Timber Capacities for North American Oregon in the Royal Exhibtion Building, Melbourne
Timber Capacities for North American Oregon in the Royal Exhibtion Building, Melbourne
(OP)
Hi,
I have a current job where I have to verify an existing timber dome in Melbourne, Australia against some temporary scaffold loading (in place for <6 months)and I have a question about material strength assumptions.
I am verifying the main timber dome of the Royal Exhbition Building, Melbourne, Australia. The structure was completed in 1880 and has remained largely unchanged, the existing timber being in good condition.
I have several reliable sources which say that the structure was built from "imported Oregon". I am guessing that this would have been imported from the USA. I wondered if anybody had any information about the strength characteristics of American Oregon around this period?
Thanks
I have a current job where I have to verify an existing timber dome in Melbourne, Australia against some temporary scaffold loading (in place for <6 months)and I have a question about material strength assumptions.
I am verifying the main timber dome of the Royal Exhbition Building, Melbourne, Australia. The structure was completed in 1880 and has remained largely unchanged, the existing timber being in good condition.
I have several reliable sources which say that the structure was built from "imported Oregon". I am guessing that this would have been imported from the USA. I wondered if anybody had any information about the strength characteristics of American Oregon around this period?
Thanks
RE: Timber Capacities for North American Oregon in the Royal Exhibtion Building, Melbourne
Nineteenth century data on some timber properties does exist but tests were just being developed so some results may seem odd by today's standards. The most accessible records are in the Trautwine's Civil Engineer's Pocket Book series (tests make before 1888). There will be some data on spruce, but most interest at that time was southern pine and oak.
Other sources are 19th & early 20th century engineering "Pocket Books". I cataloged a number of these pocket books on my website: Link. In particular, see the pages 184 thru 190 of the 1893 Carnegie Pocket Companion. (It summarizes the 1888 Trautwine data.)
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RE: Timber Capacities for North American Oregon in the Royal Exhibtion Building, Melbourne
Testing some pieces, as SRE mentions, would be a good approach.
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RE: Timber Capacities for North American Oregon in the Royal Exhibtion Building, Melbourne
RE: Timber Capacities for North American Oregon in the Royal Exhibtion Building, Melbourne
RE: Timber Capacities for North American Oregon in the Royal Exhibtion Building, Melbourne
Mike McCann, PE, SE (WA)
RE: Timber Capacities for North American Oregon in the Royal Exhibtion Building, Melbourne
I am very appreciative of all this information and at the very least it will give me enough information to relate the timber to the closest likely strength within the Australian Standard. I will review all of this information with relish and digest! Slide Rule Era, as per usual you have useful information for just about everything!
JAE - with respect to your comments, do you mean the properties have changed due to degradation i.e. rotting or that I should consider the usual load duration/creep effects? I have a condition survey that states that the timber is in excellent condition so am not accounting for any degradation over time.
One of my colleagues mentioned that it is likely that the timber imported from the USA back them was felled from 'natural growth' forests which would likely be stronger than the farmed timber used nowadays given it's slow growth. I am not so sure about this as I imagine that by 1880 the USA would have been growing Oregon by the forest loads given it's worth back then. Any thoughts?
I will try to send a photo of the final scaffold installation for your interests, as scaffold goes, it is about as sexy as it gets!
RE: Timber Capacities for North American Oregon in the Royal Exhibtion Building, Melbourne
I think Mike McCann's guess of allowable bending stresses is in the ballpark, with about 75% of that for compression parallel to grain.
RE: Timber Capacities for North American Oregon in the Royal Exhibtion Building, Melbourne
I saw an example of this at Offutt AFB in Bellevue, NE, a several years ago where they had old wood trusses (flat rough sawn bottom chords and glue laminated arched top chords).
These trusses spanned over a large space (originally used for construction of bombers back in WWII). The bottom chords had numerous splits - very tight jagged things at several bolted split-ring joints. The trusses were very high above the floor and in the winter the upper reaches of the space was kept very warm and very dry.
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RE: Timber Capacities for North American Oregon in the Royal Exhibtion Building, Melbourne
"Evaluation of Recycled Timber Members"
Results happen to relate to Douglas Fir which is likely relevant to the project.
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