Overview Of Manchesters Castlefeild Viaducts History Essay

Overview Of Manchesters Castlefeild Viaducts History Essay The Castlefield viaducts form a part of the citys fascinating network of transport infrastructure, which includes canals, waterways, tram, rail and road. Starting from the period of their construction, these viaducts have been standing as a constant and dominating feature on the Manchester skyline. They are unique with respect to their historic significance and construction. Its stunning architectural beauty is beyond adequate description, particularly at dawn and sunset.   In the 20th century the viaducts underwent a dramatic renaissance, and they were brought back into productive use and glory. Though time and lack of substantive maintenance are inciting threats to the life and beauty of the structure, they are in surprisingly good condition given their age. Proper maintenance and replacements will slow down the deterioration process of the structure. This report covers the structural, historical and architectural significance of the Castlefield viaducts. It highlights how the ageing infrastructures of the viaducts were effectively transformed to a landmark structure of the modern era. The restoration of the viaducts has given a dramatic revival to the Castlefield area, thus making use of the previously disfunctional structure. Thus our aim is to stress the importance of conserving the antiquated structures by making use of the scientific and technical knowledge gained through the ages. CONTENTS LIST OF FIGURES Figure Description Source Cover image Castlefield viaducts in 2010 Photograph supplied by author 1.1 Castlefield viaducts in 1890 Waterways into Castlefield, John C Fletcher 1.2 Castlefield viaducts: An aerial view www.webbaviation.uk 1.3 Castlefield viaducts in 1892 A walk round Castlefield, Derek Brumhead and Terry Wyke 2.1 Roman fort of Mamucium www.bbc.co.uk 2.2 Castlefield excavations A walk round Castlefield, Derek Brumhead and Terry Wyke 2.3 Cornbrook and Great Northern viaducts www.panoramio.com 2.4 Northern Brick viaduct www.panoramio.com 2.5 Flowchart showing birth history of viaducts Drawing supplied by the author 4.1 Botanical growth on the corners of the viaduct www.forgottenrelics.co.uk 4.2 Use of cherry pickers in removing corrosion www.forgottenrelics.co.uk 4.3 Breakage and corrosion of iron sections www.forgottenrelics.co.uk 6.1 Architectural beauty of viaducts www.creativity103.com 6.2 Economical use of spaces beneath the brick arches of the viaduct Drawings supplied by the author A.1.1 Great Northern viaduct :picture from past www.canalarchieve.org.uk A.1.2 Great Northern viaduct: present picture http://manchesterhistory.net A.2.1 Northern Brick viaduct: picture from past www.canalarchieve.org.uk A.2.2 Northern Brick viaduct: present picture http://manchesterhistory.net A.3.1 Iron columns of the viaduct: picture from past www.canalarchieve.org.uk A.3.2 Iron columns of the viaduct: present picture www.barrymillerphotographics.co.uk A.4.1 Cast-iron arch of viaduct: picture from past www.canalarchieve.org.uk A.4.2 Cast-iron arch of viaduct: present picture www.engineering-timelines.com B.1 Plan of Castlefield in 1905 A walk round Castlefield, Derek Brumhead and Terry Wyke B.2 Plan of Castlefield in 1988 Waterways into Castlefield, John C Fletcher B.3 Aerial photograph of Castlefield by Paul Tomlin Waterways into Castlefield, John C Fletcher B.4 Plan and section of the junction between the Manchester and Birmingham and Liverpool and Manchester Railways. www.freepages.com 1. INTRODUCTION The Castlefield viaducts are the excellent examples of 19th century attitude to engineering. Their heroic brute scale is romanticised by the castellalated turrets adorning the structure. The name Castlefield is a short form of field of the castle or fort. Castlefield  is an  inner city  area of  Manchester, in  North West England. It is arguably one of the most historically important areas in the world. Innovations have proliferated here and many artefacts have been constructed. In 79 AD the Romans built their fort on elevated ground, and canals were dug to allow natural watercourses to be diverted to mountain water levels. The worlds very first railway station was introduced in Castlefield in 1830, to allow the first rail transportation of coal