Misplaced Pages

#211788

45-872: The Jurassic Skyline tower (known until mid-2015 as the Weymouth Sea Life Tower ) was an observation tower on Weymouth Pier in Weymouth, Dorset , England. It was situated next to Weymouth Beach and the Weymouth Pavilion , where it overlooked Weymouth town, the beach , the Pavilion , the Old Harbour , Nothe Gardens , the Nothe Fort , and Portland Harbour . It opened on 22 June 2012. The tower stood 53 metres (174 feet) high. The clear-fronted passenger gondola could turn

90-509: A flag pole at its top. Some of these towers are permanently accessible, either free or with the payment of an admission fee. Others are accessible only at certain times, in most cases only with the payment of an admission fee. At these towers the platform is usually open, with some having a restaurant in the basement. There are also towers with a much more extensive use; for example. the observation tower on Rossberg mountains in Reutlingen contains

135-657: A full 360 degrees as it rose during operation, and accommodated 69 passengers at a time. Each tower session lasted approximately 15 minutes. A total of 1,100 tons of concrete was used during building; the tower itself weighed 140 tons. It offered views of the English Channel and the surrounding countryside; on a clear day, views at the highest point were said to extend down the Dorset coast to Lulworth Cove and Durdle Door . The tower received national attention in September 2017 after

180-460: A hotel within its structure. Although most of these towers were initially built before World War I , such structures are still being built, in particular as attractions at horticultural shows . Modern observation towers are in most cases no longer built of brick, but concrete, steel and wood are used as the preferred building materials. Permanent observation towers are also sometimes found in amusement parks , however in parks where each attraction

225-515: A lighthouse is usually between 10 and 50 metres high, and is almost always open air. Some sports facilities have high buildings with observation decks. This is often the case at ski jumps, as these have a tower and are usually unused in the summer. In addition, there are other sports facilities with observation decks, like the inclined tower of the Montreal Olympic stadium. Access to the platform of nearly all sports facilities with observation deck

270-402: A restaurant. The height of these platforms, which can be glassed or open-air depending on the height of the building, where they are most common on the topmost floor. As a rule access usually requires the payment of an admission fee, is possible by elevator only at dedicated opening times. Also numerous water towers have, a usually open-air observation deck opened for public traffic, whose height

315-428: A rule an elevator is available in these buildings for the visitors of the observation deck, as the observation deck lies usually very highly (mostly within the range between 50 and 200 metres, at some towers also more highly). Many of these towers have also a tower restaurant, which can be designed as revolving restaurant. While tower restaurants for the protection of the restaurant guests from the wind are in closed rooms,

360-609: A rule, since these buildings are mostly not higher than 20 metres. Active watch towers are not as a rule accessible to the public, since they usually serve for the monitoring of sensitive ranges. However watch towers can be quite ordered for forest fire monitoring a platform accessible for the public or be used during times without forest fire risk as observation towers. Shut down watch towers can however be easily converted to observation towers. Also some radio towers were so built that they can be used apart from their function as transmitting tower also as observation tower. A condition for this

405-433: A t-antenna for medium wave and stands on insulators. However one notices at the first experimental transmissions that at the tower voltages would arise, which would have unpleasant consequences for visitors and so the tower was grounded by the elevator shaft. However this shifted direction of main beam of transmitter away from actual supply area, the city of Berlin. As before World War II nearly whole radio traffic took place in

450-428: Is a considerable amount of lawful unlicensed activity (cordless phones, wireless networking) clustered around 900 MHz and 2.4 GHz, regulated under Title 47 CFR Part 15 . These ISM bands —frequencies with a higher unlicensed power permitted for use originally by Industrial, Scientific, Medical apparatus—are now some of the most crowded in the spectrum because they are open to everyone. The 2.45 GHz frequency

495-669: Is a sufficiently stable construction, which permits a permanent safe visitor entrance without interruption of the transmission services. This is the case for towers for radio services in the UHF/VHF-range the case, not however for most types of radio towers for long and medium wave, why a use of these structures as observation tower is impossible in most cases. That the use of a tower as radio tower for medium wave and observation tower not well fits, showed up in Radio Tower Berlin , which originally carried together with an 80 metres high mast

