Misplaced Pages

#187812

81-409: Vockerode has been the site of a power plant for almost 60 years. While the four chimneys of the plant were demolished in 2001, much of the original building still exists today. Till 2013 it was used for events and art display. Today plant is unsafe and closed to public. The first block of the lignite-fired power plant (6 x 35 MW ) was built between 1937 and 1940. After 1943 installation was begun on

162-478: A boiler , stove , furnace , incinerator , or fireplace from human living areas. Chimneys are typically vertical, or as near as possible to vertical, to ensure that the gases flow smoothly, drawing air into the combustion in what is known as the stack, or chimney effect . The space inside a chimney is called the flue . Chimneys are adjacent to large industrial refineries , fossil fuel combustion facilities or part of buildings, steam locomotives and ships. In

243-410: A fuel . Deposits of this substance can interfere with the airflow and more importantly, they are combustible and can cause dangerous chimney fires if the deposits ignite in the chimney. Heaters that burn natural gas drastically reduce the amount of creosote buildup due to natural gas burning much cleaner and more efficiently than traditional solid fuels. While in most cases there is no need to clean

324-405: A 15 kilometres long line. In 1971 a gas turbine power plant was built, which consisted of six 27 MW units. Between 1972 and 1974 greenhouse facilities were built on an area of 64 hectares , which were heated by the power plant, for growing tomatoes and cucumbers . The green house facilities were shut down in 1991, and demolished in 1997. In 1994 the lignite power plant was shut down. In 1998

405-613: A cap and be insulated if they service solid fuel appliances, but following the manufacturer's instructions carefully. Aluminum and galvanized steel chimneys are known as class A and class B chimneys. Class A are either an insulated, double wall stainless steel pipe or triple wall, air-insulated pipe often known by its genericized trade name Metalbestos. Class B are uninsulated double wall pipes often called B-vent, and are only used to vent non-condensing gas appliances. These may have an aluminum inside layer and galvanized steel outside layer. Concrete flue liners are like clay liners but are made of

486-454: A central circular tower, 62 feet (19 m) in diameter, with six, large solid buttresses projecting outwards to form an hexagonal design, unique in England. It was made from magnesian limestone and 28 metres (92 ft) tall with walls up to 15 feet (4.6 m) thick in places. It has four floors: a ground floor that serves as a basement and a vaulted stone support for the chamber above;

567-547: A circular central tower with six massive buttresses ; its four floors would have included a main chamber and a private chamber for the lord above it. Although militarily weak, the design would have been a powerful symbol of Hamelin Plantagenet's new social status as a major lord. Conisbrough Castle was founded by William de Warenne , the first Earl of Surrey , who had taken part in the Norman conquest of England in 1066 and

648-591: A concrete windshield with a number of flues on the inside. The 300 m (980 ft) high steam plant chimney at the Secunda CTL 's synthetic fuel plant in Secunda, South Africa consists of a 26 m (85 ft) diameter windshield with four 4.6 metre diameter concrete flues which are lined with refractory bricks built on rings of corbels spaced at 10 metre intervals. The reinforced concrete can be cast by conventional formwork or sliding formwork. The height

729-590: A divorce in 1316 failed in the law courts. John blamed Thomas , the Earl of Lancaster , for this and in response he kidnapped Thomas' wife; Thomas then retaliated by seizing Conisbrough Castle. Edward II intervened in the dispute and confirmed Thomas as the new owner of the castle. In 1322, however, Thomas rebelled against the King and was executed, resulting in Edward taking control of Conisbrough himself. The King visited

810-399: A downdraft of smoke and wind down the chimney. An H-style cap is a chimney top constructed from chimney pipes shaped like the letter H. It is an age-old method of regulating draft in situations where prevailing winds or turbulences cause downdraft and back-puffing. Although the H cap has a distinct advantage over most other downdraft caps, it fell out of favor because of its bulky design. It

891-662: A flue liner. Chimneys built without a liner can usually have a liner added, but the type of liner needs to match the type of appliance it services. Flue liners may be clay or concrete tile, metal, or poured in place concrete. Clay tile flue liners are very common in the United States, although it is the only liner that does not meet Underwriters Laboratories 1777 approval and frequently they have problems such as cracked tiles and improper installation. Clay tiles are usually about 2 feet (0.61 m) long, available in various sizes and shapes, and are installed in new construction as

