malta in 870 AD, by 1241, the Gran Castello or Cittadella on Gozo was definitely fortified, although a settlement on the hill had existed since the Bronze Age. The citys fortifications were improved over the years, and the walls of the city that still stand today were built around the 15th century by the Crown of Aragon. The Castrum Maris was built sometime in the Middle Ages, the castle definitely existed by the 13th century, and it was involved in the Battle of Malta of 1283. By the early 16th century, it belonged to the de Nava family, in the early 15th century, the local militia had a number of watch posts around the Maltese islands, and in some cases there might have been fortified coastal watchtowers at these posts. One of these towers is known to have built at St Elmo Point on the Sciberras Peninsula by the Aragonese in 1488
Fortifications of Malta
–
Fort Saint Angelo in
Birgu
Fortifications of Malta
–
The Nuffara plateau in
Xagħra, which housed a fortified settlement in the Bronze Age.
Fortifications of Malta
–
The northern walls of the
Cittadella were built in the 15th century
6.
Moat
–
A moat is a deep, broad ditch, either dry or filled with water, that is dug and surrounds a castle, fortification, building or town, historically to provide it with a preliminary line of defence. In some places evolved into more extensive water defences, including natural or artificial lakes, dams. In older fortifications, such as hillforts, they are referred to simply as ditches. In later periods, moats or water defences may be largely ornamental and they could also act as sewerage. Some of the earliest evidence of moats has been uncovered around ancient Egyptian castles, one example is at Buhen, a castle excavated in Nubia. Other evidence of ancient moats is found in the ruins of Babylon, and in reliefs from ancient Egypt, Assyria, and other cultures in the region. Evidence of early moats around settlements has been discovered in archaeological sites throughout Southeast Asia, including Noen U-Loke, Ban Non Khrua Chut, Ban Makham Thae. The use of the moats could have been either for defensive or agriculture purposes, moats were excavated around castles and other fortifications as part of the defensive system as an obstacle immediately outside the walls. In suitable locations they might be filled with water, a moat made access to the walls difficult for siege weapons, such as siege towers and battering rams, which needed to be brought up against a wall to be effective. A water-filled moat made the practice of mining, digging tunnels under the castles in order to effect a collapse of the defences, segmented moats have one dry section and one section filled with water. Dry moats cut across the part of a spur or peninsula are called neck ditches. Moats separating different elements of a castle, such as the inner and outer wards are cross ditches, the shared derivation implies that the two features were closely related and possibly constructed at the same time. The term moat is also applied to natural formations reminiscent of the artificial structure, the walls were further protected from infantry attack by wet or dry moats, sometimes in elaborate systems. When this style of fortification was superseded by lines of forts in the mid-19th century. The Walls of Benin were a combination of ramparts and moats, called Iya and it was considered the largest man-made structure lengthwise, second only to the Great Wall of China and the largest earthwork in the world. With more recent work by Patrick Darling, it has established as the largest man-made structure in the world. It enclosed 6,500 km² of community lands and its length was over 16,000 km of earth boundaries. It was estimated that earliest construction began in 800 and continued into the mid-15th century, the walls are built of a ditch and dike structure, the ditch dug to form an inner moat with the excavated earth used to form the exterior rampart
Moat
–
The moated manor house of
Baddesley Clinton in Warwickshire, England
Moat
–
North view of the fortress of
Buhen in
Ancient Egypt.
Moat
–
A medieval moat castle in
Steinfurt, Germany
Moat
–
The 17th century fortified town of
Naarden,
Netherlands, showing bastions projecting into the wet moat
7.
Bascule bridge
–
A bascule bridge is a moveable bridge with a counterweight that continuously balances a span, or leaf, throughout its upward swing to provide clearance for boat traffic. It may be single or double leafed, the name comes from the French term for balance scale, which employs the same principle. Bascule bridges have been in use since ancient times, however, it was not until the adoption of steam power in the 1850s that very long, heavy spans could be moved quickly enough for practical application. There are three types of bridge designs, and counterweights required to balance a bascules span may be located either above or below the bridge deck. The fixed-trunnion rotates around an axle that raises the span. The Chicago bascule name derives from the location where it is widely used, the rolling lift trunnion, raises the span by rolling on a track resembling a rocking chair base. The Scherzer rolling lift is a refinement patented in 1893 by the American engineer William Donald Scherzer, the rarer Rall type combines rolling lift with longitudinal motion on trunnions when opening. It was patented by Theodor Rall, one of the few surviving examples is the Broadway Bridge, in Portland, Oregon. Drawbridge List of bascule bridges Moveable bridges for a list of movable bridge types
Bascule bridge
–
Tower Bridge, London.
Bascule bridge
–
This animation shows the movement of a double leaf bascule.
Bascule bridge
–
Mystic River Bascule Bridge, Mystic, Connecticut
Bascule bridge
–
Rolling lift
Pegasus Bridge over the Caen Canal, Normandy, France
8.
Vertical-lift bridge
–
A vertical-lift bridge or just lift bridge is a type of movable bridge in which a span rises vertically while remaining parallel with the deck. The vertical lift offers several benefits over other movable bridges such as the bascule, generally speaking they cost less to build for longer moveable spans. The counterweights in a lift are only required to be equal to the weight of the deck. As a result, heavier materials can be used in the deck, although most vertical-lift bridges use towers, each equipped with counterweights, some use hydraulic jacks located below the deck. An example is the 52-foot span bridge at St Paul Avenue in Milwaukee, another design used balance beams to lift the deck, with pivoting bascules located on the top of the lift towers. An example of this kind was built at La Salle in Illinois, the biggest disadvantage to the vertical-lift bridge is the height restriction for vessels passing under it. This is a result of the deck remaining suspended above the passageway, Ryde Bridge – road – Ryde, New South Wales – opened 1935, now permanently lowered Hexham Bridge – road – Hexham, New South Wales – opened 1952. In addition, there are also Bridges 13,17 and 18 on the Welland Recreational Waterway, however, these bridges have not been operational since 1973. Bridges 13 and 18 have had their counterweights removed while the machinery for Bridge 17 has been dismantled, in addition, Bridge 18 no longer possesses its towers, they were removed for ease of maintenance. Burlington Canal Lift Bridge, over the Burlington Canal, Burlington, information is available from Built 1962. Second Narrows Bridge Vancouver, BC over Burrard Inlet, Okanagan Lake Bridge in Kelowna, BC across Okanagan Lake – replaced in 2008. Shippagan Bridge Shippagan, NB over Shippagan Bay, sir Ambrose Shea Bridge, Placentia, NL. Pont Gustave-Flaubert – crossing the Seine at Rouen, this bridge is the highest vertical-lift bridge in Europe. It is 670 m long, with a span of 116 metres, a striking design feature, the two road sections are mounted outside the central towers. The bridge was designed by François Gillard and Aymeric Zublena and opened to traffic on 25 September 2008. It is named after the author Gustave Flaubert who was born in Rouen, the central lift span is 117m long and can be lifted vertically up to 53m to let tall ships pass underneath. The bridge is 575m long with the lift span weighing around 2,600 tonnes. Its width varies from 32 to 45m and it will be used by cars, trams, cyclists and it can handle 43,000 vehicles a day and will reduce traffic congestion in Bordeaux
Vertical-lift bridge
–
The
Bridgewater Bridge is one of the last remaining operational vertical-lift bridges in Australia
Vertical-lift bridge
–
An animation showing how a vertical-lift bridge operates with vehicular and shipping traffic
Vertical-lift bridge
–
The
Pont Jacques Chaban-Delmas 's approx. 110-metre (360 ft) lift span is likely the longest in Europe, but that of the
Pont Gustave-Flaubert is very nearly as long.
