Unknown Steel Bar Joist

[trence76]

This is my first post, so bear with me. I was out on a survey last week and came across a very unfamiliar type of open web steel bar joist. The bottom chord looks like back to back steel angles, but upon closer inspection, it is one continuous piece of steel as if the vertical legs of an angle are connected. No research I could find matched my description, and I'm posting this because my department head came upon a similar open web steel bar joist in his survey last week (far more experienced than I) and he has not seen this type of joist before either. The top chord is similar just the inverse of my description above for the bottom chord.

If anyone has any knowledge of a manufacture for this type of joist, or could help in any way, that would be great. Thanks.

 

[Bagman2524]

The bottom piece is probably a WT section. Try the Steel Joist Institute website (steeljoist.org).

 

[SlideRuleEra]

You may have come across one of the obsolete trusses from the 1920's, or later. See this article in the Structure Magazine:

http://www.structuremag.org/article.aspx?articleID=919

Also, check the information about obsolete bar joists on this page of my website:

http://www.slideruleera.net/contributions.html

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[BAretired]

Did the chord look like the attached? If so, they were manufactured by Great West Steel Industries Ltd. (no longer in business). See the following link:

http://www.trademarkia.com/gws-73001180.html

I have the joist catalogue in my files...if you need a particular size, let me know.

BA

 

[msquared48]

What does the attachment of the web members to the top and bottom chord look like?

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[WCPE]

Hi there,
I see mention of Great West Steel Industries in this thread - I'm looking for data on a 24" joist 48'span, which I believe is a GWS product circa 1970. I have attached photo of the bottom chord. Webs are seamed tubing type with seams welded intermittently and tubing butt welded to top and bottom chord. Bottom chord width is 5 5/8" x 0.137"

Thanks in advance to any kind person who may be able to post or send me the manufacturers' data.

 

[BAretired]

The profile I attached earlier is a Great West Steel chord. What you are showing looks more like an Anthes Allspan joist produced by Anthes Steel Products Limited. I believe, however that Anthes was acquired by GWS some time prior to 1970.

http://www.eng-tips.com/viewthread.cfm?qid=285980

The two page attachment includes the Design Table for your span range and Allspan Dimensions and Properties.

I believe there was an American company who produced a profile very similar to this one, but I forget the name. Perhaps someone else will remember.

BA

 

[WCPE]

Chapeau to you BA!
The drawings I have denote 2411 joists, which are shown on the tables you have provided. Can you confirm that the Anthes V-section size matches my field measurement (#10 = 5 5/8" )?

Thanks again.

 

[BAretired]

According to my information, an Anthes Allspan 2411 joist would be 24" deep with a #11 top chord and a #10 bottom chord.

The #11 top chord has t = 0.142" and W = 6 3/16".
The #10 bottom chord has t = 0.128" and W = 5 5/8".

BA