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62-467: It was believed that before the construction of the Cloaca Maxima , which probably follows the course of an ancient stream called Spinon , the area was a swamp, though this claim has been disproven by core samples taken from Velabrum in 1994. Varro claims there are two velabra , one maius and one minus , with the smaller emerging from the drainage of a swamp close to the northern side of

124-527: A Roman senator and scholar, praised the sewage system in Variae . The Cloaca Maxima was a symbol of Roman civilization, and its superiority to others. Roman authors were not the only people to praise the Cloaca Maxima. British writer Henry James stated that it gave him: "the deepest and grimmest impression of antiquity I have ever received." The system of Roman sewers was much imitated throughout

186-420: A butt transom , is placed hard against the outside face of the structure. Sometimes it is possible to use anchor ties (also called bolt ties ), these are ties fitted into holes drilled in the structure. A common type is a ring bolt with an expanding wedge which is then tied to a node point. The least 'invasive' tie is a reveal tie . These use an opening in the structure but use a tube wedged horizontally in

248-489: A nylon or polyester matrix. Because of the high cost of composite tube, it is usually only used when there is a risk from overhead electric cables that cannot be isolated. Steel tubes are either 'black' or galvanised. The tubes come in a variety of lengths and a standard outside diameter of 48.3 mm. (1.5 NPS pipe ). The chief difference between the two types of metal tubes is the lower weight of aluminium tubes (1.7 kg/m as opposed to 4.4 kg/m). Aluminium tube

310-418: A tourist attraction . Some parts of the sewer are still used today. Whilst still being used, it was highly valued as a sacred symbol of Roman culture , and Roman engineering . According to tradition, it may have initially been constructed around 600 BC under the orders of the king of Rome , Tarquinius Priscus . He ordered Etruscan workers and the plebeians to construct the sewers. Before constructing

372-442: A ledger extending out from the scaffold at an angle of less than 75° and securely founded. A transom at the base then completes a triangle back to the base of the main scaffold. Bamboo scaffolding is a type of scaffolding made from bamboo and widely used in construction work for centuries. Many famous landmarks , notably The Great Wall of China , were built using bamboo scaffolding, and its use continues today in some parts of

434-525: A license. Older scaffolders generally learned in apprenticeships , and may have been able to gather more hands-on experience. Material shortages are also a contributing factor to the decline. The bamboo scaffolding material was imported from mainland China . Bamboo—which matures after three years to the wide diameter and thick skin perfect for scaffolding—came from the Shaoxing area in Guangdong . Over

496-425: A main pipe. At this stage it might have had no roof. However, wooden holes spread throughout the sewer indicate that wooden bridges may have been built over it, which possibly functioned as a roof. Alternatively, the holes could have functioned as a support for the scaffolding needed to construct the sewer. The Cloaca Maxima may also have originally been an open drain, formed from streams originating from three of

558-549: A maximum span of 3.25 m. The minimum overhang for all boards is 50 mm and the maximum overhang is no more than 4x the thickness of the board. Good foundations are essential. Often scaffold frameworks will require more than simple base plates to safely carry and spread the load. Scaffolding can be used without base plates on concrete or similar hard surfaces, although base plates are always recommended. For surfaces like pavements or tarmac base plates are necessary. For softer or more doubtful surfaces sole boards must be used, beneath

620-421: A right-angle coupler. Swivel couplers are to connect tubes at any other angle. The actual joints are staggered to avoid occurring at the same level in neighbouring standards. The spacings of the basic elements in the scaffold are fairly standard. For a general purpose scaffold the maximum bay length is 2.1 m, for heavier work the bay size is reduced to 2 or even 1.8 m while for inspection a bay width of up to 2.7 m

682-412: A single standard a sole board should be at least 1,000 square centimetres (160 in ) with no dimension less than 220 millimetres (8.7 in), the thickness must be at least 35 millimetres (1.4 in). For heavier duty scaffold much more substantial baulks set in concrete can be required. On uneven ground steps must be cut for the base plates, a minimum step size of around 450 millimetres (18 in)