SECTION 10

#1732797869188

972-475: A fortified burh at Conisbrough itself. William built his castle on a rocky Magnesian Limestone spur surrounded by steep banks, and the fortification included a motte , an inner bailey protected by an earth bank and palisades , an outer bailey , and possibly a timber keep . The castle was located around 175 feet (53 m) above the river and would have dominated this part of the Don Valley . It

1053-668: A gas chimney on an annual basis that does not mean that other parts of the chimney cannot fall into disrepair. Disconnected or loose chimney fittings caused by corrosion over time can pose serious dangers for residents due to leakage of carbon monoxide into the home. Thus, it is recommended—and in some countries even mandatory—that chimneys be inspected annually and cleaned on a regular basis to prevent these problems. The workers who perform this task are called chimney sweeps or steeplejacks . This work used to be done largely by child labour and, as such , features in Victorian literature . In

1134-430: A metal flue. Bracing or strapping old masonry chimneys has not proven to be very effective in preventing damage or injury from earthquakes. It is now possible to buy "faux-brick" facades to cover these modern chimney structures. Other potential problems include: Several chimneys with observation decks were built. The following possibly incomplete list shows them. At several thermal power stations at least one smokestack

1215-507: A noncombustible wall thimble allows a vent pipe to run directly through the external wall. On a pitched roof where a chimney penetrates a roof, flashing is used to seal up the joints. The down-slope piece is called an apron, the sides receive step flashing and a cricket is used to divert water around the upper side of the chimney underneath the flashing. Industrial chimneys are commonly referred to as flue-gas stacks and are generally external structures, as opposed to those built into

1296-415: A partial view of the property from the road and the events portrayed in the novel, set at the end of the 12th century, are fictitious; Scott believed the castle to have been Saxon in origin, a view shared by many 19th-century commentators. Although the writer John Wainwright was still able to praise the "picturesque view" around the castle in 1826, the antiquarian Ecroyd Smith commented with concern in 1887 on

1377-451: A range of what the historian Stephen Johnson terms "colourful if rather unlawful dealings"; one was ultimately charged with having conducted "devilish and innumerable oppressions". Further work was carried out in the castle during John's ownership, including modernising the castle hall and solar. The castle passed to John's grandson, also called John , who, in 1304, married Joan de Barr . The marriage broke down but John's attempts to gain

1458-413: A refractory cement and are more durable than the clay liners. Poured in place concrete liners are made by pouring special concrete into the existing chimney with a form. These liners are highly durable, work with any heating appliance, and can reinforce a weak chimney, but they are irreversible. A chimney pot is placed on top of the chimney to expand the length of the chimney inexpensively, and to improve

1539-626: A second block (12 x 36 MW) was built to provide for growing electricity demands of industry and households in the German Democratic Republic . On July 22, 1960 an Ilyushin Il-14 plane of the GDR armed forces flying through dense fog scratched one of the chimneys and crashed. Seven people on board the plane and a worker on the ground were killed. After 1968 the city of Dessau was supplied with heat from Vockerode Power Plant via

1620-412: A short vertical chimney in a remote location where the fumes would cause less harm. Lead and silver deposits formed on the inside of these long chimneys, and periodically workers would be sent along the chimneys to scrape off these valuable deposits. As a result of the limited ability to handle transverse loads with brick, chimneys in houses were often built in a "stack", with a fireplace on each floor of

1701-456: A stone curtain wall defended by six mural or fortified towers and the castle keep. The inner bailey would have included a hall , solar , chapel and other service buildings of which only the foundations survive. The design of Conisbrough's keep is unique in England, and the historians Oliver Creighton and Stephen Johnson consider it an "architectural gem" and "one of the finest examples of late Norman defensive architecture". The keep comprises

SECTION 20

#1732797869188

1782-466: A three-way agreement in 1988 with the Ivanhoe Trust, a local charity designed to generate new employment in the region. Under this agreement the trust would manage the site, English Heritage would maintain the historic fabric of the castle, while the council would construct a new visitors' centre. A new, controversial visitor's centre was built in the style of a collection of jousting tents, while

1863-433: A vertical sequence of rooms, with a vaulted, hexagonal chapel leading off the private chamber, cut into one of the buttresses. Most of the castle would have been very dark due to the lack of natural light. The main chamber, however, had a large window, 1 foot 10 inches (0.56 m) by 4 feet 8 inches (1.42 m), with deep recesses to allow for the thickness of the walls; two carved seats sat alongside