Vertical-lift bridge
–
Kattwyk Bridge, in Hamburg, Germany, with its lift span raised
9.
Swing bridge
–
Small swing bridges as found over canals may be pivoted only at one end, opening as would a gate, but require substantial underground structure to support the pivot. In its closed position, a bridge carrying a road or railway over a river or canal, for example. When a water vessel needs to pass the bridge, road traffic is stopped, as this type requires no counterweights, the complete weight is significantly reduced as compared to other moveable bridges. Where sufficient channel is available to have individual traffic directions on each side, the central support is often mounted upon a berm along the axis of the watercourse, intended to protect the bridge from watercraft collisions when it is opened. This artificial island forms an excellent construction area for building the movable span as the construction will not impede channel traffic, for a symmetrical bridge, the central pier forms a hazard to navigation. Asymmetrical bridges may place the pivot near one side of the channel, where a wide channel is not available, a large portion of the bridge may be over an area that would be easily spanned by other means. A wide channel will be reduced by the pivot and foundation. If struck from the water near the edge of the span, buna River Bridge, in Shkodra, Albania. Puente de la Mujer, an asymmetrical cable-stayed span, the Sale Swing Bridge, Sale, Victoria, Australia. Dunalley Bridge, Dunalley, Tasmania Still in use, Belize City Swing Bridge, Belize City, Belize. Oldest such bridge in Central America and one of the few manually operated swing bridge in world still in operation, the longest swing bridge span is 340 metres, by the El Ferdan Railway Bridge across the Suez Canal. Le pont tournant rue Dieu, across the Canal Saint-Martin in Paris, is a location in the 1938 film Hôtel du Nord. Kalpaka Tilts, Liepāja, connecting the city with the former Russian/Soviet port Karosta, the Abtsewoudsebrug in Delft, close to the Technische Universiteit Delft, is a bridge of this type. 52°0′5. 71″N 4°21′50. 10″E Theres another one on the channel between Ghent and Terneuzen at Sas Van Gent, many inner cities have swing bridges, since these require less street space than other types of bridges. Kopu Bridge, Waihou River, near Thames, New Zealand A swing bridge at the Gatun Locks provides the only road passage over the Atlantic side of the Panama Canal and this is a small bridge that swings out from each side. Another larger swing bridge at the Miraflores Locks is on the Pacific side but is used, having been supplanted by the Bridge of the Americas. Crosskeys Bridge - carries the A17 road over the River Nene in Lincolnshire Folkestone Harbour railway station - railway bridge on the branch line, goole railway swing bridge Glasson Dock swing bridge Hawarden Railway Bridge - rail. Many are manually operated, carrying only farm tracks, but a significant number carry road traffic and are mechanised for boater operation, manchester Ship Canal at Latchford, Stockton Heath and Lower Walton in Warrington, and also slightly further west at Moore
Swing bridge
–
BNSF Railway bridge across the Columbia River in Portland, Oregon, showing the swing-span section turning.
Swing bridge
–
Swing bridge
Swing bridge
–
Swing Bridge for pedestrians, in motion with
yacht approaching, at
Victoria & Alfred Waterfront, Cape Town.
Swing bridge
–
The point at which the Pyrmont Bridge of Sydney swings
10.
Middle Ages
–
In the history of Europe, the Middle Ages or Medieval Period lasted from the 5th to the 15th century. It began with the fall of the Western Roman Empire and merged into the Renaissance, the Middle Ages is the middle period of the three traditional divisions of Western history, classical antiquity, the medieval period, and the modern period. The medieval period is subdivided into the Early, High. Population decline, counterurbanisation, invasion, and movement of peoples, the large-scale movements of the Migration Period, including various Germanic peoples, formed new kingdoms in what remained of the Western Roman Empire. In the seventh century, North Africa and the Middle East—once part of the Byzantine Empire—came under the rule of the Umayyad Caliphate, although there were substantial changes in society and political structures, the break with classical antiquity was not complete. The still-sizeable Byzantine Empire survived in the east and remained a major power, the empires law code, the Corpus Juris Civilis or Code of Justinian, was rediscovered in Northern Italy in 1070 and became widely admired later in the Middle Ages. In the West, most kingdoms incorporated the few extant Roman institutions, monasteries were founded as campaigns to Christianise pagan Europe continued. The Franks, under the Carolingian dynasty, briefly established the Carolingian Empire during the later 8th, the Crusades, first preached in 1095, were military attempts by Western European Christians to regain control of the Holy Land from Muslims. Kings became the heads of centralised nation states, reducing crime and violence, intellectual life was marked by scholasticism, a philosophy that emphasised joining faith to reason, and by the founding of universities. Controversy, heresy, and the Western Schism within the Catholic Church paralleled the conflict, civil strife. Cultural and technological developments transformed European society, concluding the Late Middle Ages, the Middle Ages is one of the three major periods in the most enduring scheme for analysing European history, classical civilisation, or Antiquity, the Middle Ages, and the Modern Period. Medieval writers divided history into periods such as the Six Ages or the Four Empires, when referring to their own times, they spoke of them as being modern. In the 1330s, the humanist and poet Petrarch referred to pre-Christian times as antiqua, leonardo Bruni was the first historian to use tripartite periodisation in his History of the Florentine People. Bruni and later argued that Italy had recovered since Petrarchs time. The Middle Ages first appears in Latin in 1469 as media tempestas or middle season, in early usage, there were many variants, including medium aevum, or middle age, first recorded in 1604, and media saecula, or middle ages, first recorded in 1625. The alternative term medieval derives from medium aevum, tripartite periodisation became standard after the German 17th-century historian Christoph Cellarius divided history into three periods, Ancient, Medieval, and Modern. The most commonly given starting point for the Middle Ages is 476, for Europe as a whole,1500 is often considered to be the end of the Middle Ages, but there is no universally agreed upon end date. English historians often use the Battle of Bosworth Field in 1485 to mark the end of the period
Middle Ages
–
The
Cross of Mathilde, a
crux gemmata made for
Mathilde, Abbess of Essen (973–1011), who is shown kneeling before the Virgin and Child in the
enamel plaque. The body of Christ is slightly later. Probably made in
Cologne or
Essen, the cross demonstrates several medieval techniques:
cast figurative sculpture,
filigree, enamelling, gem polishing and setting, and the reuse of Classical
cameos and
engraved gems.
Middle Ages
–
A late Roman statue
depicting the four Tetrarchs, now in
Venice
Middle Ages
–
Coin of
Theodoric
Middle Ages
–
Mosaic showing
Justinian with
the bishop of
Ravenna, bodyguards, and courtiers
11.