as canal basins were so numerous that the only practical means of utilising railway transport was to build viaducts. C:UsersreminDesktopDSC01024.JPG Figure 1.1: Castlefield viaducts in1890 Castlefield is conspicuous by its viaducts and its canals. The viaducts have become an indelible part of the landscape, valued and treasured as part of Manchesters industrial heritage. The fact of increasing the efficiency of transportation, paved way for the construction of the Castlefield viaducts. Gradually plans were evolved not only to conserve the area but also to promote leisure and tourism. C:UsersreminDesktopcourse workbridge-castlefield-c8675.jpg Figure 1.2: Castlefield viaducts: An aerial view During the 20th century both canal and railway transport declined and the area became somewhat derelict. The railway complex in Liverpool Road was sold to a conservation group and became the  Greater Manchester Museum of Science and Industry. C:UsersreminDesktopDSC01036.JPG Figure 1.3: Castlefield viaducts in 1892 2. HISTORIC RESEARCH 2.1. BRIEF DESCRIPTION OF SITE AND STRUCTURE Castlefield is the site of the original Roman fort of Mamucium or Mamceaster (mam from the Celtic name for hill and ceaster derived from the Latin word for a walled town). The fort was about five acres in size and guarded important route ways to and from Chester, York and the Chesire salt wiches. The roads, railways and canals of the Industrial Revolution destroyed most of the surface remains of the fort and the vicus. The price of coal was halved, making steam power commercially viable. The Rochdale Canal and a network of private branch canals joined the Bridgewater at Lock 92 in Castlefield. The Bridgewater Canal company  connected their canal to the adjacent Mersey and Irwell Navigation and the Rochdale Canal Company  constructed its Manchester and Salford Junction Canal. Figure 2.2 Castlefield excavations Figure 2.1 Roman fort of Mamucium Artists impression of Roman Mamucium (c) Graham Sumner C:UsersreminDesktopDSC01034.JPG As new railway companies needed to access the city centre through largely built-up areas, only one option lay open to them the building of viaducts to carry traffic over the city. The railway lines the central cast iron arch of the Manchester South Junction Altrincham 1848 viaduct, with 1877 wrought iron Cheshire Lines Cornbrook viaduct obscured, and the massive piers of the 1894 disused Great Northern Viaduct behind constructed over the course of half-a-century provided leading railway companies with the access to the city centre. These viaducts provided a splendid solution illustration to the problem of carrying a railway across the city. The townscape of southern Manchester was given a new transformation by the railway and the Castlefield viaducts. In fact these viaducts are still the engineering beauties of Manchester especially Castlefield. C:UsersreminDesktopphotos1.jpg Figure 2.3.Cornbrook and Great Northern viaducts C:UsersreminDesktopphotos2.jpg Figure 2.4: Northern Brick viaduct 2.2. BIRTH OF CASTLEFIELD VIADUCTS The arrival of the Bridgewater Canal in Castlefield in July 1761 led to a series of developments which eventually caused the construction of the Castlefield viaducts. These developments are indicated pictorially as shown below. Arrival of the Bridgewater Canal (marked Industrial Revolution) Joining of the Rochdale Canal and other private canals with the Bridgewater Canal Construction of warehouses and storehouses prompted the need for accessing city centre Decrease in the price of coal gave the idea of constructing railway lines for transportation. Construction of the Castlefield viaducts for enabling railway transportation Figure 2.5 Flowchart showing birth history of viaducts 3. STRUCTURAL OVERVIEW ORIGINAL STRUCTURE The cast iron arch railway bridge over the wharves by the Bridgewater Canal at Castlefield forms part of the long brick viaduct taking the Altrincham branch of the Manchester South Junction Altrincham Railway (MSJAR) into Deansgate Station. The MSJAR was Manchesters first suburban line. It ran from Manchester Piccadilly via Oxford Road and Deansgate (with a branch line to Altrincham). The bridge spans 31.9m. Like eight of its siblings (the exception being the Water Street MSJAR bridge), it has six cast iron ribs each made in five pieces and bolted