1944-563: A water tank on their structure. This combination has the advantage that the warm smoke running through the chimney prevents the water in the tank from freezing. Before World War II such structures were not uncommon, especially in countries influenced by Germany. Chimneys can carry antennas for radio relay services, cell phone transmissions, FM-radio and TV on their structure. Also long wire antennas for mediumwave transmissions can be fixed at chimneys. In all cases it had to be considered that these objects can easily corrode especially when placed near

2025-555: Is a medieval fortification in Conisbrough , South Yorkshire , England. The castle was initially built in the 11th century by William de Warenne , the Earl of Surrey , after the Norman conquest of England in 1066. Hamelin Plantagenet, the illegitimate, parvenu brother of Henry II, acquired the property by marriage in the late 12th century. Hamelin and his son William rebuilt the castle in stone, including its prominent 28-metre (92 ft)-high keep . The castle remained in

2106-433: Is called "natural draught/draft", "natural ventilation" , "chimney effect", or " stack effect ". The taller the stack, the more draught or draft is created. There can be cases of diminishing returns: if a stack is overly tall in relation to the heat being sent out of the stack, the flue gases may cool before reaching the top of the chimney. This condition can result in poor drafting, and in the case of wood burning appliances,

2187-439: Is combusted in a stove, oven, fireplace, hot water boiler, or industrial furnace, the hot combustion product gases that are formed are called flue gases. Those gases are generally exhausted to the ambient outside air through chimneys or industrial flue-gas stacks (sometimes referred to as smokestacks). The combustion flue gases inside the chimneys or stacks are much hotter than the ambient outside air and therefore less dense than

2268-415: Is common for the metal to become warped over time, thus further degrading the ability of the throat damper to seal. However, the advantage of a throat damper is that it seals off the living space from the air mass in the chimney, which, especially for chimneys positioned on an outside of wall of the home, is generally very cold. It is possible in practice to use both a top damper and a throat damper to obtain

2349-517: Is found mostly in marine use but has been regaining popularity due to its energy-saving functionality. The H-cap stabilizes the draft rather than increasing it. Other downdraft caps are based on the Venturi effect , solving downdraft problems by increasing the updraft constantly resulting in much higher fuel consumption. A chimney damper is a metal plate that can be positioned to close off the chimney when not in use and prevent outside air from entering

2430-460: Is protected under UK law as a Grade I listed building and as a Scheduled Ancient Monument . Conisbrough Castle has an outer and an inner bailey, approximately 260 by 120 feet (79 by 37 m) and 290 by 205 feet (88 by 62 m) across respectively. The castle was entered through the outer bailey, a rectangular enclosure protected by earthworks, which would have contained the castle's barns, stables, and other service facilities. A drawbridge on

2511-419: Is the minimum required flow area from water heater tank and A f =19.6 inch is the minimum flow area from a furnace of a central heating system. Gas fired appliances must have a draft hood to cool combustion products entering the chimney and prevent updrafts or downdrafts. A characteristic problem of chimneys is they develop deposits of creosote on the walls of the structure when used with wood as

Vockerode Power Plant - Misplaced Pages Continue

2592-400: Is to ensure the pollutants are dispersed over a wider area to meet legal or other safety requirements. A flue liner is a secondary barrier in a chimney that protects the masonry from the acidic products of combustion, helps prevent flue gas from entering the house, and reduces the size of an oversized flue. Since the 1950s, building codes in many locations require newly built chimneys to have

2673-656: Is used as electricity pylon. The following possibly incomplete list shows them. Nearly all this structures exist in an area, which was once part of the Soviet Union. Although this use has the disadvantage that conductor ropes may corrode faster due to the exhaust gases, one can find such structures also sometimes in countries not influenced by the former Soviet Union. An example herefore is one chimney of Scholven Power Plant in Gelsenkirchen, which carries one circuit of an outgoing 220 kV-line. Chimneys can also carry

2754-589: The Duke of York , who controlled it until 1402. Edmund's eldest son, Edward , owned it until 1415, when it passed to Maud Clifford, the widow of Edmund's younger son Richard , who lived there until 1446. Richard of York then inherited the castle, and on his death in 1460 during the Wars of the Roses it passed to his son Edward , who seized the throne in 1461, bringing Conisbrough back into Crown ownership once again. By

