Talk:Through arch bridge

Early comments

I have attempted to clean up this stub a little bit. I could not rescue this passage, as I don't know what it is attempting to communicate:

"Where the arch cannot neither supported from below nor brought to completion by flying cantilevers it is brought out from each landing point using temporary cable stays supported from temporary towers, kept from tipping inward by stays downward to earth anchors."

Perhaps someone with some civil engineering knowledge can edit it appropriately. Molinari 03:15, 11 Feb 2005 (UTC)

This doesn't seem to be a very common term for a common type of bridge. Through arch bridge seems slightly better but still uncommon. Any ideas? --SPUI (T - C) 10:00, 25 May 2006 (UTC)

Hi everyone. I prefer the name through arch over compression arch suspended span. On the issue of combining this article with tied arch bridge, I'm against it. While a tied (or bowstring) arch bridge is a through arch, not all through arches are tied arches. A tied arch (such as the Fort Pitt Bridge) uses the deck as a tension element, to keep the arch from collapsing, while an untied arch (such as the Sydney Harbour Bridge) uses the ground (and sometimes the rigidity of its truss structure) to counter the outward horizontal thrust of the arch. Robshill 19:47, 26 May 2006 (UTC)

A tied arch could be considered a subtype of suspended deck type, since it is possible to use compression in the arch without tension in the suspended deck. Also, wouldn't a through arch bridge be another type than suspended deck (the roadbead supported by and running between the arches)? - Leonard G. 15:47, 11 July 2006 (UTC)

Tied Arch

I do not know what the fuss is about. The tied arch is completely different in how it is supported as compared to the compression arch (although all arches do act in compression). The compression arch suggests that the earth is the horizontal reaction force of the arch, while the tie suggests that the arch resists its own force. They should not be combined as one type.

Where did this name come from?

Where did the name "compression arch suspended-deck bridge" come from? I cannot find any references for it.

• A search of ASCE's civil engineering database (journals, proceedings, magazines) does not show the string in use (here).
• A search of google books now turns up circular references back to Wikipedia as Webster's is now sourcing Wikpedia when writing a lexicon (here).
• Google scholar only shows two papers (here). They are both by students who source their material to websites (including Wikipedia).

I have researched this and can only conclude that the term is not in use by bridge engineers. That means that this term does not meet WP:Verifiability. Bridge engineering is technical subject that has had textbooks and peer-reviewed papers published for more than a century. We should be able to find sources for terms that meet the highest standards of WP:Reliable sources. My recommendation is that this article be moved to steel arch. It can be put in categories for Category:Steel arch bridges and Category:Through arch bridges. - ¢Spender1983 (talk) 03:39, 6 April 2009 (UTC)

Here is a source to define the term through arch. - ¢Spender1983 (talk) 01:01, 9 April 2009 (UTC)

• Tonias, Demetrios E. (1994). Bridge Engineering (Google books). McGraw-Hill Professional. p. 14. ISBN 9780070650732. Retrieved 2009-04-08. When the deck is suspended from the steel arch, the structure is called a through arch. {{cite book}}: Cite has empty unknown parameter: |1= (help)

This is what happens when a Wikipedia article uses a made up term. The circular references begin, until Wikipedia's invention takes over other sources! (I had noticed elsewhere that Websters Online uses material from Wikipedia.) I also have been wondering where this term originated. Through arch redirects to this article. —Mattisse (Talk) 01:08, 9 April 2009 (UTC)

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Another one supporting through truss through arch; it does not mention "compression arch suspended-deck bridge". This is the first I have heard of a "sickle arch".

• Bennett, David (1999). The Creation of Bridges (Google books snippet view). Aurum Press. p. 74. ISBN 9781854106513. Retrieved 2009-04-12. There is the through arch, sometimes called a "sickle arch," where part of the bridge deck is suspended from the arch and part of it is supported by columns from below.

On the plus for reliability, the author is a chartered engineer. The publisher (Aurum Press) has been in business since 1976. Not a long time in technical terms, but not "fly by night" either. - ¢Spender1983 (talk) 04:21, 12 April 2009 (UTC)

• And Through truss now redirects to Truss bridge. —Mattisse (Talk) 15:00, 12 April 2009 (UTC)

Sorry, I meant through arch. That's what the quote from the book uses. - ¢Spender1983 (talk) 18:44, 12 April 2009 (UTC)

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Another source validating "deck arch bridge," "through arch bridge," and "half-through arch bridge" as types of bridges, but not validating "compression arch suspended-deck bridge".