Gatehouse
–
A gatehouse, in architectural terminology, is a building enclosing or accompanying a gateway for a castle, manor house, fort, town or similar buildings of importance. Gatehouses made their first appearance in the early antiquity when it became necessary to protect the entrance to a castle or town. Over time, they evolved into very complicated structures with many lines of defence, strongly fortified gatehouses would normally include a drawbridge, one or more portcullises, machicolations, arrow loops and possibly even murder-holes where stones would be dropped on attackers. In some castles, the gatehouse was so strongly fortified it took on the function of a keep, examples of such gate keeps can be found at Bodiam Castle and Beaumaris Castle. In the late Middle Ages, some of these arrow loops might have converted into gun loops. Sometimes gatehouses formed part of fortifications, perhaps defending the passage of a bridge across a river or a moat. York has four important gatehouses, known as Bars, in its city walls, the French term for gatehouse is logis-porche. This could be a large, complex structure that served both as a gateway and lodging or it could have composed of a gateway through an enclosing wall. A very large gatehouse might be called a châtelet, at the end of the Middle Ages, many gatehouses in England and France were converted into beautiful, grand entrance structures to manor houses or estates. Many of them became a separate feature free-standing or attached to the manor or mansion only by an enclosing wall, by this time the gatehouse had lost its defensive purpose and had become more of a monumental structure designed to harmonise with the manor or mansion. On the continent of Europe, there are examples of surviving gatehouses in France, Austria. Bargate, in Hampshire is a gatehouse in the city centre of Southampton. Constructed in 1180 as part of the Southampton town walls Ightham Mote, Durham Castle, in Durham has an 11th-century gatehouse that is now used as accommodation for students attending University College, Durham. Layer Marney Tower, the apotheosis of the Tudor gatehouse, stokesay Castle, a 13th-century fortified manor house in Shropshire has a Jacobean half-timbered gatehouse. Stanway House, Stanway, Gloucestershire, where the gatehouse measures 44 ft. by 22 ft. and has three storeys, westwood House, Worcestershire, which has a frontage of 54 ft. with two storeys. Burton Agnes Hall, East Riding of Yorkshire, which has three storeys and is flanked by octagonal towers at the angles. Hylton Castle, Hylton, Sunderland, although it is an actual castle, château de Châteaubriant, two gatehouses, one for the lower bailey, one for the upper ward. Château de Suscinio, a large 15th-century gatehouse in the style, Morbihan
Gatehouse
–
Gatehouse reconstruction from ancient
Babylon
Gatehouse
–
The southern entrance to York, Micklegate Bar
Gatehouse
–
The entrance to the University of Manchester, built in 1902
Gatehouse
–
Barbican gate of
Glenarm Castle,
Co. Antrim
12.
Deck (bridge)
–
A bridge deck or road bed is the roadway, or the pedestrian walkway, surface of a bridge, and is one structural element of the superstructure of a bridge. It is not to be confused with any deck of a ship, the deck may be constructed of concrete, steel, open grating, or wood. Sometimes the deck is covered with concrete or other pavement. The concrete deck may be a part of the bridge structure or it may be supported with I-beams or steel girders. When a bridge deck is installed in a truss, it is sometimes called a floor system. A suspended bridge deck will be suspended from the structural elements on a suspension or arch bridge. On some bridges, such as a tied-arch or a cable-stayed, structural engineers have several principal categories of bridge decks, for the purposes of analytic techniques. A beam deck is one where the deck and any supporting structure act together as a single beam, a grid deck uses beams and diaphragms as the supporting structure. The supporting system of a deck is analyzed using a grillage analysis. A slab deck is one where the deck is analyzed as a plate, if the slab has a stiffness that is different in two directions, then the deck is known and analyzed as an orthotropic deck. A beam and slab deck is one where the beams may deflect somewhat independently, a cellular deck is one where a number of thin slabs and webs will enclose cells within the deck. A boxgirder deck is one where the forms the top of the box girder during analysis. In the case of a bridge, when the railway track and ties are supported on load carrying elements of the superstructure. When the track rests upon ballast, which is carried by the superstructure of the bridge. A third type of support is direct fixation, where ties are not used. Bridge - for an index of various bridge types Bridge bearing Orthotropic deck Roadbed types Composite Bridge Decking
Deck (bridge)
–
An open-deck railway bridge in
Leflore County, Mississippi
Deck (bridge)
–
The various part of a truss bridge.
13.
Hinge
–
A hinge is a mechanical bearing that connects two solid objects, typically allowing only a limited angle of rotation between them. Two objects connected by an ideal hinge rotate relative to each other about an axis of rotation. Hinges may be made of material or of moving components. In biology, many joints function as hinges like the elbow joint, there are many types of door hinges. The main types include, Spring hinge which is a hinge made to provide assistance in the closing or the opening of the hinge leaves. A spring is a component of a hinge, that force to secure a hinge closed or keep a hinge opened. Barrel hinge which is a sectional barrel secured by a pivot, pivot hinges which pivot in openings in the floor and the top of the door frame. Also referred to as a double-acting floor hinge and this type is found in ancient dry stone buildings and rarely in old wooden buildings. These are also called haar-hung doors and they are a low cost alternative for use light weight doors. Butt/Mortise hinges usually in threes or fours, which are inset into the door, most residential hinges found in the U. S. are made of steel, although mortise hinges for exterior doors are often made of brass or stainless steel to prevent corrosion. Case hinges Case hinges are similar to a butt hinge however usually more of a nature most commonly used in suitcases, briefcases. Continuous hinges, or piano hinges This type of hinge is also known as a piano hinge and it runs the entire length of the door, panel, or box. Continuous hinges are manufactured with or without holes and these hinges also come in various thicknesses, pin diameters, and knuckle lengths. Concealed hinges Used for furniture doors and they are made of two parts, One part is the hinge cup and the arm, the other part is the mounting plate. Also called cup hinge, or Euro hinge, as they were developed in Europe, most such concealed hinges offer the advantage of full in situ adjustability for standoff distance from the cabinet face as well as pitch and roll by means of two screws on each hinge. Butterfly hinges, or Parliament Hinges These were known as dovetail hinges from the 17th century onwards and can be found on old desks and cabinets from about 1670 until the 18th century. The form of these hinges varied slightly between manufacturers, and their size ranged from the large for heavy doors to the tiniest decorative hinge for use on jewellery boxes. Many hinges of this type were exported to America to support the home trades limited supply and they are still found to be both fairly cheap and decorative, especially on small items
Hinge
–
A barrel hinge
Hinge
–
Old construction of hinges in the dry stone wall near
Bignasco.
Hinge
–
A flushed door hinge.
Hinge
–
A barrel hinge made of wrought iron.
14.