SECTION 10

#1732863111212

540-530: Is for cellphones , allowing handheld mobile phones be connected to the public switched telephone network and the Internet . Current 3G and 4G cellular networks use UHF, the frequencies varying among different carriers and countries. Satellite phones also use this frequency in the L band and S band . UHF channels are used for digital television broadcasting on both over the air channels and cable television channels . Since 1962, UHF channel tuners (at

585-436: Is in contrast to the entrance of the church usually only possible under payment an admission fee at the opening times of the church. The height of the observation decks is usually in the range between 20 and 50 metres. The platform is nearly always open-air. Some lighthouses have an observation deck open to the public. Access is usually by stairs. An admission fee is often charged and hours may be limited. The observation deck of

630-486: Is mostly as the height of older observation towers in the height range between 10 and 50 metres. It can be reached depending upon tower by stairs or by an elevator. Some water towers have also a tower restaurant. Prospect platforms of water towers are nearly only accessible under payment during the opening times, which are different for each tower. Also some church towers possess observation decks. However elevators are only available in rare cases. The entrance of this platform

675-427: Is not separately paid for, panorama rides are preferred. Watch towers are observation towers, on which persons supervise a larger area. Strictly speaking, control towers also fall into this category, although surveillance from these structures is mostly done in a non-optical way using Radar . Watch towers usually have a closed pulpit to protect the observer against bad weather. Watch towers do not have an elevator as

720-551: Is only possible during opening times after paying an admission fee. Depending upon the building the access can be done by an elevator and/or a stairway. The platforms can be vitreous or open. The height above ground lies usually between 10 and 50 metres. Fire lookout towers have been used widely in Australia, Canada, and the United States to hoist fire lookout persons to heights where they can identify and report new wildfires. In

765-452: Is the standard for use by microwave ovens , adjacent to the frequencies allocated for Bluetooth network devices. The spectrum from 806 MHz to 890 MHz (UHF channels 70 to 83) was taken away from TV broadcast services in 1983, primarily for analog mobile telephony . In 2009, as part of the transition from analog to digital over-the-air broadcast of television , the spectrum from 698 MHz to 806 MHz (UHF channels 52 to 69)

810-877: The Henninger Turm , a grain silo with tower restaurant and observation deck in Frankfurt, the bell tower of Berlin Olympic stadium , whose platform is accessible by an elevator, the winding tower of the mining industry museum in Bochum, which has an open-air observation deck to which an elevator runs or a wind turbine in Holtriem wind park, which is equipped with a closed platform accessible over stairs. Also aerial tramway support towers, which serve as observation tower (and aerial tramway station), were realized, like Torre Jaume I in Barcelona. Even on

855-498: The UHF / VHF range ( FM sound broadcasting , TV, public rural broadcasting service, and portable radio service). In some cases this usage of the tower is at least as important as its use as an observation tower. Such towers are usually called TV towers or telecommunication towers. Many towers are also equipped with a tower restaurant and allow visitors access via elevators. Also common is the usage of water towers as observation towers. As in

900-494: The wavelengths of UHF waves are comparable to the size of buildings, trees, vehicles and other common objects, reflection and diffraction from these objects can cause fading due to multipath propagation , especially in built-up urban areas. Atmospheric moisture reduces, or attenuates , the strength of UHF signals over long distances, and the attenuation increases with frequency. UHF TV signals are generally more degraded by moisture than lower bands, such as VHF TV signals. As

945-527: The 18-metre deep foundations started. The ground-level reception building was the last part of the tower to be built in June 2012, in time for the Olympic events. The idea of such a tower had been put forward in 2009-10. After a number of sites across Europe were considered, Weymouth was selected due to its far-reaching vistas and its closeness to the Sea Life Park. The tower had been funded by private money as one of

SECTION 20

#1732863111212

990-583: The 90-strong worldwide attraction network operated by the Poole-based Merlin Entertainments , who also own the nearby Sea Life Park and the Pirate Adventure Golf at Lodmoor Country Park. Completed a week ahead of schedule, an early running of the tower was enjoyed by a host of VIP guests, including borough mayor Margaret Leicester, and local councillors and business community representatives. The tower's original five-year permission

1035-617: The ITU UHF band: the L band between 1 and 2 GHz and the S band between 2 and 4 GHz. Radio waves in the UHF band travel almost entirely by line-of-sight propagation (LOS) and ground reflection; unlike in the HF band there is little to no reflection from the ionosphere ( skywave propagation), or ground wave . UHF radio waves are blocked by hills and cannot travel beyond the horizon, but can penetrate foliage and buildings for indoor reception. Since