2835-490: The Middle Ages in some parts of Europe, a stepped gable design was developed, partly to provide access to chimneys without use of ladders. Masonry (brick) chimneys have also proven to be particularly prone to crumbling during earthquakes . Government housing authorities in cities prone to earthquakes such as San Francisco , Los Angeles , and San Diego now recommend building new homes with stud-framed chimneys around

2916-504: The United States , the term smokestack industry refers to the environmental impacts of burning fossil fuels by industrial society, including the electric industry during its earliest history. The term smokestack (colloquially, stack ) is also used when referring to locomotive chimneys or ship chimneys , and the term funnel can also be used. The height of a chimney influences its ability to transfer flue gases to

2997-428: The gatehouse of the inner bailey, complete with an additional corner turret. The remains of the collapse of the curtain wall are still visible in the ditch. Various buildings were constructed along the inside of the inner bailey wall of similar rough stonework to the curtain wall, but only their foundations remain today. In the south-west corner was the solar block, containing the solar and various chambers. Along

3078-410: The local council , the state agency English Heritage and a local charitable trust to develop the castle. The keep was re-roofed and re-floored in the 1990s with the help of European Union funding. English Heritage took over control of the castle in 2008 and continues to operate the property as a tourist attraction. The castle is made up of an inner and an outer bailey , the former surrounded by

3159-421: The 16th century Conisbrough Castle was in a poor state of repair, and a royal survey carried out in 1537 and 1538 showed that the gates, bridge and parts of the walls had collapsed in a spectacular land slippage, and that one floor of the keep had also fallen in. The collapse of the walls was a consequence of the instability of the topsoil on top of the limestone spur, which was a mixture of clay and sandstone; once

3240-410: The 17th century and the remains were bought by the Duke of Leeds in 1737. Sir Walter Scott used the location for his 1819 novel Ivanhoe and by the end of the 19th century the ruins had become a tourist attraction. The state took over the management of the property in 1950, but by the 1980s the visitor facilities were felt to be unsuitable, leading to a three-way partnership being created between

3321-433: The 1st floor through a hole in the stone floor. The keep was designed as a private tower for Hamelin Plantagenet, rather than a grander residence. As a result, it was not designed to accommodate several different households and its layout was simpler than that seen at the contemporary keep of Orford Castle , for example. The 2nd and the 3rd floor would have served as the main chamber and the lord's private chamber, forming

Vockerode Power Plant - Misplaced Pages Continue

3402-413: The ambient air. That causes the bottom of the vertical column of hot flue gas to have a lower pressure than the pressure at the bottom of a corresponding column of outside air. That higher pressure outside the chimney is the driving force that moves the required combustion air into the combustion zone and also moves the flue gas up and out of the chimney. That movement or flow of combustion air and flue gas

3483-419: The antiquarian George Clark recommended urgent work to repair the stonework. If finances allowed it, he also urged the reinstallation of a roof and wooden floors. Limited repairs were subsequently approved by the trustees of Lord Conyers, although Clark's colleague, A. Ellis, expressed concerns that railings to protect the visitors who routinely climbed to the top of the keep had not been funded. A reported £500

3564-581: The benefits of both. The two top damper designs currently on the market are the Lyemance (pivoting door) and the Lock Top (translating door). In the late Middle Ages in Western Europe the design of stepped gables arose to allow maintenance access to the chimney top, especially for tall structures such as castles and great manor houses . When coal, oil, natural gas, wood, or any other fuel

3645-429: The bricks around tile liners. To control downdrafts, venting caps (often called chimney pots ) with a variety of designs are sometimes placed on the top of chimneys. In the 18th and 19th centuries, the methods used to extract lead from its ore produced large amounts of toxic fumes. In the north of England, long near-horizontal chimneys were built, often more than 3 km (2 mi) long, which typically terminated in

3726-491: The castle in 1322, and spent 40 marks on repairing both Conisbrough and the neighbouring castle of Pontefract. Edward was overthrown by his wife Isabella in 1326 and the castle was returned to John. John had hoped to pass the property to his mistress and two illegitimate sons, but he outlived them and on his death in 1347 it reverted to the control of the Crown. Edward III gave the castle to his own son, Edmund of Langley ,