Portcullis
–
Portcullises fortified the entrances to many medieval castles, securely closing off the castle during time of attack or siege. Every portcullis was mounted in vertical grooves in the walls of the castle, often, two portcullises to the main entrance would be used. The one closer to the inside would be closed first, and this was used to trap the enemy, and often, burning wood or fire-heated sand would be dropped onto them from the roof or murder-holes. Hot oil, however, was not commonly used in this manner, contrary to popular belief, arrowslits in the sides of the walls enabled archers and crossbowmen to eliminate the trapped group of attackers. In England, working portcullises survive at the Tower of London, Monk Bar in York, Amberley Castle, since then, the portcullis has been a moderately common motif of English heraldry, especially that heraldry dating from the Tudor period. The heraldic office of Portcullis Pursuivant of Arms in Ordinary, a officer of arms in the College of Arms at London. It is through Lord Charles Somerset, son of the 5th Duke of Beaufort, Somerset established several towns during his governorship at the then Cape Colony and named them for his family. These include Worcester, Somerset West, Fort Beaufort and Beaufort West, institutions that derive the portcullis from these arms include a school, chamber of commerce and a rugby club. Other South African coats of arms include a portcullis are not necessarily related to either Lord Somerset or any of the town named for. A portcullis—fitted well with the scheme, since then, the portcullis has become the primary symbol of Parliament, an office building for Members of Parliament, opened in 2001, is named Portcullis House. A portcullis was previously found on the British one penny coin and on the pre-decimal thrupenny bit, the badge of the Canada Border Services Agency also bore a portcullis, symbolising the agencys role as gatekeeper of goods into Canada. Though these do not appear in gateways of castles unless the blazon specifies them and it is often shown with chains attached, even when the blazon does not mention them. Arrow slit Castle Hoarding Machicolation Murder-hole Sally port Yett Kaufmann, J. E. Kaufmann, the Medieval Fortress, Castles, Forts and Walled Cities of the Middle Ages
Portcullis
–
Portcullis at
Cahir Castle
15.
Machicolations
–
The word derives from the Old French word machecol, mentioned in Medieval Latin as machecollum, probably from Old French machier crush, wound and col neck. Machicolate is only recorded in the 18th century in English, but a verb machicollāre is attested in Anglo-Latin, the Spanish word denoting this structure, matacán, is similarly composed from matar canes meaning roughly killing dogs, the latter being a reference to infidels. The design of a machicoulis, commonly known as drop box, in Arab fortifications they are usually found on defensive walls. The original Arab design was small, and similar to the domestic wooden balcony known as Mashrabiya. However, different from the balcony, for defense purposes it prominently features a wide opening at the bottom. The opening allows the dropping of hot water or oil and other material intended to harm to the enemy below. The feature of a closed balcony also allows to cover while making use. A hoarding is a structure made of wood, usually temporarily constructed in the event of a siege. Advantages of machicolations over wooden hoardings include the strength and fire resistance of stone. Machicolations were more common in French castles than English, where they were restricted to the gateway. One of the first examples of machicolation that still exists in northern France is Château de Farcheville built in 1291 outside Paris, similar to a machicolation is a smaller version which opens as a balcony, generally from a tower rather than a larger structure. Machicolations were a feature in many towers and rural buildings in Malta until the 18th century. Buildings with machicolations include Cavalier Tower, Gauci Tower, the Captains Tower, machicolation was later used for decorative effect with spaces between the corbels but without the openings, and subsequently became a characteristic of many non-military buildings. Bretèche Arrow slit Hoarding Murder hole Media related to Machicolations at Wikimedia Commons Glossary of Medieval Art and Architecture, machicolation
Machicolations
–
Functional machicolation at
Château de Pierrefonds
16.
Arrow slits
–
An arrowslit is a thin vertical aperture in a fortification through which an archer can launch arrows. The interior walls behind an arrow loop are often cut away at an angle so that the archer has a wide field of view. Arrow slits come in a remarkable variety, a common and recognizable form is the cross. Balistraria can often be found in the walls of medieval battlements beneath the crenellations. The invention of the arrowslit is attributed to Archimedes during the siege of Syracuse in 214–212 BC, slits of the height of a man and about a palms width on the outside allowed defenders to shoot bows and scorpions from within the city walls. Although used in late Greece and Roman defences, arrowslits were not present in early Norman castles and they are only reintroduced to military architecture towards the end of the 12th century, with the castles of Dover and Framlingham in England, and Richard the Lionhearts Château Gaillard in France. In these early examples, arrowslits were positioned to protect sections of the castle wall, in the 13th century, it became common for arrowslits to be placed all around a castles defences. In its simplest form, an arrowslit was a vertical opening, however. It was common for arrowslits to widen to a triangle at the bottom, called a fishtail, immediately behind the slit there was a recess called an embrasure, this allowed a defender to get close to the slit without being too cramped. The width of the slit dictated the field of fire, but the field of vision could be enhanced by the addition of horizontal openings, they allowed defenders to view the target before it entered range. Usually, the slits were level, which created a cross shape. When an embrasure linked to more than one arrowslit it is called a multiple arrowslit, embrasure Loophole, legal term Notes Bibliography Media related to Arrowslits at Wikimedia Commons
Arrow slits
–
An arrowslit at
Corfe Castle. This shows the inside - where the archer would have stood.
Arrow slits
–
An arrowslit at
White Castle, Wales.
17.
Tower
–
A tower is a tall structure, taller than it is wide, often by a significant margin. Towers are distinguished from masts by their lack of guy-wires and are therefore, along with tall buildings, Towers are specifically distinguished from buildings in that they are not built to be habitable but to serve other functions. Towers can be stand alone structures or be supported by adjacent buildings or can be a feature on top of a structure or building. Old English torr is from Latin turris via Old French tor, the Latin term together with Greek τύρσις was loaned from a pre-Indo-European Mediterranean language, connected with the Illyrian toponym Βου-δοργίς. The oldest known may be the stone tower in walls of Neolithic Jericho. Some of the earliest towers were ziggurats, which existed in Sumerian architecture since the 4th millennium BC, the most famous ziggurats include the Sumerian Ziggurat of Ur, built the 3rd millennium BC, and the Etemenanki, one of the most famous examples of Babylonian architecture. The latter was built in Babylon during the 2nd millennium BC and was considered the tallest tower of the ancient world, some of the earliest surviving examples are the broch structures in northern Scotland, which are conical towerhouses. These and other examples from Phoenician and Roman cultures emphasised the use of a tower in fortification, for example, the name of the Moroccan city of Mogador, founded in the first millennium BC, is derived from the Phoenician word for watchtower. The Romans utilised octagonal towers as elements of Diocletians Palace in Croatia, which monument dates to approximately 300 AD, while the Servian Walls, the Chinese used towers as integrated elements of the Great Wall of China in 210 BC during the Qin Dynasty. Towers were also an important element of castles, other well known towers include the Leaning Tower of Pisa in Pisa, Italy built from 1173 until 1372 and the Two Towers in Bologna, Italy built from 1109 until 1119. The Himalayan Towers are stone towers located chiefly in Tibet built approximately 14th to 15th century, up to a certain height, a tower can be made with the supporting structure with parallel sides. However, above a height, the compressive load of the material is exceeded. This can be avoided if the support structure tapers up the building. A second limit is that of buckling—the structure requires sufficient stiffness to avoid breaking under the loads it faces, many very tall towers have their support structures at the periphery of the building, which greatly increases the overall stiffness. A third limit is dynamic, a tower is subject to varying winds, vortex shedding and these are often dealt with through a combination of simple strength and stiffness, as well as in some cases tuned mass dampers to damp out movements. Varying or tapering the outer aspect of the tower with height avoids vibrations due to vortex shedding occurring along the building simultaneously. Although not correctly called towers many modern skyscraper are often called towers, in the United Kingdom, tall domestic buildings are referred to as tower blocks. In the United States, the original World Trade Center had the nickname the Twin Towers, the tower throughout history has provided its users with an advantage in surveying defensive positions and obtaining a better view of the surrounding areas, including battlefields
Tower
–
The
Eiffel Tower in
Paris,
France
Tower
–
Azadi Tower in
Tehran,
Iran, depicting
Persian Architecture styles of various eras
Tower
–
The
Two Towers in
Bologna,
Italy
Tower
–
CN Tower (world's sixth tallest freestanding structure) in
Toronto,
Ontario,
Canada
18.