1080-469: The UHF spectrum is used worldwide for land mobile radio systems, two-way radios used for voice communication for commercial, industrial, public safety, and military purposes. Examples of personal radio services are GMRS , PMR446 , and UHF CB . The most rapidly-expanding use of the band is Wi-Fi ( wireless LAN ) networks in homes, offices, and public places. Wi-Fi IEEE 802.11 low band operates between 2412 and 2484 MHz. A second widespread use

1125-417: The United States, there once were over 5,000 fire lookout towers. Areas where birdlife congregates are often associated with bird observation towers to assist with viewing. Hyperboloid structures have a hyperboloid shape that is usually lattice framework and an observation deck on top. There are also some very different observation towers, which don't fit into other categories. Examples for this are

1170-784: The atmosphere warms and cools throughout the day. The length of an antenna is related to the length of the radio waves used. Due to the short wavelengths, UHF antennas are conveniently stubby and short; at UHF frequencies a quarter-wave monopole , the most common omnidirectional antenna is between 2.5 and 25 cm long. UHF wavelengths are short enough that efficient transmitting antennas are small enough to mount on handheld and mobile devices, so these frequencies are used for two-way land mobile radio systems , such as walkie-talkies , two-way radios in vehicles, and for portable wireless devices ; cordless phones and cell phones . Omnidirectional UHF antennas used on mobile devices are usually short whips , sleeve dipoles , rubber ducky antennas or

1215-674: The case of TV towers the visitor will usually reach the observation deck by elevator, which is usually at a lower height above ground The typical height of the observation deck of water towers is 20 metres up to 50 metres, while the typical height of the platform of TV towers is from 80 metres up to 200 metres. Finally, some church towers may have observation decks, albeit often without an elevator. Many other buildings may have towers which allow for observation. In particular prior to World War I rambler associations, and some municipalities, built observation towers on numerous summits. Usually these towers were built of stone, however sometimes wood or iron

1260-465: The countryside, as they must rise over trees and other obstacles to ensure clear vision. Older control rooms have often been likened to medieval chambers. The heavy use of stone, iron, and wood in their construction helps to create this illusion. Modern towers frequently have observation decks or terraces with restaurants or on the roof of mountain stations of an aerial ropeway. Frequently observation towers are used also as location of radio services within

1305-457: The desire existed to provide these towers with a tower restaurant and an observation deck, in order to make the building of towers more economical via admission fees and increased notability. Several water towers were also built with this in mind, but many have not survived to the modern day. Ultra high frequency Ultra high frequency ( UHF ) is the ITU designation for radio frequencies in

1350-533: The elevator in the late 19th century made taller observation decks possible. Most notably, the Eiffel Tower and the Blackpool Tower were built in this era. Radio towers developed as combined sending and observation tower between 1924 and 1926 in the city of Berlin . After World War II , a great need for tall observation towers arose, due to their dual usage as television and radio transmitters. In large cities,

1395-668: The gondola became stuck and could not descend; 13 people were winched off by helicopter as the weather prevented other modes of safe rescue. In August 2019, the tower was announced to be permanently closed and was subsequently removed. The tower, designed as a temporary tourist attraction, took eight months to build at a cost of £3.5 million. It was designed in Germany and built in Hungary and France, before being shipped in sections to be assembled on site. Work commenced in October 2011, when excavation of

Jurassic Skyline - Misplaced Pages Continue

1440-464: The long -, medium and shortwave range, first after World War II with introduction of radio services in UHF/VHF-range required towers only acting as antenna carriers, radio towers with observation decks built. For this the closed reinforced concrete construction way was nearly always used. Radio towers with observation decks often serve for TV transmission or for radio relay link services and are called therefore usually TV tower or telecommunication tower. As

1485-483: The planar inverted F antenna (PIFA) used in cellphones. Higher gain omnidirectional UHF antennas can be made of collinear arrays of dipoles and are used for mobile base stations and cellular base station antennas . The short wavelengths also allow high gain antennas to be conveniently small. High gain antennas for point-to-point communication links and UHF television reception are usually Yagi , log periodic , corner reflectors , or reflective array antennas . At