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744-406: A solid fit. Box ties are used to attach the scaffold to suitable pillars or comparable features. Two additional transoms are put across from the lift on each side of the feature and are joined on both sides with shorter tubes called tie tubes. When a complete box tie is impossible a l-shaped lip tie can be used to hook the scaffold to the structure, to limit inward movement an additional transom,

806-437: A specific colour to paint the scaffolding with, in order that quick visual identification can be made in case of theft. All components that are made from metal can be painted but items that are wooden should never be painted as this could hide defects. Despite the metric measurements given, many scaffolders measure tubes and boards in imperial units, with tubes from 21 feet down and boards from 13 ft down. Bamboo scaffolding

868-456: A standard width (225 mm) and are a maximum of 3.9 m long. The board ends are protected either by metal plates called hoop irons or sometimes nail plates, which often have the company name stamped into them. Timber scaffold boards in the UK should comply with the requirements of BS 2482. As well as timber, steel or aluminium decking is used, as well as laminate boards. In addition to the boards for

930-886: A work crew and materials to aid in the construction, maintenance and repair of buildings , bridges and all other human-made structures. Scaffolds are widely used on site to get access to heights and areas that would be otherwise hard to get to. Unsafe scaffolding has the potential to result in death or serious injury. Scaffolding is also used in adapted forms for formwork and shoring, grandstand seating, concert stages, access/viewing towers, exhibition stands, ski ramps, half pipes and art projects. There are six main types of scaffolding used worldwide today. These are tube and coupler (fitting) components, prefabricated modular system scaffold components, H-frame / façade modular system scaffolds, suspended scaffolds, timber scaffolds and bamboo scaffolds (particularly in China, India and Hong Kong). Each type

992-476: A working scaffold is to provide a safe working platform and access suitable for work crews to carry out their work. The European Standard sets out performance requirements for working scaffolds. These are substantially independent of the materials of which the scaffold is made. The standard is intended to be used as the basis for enquiry and design. The basic components of scaffolding are tubes, couplers and boards. The basic lightweight tube scaffolding that became

1054-402: Is allowed. The scaffolding width is determined by the width of the boards, the minimum width allowed is 600 mm but a more typical four-board scaffold would be 870 mm wide from standard to standard. More heavy-duty scaffolding can require 5, 6 or even up to 8 boards width. Often an inside board is added to reduce the gap between the inner standard and the structure. The lift height,

1116-432: Is diminishing due to shortages in labor and material. Despite the lack of labor force and material, recently safety issues have become another serious concern. The labor shortage may be due to the reluctance of younger generations to become scaffolders. "They even think that it’s a dirty and dangerous job. They are not going to do that kind of work," said Yu Hang Flord, who has been a scaffolder for 30 years and later became

1178-401: Is made from several components which often include: Specialized components used to aid in their use as a temporary structure often include heavy duty load bearing transoms, ladders or stairway units for the ingress and egress of the scaffold, beams ladder/unit types used to span obstacles and rubbish chutes used to remove unwanted materials from the scaffold or construction project. Sockets in

1240-408: Is more flexible and has a lower resistance to stress. Tubes are generally bought in 6.3 m lengths and can then be cut down to certain typical sizes. Most large companies will brand their tubes with their name and address in order to deter theft. Boards provide a working surface for scaffold users. They are seasoned wood and come in three thicknesses (38 mm (usual), 50 mm and 63 mm) are

1302-535: Is not for reasons of poverty (especially in the cities) but to add more aesthetics to these centres. Bamboo materials are still used in the construction of some bukas (local restaurants) in rural areas. Forms of bamboo scaffolding include: Only double-row bamboo scaffold is allowed to be used for working at height. The perimeter of bamboo scaffold should be covered by nylon mesh against falling objects. The lapping of nylon mesh should be at least 100 mm wide. Suitable means of access should be provided from

