Editing Tay Bridge (section)

==Second bridge==
===Proposals===
Almost immediately following the Tay Bridge failure, the North British Railway company began to develop plans for its reconstruction or replacement.<ref name = "fife pictor"/> During 1880, barely six months after the accident, the North British Railway (Tay Bridge) Bill for a construction of a new bridge was submitted to Parliament. The bill was reviewed by a special committee, chaired by [[Massey Lopes|Sir Lopes Massey Lopes, 3rd Baronet]]; Lopes drew attention to the substantial pressure for safety factors to be considered in light of the loss of the earlier bridge, including the need to examine the suitability of the location.<ref name = "fife pictor"/> In response to this inquiry, Mr Walker, the general manager of the North British Railway, stated his opinion that there was no more suitable site than what had been chosen, emphasising the relatively large interchange of traffic in the area and the importance of making the line as direct as practically possible. Additionally, a number of local witnesses, who included several leading merchants from Dundee, spoke favourably of the proposed location.<ref name = "fife pictor">[http://www.newportarchive.co.uk/Texts/millar_bridges.php "Fife Pictorial & Historical: Vol. II, A H Millar, 1895: pp. 287–295."] ''newportarchive.co.uk'', retrieved: 9 May 2018.</ref>

Plans for the reconstructed bridge were submitted by civil engineer [[James Brunlees|Sir James Brunlees]].<ref name = "fife pictor"/> His proposed design would have involved doubling the piers of the first bridge by installing the new columns on the east side of each of the existing piers, while arched brickwork would have been used to join the old and new elements alike. On top of these foundations, a brick decking would be laid that was wide enough to carry two sets of girders as well as a double-track layout.<ref name = "fife pictor"/> Brunlees proposed that the permanent way should be laid on the upper booms of the girders. The addition of bowstring girders, positioned {{convert|20|ft|m|abbr=}} high over the fairway, was considered to have much less exposure to the wind and greater lateral stiffness than the girders of the first bridge.<ref name = "fife pictor"/> The girders would also have been doubled, to be capable of resisting {{convert|200|lb|kg|abbr=}} to the square foot of wind pressure, while the piers as designed were to be capable of resisting a pressure of 900 lb per square foot. Overall, Brunlees' proposed structure would have possessed greater strength for resisting lateral pressure over the original.<ref name = "fife pictor"/> This proposal had an estimated total cost of £356,323. While it was carefully considered, the Board of Trade regarded the practice of connecting the old bridge to a new design to be dangerous. It rejected both the proposed design and the overall bill.<ref name = "fife pictor"/>

{{Infobox UK legislation
| short_title           = North British Railway (New Tay Viaduct) Act 1881
| type                  = Act
| parliament            = Parliament of the United Kingdom
| long_title            = An Act to provide for the restoration of the Railway communication across the Tay, near Dundee; and for other purposes.
| year                  = 1881
| citation              = [[44 & 45 Vict.]] c. cxxxvii
| introduced_commons    = 
| introduced_lords      = 
| territorial_extent    = 
| royal_assent          = 18 July 1881
| commencement          = 
| expiry_date           = 
| repeal_date           = 
| amends                = 
| replaces              = 
| amendments            = 
| repealing_legislation = 
| related_legislation   = 
| status                = 
| legislation_history   = 
| theyworkforyou        = 
| millbankhansard       = 
| original_text         = https://www.legislation.gov.uk/ukla/Vict/44-45/137/pdfs/ukla_18810137_en.pdf
| revised_text          = 
| use_new_UK-LEG        = 
| UK-LEG_title          = 
| collapsed             = yes
}}
The North British Railway, placing great importance on the connection between Fife and Forfarshire, was committed to developing a viable design.<ref name = "fife pictor"/> During August 1880, the noted railway engineer [[William Henry Barlow]], of Barlow & Sons, London, was consulted on the matter. Following experiments upon the first bridge's remains, Barlow gave his opinion that the intact portions should be abandoned in favour of a new structure spanning between the two shores.<ref name = "fife pictor"/> Adopting this as the basis of their next submission, a new bill was raised and put before a select committee of the [[House of Commons]] on 10 May 1881. With little alteration or suggestions issued, this was soon passed,<ref name = "fife pictor"/> becoming the '''{{visible anchor|North British Railway (New Tay Viaduct) Act 1881}}''' ([[44 & 45 Vict.]] c. cxxxvii). During November 1881, a contract for the new bridge's construction was awarded to [[Sir William Arrol & Co.|Messrs William Arrol & Co]] of Glasgow. For the new bridge's design, Messrs Barlow elected to refrain from using any untested engineering principles, instead choosing to strictly adhere to established methodology.<ref name = "fife pictor"/>

