Steel Bulb Beam 3

[bridgebuster]

A co-worker called me this morning and wanted to know if I ever heard of a bulb beam; I've heard of bulb angles and channels but not beams. She didn't have a detail other than a call out on a framing plan for a bridge built in the 1920's. It sounded to me like some type of supplemental framing for the deck.

Take a look at the attached photo. It's from a Carnegie handbook dated 1909 (these beams seem to have disappeared by 1930). Has any one ever come across these? I'm just wondering what they were primarily used for; shipbuilding? car building?

Thanks

 

[TehMightyEngineer]

I've known they exist but never seen one in the field but about the oldest steel I've worked with was 1930s era, maybe 1910. After a little google-fu it does appear that they were for car building.

Maine EIT, Civil/Structural.

 

[TehMightyEngineer]

That's railcar building, btw. My "source":

http://books.google.com/books?id=sB...onepage&q=bulb beam steel carbuilding&f=false

Maine EIT, Civil/Structural.

 

[bridgebuster]

Thanks for the info. I forgot about Google; hectic day. I took today off to celebrate my birthday but between phone calls and e-mails I've been working since 8:00 AM. I think it might be a three martini dinner

 

[dhengr]

Bridgebuster:
I don’t know about bulb-channels, never saw or heard of one. My earliest Carnegie Pocket Companion is from 1923 and the bulb-beam is not shown in this book. I do know about bulb-angles, they were used for ship building and railcar building, I’ve used them, where they wanted a fairly well balanced bending member, volume or area wise, section props. wise, btwn. the two flg. areas and they wanted the outstanding flg./leg to be fairly bulky to take some abuse from loading and handling impacts, and the like. The bulb-angles were used particularly for the top chords of sides and end of gondola cars. In affect, the top flg. of a deep pl. girder (the sides) and they took a real beating during loading and unloading.

RE: the bulb-beam, I suspect, as your co-worker found or seems to imply, these were primarily intended for bridge decks and bldg. fl. slabs, where again they wanted a fairly balanced bending section to carry the dead load during construction and a bot. flg. for final tension and forming. Then they infilled will clay tiles and/or conc. and the conc. became the compression element. They didn’t worry much about conc. bond area at the top flg. and they had no need for a flat top flg. to support formwork, shear studs and the like. They also paid less attention to lateral stability of the compression flg. than we do today. But, given the level of development of Structural Engineering and the analysis methods of that era, those systems seemed to work pretty well.

 

[hokie66]

Similar to a bulb tee, as used in Tectum and gypsum roof decks. I haven't seen the bulb beams.

Happy birthday, bridgebuster.

 

[bridgebuster]

Interesting points about floor framing; makes sense.

Thanks for your well wishes homie.

 

[bkal]

I've come across bulb flats (similar to the bulb beams but without the flange) and they were used mainly as stiffeners for plated structures. The designs were from 70-ies, I think.

 

[bridgebuster]

Sorry I meant hokie

 

[SlideRuleEra]

Happy Birthday, Bridgebuster! As TME, dhengr, and hokie have noted the primary use for bulb sections appears to have been for ship and railcar construction. Here is an article that sheds some light on the history of bulb section use in shipbuilding. It appears that bulb sections were popular during World War I (1914 - 1918) when ships were being built to British standards for the war effort. Seems reasonable to assume that railcar and bridge uses took advantage of the bulb sections made available for ship building. Here is the link to the November 1915 article:

http://books.google.com/books?id=EK...EQ6AEwBjgU#v=onepage&q=bulb beam steel&f=true

Note: The 1917 Carnegie Pocket Companion has several pages on the properties of bulb beams and angles. I'll have to scan this book for my website.

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[bridgebuster]

Thank you SlideRuleEra!

I enjoyed the article. It correlates with what I saw in various Carnegie manuals. The bulb beam is shown in an 1893 manual; not shown in 1903; reappears in 1914 I don't have 1917; not shown in 1923. Oddly, nothing in the American Bridge Company manuals I looked at.

Perhaps the next mystery to solve is how the "government anchor" got it's name. I had three years of drafting in high school. In senior year I took steel detailing. One day, the teacher said, "this is a government anchor but nobody knows why it's called that.".

 

[SlideRuleEra]

Bridgebuster - Seems that the "government anchor" got its name from the fact that it was often specified in work on U.S. Government projects. See this page of the 1913 book "Erection and Inspection of Iron and Steel Construction":

http://books.google.com/books?id=C1...AEwAA#v=onepage&q="government anchor"&f=false

This appears to be confirmed by an older reference, 1902 book "American Architect and Architecture, Volume 75" that says the term "Government Anchor" is a shortened version of "United States Government Anchor":

http://books.google.com/books?id=4v...v=onepage&q="government anchor" steel&f=false

... not absolute proof, but pretty good evidence.

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[bridgebuster]

It looks like another mystery is solved!