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1364-399: Is recommended. A working platform requires certain other elements to be safe. They must be close-boarded, have double guard rails and toe and stop boards. Safe and secure access must also be provided. Scaffolds are only rarely independent structures. To provide stability for a scaffolding (at left) framework ties are generally fixed to the adjacent building/fabric/steelwork. General practice

1426-531: Is to attach a tie every 4 m on alternate lifts (traditional scaffolding). Prefabricated System scaffolds require structural connections at all frames - i.e. 2–3 m centres (tie patterns must be provided by the System manufacturer/supplier). The ties are coupled to the scaffold as close to the junction of standard and ledger (node point) as possible. Due to recent regulation changes, scaffolding ties must support +/- loads (tie/butt loads) and lateral (shear) loads. Due to

1488-471: Is widely used in Hong Kong and Macau , with nylon straps tied into knots as couplers. In India, bamboo or other wooden scaffolding is also mostly used, with poles being lashed together using ropes made from coconut hair ( coir ). The key elements of the scaffolding are the standard , ledger and transoms . The standards, also called uprights, are the vertical tubes that transfer the entire weight of

1550-506: The Cloaca Maxima may have been praised due to its age and its demonstration of engineering prowess. Livy describes the sewer as: Works for which the new splendor of these days has scarcely been able to produce a match.— Titus Livius, Titus Livius, The History of Rome, Book 1 The writer Pliny the Elder describes the Cloaca Maxima as an engineering marvel due to its ability to withstand floods of filthy waters for centuries. Cassiodorus ,

1612-956: The Forum Augustum and followed the natural course of the suburbs of ancient Rome, which led between the Quirinal , Viminal , and Esquilline Hills . It also passed by the Forum of Nerva , the Arch of Janus , the Forum Boarium , the Basilica Aemilia , and the Forum Romanum , ending at the Velabrum . The sewer's outfall was by the Ponte Rotto and Ponte Palatino . Some of this is still visible today. The branches of

1674-530: The Forum Boarium . In more recent times, the remaining passages have been connected to the modern-day sewage system, mainly to cope with problems of backwash from the river. After the fall of the Roman empire the Cloaca Maxima continued to be used. In the 1600s the Cardinal Chamberlain imposed a tax on residents of Rome in order to pay for the upkeep of the sewer. By the time of the 1800s

1736-477: The Ponte Rotto and Ponte Palatino . It began as an open air canal, but it developed into a much larger sewer over the course of time. Agrippa renovated and reconstructed much of the sewer. This would not be the only development in the sewers. By the first century CE all eleven Roman aqueducts were connected to the sewer. After the Roman Empire fell the sewer still was used. By the 19th century, it became

1798-467: The "Scaffixer" in either 1907 or 1910, a coupling device far more robust than rope which revolutionized scaffolding construction. In 1913, his company was commissioned for the reconstruction of Buckingham Palace , during which his Scaffixer gained much publicity. Palmer-Jones followed this up with the improved "Universal Coupler" in 1919 - this soon became the industry standard coupling and has remained so to this day. Advancements in metallurgy throughout

1860-555: The Cloaca Maxima became popular as a tourist attraction . From 1842 to 1852 sections of the sewer were drained . Pietro Narducci , an Italian engineer was hired by the city of Rome to survey and restore the parts of the sewer by the Forum and the Torre dei Conti in 1862. In 1890 Otto Ludwig Richter , a German archaeologist created a map of the sewers. These efforts renewed public interest in sanitation . The Cloaca Maxima started at

1922-459: The Cloaca Maxima, Priscus, and his son Tarquinius Superbus , worked to transform the land by the Roman forum from a swamp into a solid building ground, thus reclaiming the Velabrum . In order to achieve this, they filled it up with 10-20,000 cubic meters of soil, gravel, and debris. At the beginning of the sewer's life it consisted of open-air channels lined up with bricks centered around