===Design details===
[[Image:Tay Rail Bridge and Signal Box Wormit 2.JPG|thumb|right|Tay Bridge and Signal Box Wormit]]
[[File:Crossing the Tay Rail Bridge (northwards looking east).webm|thumb|right|Video showing view from northbound passenger train crossing bridge towards Dundee. Camera pointing primarily eastwards. (Contains some flickering).]]
[[File:Train crossing Tay Bridge (June 2019).webm|thumb|right|Video showing train approaching the Dundee end of the bridge.]]

The second Tay Bridge is a straightforward pier-and-lattice girder bridge; aside from its considerable length, it lacks any distinguishing characteristics.<ref name = "fife pictor"/> It has an overall length of {{convert|10780|ft||abbr=}}, which is covered by a total of 85 spans. These spans are ordinary brick arches, backed by cement concrete and set on top of piers which are supported by pairs of columns.<ref name = "fife pictor"/> Wanting to avoid a repeat of the fate of the First Tay Bridge, a principal intention of the design is stability, followed in importance by measures to minimise the bridge's weight and the adoption of aesthetically pleasing shaping where possible without compromising on structural strength.<ref name = "fife pictor"/>

The piers, which are primarily built from brick and concrete, are enclosed by a [[wrought iron]] caisson up to the low-water mark, above which a brick exterior is used, which cannot be infiltrated by water.<ref name = "fife pictor"/> The submerged portions are cased with blue vitrified brick. Above the high-water mark, each pair of piers has a connecting masonry section, terminating at the superstructure's base.<ref name = "fife pictor"/> Due to the high proportion of masonry on the piers, they were extremely heavy, which meant that Messrs Barlow worked to minimise the structure's weight without the piers being weakened. As such, a graceful iron superstructure was adopted.<ref name = "fife pictor"/>

Above the brickwork, two firmly braced octagonal columns continued upwards to meet the inner members in the form of an arch.<ref name = "fife pictor"/> Other members were used to provide a bed for the girders to provide for substantial pier that took much of its weight away from the basal area. Since the Second Tay Bridge's completion, the lattice girder arrangement has become a commonplace feature, near-universally adopted for bridge construction.<ref name = "fife pictor"/> The configuration provides for a high levels of compression strain despite the girders being comparatively light. The decking is composed of steel and is surrounded both sides of the bridge by a closely knit latticework, which functions as a wind screen as well as somewhat protecting the workers.<ref name = "fife pictor"/>

===Construction===
On 9 March 1882, the work on the second bridge commenced, located {{convert|18|m}} upstream of, and parallel to, the original bridge.<ref name = "fife pictor"/> The first portions of the bridge to be erected were built upon the southern shore; work proceeded for some time before construction activities were initiated on the northern shore.<ref name = "fife pictor"/> Despite this, the majority of the bridge was erected simultaneously at both ends, continuing until the centre girders were connected and the junction was completed. Only some of the girders of the old bridge were reused for the new structure, and none were used without being subjected to considerable testing beforehand.<ref name = "fife pictor"/> It is believed that fourteen men died during the bridge's construction, most by drowning.{{Citation needed|date=May 2018}}