Windlass
–
For the tool used to raise paddle gear on canal locks, see Windlass The windlass is an apparatus for moving heavy weights. Typically, a windlass consists of a cylinder, which is rotated by the turn of a crank or belt. A winch is affixed to one or both ends, and a cable or rope is wound around the winch, pulling a weight attached to the opposite end. The oldest depiction of a windlass for raising water can be found in the Book of Agriculture published in 1313 by the Chinese official Wang Zhen of the Yuan Dynasty. Vitruvius, a military engineer writing about 28 B. C. defined a machine as a combination of timber fastened together, until nearly the end of the nineteenth century it was held that these five mechanical powers were the building blocks from which all more complex assemblages were constructed. During the Middle Ages the windlass was used to raise materials for the construction of such as in Chesterfields crooked spire church. By the Late Middle Ages most European crossbows employed a windlass as a mechanism, which helped to pull heavier crossbows. Windlasses are sometimes used on boats to raise the anchor as an alternative to a vertical capstan, the rod or stick used to tighten a tourniquet in surgical procedures is called a windlass. The handle used to open locks on the UKs inland waterways is called a windlass, Windlass can be used to raise water from a well. The oldest description of a windlass, a rotating wooden rod installed across the mouth of a well, is found in Isidore of Sevilles Origenes. Windlass have also used in gold mining. A windlass would be constructed above a shaft which allowed heavy buckets to be hauled up to the surface and this process would be used until the shaft got below 40 metres deep when the windlass would be replaced by a whip or a whim. In a differential windlass, also called a Chinese windlass, there are two coaxial drums of different radii r and r, the rope is wound onto one drum while it unwinds from the other, with a movable pulley hanging in the bight between the drums. Since each turn of the crank raises the pulley and attached weight by only π, very large mechanical advantages can be obtained
Windlass
–
Turnbridge Windlass Lift road bridge over
Huddersfield Broad Canal
19.
Alnwick Castle
–
Alnwick Castle is a castle and stately home in Alnwick in the English county of Northumberland. It is the seat of the Duke of Northumberland, built following the Norman conquest and it is a Grade I listed building and as of 2012 received over 800,000 visitors per year. Alnwick Castle guards a road crossing the River Aln. Yves de Vescy, Baron of Alnwick, Beatrix de Vesci, daughter of Yves de Vescy married Eustace Fitz John, Constable of Chestershire and Knaresborough. By his marriage to Beatrix de Vesci he gained the Baronies of Malton, the castle was first mentioned in 1136 when it was captured by King David I of Scotland. At this point it was described as very strong and it was besieged in 1172 and again in 1174 by William the Lion, King of Scotland and William was captured outside the walls during the Battle of Alnwick. Eustace de Vesci, lord of Alnwick, was accused of plotting with Robert Fitzwalter against King John in 1212, in response, John ordered the demolition of Alnwick Castle and Baynards Castle, however, his instructions were not carried out at Alnwick. When the Vescy family became extinct, Alnwick Castle and the manor were bequeathed to Antony Bek the Bishop of Durham. The Percy family benefited from Englands wars with Scotland, through his military accomplishments Henry Percy, 1st Baron Percy, in 1309 he purchased the barony of Alnwick from Bek, and it has been owned by the Percy family, the Earls and later Dukes of Northumberland since. The stone castle Henry Percy bought was a modest affair, though he did not live to see its completion, the building programme turned Alnwick into a major fortress along the Anglo-Scottish border. His son, also called Henry, continued the building, the Abbots Tower, the Middle Gateway and the Constables Tower survive from this period. The work at Alnwick Castle balanced military requirements with the familys residential needs, in 1345 the Percys acquired Warkworth Castle, also in Northumberland. Though Alnwick was considered prestigious, Warkworth became the familys preferred residence. The Percy family were lords in northern England. Henry Percy, 1st Earl of Northumberland, rebelled against King Richard II, the earl later rebelled against King Henry IV and after defeating the earl in the Battle of Shrewsbury, the king chased him north to Alnwick. The castle surrendered under the threat of bombardment in 1403, during the Wars of the Roses, castles were infrequently engaged in battle and conflict was generally based around combat in the field. It was held against King Edward until its surrender in mid-September 1461 after the Battle of Towton, re-captured by Sir William Tailboys, during the winter it was surrendered by him to Hastings, Sir John Howard and Sir Ralph Grey of Heton in late July 1462. Grey was appointed captain but surrendered after a siege in the early autumn. King Edward responded with vigour and when the Earl of Warwick arrived in November Queen Margaret and her French advisor and they organised a mainly Scots relief force which, under George Douglas, 4th Earl of Angus and de Brézé, set out on 22 November
Alnwick Castle
–
Alnwick Castle
Alnwick Castle
–
Alnwick Castle by
J.M.W. Turner
Alnwick Castle
–
Alnwick Castle,
chromolithograph by
Alexander Francis Lydon, 1870
Alnwick Castle
–
The exterior of Alnwick Castle from the north west
20.