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1984-523: The Forum: if there was any drainage the distinction between the two was largely forgotten by the last century BC when it was referred to in the plural for both. Ancient authorities state that in this marshy area the roots of a fig tree ( Ficus Ruminalis ) caught and stopped the basket carrying Romulus and Remus as it floated along on the Tiber current. The place therefore has a high symbolic significance. It

2046-530: The Roman Empire, especially when combined with copious supplies of water from Roman aqueducts . The sewer system in Eboracum —the modern-day English city of York —was especially impressive and part of it still survives. [REDACTED] Media related to Cloaca Maxima at Wikimedia Commons Scaffolding Scaffolding , also called scaffold or staging , is a temporary structure used to support

2108-478: The braces are fitted to the ledgers they are called ledger braces. To limit sway a facade brace is fitted to the face of the scaffold every 30 metres or so at an angle of 35°-55° running right from the base to the top of the scaffold and fixed at every level. Of the couplers previously mentioned, right-angle couplers join ledgers or transoms to standards, putlog or single couplers join board bearing transoms to ledgers - Non-board bearing transoms should be fixed using

2170-561: The building or ground level to the scaffold such as gangway, stairs and ladder etc. Sloping catch fans shall be erected at a level close to the first floor and at no more than 15 metres, vertical intervals should give a minimum horizontal protection coverage of 1500 mm. Large catch fans should be erected at specific locations to protect the public and/or workers underneath. A suitable receptacle, covered with galvanized zinc sheet, should be provided within each catch-fan to trap falling objects. Steel brackets shall be provided for supporting

2232-439: The different nature of structures there is a variety of different ties to take advantage of the opportunities. Through ties are put through structure openings such as windows. A vertical inside tube crossing the opening is attached to the scaffold by a transom and a crossing horizontal tube on the outside called a bridle tube. The gaps between the tubes and the structure surfaces are packed or wedged with timber sections to ensure

2294-576: The director of Wui Fai Holdings, a member of the Hong Kong and Kowloon Scaffolders General Merchants Association. "They refuse to step in, although we give them high pay. They are scared of it. Young generations do not like jobs that involve hard work." Another reason fewer people are becoming scaffolders is that new recruits need to undergo training with the Hong Kong Construction Industry Council in order to acquire

2356-403: The early 20th century saw the introduction of tubular steel water pipes (instead of timber poles) with standardized dimensions, allowing for the industrial interchangeability of parts and improving the structural stability of the scaffold. The use of diagonal bracings also helped to improve stability, especially on tall buildings. The first frame system was brought to market by SGB in 1944 and

2418-613: The fittings which hold the tubes together. The most common are called scaffold couplers, and there are three basic types: right-angle couplers , putlog couplers and swivel couplers . To join tubes end-to-end joint pins (also called spigots) or sleeve couplers are used. Only right angle couplers and swivel couplers can be used to fix tube in a 'load-bearing connection'. Single couplers are not load-bearing couplers and have no design capacity. Other common scaffolding components include base plates, ladders , ropes , anchor ties, reveal ties, gin wheels, sheeting, etc. Most companies will adopt

2480-541: The main sewer all appear to be 'official' drains that would have served public toilets, bathhouses and other public buildings. The extraordinary greatness of the Roman Empire manifests itself above all in three things: the aqueducts, the paved roads, and the construction of the drains. Dionysius of Halicarnassus , Ant. Rom. 3.67.5 The Cloaca Maxima was large enough for "wagons loaded with hay to pass" according to Strabo . It could transport one million pounds of waste, water, and unwanted goods, which were dumped into

2542-410: The main transoms to provide extra support for boards. In Canada this style is referred to as "English". "American" has the transoms attached to the standards and is used less but has certain advantages in some situations. As well as the tubes at right angles there are cross braces to increase rigidity, these are placed diagonally from ledger to ledger, next to the standards to which they are fitted. If

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2604-523: The neighboring hills, that were channeled through the main Forum and then on to the Tiber. As building space within the city became more valuable, the drain was gradually built over. By the time of the late Roman Republic this sewer became the city's main storm drain . It developed into a system 1,600 meters long. By the time of the Second Century BCE it had a 101 meter long canal that