3807-521: The changing character of the location, in particular the factories that were growing up around the new railway line and the "murky atmosphere" the industrial works created. In 1859 Francis D'Arcy-Osborne , the Duke of Leeds, died, leaving Conisbrough to his nephew, Sackville Lane-Fox , the Baron Conyers . The keep remained in good condition, but by 1884 it was apparent that repairs were needed and

3888-403: The chimney and making it onto the roof. Although the masonry inside the chimney can absorb a large amount of moisture which later evaporates, rainwater can collect at the base of the chimney. Sometimes weep holes are placed at the bottom of the chimney to drain out collected water. A chimney cowl or wind directional cap is a helmet-shaped chimney cap that rotates to align with the wind and prevent

3969-459: The chimney is built. A refractory cement is used between each tile. Metal liners may be stainless steel, aluminum, or galvanized iron and may be flexible or rigid pipes. Stainless steel is made in several types and thicknesses. Type 304 is used with firewood , wood pellet fuel , and non-condensing oil appliances, types 316 and 321 with coal, and type AL 29-4C is used with high efficiency condensing gas appliances. Stainless steel liners must have

4050-430: The chimney's draft . A chimney with more than one pot on it indicates that multiple fireplaces on different floors share the chimney. A cowl is placed on top of the chimney to prevent birds and other animals from nesting in the chimney. They often feature a rain guard to prevent rain or snow from going down the chimney. A metal wire mesh is often used as a spark arrestor to minimize burning debris from rising out of

4131-657: The clay was washed away over time, the remaining sandstone proved extremely unstable and liable to crack. Henry VIII gave the ruins to the Carey family, who retained it until it passed by marriage into first the Heviningham and then the Coke families. The castle was not involved in the events of the English Civil War in the 17th century, and escaped the slighting that affected many similar properties, probably because

SECTION 50

#1732797869188

4212-401: The collapse of the outer walls had already made it indefensible and of little military value. In 1737, after the death of Edward Coke, the castle and the surrounding manor were bought by Thomas Osborne , the Duke of Leeds , for £22,500. In 1811 the novelist Sir Walter Scott passed by the castle and later used it as the location for his novel Ivanhoe , published in 1819. Scott only had

4293-435: The cooling of the gases before emission can cause creosote to condense near the top of the chimney. The creosote can restrict the exit of flue gases and may pose a fire hazard. Designing chimneys and stacks to provide the correct amount of natural draft involves a number of design factors, many of which require iterative trial-and-error methods. As a "first guess" approximation, the following equation can be used to estimate

4374-463: The development of Mortemer Castle in France, where a similar keep was built on top of a motte, and Conisbrough might also have had resemblances to Sandal Castle in the north of England, also owned by the earls. The design of the keep was poor from a military perspective. The central circular tower provided defensive advantages but the buttresses introduced 12 vulnerable corners into the stonework, and

4455-421: The exhaust. Sometimes chimneys were converted into radio towers and are not useable as ventilation structure any more. As chimneys are often the tallest part of a factory, they offer the possibility as advertising billboard either by writing the name of the company to which they belong on the shaft or by installing advertisement boards on their structure. At some power stations, which are equipped with plants for

4536-452: The external environment via stack effect . Additionally, the dispersion of pollutants at higher altitudes can reduce their impact on the immediate surroundings. The dispersion of pollutants over a greater area can reduce their concentrations and facilitate compliance with regulatory limits. Industrial chimney use dates to the Romans , who drew smoke from their bakeries with tubes embedded in

4617-474: The family line into the 14th century, despite being seized several times by the Crown . The fortification was then given to Edmund of Langley , passing back into royal ownership in 1461. Conisbrough Castle fell into ruin, its outer wall badly affected by subsidence , and was given to the Carey family in the 16th century. Its derelict state prevented it from involvement in the English Civil War of

4698-606: The fire, meaning more heat could escape into the room. Because the air going up the shaft was cooler, these could be made of less fireproof materials. Another step in the development of chimneys was the use of built-in ovens which allowed the household to bake at home. Industrial chimneys became common in the late 18th century. Chimneys in ordinary dwellings were first built of wood and plaster or mud. Since then chimneys have traditionally been built of brick or stone, both in small and large buildings. Early chimneys were of simple brick construction. Later chimneys were constructed by placing