• Troyano, Leonardo Fernandez (2003). Bridge Engineering: A Global Perspective (Google books (limited preview)). Thomas Telford. p. 274. ISBN 9780727732156. Retrieved 2009-04-12.

There are three types of arch depending on the position of the gradient to the arch:

• The bridge with an upper deck (deck arch bridge) has the deck above the arch; most arch and all stone bridges are like this.
• The bridge with an intermediate deck (half-through arch bridge) has the deck at an intermiediate height between the springings and the crown of the arch. In order not to invade the carriageway, the latter has to divide into two side rings or be located in the middle; the deck will be suspended from it in the central area and will be supported on it at the ends.
• The bridge with a lower deck, which can also be called upper arch (through arch bridge) has the deck at the height of the springings. … The deck is generally suspended from the arch with suspenders, which are tension elements and as such do not require rigidity; they are made in most bridges with cables.

Leoardo Troyano, Bridge Engineering: A Global Perspective

I am still unable to locate any bridge engineering books that verify the term compression arch suspended-deck bridge. - ¢Spender1983 (talk) 05:03, 12 April 2009 (UTC)

• Then there is Truss arch bridge. —Mattisse (Talk) 15:06, 12 April 2009 (UTC)

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This book The Manual of Bridge Engineering has a long chapter on arch bridges. It does not mention the "compression arch suspended-deck bridge" as a type of arch bridge. - ¢Spender1983 (talk) 03:45, 5 May 2009 (UTC)

RfC: the name "Compression arch suspended-deck bridge"

I have done some research (as seen above on this talk page) that leads me to believe that the term "Compression arch suspended-deck bridge" is not a real term. The term dates back to July 2004 when it was added to the bridge article. Now it can be found to have spread around the internet.
Bridge design is a highly technical, well-published field of science. One should be able to find a reliable, scholarly source that defines or uses this term. I have not been able to do this.
I am requesting comment because I would like some help to find out if this term is for real or if it should be removed from Wikipedia. -- ¢Spender1983 (talk) 08:04, 15 November 2009 (UTC)

I'm not an engineer, but it seems like nonsense to me. Look e.g. of the picture of the Sydney Harbour Bridge being built. If the arch relies on compression to stay up it could not be built like that. That's not to say there's no compression, but there will be both compression and tension, just as in a truss bridge, made possible by the use of steel. The advantage of modern materials is bridges no longer have to be just under compression, so a far greater range of structures are possible. To describe the arch in these bridges as a "compression arch" just seems wrong, perhaps a misapplication of how bridges used to be made.

The term "through arch" seems correct, but has nothing to do with compression. See e.g. [here]. If the page were renamed to that and the bits about compression removed it would make sense to me. JohnBlackburne (talk) 19:26, 8 December 2009 (UTC)

As no-one else has come up with anything I've renamed the page to "Through arch bridge". Unlike the former name it has at least some support and also seems to match how the names used already here, based on existing redirects. The previous name was not only unsourced but misleading as a bridge like this is not held up by compression, or at least not primarily by it. --JohnBlackburne^words_deeds 07:46, 12 January 2010 (UTC)

I've added a reference and a couple of alternate names which I came across in searching. Although it seems to be a type of bridge, or at least a way of describing them, it does not seem to have a single name, and hopefully the other names will help editors find references.--JohnBlackburne^words_deeds 08:01, 12 January 2010 (UTC)

Shouldn't Compression arch suspended-deck bridge be deleted? There are many articles that link to it, and we can fix that. But if it has been determined that it is not a legitimate term then it should be deleted so it that future attempts to link to it show up as red links. - ¢Spender1983 (talk) 06:28, 13 January 2010 (UTC)

I wouldn't delete the redirect, at least not yet and perhaps not ever. But if we're correct that "Compression arch suspended-deck bridge" is a made up term that arose on WP then it may need cleaning up so any references to it, or at least all those in articles, are changed to a more acceptable name. Here are all the pages that link to the redirect which would be a good place to start. --JohnBlackburne^words_deeds 09:25, 13 January 2010 (UTC)

Sydney Harbour Bridge design

I've changed it to the Hell Gate Bridge, and included a reference. Looking at images of the two it seems this is the case - the SHB shares far more similarities with the HGB than the Tyne Bridge, to the point that they're almost identical. If you have any cited evidence to suggest otherwise, feel free to change it. NotTarts (talk) 00:41, 4 February 2012 (UTC)

There is a difference between "design", "engineering" and "looks a bit like". The design was simply a through-arch bridge in riveted steel. By the 1920s this was an established design; there was no need to slavishly copy anything, be it Hells Gate or Tyne - this was now just an "off the shelf" design. Was the design directly inspired by it? - I've no idea, but there just wasn't any need for it to be.