2666-462: The number of mosquitos, thereby limiting the spread of malaria by draining marshy areas. Animals, including rats, could find their way into the sewer. The Cloaca Maxima was a highly valued feat of engineering . It may have even been sacrosanct . Since the Romans viewed the movement of water to be sacred, the Cloaca Maxima may have had a religious significance. Aside from religious significance,

2728-473: The opening. The reveal tube is usually held in place by a reveal screw pin (an adjustable threaded bar) and protective packing at either end. A transom tie tube links the reveal tube to the scaffold. Reveal ties are not well regarded, they rely solely on friction and need regular checking so it is not recommended that more than half of all ties be reveal ties. If it is not possible to use a safe number of ties rakers can be used. These are single tubes attached to

2790-439: The past two decades, firms have had to look to Guangxi instead. The industry's fear is that one day supplies will be blocked due to export embargoes and environmental concerns. Attempts to import bamboo from Thailand , or switch to synthetic or plastic bamboo, have so far proved unsuccessful. In many African countries, notably Nigeria , bamboo scaffolding is still used for small scale construction in urban areas. In rural areas,

2852-577: The sewer, which could be traversed by canal at this point. Manholes were decorated with marble reliefs, and canals were made of Roman concrete and flint . The eleven aqueducts which supplied water to Rome by the 1st century AD were finally channeled into the sewers after having supplied many of the public baths such as the Baths of Diocletian and the Baths of Trajan , as well as the public fountains, imperial palaces and private houses. The continuous supply of running water helped to remove wastes and keep

2914-427: The sewers clear of obstructions. The best waters were reserved for potable drinking supplies, and the second quality waters would be used by the baths, the outfalls of which connected to the sewer network under the streets of the city. The Cloaca Maxima was well maintained throughout the life of the Roman Empire and even today drains rainwater and debris from the center of town, below the ancient Forum, Velabrum , and

2976-406: The spacing between ledgers, is 2 m, although the base lift can be up to 2.7 m. The diagram above also shows a kicker lift, which is just 150 mm or so above the ground. Transom spacing is determined by the thickness of the boards supported, 38 mm boards require a transom spacing of no more than 1.2 m while a 50 mm board can stand a transom spacing of 2.6 m and 63 mm boards can have

3038-419: The standard and revolutionised scaffolding, becoming the baseline for decades, was invented and marketed in the mid-1950s. With one basic 24 pound unit a scaffold of various sizes and heights could be assembled easily by a couple of labourers without the nuts or bolts previously needed. Tubes are usually made either of steel or aluminium . Composite scaffolding uses filament-wound tubes of glass fibre in

3100-502: The standard of scaffold at about six floor intervals. The horizontal distance between steel brackets is about 3 metres. Mild steel bars or similar materials are required to tie any structure to maintain the bamboo scaffold in its position on every floor. The distance of adjacent putlogs is about 3 to 4 metres. Every working platform must be at least 400 mm wide and closely boarded by planks. The edges of working platforms should be protected by no less than 2 horizontal bamboo members of

3162-591: The streets, swamps, and rivers near Rome. They were all carried out to the Tiber River by the sewer. It used gutters to collect rainwater, rubbish , and spillage , and conduits to dispense up to ten cubic meters of water per second. Vaults were closed with flat panels or rocks were used in the construction. This sewer used a trench wall to hold back sediments . Some of its water was still polluted , contaminating water many depended on for irrigation , swimming , bathing , and drinking . The sewer reduced

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3224-467: The structure to the ground where they rest on a square base plate to spread the load. The base plate has a shank in its centre to hold the tube and is sometimes pinned to a sole board . Ledgers are horizontal tubes which connect between the standards. Transoms rest upon the ledgers at right angles. Main transoms are placed next to the standards, they hold the standards in place and provide support for boards; intermediate transoms are those placed between