4779-407: The fireplace from the chimney. The advantage of a top damper is the tight weatherproof seal that it provides when closed, which prevents cold outside air from flowing down the chimney and into the living space—a feature that can rarely be matched by the metal-on-metal seal afforded by a throat damper. Additionally, because the throat damper is subjected to intense heat from the fire directly below, it

4860-407: The first floor, through which the keep was accessed; two upper floors and a roof walk, which was probably covered by a pentice and defended by battlements . The current concrete stairs to the keep are modern, and the original medieval stairway, made from timber and stone, would have incorporated a drawbridge just before the castle doors. The basement contained a well, which could also be drawn from

4941-420: The floors and roof of the keep were reinstalled between 1993 and 1995 with European Union funding, in an attempt to limit the erosion of the castle stonework. Visitor numbers following the investments fell far short of expectations, however, and by 2006 had settled at around 30,000 each year, only slightly above the level in the early 1980s. The external facilities did not age well and funding shortages led to

SECTION 60

#1732797869188

5022-462: The gas turbine power plant was shut down and on September 22, 2001 the chimneys were demolished by explosives. In 2005 the oil tanks of the gas turbine plant were demolished. 51°50′44″N 12°21′31″E  /  51.845429°N 12.358632°E  / 51.845429; 12.358632 Chimney A chimney is an architectural ventilation structure made of masonry, clay or metal that isolates hot toxic exhaust gases or smoke produced by

5103-439: The house sharing a single chimney, often with such a stack at the front and back of the house. Today's central heating systems have made chimney placement less critical, and the use of non-structural gas vent pipe allows a flue gas conduit to be installed around obstructions and through walls. Most modern high-efficiency heating appliances do not require a chimney. Such appliances are generally installed near an external wall, and

5184-426: The interior space, and can be opened to permit hot gases to exhaust when a fire is burning. A top damper or cap damper is a metal spring door placed at the top of the chimney with a long metal chain that allows one to open and close the damper from the fireplace. A throat damper is a metal plate at the base of the chimney, just above the firebox, that can be opened and closed by a lever, gear, or chain to seal off

5265-529: The natural draught/draft flow rate by assuming that the molecular mass (i.e., molecular weight) of the flue gas and the external air are equal and that the frictional pressure and heat losses are negligible: Q = C A 2 g H T i − T e T e {\displaystyle Q=C\,A\,{\sqrt {2\,g\,H\,{\frac {T_{i}-T_{e}}{T_{e}}}}}} where: Combining two flows into chimney: A t + A f < A , where A t =7.1 inch

5346-536: The new audio-visual effects in the keep being turned off to save money. Discussions between the three partners about the future of the castle took place, but relations broke down and English Heritage resumed the direct management of the castle in 2008. The castle was closed for a £1.1 million programme of renovations in 2013, funded by the Heritage Lottery Fund , as part of which a new visitors' centre and visitor facilities were constructed. The castle

5427-404: The north side was the hall, pushed into an awkward corner of the curtain wall, 70 by 30 feet (21.3 by 9.1 m) in size and originally probably built two storeys high. Initially constructed with a central hearth, a fireplace was added into the outer wall in the later 13th century. Alongside the hall were a kitchen and pantry , the former with a cellar. On the south-east side of the inner bailey

5508-482: The northern side of the outer bailey, now replaced by an earth causeway, linked it with the inner bailey. The oval inner bailey was formed by scarping and counter-scarping the natural contours of the hill, producing a bank, now largely destroyed, and a protective ditch. The early 13th-century curtain wall is mostly of roughly dressed, coursed stone, up to 7 feet (2.1 m) thick and 35 feet (11 m) high, with two sections repaired with ashlar facings. The wall

5589-692: The removal of sulfur dioxide and nitrogen oxides , it is possible to use the cooling tower as a chimney. Such cooling towers can be seen in Germany at the Großkrotzenburg Power Station and at the Rostock Power Station . At power stations that are not equipped for removing sulfur dioxide, such usage of cooling towers could result in serious corrosion problems which are not easy to prevent. Download coordinates as: Conisbrough Castle Conisbrough Castle

5670-491: The site between 1967 and 1969, exposing the foundations of the buildings in the inner bailey, and then from 1973 to 1977, examining options for future visitor facilities. By 1984, when the government agency English Heritage took over the management of the property, the condition of the visitor services was unsatisfactory and the industrial character of the surrounding area was discouraging tourists. In response, English Heritage and Doncaster Metropolitan Borough Council formed