Engineering is another matter. As well as the concept for a bridge, and even the broad architectural drawings, there needs to be an engineering design produced, and the actual building work carried out. In the Sydney case, this was controversially by placing the work with Dorman Long of Middlesbrough, who already had the experience of working on the Tyne and other bridges. This was so controversial in Australia that it was only permitted with an agreement that the work itself would be carried out by Australian labourers.

The "looks a bit like" aspect is clearly close to the Hells Gate than the Tyne, but that's because the Tyne has steep narrow banks, unlike both the Hells Gate & Sydney. Andy Dingley (talk) 11:38, 4 February 2012 (UTC)

"Iconic"

The use of 'iconic' here is problematic, not least because it has become a controversial, contemporary cliche, little more than a kind of 'Wow!' word. Worse, every user seems to use it with their own idea of its meaning, expressing a subjective judgement and not an objective fact, which makes it inappropriate for an encyclopaedic article. (https://en.wikipedia.org/wiki/Cultural_icon) In the context of this article, it might be understood in the sense of the original example of this type of bridge design. However, in the Wikipedia article devoted to the Tyne Bridge, it is stated that the Tyne Bridge and the Sydney Harbour Bridge both "derived their design from the Hell Gate Bridge in New York City". So here to call the Tyne Bridge "the original example of this type of bridge design" would simply be incorrect. In fact, in justifying his reversion of my original deletion, Andy Dingley set out how he was using 'iconic' to mean 'something emblematic of a place'. In that sense, isn't the Sydney Harbour Bridge just as 'iconic' as the Tyne Bridge? Applying it only to one of the named bridges here just looks like subjective bias. Such a reference would properly belong in the article devoted to the bridge itself, not here. I don't think this article needs this word at all. Blurryman (talk) 23:08, 2 April 2017 (UTC)

So is your confused single paragraph here about development history of bridges, or about a descriptive word in this article? Yes, the Sydney Harbour bridge is equally iconic to the Tyne - Of this type of bridge, these are the two worldwide that are distinctive icons of their cities. Runcorn Bridge might almost make such a case, but hardly Runcorn. Both are iconic representations of their cities, not of the bridge type. Hells Gate is not similarly well known or recognised, for either the location or the type.

I cannot imagine why you would present the Tyne Bridge as "the original example of this type of bridge design". Fortunately only you seem to be advocating this. Although a moment's study will show that it's distinctly different from either Hells Gate or Sydney, having an arch truss that is far shallower, and obviously independent of the masonry towers. However WP does not describe bridge design to such a level of detail.

Other than simply repeating your own deletion, which no-one else seems to have agreed with, what's your point? Andy Dingley (talk) 23:59, 2 April 2017 (UTC)

I agree with the removal of "iconic". Unsourced terms such as this fall under WP:PEACOCK. Meters (talk) 18:25, 3 April 2017 (UTC)

the most celebrated and most iconic of the seven bridges crossing the River Tyne Calls for the the iconic Tyne Bridge to be given a facelift as it starts to look a bit shabby The Iconic Tyne Bridge Newcastle upon Tyne's iconic Quayside and Tyne Bridge Andy Dingley (talk) 22:10, 3 April 2017 (UTC)

The majority of those sources are not something we can use. Two of them are nothing but sites selling photos, and one's a tourism site. Not even close to being reliable sources for the use of such a term. The Chronicle may an acceptable source (I'd prefer something non-local), but it (and the others, for that matter) do not describe the bridge as an iconic example of a through arch bridge. If you intended to say that this bridge is simply an icon of the particular city then the place to do so is in the article about the bridge, or the city, not here. It's not appropriate in this article, and it is confusing since it can be interpreted as meaning that the bridge is an iconic example of the type of bridge. In my opinion, this term should be left out. I would only accept it with a citation to an authority on bridge design history calling this an iconic example, and even then I would probably use it as a direct quote to show that it was a subjective term used by a particular expert. Meters (talk) 22:36, 3 April 2017 (UTC)

But no-one is describing it " as an iconic example of a through arch bridge", rather it (and Sydney) are iconic representations of their city. You claimed this was unsourced, and implicitly unsourceable. Clearly it isn't. Andy Dingley (talk) 22:42, 3 April 2017 (UTC)

Then, as I said, it does not belong in this article at all. We don't need puffery about which bridges are considered iconic representations of their cities. I am in full agreement with User:Blurryman. Meters (talk) 22:46, 3 April 2017 (UTC)

And I clearly did not say it was implicitly unsourceable. Meters (talk) 22:48, 3 April 2017 (UTC)