together. The ribs are braced with cruciform cast iron sections. The twin railway tracks were carried on cast iron deck plates (the Altrincham line is no longer in use).The Altrincham branch viaduct had a second cast iron rib arch bridge by Baker, over Egerton Street. It was reconstructed in steel in 1976. The Northern Brick viaduct is entirely elevated on more than 2 miles of viaduct. Most of this viaduct comprises 224 brick arches, averaging 30feet in height and span, and 28feet in width. Foundations typically extend 30-35feet below the ground level. Near Ordsall Lane the railway crosses the Irwell with two much longer 65feet span brick arches, supported by a pillar in the middle of the river. A brick arch with a span of 80feet was required to bridge the canal branch. Supplementing the brick arches, the cast-iron bridges cross 26 streets and canals. Originally, flat-girder bridges were ear marked for these sections of the viaduct, but when an example of this type of bridge collapsed under a train in Chester in May 1847 the plans were altered amid safety doubts. In total, 28 cast-iron bridge sections were required (three at Knott Mill), all of them spanning 70ft, except for the example over the Rochdale Canal which spans 105ft. The bridges were obtained by engineer David Bell house from the foundries of E.T. Bell house. On the viaducts south side is the high-level iron truss girder viaduct of 1877 built for the  Cheshire Lines Committee by the  Midland Railway. It is known as Cornbrook Viaduct. The viaduct is a red brick and  wrought iron  truss girder construction. Building work started in 1873 and was completed in 1877. When it opened in 1877, it carried trains coming from a temporary station to  Irlam  and  Warrington, and  Chorlton  via a branch line. The temporary station was replaced by  Sir John Fowlers Manchester  Central Station  in 1880, which operated until 1969 and is now used as an exhibition centre (G-MEX). The through lattice girder design, predominantly of wrought iron, is around 330m in length, comprising eight spans. Formed from segmental castings and founded at a depth of 6.1m, the piers diameter tapers from 4.6m at their base to 3.2m at ground level. They are concrete-filled and tied to their neighbour by a girder dealing with lateral forces. Behind decorative castellation, bearing plates support the heavy end posts of 16 trusses, the longest of which reaches 53m. Each pair is restrained by brace beams at 6.4m centres. Span 7 is acutely trapezoidal, allowing span 8 to cross the Ordsall Lane line on a skew of around 65 ° its southern truss benefits from an additional orphaned column. The bottom chord of each truss forms a channel. The transverse bearers hold the deck plates and ribs to which the running rails are fastened. To the north is the 1894 Great Northern viaduct that served the  Great Northern Railways (GNR) warehouse. The high-level  tubular steel  viaduct is decorated with turrets. It was built for the Great Northern Railway Company and carried GNR trains to the companys Deansgate warehouse until 1963. Richard Johnson was a Chief Engineer of the GNR. The Cornbrook and Great Northern viaducts stood disused for many years. When a route for the  Metrolink  trams was investigated, the Cornbrook Viaduct was found to be in much better condition than the 1894 one. It was chosen for refurbishment (1990-1991) and is currently used by Metrolink trams going to Altrincham. During the regeneration of the Castlefield basin, a spectacular footbridge was built from Slate Wharf to Catalan Square. This is the Merchants Bridge, where the 3m wide deck is hung by 13 hangers from the steel arches. The span is 40m. The designers,  Whitby and Bird  acknowledge the influence of  Santiago Calatrava. The three viaducts passed right through the ancient Roman site, virtually obliterating it, as the opening of the Rochdale Canal had already destroyed much of it, as well as the old town of Aldport. Except the Great Northern viaduct all the other viaducts are still in use. The Great northern viaduct is now offered for sale. 3.2. FUNCTION The Northern Brick viaduct carried the double tracks between Manchester Piccadilly via Oxford Road railway station and Knott Mill railway station, then turns south west, crossed the canal basin and headed for Altrincham.   