1530-417: The prospect platform can be open or in a closed room. An open platform is more favourable for photographing, since no reflexes at the disk arise, while closed platforms are for many visitors more pleasant. Prospect outlooks on TV towers are opened only at certain times and their entrance is possible only under payment of an admission fee. Also numerous highrise buildings have observation decks , sometimes even

1575-505: The pylons of suspension bridges were already observation decks installed, as the example of Nový Most in Bratislava shows. A very unusual observation tower is Pont basculant de la Seyne-sur-Mer . It was once a bascule bridge, now permanently put upright and used as observation tower. In Germany, observation towers first appeared on the countryside at the end of the 18th century. These early towers were often built by wealthy aristocrats . It

1620-551: The range between 300  megahertz (MHz) and 3  gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter (one decimeter ). Radio waves with frequencies above the UHF band fall into the super-high frequency (SHF) or microwave frequency range. Lower frequency signals fall into the VHF ( very high frequency ) or lower bands. UHF radio waves propagate mainly by line of sight ; they are blocked by hills and large buildings although

1665-414: The slot antenna or reflective array antenna are used: the slotted cylinder, zig-zag, and panel antennas. UHF television broadcasting channels are used for digital television , although much of the former bandwidth has been reallocated to land mobile radio system , trunked radio and mobile telephone use. Since at UHF frequencies transmitting antennas are small enough to install on portable devices,

1710-517: The time, channels 14 to 83) have been required in television receivers by the All-Channel Receiver Act . However, because of their more limited range, and because few sets could receive them until older sets were replaced, UHF channels were less desirable to broadcasters than VHF channels (and licenses sold for lower prices). A complete list of US Television Frequency allocations can be found at Pan-American television frequencies . There

1755-399: The top end of the band, slot antennas and parabolic dishes become practical. For satellite communication, helical and turnstile antennas are used since satellites typically employ circular polarization which is not sensitive to the relative orientation of the transmitting and receiving antennas. For television broadcasting specialized vertical radiators that are mostly modifications of

1800-595: The tower was permanently closed as a result of declining visitor numbers. It was sold to another company and dismantled. 50°36′37″N 2°26′47″W  /  50.610158°N 2.446400°W  / 50.610158; -2.446400 Observation tower Observation towers that are used as guard posts or observation posts over an extended period to overlook an area are commonly called watchtowers instead. Similar instances of observation towers are recognised as crow's nests , observatories , viewing platforms , etc. Observation towers are an easily visible sight on

1845-460: The transmission through building walls is strong enough for indoor reception. They are used for television broadcasting , cell phones , satellite communication including GPS , personal radio services including Wi-Fi and Bluetooth , walkie-talkies , cordless phones , satellite phones , and numerous other applications. The IEEE defines the UHF radar band as frequencies between 300 MHz and 1 GHz. Two other IEEE radar bands overlap

Jurassic Skyline - Misplaced Pages Continue

1890-485: The visual horizon sets the maximum range of UHF transmission to between 30 and 40 miles (48 to 64 km) or less, depending on local terrain, the same frequency channels can be reused by other users in neighboring geographic areas ( frequency reuse ). Radio repeaters are used to retransmit UHF signals when a distance greater than the line of sight is required. Occasionally when conditions are right, UHF radio waves can travel long distances by tropospheric ducting as

1935-657: Was also used. At nearly all these towers access to the observation deck , usually at a height of between 5 and 40 metres, is only possible by way of stairs. Most of these towers are used only for tourism, however some of these towers might also be used, at times of high forest fire risk, as fire observation posts or in times of war as military observation posts with anti-aircraft positions placed beside it. Further uses were not intended at most of these buildings, although some of these towers today now carry antennas for police/fire engine radios, portable radio or low power FM- and TV-transmitters. Older observation towers frequently have

1980-557: Was extended in 2017 for a further five years. Thirteen people got stuck up the tower when it malfunctioned on 5 September 2017. They were winched to safety by a coastguard helicopter . Following an investigation, the tower re-opened on 22 October. After its standard period of closure over the winter period, the tower failed to reopen at the beginning of the peak season in April 2019. Merlin Entertainments later announced on 2 August 2019 that

2025-510: Was not until the mid-19th century that citizens took control of the construction of such towers. In Austria and Switzerland many observation towers were established by alpine and tourist associations, and continue to be cared for by them. In the Waldigen Mountains , many citizen committees were active. Because of the long reign of emperor Franz Joseph , many observation decks carry the name "anniversary observation platform". The invention of

#211788