Herstmonceux Castle
–
Herstmonceux Castle is a brick-built castle near Herstmonceux, East Sussex, England. From 1957 to 1988 its grounds were the home of the Royal Observatory, today it is used by the Bader International Study Centre of Queens University, Canada. Herstmonceux Castle is one of the oldest significant brick buildings still standing in England, the builders of Herstmonceux Castle concentrated more on grandeur and comfort than on defence. Herstmonceux Castle is home to events throughout the year, including the annual Englands Medieval Festival on August Bank Holiday weekend, the parks and gardens of Herstmonceux Castle and Place are Grade II* listed on the Register of Historic Parks and Gardens. By the end of the century, the family at the manor house at Herst had considerable status. Written accounts mention a lady called Idonea de Herst, who married a Norman nobleman named Ingelram de Monceux, around this time, the manor began to be called the “Herst of the Monceux”, a name that eventually became Herstmonceux. A descendant of the Monceux family, Roger Fiennes, was responsible for the construction of Herstmonceux Castle in the County of Sussex. It was this position as treasurer which enabled him to afford the £3,800 construction of the original castle, the result is not a defensive structure, but a palatial residence in a self-consciously archaising castle style. In 1541, Sir Thomas Fiennes, Lord Dacre, was tried for murder, the profligacy of the 15th Baron Dacre, heir to the Fiennes family, forced him to sell in 1708 to George Naylor, a lawyer of Lincoln’s Inn in London. Bethaia Naylor, who became the heiress of Herstmonceux on the death of her brothers daughter, married Francis Hare and produced son Francis. Thomas Lennard, 17th Baron Dacre, was exercised as to commission James Lamberts Jnr of Lewes to record the building in 1776. The existing interiors largely date to this period, incorporating architectural antiques from England, the one major change in planning was the combination of the four internal courtyards into one large one. The restoration work, regarded as the apex of Godfreys architectural achievement, was described by the critic Nikolaus Pevsner as executed exemplarily, the property passed through the hands of private owners until it was sold in 1946 to the Admiralty. In 1957 the Herstmonceux Castle grounds became the home of the Royal Greenwich Observatory and remained so until 1988, several of the telescopes remain but the largest telescope, the 100 inch aperture Isaac Newton Telescope was moved to La Palma, Canary Islands in the 1970s. The estate provides housing to the Equatorial Telescope Buildings, which have been converted to a science centre for schoolchildren. The empty dome for the Newton Telescope remains on site and is a landmark. Bader later contacted then-Principal of Queens University, David Chadwick Smith, asking if a castle might fit into the schools plans, in 1994, after intensive renovations, the Queens International Study Centre was opened. In late January 2009, the ISC was renamed the Bader International Study Centre, the castle was used for filming part of The Silver Chair, a 1990 BBC adaptation of the book by C. S. Lewis
Herstmonceux Castle
–
Herstmonceux Castle, seen from the south-west
Herstmonceux Castle
–
Floor plan of the original house; (l) ground floor, (r) first floor
Herstmonceux Castle
–
Royal Greenwich Observatory at Herstmonceux
Herstmonceux Castle
–
Interior corridor of the castle
21.
Helmingham Hall
–
Helmingham Hall is a moated manor house in Helmingham, Suffolk, England. It was begun by John Tollemache in 1480 and has been owned by the Tollemache family ever since, the house is built around a courtyard in typical late medieval/Tudor style. The present Helmingham Hall may have initially constructed in 1510 on the site of an earlier house called Creke Hall. The exterior was altered between 1745–1760, again in 1800 by John Nash, and in 1840, the original half-timbered walls have been concealed by brick and tiles. The house is surrounded by a moat 60 feet wide, over which it is reached only by two working drawbridges, which have pulled up every night since 1510. These were originally operated with a windlass but in recent years this has been replaced by an electric motor, the house is not open to the public and Helmingham is best known for its fine garden, which is open on a regular basis. It is a mixed garden with extensive borders, a rose garden, a knot garden, a parterre. Beyond the garden there is a 400-acre park with herds of red, the Church of St Mary on the edge of the park has connections with the Tollemache family dating back to the Middle Ages. The Tollemaches of Helmingham own one of the only two English Orpharion viols and their instrument is dated 1580 and bears the label of John Rose, an English viol-maker of the 16th century. Four John Rose viols survive, the one in private hands is that belonging to the Tollemache family. It is believed to have made for Queen Elizabeth I who presented it to them during one of her visits to Suffolk. The Tollemache lute manuscript was acquired from the Helmingham Hall collections and it was written by Henry Sampson. Map sources for Helmingham Hall Official site Historic England
Helmingham Hall
–
Helmingham Hall
Helmingham Hall
–
Helmingham Hall circa 1880.
22.
Trunnion
–
A trunnion is a cylindrical protrusion used as a mounting or pivoting point. First associated with cannon, they are an important military development, alternatively, a trunnion is a shaft that positions and supports a tilting plate. This is a misnomer, as in reality it is a cradle for the true trunnion, in mechanical engineering, it is one part of a rotating joint where a shaft is inserted into a full or partial cylinder. In a cannon, the trunnions are two projections cast just forward of the center of mass of the cannon and fixed to a two-wheeled movable gun carriage. As they allowed the muzzle to be raised and lowered easily, with the creation of larger and more powerful siege guns in the early 15th century, a new way of mounting them had to be specially designed. Stouter gun carriages were created with reinforced wheels, axles, guns would be up to eight feet in length and shoot iron projectiles weighing from twenty-five to fifty pounds. These wrought iron balls when discharged were comparable in range and accuracy with stone-firing bombards, trunnions were mounted near the center of mass to allow the barrel to be elevated to any desired angle, without having to dismount it from the carriage upon which it rested. Some guns had a set of trunnions placed several feet back from the first pair. The gun would recoil causing the carriage to move backwards several feet and it became easier to rapidly transport these large siege guns, maneuver them from transportation mode to firing position, and they could go wherever a team of men or horses could pull them. Due to its capabilities, the French- and Burgundy-designed siege gun, equipped with its trunnions, king Charles VIII and the French army used this new gun in the 1494 invasion of Italy. Although deemed masters of war and artillery at that time, Italians had not anticipated the innovations in French siege weaponry. Prior to this, field guns were huge, large-caliber bombards, superguns that. Cities that had proudly withstood sieges for up to seven years fell swiftly with the advent of new weapons. Defensive tactics and fortifications had to be altered since these new weapons could be transported so speedily and these towers would be deemed trace Italienne. Whoever could afford these new weapons had the advantage over their neighbors and smaller sovereignties. Smaller states, such as the principalities of Italy, began to conglomerate, preexisting stronger entities, such as France or the Habsburg emperors, were able to expand their territories and maintain tighter control. With the threat of their land and castles being seized, the nobility began to pay their taxes, on firearms, the barrel is sometimes mounted in a trunnion, which in turn is mounted to the receiver. This usage is common for tubular or pressed metal frame guns, such as the AK-47, PPSh-41, Uzi, Sten, and others
Trunnion
–
The trunnions are the protrusions from the side of the barrel that rest on the carriage.
Trunnion
–
Trunnion positions saw table and provides a pivot point.
Trunnion
–
15th-century depiction of a cannon with trunnions
Trunnion
–
Philadelphia Penrose bridge c. 1880 (shown open) swings on a Trunnion Bearing.
23.
Linkspan
–
A linkspan or link-span is a type of drawbridge used mainly in the operation of moving vehicles on and off a RO-RO vessel or ferry, particularly to allow for tidal changes in water level. The first linkspans appeared at the end of the 19th century when train ferries came into operation, each rail ferry berth has to be specifically designed to make sure that it fitted one class of ship. In most of these vessels it was possible to carry some road vehicles. By the mid 20th century with the rise of road transport, using the ramp for access has limitations in that if there is any significant tidal range, gradients on this ramp become too steep to be manageable. The operation of vessels was initially limited to areas such as the Baltic. Very soon there was a demand for ferries to be used in tidal waters. Ship’s ramps were also developed in size, as was forward access through a bow door closed by a drawbridge ramp inside a visor and these features are now common to most Ro Ro drive through ships. Initially a linkspan was a ramp that was attached to the pier at one end and was suspended above the water at the other. The aim of all this is to have the linkspan at the same height above the water as that of the car deck on whichever ferry happens to be docking at the time. All that is then needed is for a ramp to be lowered, in ports such as Dover a Marine Development double deck linkspan can be found where two decks of a large ferry can be loaded simultaneously. To ensure that the tracks on the train ferry or car float. To be certain that the tracks do not have a step at the junction of ship and linkspan. It is also fitted with a pin that ensures the linkspan is in the exact athwart ships position. To protect the linkspan from impact as the ship makes its final approach and these absorb the energy of the ferry’s impact, guide its stern and hold it from moving sideways when finally berthed. These guide fenders also prevent excessive loads being transferred to the locating pin, as the trains roll onto or off the ship its freeboard and trim will change significantly. The linkspan moving with the ship provides acceptable gradients which for railway traffic should not exceed 1,25 and this relatively shallow gradient limited the areas where train ferries could operate. Where the tide is only 2 meters for example the linkspan must have a length of at least 50 meters, for any greater tide, the linkspan must be very long, other problems also arise which can be very costly to solve. Rail linkspans are generally supported at their outer end by counterweights and this means that when the linkspan is lowered onto the ship’s ledge only a small proportion of its weight rests there
Linkspan
–
Derelict rail linkspan in New York
24.