It forms part of the long brick viaduct taking the Altrincham branch of the Manchester South Junction Altrincham Railway through Knott Mill Station. The Cornbrook viaduct is carried across Castlefield Basin on huge castellated brick piers and where it crosses the Bridgewater Canal an immense bridge of lattice girders was constructed with twin spans of 44 metres and 62 metres. It carried trains coming from a temporary station to Irlam and Warrington, and Chorlton via a branch line. At present 15 trams per hour (tph) use the Cornbrook viaduct which has fixed block two aspect signalling. When Phase 3a of the development process is complete, there will be 25 tph along the Cornbrook Viaduct. The Great Northern viaduct served the  Great Northern Railways warehouse i n Deansgate by carrying GNR trains to the companys warehouse until 1963. 3.3. CONSTRUCTION MATERIALS AND TECHNOLOGY The Northern Brick viaduct in the group of Castlefield viaducts and its impressive cast iron arch bridge was designed by  David Bellhouse and William Baker respectively. This is the largest cast iron arch bridge in the Castlefield area with a span of 104 feet. Each of the six cast iron ribs are made in five pieces and bolted together. They are braced with cruciform cast iron sections and the twin railway tracks were carried on cast iron deck plates. The project was a very large one, at least in terms of material: 300,000 cubic feet of stone 50,000,000 bricks and 3,000 tons of wrought iron. The ground was broken for the new line early in 1846. Subsequently, the railway ran into some financial difficulties that delayed work for about 18 months so that the railway was not completed until 1849. Brick arches were constructed by laying the bricks and mortar over scaffolding, which would maintain the arch shape until the mortar had set and the form was self-supporting. This scaffolding was usually left in place for two to three weeks after the brickwork had been completed. However, in January 1849 a section of the viaduct near Gloucester Street, just to the west of Oxford Road station, collapsed upon removal of the supporting scaffolding, killing several workers. An inquest revealed that wet weather had caused the mortar to set more slowly than anticipated. As a consequence, the scaffolding was left in place for longer periods, especially during the inclement winter months. No other major accidents occurred during the rest of the MSJARs construction. Red brick and  wrought iron  form the major raw materials for the construction of The Cornbrook Viaduct. The Great Northern viaduct makes use of tubular steel construction. Decorative fittings in the form of small towers rising above and resting on the main structure adds beauty to the viaduct. 4. RESTORATION 4.1. WAY TO RESTORATION The restoration of the Castlefield viaducts gave a dramatic revival to the area, with the viaducts being brought back into productive use. The Annual Report on Built Heritage, 2006/07 categorised the Castlefield viaducts into Grade II, which indicated that the structure is of special interest, warranting every effort to preserve them. Castlefields ageing infrastructure of the 1800s has been revived and in its place is one of Europes leading city break destinations, with some of the best shopping and most vibrant nightlife in the world.   By the 1970s the Castlefield area was decaying rapidly and was typical of many of the areas on the fringe of the city centre. In the early 1970s, excavations uncovered part of the site of the Roman fort. The process of removing the extensive, waist-high vegetation from the deck was relatively straightforward. Far more challenging has been the subsequent descaling work, ridding the viaduct of its loose material with hammers and scrapers. The abseil operation is self-contained, with collection bags and catch nets ensuring nothing falls to the ground. Progressing from west to east, the five spans of the first phase took place. But remaining phases were logistically more complex. The imaginative and sensitive conservation of the viaducts was to be achieved with high standards of urban design. When the Great Northern Railway Goods Warehouse was erected in 1898, the viaduct was widened on the north side to take four tracks, and a new spur built across Deansgate. The second cast iron rib arch bridge of the Altrincham