3286-510: The use of bamboo scaffolding for construction is common. In fact, bamboo is an essential building and construction commodity in Nigeria; the bamboo materials are transported on heavy trucks and trailers from rural areas (especially the tropical rain forest) to cities and the northern part of Nigeria. Some of the structures in relaxation and recreation centres, both in urban and rural areas of Nigeria, are put in place using bamboo materials. This

3348-505: The walls around the paleolithic cave paintings at Lascaux , suggest that a scaffold system was used for painting the ceiling, over 17,000 years ago. The Berlin Foundry Cup depicts scaffolding in ancient Greece (early 5th century BC). Egyptians, Nubians and Chinese are also recorded as having used scaffolding-like structures to build tall buildings. Early scaffolding was made of wood and secured with rope knots. Scaffolding

3410-403: The working platform, there are sole boards which are placed beneath the scaffolding if the surface is soft or otherwise suspect, although ordinary boards can also be used. Another solution, called a scaffpad, is made from a rubber base with a base plate moulded inside; these are desirable for use on uneven ground since they adapt, whereas sole boards may split and have to be replaced. Couplers are

3472-677: The world. Bamboo scaffolding was first introduced into the building industry in Hong Kong immediately after colonization in the 1800s. It was widely used in the building of houses and multi-story buildings (up to four stories high) prior to the development of metal scaffolding. It was also useful for short-term construction projects, such as framework for temporary sheds for Cantonese Opera performances. There are three types of scaffolding in Hong Kong: In 2013, there were 1,751 registered bamboo scaffolders and roughly 200 scaffolding companies in Hong Kong. The use of bamboo scaffolding

3534-560: Was also used as a marketplace and a centre of commerce , connecting the Palatine with the two major fora. Plautus ( Captivi 489) mentions it as a place where oil-sellers were found, and a scholiast (ancient commentator) on Horace ( Satires 2.3.229) states: "Velabrum is a place in Rome where everything connected with food and delicacies was on sale." Even after the Cloaca was built, the area

3596-413: Was covered up and expanded into a sewer. Pliny the Elder , writing in the late 1st century, describes the early Cloaca Maxima as "large enough to allow the passage of a wagon loaded with hay." Eventually, the sewer could not continue growing to keep up with the expanding city. Romans would discard waste through other openings rather than the sewers. From 31 BCE to 192 CE manholes could be used to access

3658-463: Was erected by individual firms with wildly varying standards and sizes. The process was revolutionized by Daniel Palmer Jones and David Henry Jones. Modern day scaffolding standards, practices and processes can be attributed to these men and their companies: Rapid Scaffold Tie Company Ltd, Tubular Scaffolding Company and Scaffolding Great Britain Ltd (SGB). David Henry Jones and Daniel Palmer Jones patented

3720-590: Was one of the world's earliest sewage systems . Its name is related to that of Cloacina , a Roman goddess . Built during either the Roman Kingdom or early Roman Republic , it was constructed in Ancient Rome in order to drain local marshes and remove waste from the city. It carried effluent to the River Tiber , which ran beside the city . The sewer started at the Forum Augustum and ended at

3782-720: Was still prone to flooding from the Tiber, until the ground level was raised after the Neronian fire. Within it were the tomb of Acca Larentia along with a small temple to Felicitas . It is also the site of the Arch of Janus , the Arcus Argentariorum and the church San Giorgio al Velabro . 41°53′21″N 12°28′55″E  /  41.8892°N 12.4819°E  / 41.8892; 12.4819 Cloaca Maxima The Cloaca Maxima ( Latin : Cloāca Maxima [kɫɔˈaːka ˈmaksɪma] , lit.   ' Greatest Sewer ' ) or, less often, Maxima Cloaca ,

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3844-403: Was used extensively for the postwar reconstruction . The European Standard, BS EN 12811-1, specifies performance requirements and methods of structural and general design for access and working scaffolds. Requirements given are for scaffold structures that rely on the adjacent structures for stability. In general these requirements also apply to other types of working scaffolds. The purpose of

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