5751-484: The wall of a building. They are generally located adjacent to a steam-generating boiler or industrial furnace and the gases are carried to them with ductwork. Today the use of reinforced concrete has almost entirely replaced brick as a structural element in the construction of industrial chimneys. Refractory bricks are often used as a lining, particularly if the type of fuel being burned generates flue gases containing acids. Modern industrial chimneys sometimes consist of

5832-541: The walls. However, domestic chimneys first appeared in large dwellings in northern Europe in the 12th century. The earliest surviving example of an English chimney is at the keep of Conisbrough Castle in Yorkshire , which dates from 1185 AD, but they did not become common in houses until the 16th and 17th centuries. Smoke hoods were an early method of collecting the smoke into a chimney. These were typically much wider than modern chimneys and started relatively high above

5913-452: The window. A similar window was placed above it in the private chamber. The keep had relatively advanced fireplaces and flues for this period, the fireplace in the main chamber being exceptionally large and decorated with stone columns and carved capitals. Conisbrough Castle was probably similar to two other castles owned by the Warren earls. Hamelin Plantagenet was also responsible for

5994-461: The world's first commercial HVDC , the Elbe Project . It was completed in 1945, but never went in service. The power plant suffered no damage during World War II. After dismantling of the equipment during the soviet occupation the inverter hall was transformed into a workshop. A lot of equipment from the power plant was also dismantled. Between 1953 and 1959 the power plant was refurbished and

6075-416: Was defended by six mural towers along its southern and western sides, of which three still survive reasonably intact, and strengthened with pilaster buttresses along the northern edge. The bases of the walls and the towers were splayed, spreading their weight out more broadly, but their footings are only 0.6 metres (2 ft 0 in) deep in places. A barbican protected the link from the drawbridge to

6156-458: Was positioned directly opposite the village, which probably contained the old Anglo-Saxon burh. The castle was held by William's son, also called William , from 1088 to 1138, and then by his son, another William , until his death in 1147. Conisbrough and the earldom then passed through Isabel , William's daughter, to her first husband, William de Blois , and then on to her second husband, Hamelin Plantagenet , whom she married in 1163. Hamelin

6237-485: Was probably responsible for the construction of new stone curtain walls around the inner bailey, destroying the former earthwork defences in the process. The inner bailey was levelled and William built a hall and service buildings inside the castle, again in stone. Conisbrough was inherited by William's young son John de Warenne in 1239, but he was still a minor and the castle was initially managed by his mother, Maud . Under John, Conisbrough's constables carried out

6318-557: Was rewarded by his father-in-law, William the Conqueror , with extensive estates in Yorkshire , Norfolk and Sussex . As part of these, Lord de Warenne was given the manor of Conisbrough , which had previously been owned by the late Harold Godwinson . The manor took its name from the Old English name for the settlement, Cyningesburh , meaning "the king's fortress", and formed a large estate comprising 28 townships, centred on

6399-581: Was spent by the trustees renovating the castle ruins, including the construction of a lodge in the outer bailey for the castle keeper, completed in 1885, and improvements to the footpaths. Conisbrough Castle was bought by the Conisbrough local council in the 1940s, who placed the castle into the guardianship of the Ministry of Public Works in 1949, but retained the freehold ownership of the land. Two sets of archaeological excavations were carried out on

6480-457: Was the castle chapel , 20 by 40 feet (6.1 by 12.2 m) across. Conisbrough's keep was positioned on the north-east side of the inner bailey. It is an important medieval survival: the historian Sidney Toy considered it to be "one of the finest keeps in England", the archaeologist Oliver Creighton describes it as an "architectural gem" and Stephen Johnson as "one of the finest examples of late Norman defensive architecture". The keep comprises

6561-496: Was the illegitimate half-brother of King Henry II , who had arranged the marriage, and the union brought him great wealth. Hamelin extensively rebuilt the castle around 1180 to 1190, including constructing the stone keep; given his parvenu status, he probably hoped to reinforce perceptions of his new elevated rank. King John visited the castle in 1201. The castle continued in the ownership of Hamelin Plantagenet's family, passing to his son William de Warenne in 1202. William

#187812