Large quantities of materials were used in the construction of the bridge. In terms of wrought iron, 16,300 tons were used for the piers and girders; if the 118 girders from the previous bridge are also included, the total weight is believed to amount to roughly 19,000 tons.<ref name = "fife pictor"/> 3,500 tons of steel was also used, while the cast iron elements of the piers weighs 2,500 tons, for a combined 25,000 tons of iron and steel having been used. Around 10 million bricks, possessing a combined weight of 37,500 tons, were used to build both the approaches to the bridge and the cylinders.<ref name = "fife pictor"/> The total weight of the concrete used is 70,000 tons. Additionally, the bridge contains around 3,000,000 [[rivet]]s.<ref name = "fife pictor"/><ref name="paint 2012">Shirres, David. [https://www.railengineer.uk/2012/11/05/painting-the-tay-bridge/ "Painting the Tay Bridge."] ''Rail Engineer'', 5 November 2012.</ref>

The estimated cost for the second bridge was £640,000 {{Inflation|UK|640000|1884|r=2|fmt=eq|cursign=£}} ; while this figure was overrun, it did not prove to have been overly optimistic. When the construction work is broken down, the founding of the piers was calculated as having cost £282,000, the installation of the girders and parapets £268,000, while £90,000 was involved in producing the approaches and arches.<ref name = "fife pictor"/> Some additional costs of roughly £16,000 had been incurred to improve the approach to the bridge from Newport; the branch line was reconstructed for a distance of half a mile eastward. When combined with the £350,000 cost of the first Tay Bridge, the North British Railway had spent roughly a million pounds to bridge the Tay.<ref name = "fife pictor"/>

===Operational use===
[[File:Dundee & Broughty Ferry RJD 26.jpg|thumb|right|A 1910 [[Railway Clearing House]] Junction Diagram showing the Tay Bridge and connecting lines, also the ferry connecting Tayport with Broughty Ferry]]
Prior to entering service, the completed structure was subjected to an extensive examination by inspectors working for the Board of Trade.<ref name = "fife pictor"/> Being keen to avoid a repeat of the disaster of the first Tay Bridge, the second bridge was subjected to stringent testing, which in some cases simulated conditions that were far in excess of any ever likely to be encountered during the entirety of its service life. According to the reports submitted, the results from this testing were satisfying, clearing the way for operational use.<ref name = "fife pictor"/> On 11 June 1887, the first passenger-carrying trains passed along the second Tay Bridge. On 20 June 1887, which also happened to be the 50th anniversary of Queen Victoria's accession, the bridge was opened for use by general traffic.<ref name = "fife pictor"/><ref>{{cite news |title=The opening of the Tay Bridge |work=Dundee Courier |date=20 June 1887}}</ref>

The second Tay Bridge has remained in use to the present day. To protect the structure from sustaining damage, the [[double-heading]] of locomotives is restricted on trains that traverse the bridge; it has been stipulated that some combinations of consecutive locomotives must be separated by at least {{convert|60|ft|m|sigfig=2}} using [[barrier vehicle|barrier]] or reach wagons.<ref name="drivers-manual">{{cite book|title=Company Train Drivers Guide |author=Operations Training |publisher=English Welsh and Scottish Railway |issue=1 |date=April 2005 |page=29 |quote=Over the Tay Bridge double heading is prohibited … if assistance is provided from the front … at least 60 feet must be provided between}}</ref>

During 2003, a £20.85&nbsp;million strengthening and refurbishment project on the bridge won the [[British Construction Industry Awards|British Construction Industry Civil Engineering Award]], in consideration of the staggering scale and logistics involved. More than {{convert|1000|MT|ST}} of bird droppings were scraped off the ironwork lattice of the bridge using hand tools, and bagged into {{convert|25|kg|adj=on}} sacks. At the same time, hundreds of thousands of [[rivet]]s were removed and replaced, all of which was being done by workers who were in exposed conditions while high over a [[firth]] with fast-running tides.{{Citation needed|date=May 2018}}