branch viaduct was reconstructed in steel in 1976. The CLC Viaduct from Manchester Central Station to Cornbrook Junction was originally built as a two track viaduct then later widened to carry five tracks. Since the Cornbrook Viaduct was in much better condition compared to the Great Northern Viaduct, it was chosen for refurbishment in the year 1990 for a route for the  Metrolink  trams. It is currently used by Metrolink trams going to Altrincham. Central Station closed in 1969 and the viaduct was unused, except for business premises in the arches, until repaired and converted for Metrolink which opened in 1992. Repairs included pointing some 70,000 square metres of brickwork and replacing many thousands of spalled and missing bricks. Metal widening was strengthened by concrete encapsulation and local plating repairs where required. After the structural repairs had been completed the metalwork was grit blasted and painted to protect it. Corrosion damage caused by breakdown of the waterproofing system was repaired. Where needed main girder ends were encapsulated in a reinforced concrete diaphragm beam supported on new bearings. Other bearings were freed by drilling and injecting grease. The entire structure of Castlefield Bridge was lifted by 75mm as part of the work on its bearings. This improved headroom will allow future 25kV electrification of the Network Rail line from the railway Castlefield Junction, near Deansgate Station, to Ordsall Lane Junction. Subject to funding, plans are being developed for a major refurbishment to happen in 2012/13, involving a waterproofing exercise and miscellaneous repairs to restore some durability. The major challenge is to completely encapsulate the structure. The paintwork has to be restored- which seems to have been brush-applied in a single coat and causing considerable corrosion. It is important to remove the vegetation which has secured a foothold on the underside of the structure where much of the ironwork never gets the opportunity to dry. Adequate measures should be adopted to remove the blockages within the drainage system. Clearing debris from the trusses bottom chord and thereby allowing them to drain should be also given priority. 4.2. PRESENT CONDITION Though the Castlefield viaducts have given the city some of its most dramatic spaces, some limited drawbacks can be cited in relevance to the present day construction owing to the ageing infrastructure of the 1800s. One of the most important among them is the effect of corroding metallic surface. The forged bolts and fittings have become rusted. The damp conditions have been more conducive to corrosion. Periodic inspection and removal of huge amount of loose material from the corroded surface is required. The construction gave the bottom chord of truss a trough shape, which gets covered by water during rains. These corrosive water traps pose an attention seeking problem. The steelwork of the supporting columns has peeling paint and patches of rust. The iron layers have got broken at intervals.   There are evidences of staining and efflorescence and botanical growth due to the seepage of water through the brick joints. The younger but sicklier northern viaduct remains devoid of func tion except for its iconic role in the cityscape and frequent on-screen appearances. 4.3. REMEDIAL MEASURES Time and a lack of substantive maintenance and Manchesters notorious weather have not been kind to the structure. The observations confirmed that loose corrosion product was falling from the structure. The botanical growth and vegetation should be removed from the structure. Another significant maintenance work to be carried out is the descaling work. The viaducts should be made devoid of its loose material with hammers and scrapers. Descaling could be done more easily with the use of cherry pickers. The piers and soffits should be cleared and protective coatings should be applied. The iron sections should be inspected for breakages and necessary replacements should be done at intervals. Measures should be adopted to ensure waterproofing effect at the critical sections. http://www.forgottenrelics.co.uk/bridges/images/castlefield/castlefield-7.jpg http://www.forgottenrelics.co.uk/bridges/images/castlefield/castlefield-1.jpg Figure 4.2: Use of cherry pickers in removing corrosion Figure 4.1: