Talk:Thomas Viaduct

Picture of obelisk monument?
If anyone has a "clean" picture of the obelisk mounment, please consider adding it to the article. Sadly, in the HAER image it is covered with graffiti -- which hopefully has since been cleaned off. &mdash; Eoghanacht  talk 17:00, 5 April 2006 (UTC)
 * Yes it has been cleaned, belive it was done it the late or mid 80's, but no i do not have a phot tof it. --Boothy443 | trácht ar 05:16, 6 April 2006 (UTC)


 * ✅ Found a free to use trainweb picture clean and sharp. --Dp67 | QSO | Sandbox | UBX's 23:54, 1 October 2007 (UTC)


 * What is the viability of using our own personal photographs? I am often at the park where the Thomas Viaduct exists and am constantly walking through there with my kids and would be happy to get better pics of it. It would give me a good excuse to take them up to the obelisk. It is still there along with the original mile markers on either side but its been a few years since I was up on them so not sure what the shape is.Wolfstorm000 (talk) 06:10, 23 November 2010 (UTC)

Page Freshening.
I grew up in this area and spent quite a bit of time in Ellicott City, Elkridge, Relay and especially Patapsco State Park. (All of them.) I have always loved this bridge. I have been working on fixing up this page over the past few days. Anyone have any grief in changing its format? Most of everything else is the same except for a few added facts, broken things up into sections and the timeline is edited to flow smoothly together instead of afterthoughts. A few other minor changes as well.. Are there any grievances to a complete overhaul?
 * --Dp67 | QSO | Sandbox | UBX's 16:08, 3 October 2007 (UTC)

Oldest multiarch railroad bridge
There seems to be a lot of confusion about this in our sources. The fact is that the Thomas Viaduct wasn't the first; the Patterson Viaduct was constructed in 1829, and it had four arches. The Thomas Viaduct wasn't built until 1835. The Patterson doesn't survive intact; only one arch remains. But it was first. Mangoe (talk) 19:39, 24 March 2010 (UTC)

Thanks for the correction, Mangoe, looks like you're correct. Of course it could have been phrased 'oldest intact multiarch railroad bridge', but it's clear enough now. I was just trying to get rid of the 'dubious' tag. FYI, if you don't already know, there will be a celebration of the 175th anniversary of the Thomas Viaduct in July. I can get you info if you need it. I'm not a railroad expert, just a great, great, multi great nephew of Philip Thomas! :-)  Nydhogg (talk) 22:46, 24 March 2010 (UTC)

I may be missing a crucial distinction, but the Laigh Milton Viaduct in Scotland was built in 1812, of stone, for a railroad (though originally a horse-drawn one), and has 4 arches (and so is "multi-arch). The wiki page for Laigh Milton notes it as "the oldest in Scotland" but only "probably the world's earliest surviving railway viaduct on a public railway" (my emphasis), so I am not sure whether the Scottish one qualifies as the oldest in the world either.Thomas Peardew (talk) 16:49, 23 May 2013 (UTC)

When one says it's "the world's largest bridge of its kind" one has to specify what kind in order for the statement to have meaning. Is the kind the largest masonry railroad bridge built on a curve? Or what is the kind? --Wetman (talk) 15:21, 24 May 2013 (UTC)

I have researched this item for a historical designation and all of the above comments have validity. The article needs some editing ... I am working on the following material to be edited into the article. I am posting here for comment before I move it over to the main article space.
 * ''The Thomas Viaduct spans the Patapsco River and Patapsco Valley between Relay, Maryland and Elkridge, Maryland, USA. It was commissioned by the Baltimore and Ohio Railroad (B&O); built between July 4, 1833, and July 4, 1835; and named for Philip E. Thomas, the company's first president.
 * In the 1830s, there was extensive bridge-building in North America as well as Europe. The UK’s Sankey viaduct (1826-1833) by George Stephenson (“nine arches”) was 405 feet long with spans of 45 feet, rises approximately 60 feet in height. In 1966, Sankey Viaduct was recognized by the UK as having "international significance being the earliest major railway viaduct in the world." This would have taken the title for world’s longest railway viaduct in 1833. In 1834, the UK’s Corby Bridge (popularly known as Wetheral Viaduct) was completed. It was a railway viaduct 660 feet long and 100 feet in height and would have the title for world’s longest in 1834 from Sankey (660 versus 405).
 * In 1835, the Thomas viaduct at 614 feet in length (curved) with spans of 58 feet was the second-longest railroad viaduct in the world at the time of construction when compared to the Wetheral viaduct at 660 feet, but it was for a time, the most significant curved viaduct in the world and largest viaduct in the United States.
 * In 1849, the UK’s Arthington Viaduct was completed with a total viaduct length of 1,510 feet. It was curved with 21 semi-circular arches on high piers at the height of 60-90 feet. This would have taken the title for most significant curved, multiple arch stone bridge curved in the world from the Thomas viaduct. In 1850, the next largest stone multiple arch railway viaduct built in the United States after Thomas was Starrucca Viaduct in Pennsylvania. Starrucca became the largest railway viaduct in the United States, but Thomas remained the most significant curved, multiple arch stone bridge in the United States.
 * Thomas’ historical significance lay in being the earliest major curved railway viaduct in the United States and for a while, the largest. It is a classic example of a multiple arch viaduct, as its primary support system consists of open semi-circular arches spanning the distance between piers, without any walls.
 * The chief design problem arose from the construction on a curve, causing variations in span and pier width between opposite sides of the structure. The lateral pier faces were set on radial lines, for which its engineer, Benjamin Henry Latrobe, II, found few if any, precedents. The intriguing question is did Latrobe understand the nature and scale of dynamic loads on a curved structure.
 * In 1964, the Thomas viaduct was designated as a National Historic Landmark. In 2010, the bridge designated as a National Historic Civil Engineering Landmark by the American Society of Civil Engineers. The viaduct is now owned and operated by CSX Transportation and still in use today, making it one of the oldest railroad bridges in the United States still in service.

Cheers Risk Engineer (talk) 15:13, 25 September 2019 (UTC)