Langlois Bridge
–
Langlois Bridge was a drawbridge in Arles, France, which was the subject of several paintings by Vincent van Gogh in 1888. Being one of eleven drawbridges built by a Dutch engineer along the channel from Arles to Port-de-Bouc, new canals were opened up in southern France as they were needed to expand the network of canals. In the 19th century a canal was built from Arles to Bouc, locks and bridges were built, too, to manage water and road traffic. Just outside Arles, the first bridge was the officially titled Pont de Réginelle, a reconstructed bridge of the Langlois Bridge, named Pont Van Gogh, recognizing the works that Van Gogh made of the bridge, is owned by the Arles tourist board. Vincent van Gogh made several paintings, a watercolor and drawings of the Langlois bridge in a series now titled Langlois Bridge at Arles
Langlois Bridge
–
1902 photograph of the Langlois Bridge
Langlois Bridge
–
Pont Van Gogh, replica of the Langlois Bridge
Langlois Bridge
–
Langlois Bridge at Arles, watercolor. 1888. Private collection (F1480)
25.
Van Gogh
–
Vincent Willem van Gogh was a Dutch Post-Impressionist painter who is among the most famous and influential figures in the history of Western art. In just over a decade he created about 2,100 artworks, including around 860 oil paintings and his suicide at 37 followed years of mental illness and poverty. Born into a family, Van Gogh drew as a child and was serious, quiet. As a young man he worked as an art dealer, often travelling and he turned to religion, and spent time as a Protestant missionary in southern Belgium. He drifted in ill health and solitude before taking up painting in 1881 and his younger brother Theo supported him financially, and the two kept up a long correspondence by letter. His early works, mostly still lifes and depictions of peasant labourers, in 1886 he moved to Paris, where he met members of the avant-garde, including Émile Bernard and Paul Gauguin, who were reacting against the Impressionist sensibility. As his work developed he created a new approach to still lifes and his paintings grew brighter in colour as he developed a style that became fully realised during his stay in Arles in the south of France in 1888. During this period he broadened his subject matter to include trees, cypresses, wheat fields. Van Gogh suffered from episodes and delusions and though he worried about his mental stability, he often neglected his physical health, did not eat properly. His friendship with Gauguin ended after a confrontation with a razor and he spent time in psychiatric hospitals, including a period at Saint-Rémy. After he discharged himself and moved to the Auberge Ravoux in Auvers-sur-Oise near Paris and his depression continued and on 27 July 1890, Van Gogh shot himself in the chest with a revolver. He died from his injuries two days later, Van Gogh was unsuccessful during his lifetime, and was considered a madman and a failure. He became famous after his suicide, and exists in the imagination as the quintessential misunderstood genius. His reputation began to grow in the early 20th century as elements of his style came to be incorporated by the Fauves. The most comprehensive source on Van Gogh is the correspondence between him and his younger brother, Theo. Their lifelong friendship, and most of what is known of Vincents thoughts, Theo van Gogh was an art dealer and provided his brother with financial and emotional support, and access to influential people on the contemporary art scene. Theo kept all of Vincents letters to him, Vincent kept few of the letters he received, after both had died, Theos widow Johanna arranged for the publication of some of their letters. A few appeared in 1906 and 1913, the majority were published in 1914, Vincents letters are eloquent and expressive and have been described as having a diary-like intimacy, and read in parts like autobiography
Van Gogh
–
Self-Portrait, Spring 1887, Oil on pasteboard, 42 × 33.7 cm.,
Art Institute of Chicago (F 345)
Van Gogh
–
Vincent c. 1871-1872 aged 18. This photograph was taken at the time when he was working at the branch of
Goupil & Cie 's gallery in
The Hague.
Van Gogh
–
Vincent c. 1866, approx. age 13
Van Gogh
–
Van Gogh's drawing of
87 Hackford Road
26.
Wayback Machine
–
The Internet Archive launched the Wayback Machine in October 2001. It was set up by Brewster Kahle and Bruce Gilliat, and is maintained with content from Alexa Internet, the service enables users to see archived versions of web pages across time, which the archive calls a three dimensional index. Since 1996, the Wayback Machine has been archiving cached pages of websites onto its large cluster of Linux nodes and it revisits sites every few weeks or months and archives a new version. Sites can also be captured on the fly by visitors who enter the sites URL into a search box, the intent is to capture and archive content that otherwise would be lost whenever a site is changed or closed down. The overall vision of the machines creators is to archive the entire Internet, the name Wayback Machine was chosen as a reference to the WABAC machine, a time-traveling device used by the characters Mr. Peabody and Sherman in The Rocky and Bullwinkle Show, an animated cartoon. These crawlers also respect the robots exclusion standard for websites whose owners opt for them not to appear in search results or be cached, to overcome inconsistencies in partially cached websites, Archive-It. Information had been kept on digital tape for five years, with Kahle occasionally allowing researchers, when the archive reached its fifth anniversary, it was unveiled and opened to the public in a ceremony at the University of California, Berkeley. Snapshots usually become more than six months after they are archived or, in some cases, even later. The frequency of snapshots is variable, so not all tracked website updates are recorded, Sometimes there are intervals of several weeks or years between snapshots. After August 2008 sites had to be listed on the Open Directory in order to be included. As of 2009, the Wayback Machine contained approximately three petabytes of data and was growing at a rate of 100 terabytes each month, the growth rate reported in 2003 was 12 terabytes/month, the data is stored on PetaBox rack systems manufactured by Capricorn Technologies. In 2009, the Internet Archive migrated its customized storage architecture to Sun Open Storage, in 2011 a new, improved version of the Wayback Machine, with an updated interface and fresher index of archived content, was made available for public testing. The index driving the classic Wayback Machine only has a bit of material past 2008. In January 2013, the company announced a ground-breaking milestone of 240 billion URLs, in October 2013, the company announced the Save a Page feature which allows any Internet user to archive the contents of a URL. This became a threat of abuse by the service for hosting malicious binaries, as of December 2014, the Wayback Machine contained almost nine petabytes of data and was growing at a rate of about 20 terabytes each week. Between October 2013 and March 2015 the websites global Alexa rank changed from 162 to 208, in a 2009 case, Netbula, LLC v. Chordiant Software Inc. defendant Chordiant filed a motion to compel Netbula to disable the robots. Netbula objected to the motion on the ground that defendants were asking to alter Netbulas website, in an October 2004 case, Telewizja Polska USA, Inc. v. Echostar Satellite, No.02 C3293,65 Fed. 673, a litigant attempted to use the Wayback Machine archives as a source of admissible evidence, Telewizja Polska is the provider of TVP Polonia and EchoStar operates the Dish Network
Wayback Machine
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Wayback Machine
27.