Botanical growth on the corners of the viaduct C:UsersreminDesktopcourse workcs cwphotos9.jpg http://www.forgottenrelics.co.uk/bridges/images/castlefield/castlefield-4.jpg Figure 4.3: Breakage and corrosion of iron sections 5. PEOPLE AND ORGANISATIONS INVOLVED 5.1 DAVID BELLHOUSE (1792à ¢Ã¢â€š ¬Ã‚ 1866) David Bellhouse (junior) was the contractor for the construction of the Northern brick viaduct, which was completed in 1849. Bellhouse hailed from a family rich in construction and business experience. His father David Bellhouse (senior), (1764-1840) was a skilled joiner and builder. David Bellhouse (junior) started his career by erecting warehouses, mills and public buildings. During 1830, he built 5 brick warehouses for Manchester and Liverpool railway at the Liverpool road station in Manchester, the worlds first railway station. Later he took advantage of the rising railway boom due to industrial revolution and concentrated his work within Manchester and surrounding area. In 1845, Bellhouse got the contract to build the mile and three quarter long Manchester South Junction Railway. The viaduct passed very near the Bellhouse family businesses, both the timber yard and the cotton mill. In addition to building the viaduct and laying the track, Bellhouse was responsible for the purchase and demolition of buildings on the proposed site of the line, the alteration and diversion of streets. The track was laid on a thirty-foot-high arched viaduct through a densely populated part of Manchester. The railway was finally completed in 1849. The viaduct is still in operation today. Other prominent projects constructed by Bellhouse include Chorlton on Medlock Town Hall and Dispensary Exhibition house of the Manchester Botanical and Horticultural Society The Palatine Hotel Manchester Poor Law Union Moral and Industrial Training School WILLIAM BAKER (1817-1878) William Baker was a railway engineer. He designed the Northern brick viaduct, Castlefield. He started his career in 1834 at the  London and Birmingham Railway  between London and  Tring. In 1837, he worked for the  Manchester and Birmingham Railway. Later he became engineer of the  Manchester, South Junction and Altrincham Railway (MSJAR). Eventually, he was appointed as the chief engineer of the London and North Western Railway Company. He wholly constructed, or remodelled and extended, the stations of the company in London, Liverpool and Manchester, as well as the stations in Birmingham, Preston, Bolton, Crewe, Warrington and Stafford.  Baker was designer and engineer of the  Battersea Railway Bridge.  He also acted as consulting engineer to the West London Extension Railway and the  North London Railway, and in Ireland he built the Dundalk, Newry and Greenore and the North Wall Extension Railways. He was elected  MICE  in 1848. THE  CHESHIRE LINES COMMITTEE  (CLC) The  Cheshire Lines Committee  (CLC), with a route mileage of 143 miles, was the second largest  joint railway  in Great Britain. The Cheshire Lines group was formed by a joint committee of the  Great Northern Railway  (GNR), Midland railway (MR) and the  Manchester, Sheffield and Lincolnshire Railway  (MSLR) in 1862 to regulate traffic on four proposed lines in  Cheshire The Stockport Woodley Junction Railway The West Cheshire Railway The Cheshire Midland Railway The Stockport, Timperley Altringham Junction Railway There was also a decision to open important series of lines and junctions around the south of Manchester and Stockport, which provided valuable access with other railways. In 1873, Premier main line between Manchester and Liverpool opened. Shortly Liverpool central was opened. The committee studied the need of an independent terminus at Manchester. As a result, they constructed Manchester central and a new 2 track viaduct from Cornbrook to central station. There was significant passenger and goods traffic between Liverpool and Manchester during this period. The second major route, which the CLC operated, was between Manchester and Chester. Even today, the CLC line between Manchester and Liverpool is the quickest route between the cities, but are utilising Piccadilly and Lime Street stations, respectively. 5.4 RICHARD JOHNSON (1827-1924) Richard Johnson was apprenticed to a builder and contractor as a carpenter in 1840. In October 1847 he was appointed to the staff of Brydone Evans, engineers to the GNR. In 1855 he was appointed District Engineer to the GNR loop line with an office in Boston and in 1859 he became responsible for the direct Peterborough to Doncaster line. In June 1861 he became Engineer for the GNR when Mr Walter Marr Brydone retired (with Joseph Cubitt as Consulting Engineer). He observed the Welwyn tunnel accident and fire. He was in charge of constructing the Derbyshire Extension Railways, notably the viaduct at Ilkeston over old coal workings, the curved viaduct at Gilbrook, and the long Kimberley cutting. He was also involved in the Newark Dyke Bridge, the Don Bridge, the Copenhagen tunnels, and the bridge over the GER at Peterborough. Richard Johnson was the Chief Engineer of the GNR and was responsible for the design of Great Northern viaduct of Castlefield, which was constructed in 1894. He d ied in Hitchin on 9 September 1924. HENRY HEMBEROW Henry Hemberow was an engineer by profession and was appointed as Resident Engineer working under the supervision of Mr. William Baker for the construction of the MSJAR. His direct involvement in any design works is not known. It is also not known if he had any direct contributions to the Castlefield viaducts in particular. The lack of information found about him during research may suggest that the impact he made in his role here and in his career as an Engineer, was not as significant as others of his time. 6. SIGNIFICANCE OF THE STRUCTURE In the 20th century Castlefield underwent a dramatic renaissance, with many historical buildings being brought back into productive use and glory. The Castlefield viaduct provides a strong contrast to these new structures, portraying the areas rich heritage and its prominence as the birthplace of the industrial revolution. 6.1 ECONOMICAL SIGNIFICANCE The Castlefield Viaducts are of fundamental importance to the infrastructure of the area. Historically they functioned as a link for the transport of goods to the industrial centre. They are now a part of the citys efficient network of transport infrastructure, which includes canals, waterways, trams, rail and road. The viaducts dramatically transformed the scale and visibility of urban exchange of the area, without disrupting the natural landscape and long established built-in environments. They are centrally located at one of Manchesters most successful regeneration areas in recent decades. The viaducts play a significant role in strengthening the tourism base, consolidating and supporting business activity. A vibrant residential community has been established. The rapid growth of commerce and population gave rise to further renovations of the structure. 6.2. ARCHITECTURAL SIGNIFICANCE The Castlefield Viaducts are reminders of Manchester citys bold and distinguished Victorian era architecture. At sunset, the viaducts cast quite remarkable geometric shadows across the arena and over Castlefield, which is a beautiful sight and adds to the cultural feel of the area.  The viaducts provide a dynamic viewpoint for the whole of Castlefield. Through the reconfiguration and reuse of this previously disfunctional infrastructure, this area was the most visible expression of the existence of the Central Manchester development corporation between 1987 and 1997, although its gentrification has produced a lessening of the dramatic impact of the original host structure. As the backbone of the city the Castlefield viaducts have been a continual part of Manchesters regeneration, as well as its history. They are aesthetically distinctive and have landmark qualities.   Figure 6.1: Architectural beauty of the viaducts http://t1.gstatic.com/images?q=tbn:ANd9GcT6-1ZWzByHny9hPzslsIvlZmH_Mppe8by6Ym-2Uc3xwyYRtEUt=1usg=__5iZaJ3v6ohnr-SeLY92OoiLGXl8= Figure 6.2: Economical use of spaces beneath the brick arches of the viaduct http://t2.gstatic.com/images?q=tbn:ANd9GcT7Tk1yhTqk7MNltiVHnmZMMZw6Aa_s286FhXyyfkbX-VKC_hkt=1usg=__L2CIQTAEsSpRfjkObWnxa86aC2Q= 6.3. SIGNIFICANCE IN RELATION TO CONSTRUCTION INDUSTRY The Castlefield viaducts were the first of their type, and consequently are vital artefacts in the history of Manchester and the railways. They are noteworthy for both their design and size. One of the arches of the viaduct, the arch over the branch canal at Castlefield, had a span that was unus