Fortification
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Fortifications are military constructions or buildings designed for the defense of territories in warfare, and also used to solidify rule in a region during peace time. Humans have constructed defensive works for many thousands of years, in a variety of increasingly complex designs, the term is derived from the Latin fortis and facere. From very early history to modern times, walls have been a necessity for cities to survive in a changing world of invasion. Some settlements in the Indus Valley Civilization were the first small cities to be fortified, in ancient Greece, large stone walls had been built in Mycenaean Greece, such as the ancient site of Mycenae. A Greek Phrourion was a collection of buildings used as a military garrison. These construction mainly served the purpose of a tower, to guard certain roads, passes. Though smaller than a fortress, they acted as a border guard rather than a real strongpoint to watch. The art of setting out a camp or constructing a fortification traditionally has been called castramentation since the time of the Roman legions. Fortification is usually divided into two branches, permanent fortification and field fortification, there is also an intermediate branch known as semi-permanent fortification. Castles are fortifications which are regarded as being distinct from the fort or fortress in that they are a residence of a monarch or noble. Roman forts and hill forts were the antecedents of castles in Europe. The Early Middle Ages saw the creation of towns built around castles. Medieval-style fortifications were made obsolete by the arrival of cannons in the 14th century. Fortifications in the age of black powder evolved into much lower structures with greater use of ditches and earth ramparts that would absorb, Walls exposed to direct cannon fire were very vulnerable, so were sunk into ditches fronted by earth slopes. The arrival of explosive shells in the 19th century led to yet another stage in the evolution of fortification, steel-and-concrete fortifications were common during the 19th and early 20th centuries. However the advances in warfare since World War I have made large-scale fortifications obsolete in most situations. Demilitarized zones along borders are arguably another type of fortification, although a passive kind, many military installations are known as forts, although they are not always fortified. Larger forts may be called fortresses, smaller ones were known as fortalices
Fortification
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Krak des Chevaliers is one of the best-preserved Crusader
castles.
Fortification
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Bourtange star fort, restored to 1750 situation,
Groningen (province),
Netherlands.
Fortification
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The well preserved
Bulgarian medieval fort
Baba Vida.
Fortification
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Fortifications on the Iraq-Iran Border, viewed from the
ISS, 2014
28.
Ancient history
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Ancient history is the aggregate of past events from the beginning of recorded human history and extending as far as the Early Middle Ages or the Postclassical Era. The span of recorded history is roughly 5,000 years, beginning with Sumerian Cuneiform script, the term classical antiquity is often used to refer to history in the Old World from the beginning of recorded Greek history in 776 BC. This roughly coincides with the date of the founding of Rome in 753 BC, the beginning of the history of ancient Rome. In India, ancient history includes the period of the Middle Kingdoms, and, in China. Historians have two major avenues which they take to better understand the ancient world, archaeology and the study of source texts, primary sources are those sources closest to the origin of the information or idea under study. Primary sources have been distinguished from secondary sources, which cite, comment on. Archaeology is the excavation and study of artefacts in an effort to interpret, archaeologists excavate the ruins of ancient cities looking for clues as to how the people of the time period lived. The study of the ancient cities of Harappa, Mohenjo-daro, the city of Pompeii, an ancient Roman city preserved by the eruption of a volcano in AD79. Its state of preservation is so great that it is a window into Roman culture and provided insight into the cultures of the Etruscans. The Terracotta Army, the mausoleum of the First Qin Emperor in ancient China, the discovery of Knossos by Minos Kalokairinos and Sir Arthur Evans. The discovery of Troy by Heinrich Schliemann, most of what is known of the ancient world comes from the accounts of antiquitys own historians. Although it is important to take account the bias of each ancient author. Some of the more notable ancient writers include Herodotus, Thucydides, Arrian, Plutarch, Polybius, Sima Qian, Sallust, Livy, Josephus, Suetonius, furthermore, the reliability of the information obtained from these surviving records must be considered. Few people were capable of writing histories, as literacy was not widespread in almost any culture until long after the end of ancient history, the earliest known systematic historical thought emerged in ancient Greece, beginning with Herodotus of Halicarnassus. He was also the first to distinguish between cause and immediate origins of an event, the Roman Empire was one of the ancient worlds most literate cultures, but many works by its most widely read historians are lost. Indeed, only a minority of the work of any major Roman historian has survived, prehistory is the period before written history. The early human migrations in the Lower Paleolithic saw Homo erectus spread across Eurasia 1.8 million years ago, the controlled use of fire occurred 800,000 years ago in the Middle Paleolithic. 250,000 years ago, Homo sapiens emerged in Africa, 60–70,000 years ago, Homo sapiens migrated out of Africa along a coastal route to South and Southeast Asia and reached Australia
Ancient history
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Khafre's Pyramid (
4th dynasty) and
Great Sphinx of Giza (c. 2500 BC or perhaps earlier)
Ancient history
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The Mediterranean in c. the 4th century BC. Phoenician cities are labelled in yellow, Greek cities in red, and other cities in grey.
Ancient history
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Eastern Hemisphere in 500 BC.
29.
Abatis
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An abatis, abattis, or abbattis is a field fortification consisting of an obstacle formed of the branches of trees laid in a row, with the sharpened tops directed outwards, towards the enemy. The trees are usually interlaced or tied with wire, abatis are used alone or in combination with wire entanglements and other obstacles. There is evidence it was used as early as the Roman Imperial period, a classic use of an abatis was at the Battle of Carillon during the Seven Years War. The 3,600 French troops defeated an army of 16,000 British. The British found the defences almost impossible to breach and were forced to withdraw with some 2,600 casualties, an important weakness of abatis, in contrast to barbed wire, is that it can be destroyed by fire. An important advantage is that an improvised abatis can be formed in forested areas. This can be done by cutting down a row of trees so that they fall with their tops toward the enemy. An alternative is to place explosives so as to blow the trees down, abatis are rarely seen nowadays, having been largely replaced by wire obstacles. However, it may be used as a replacement or supplement when barbed wire is in short supply, a form of giant abatis, using whole trees instead of branches, can be used as an improvised anti-tank obstacle. Though rarely used by conventional military units, abatises are still officially maintained in United States Army. Furthermore, it is recommended that the trees remain connected to the stumps, US military maps record an abatis by use of an inverted V with a short line extending from it to the right. Zasechnaya cherta Pamplin Historical Park & The National Museum of the Civil War Soldier includes large and authentic reproduction of abatis used in the U. S. Civil War
Abatis
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Abatis improvised by Japanese troops during
World War II
Abatis
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Giant abatis, made from entire trees, can make an effective anti-vehicle obstacle. This formation can be achieved by use of explosives—note the splintered stumps
