Elephant Enclosures
Elephant Enclosures
(OP)
I have an odd question for everyone. Has anyone every designed an elephant enclosure? I currently have a project, where they asked us to re-design an elephant enclosure.
The only parameters that I have are that there are Concrete Filled Steel Posts, spaced at 10'-0" O.C., with (4EA) 3/4" diameter galvanized steel cables equally spaced along the posts.
Does anyone know of any design criteria resources to use for Elephant enclosures? I am having trouble finding any engineering resources for this one.
Thanks!
The only parameters that I have are that there are Concrete Filled Steel Posts, spaced at 10'-0" O.C., with (4EA) 3/4" diameter galvanized steel cables equally spaced along the posts.
Does anyone know of any design criteria resources to use for Elephant enclosures? I am having trouble finding any engineering resources for this one.
Thanks!






RE: Elephant Enclosures
RE: Elephant Enclosures
RE: Elephant Enclosures
Woodland Park Zoo in Seattle had a similar enclosure barrier, but the exhibit has been closed as the elephants were transferred to another facility some years ago.
City of Tacoma did too before Cindy died....
Still might have something in their records...
Mike McCann, PE, SE (WA)
RE: Elephant Enclosures
MotorCity - There are no issues with the current barrier function, but they are developing a new layout for the entire zoo and want to modernize the look a little and think they existing posts and foundations are "way over designed". Of course, this is a common statement from non-engineers, so I am not worried about that. I would just like some type of criteria for what is acceptable for loading, deflection, etc. to develop a good understanding of the final purpose of the enclosure.
Additionally, the top cable will be electrified.
RE: Elephant Enclosures
The zoo was Taronga Zoo in Sydney, Australia. My memory is not too clear on the details, but the re-build generally consisted of a huge, thick RC mat foundation.
RE: Elephant Enclosures
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Elephant Enclosures
That was easy. "horse kick" narrowed the search down in a hurry which, I suppose, is unsurprising. There's even a research paper in there. Not sure elephants actually kick things though. And a raging stamped would seem to be of greater concern.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Elephant Enclosures
I recall the test engineer saying it was a big change from their usual work crash testing highway barrier. FHWA is very concerned about occupant protection, but the State Department didn't much care.
RE: Elephant Enclosures
RE: Elephant Enclosures
https://www.edmonton.ca/attractions_events/documen...
https://www.aza.org/assets/2332/aza_standards_for_...
http://www.sanctuaryfederation.org/gfas/wp-content...
http://www.zoolex.org/publication/2007_new_zealand...
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
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RE: Elephant Enclosures
RE: Elephant Enclosures
Dik
RE: Elephant Enclosures
I considered using a human guardrail as a example and scaling it up. Current US male average is 5'-9" tall and weighs 195#.
A 42" guardrail is 60% of that height and is required to carry a 200# load (100% of weight) in any direction.
Scaling up to an 11' tall elephant at 13,000#, you come to a 6.6' tall rail with a 13,000" load at top.
With a spreader at the top to carry the load over 3 posts at 7' height, that calculates to a 6" Sch. 80, 50 ksi pipe.
Does this sound realistic?
RE: Elephant Enclosures
What if the elephant wants out? Are regular railings designed to withstand deliberate destruction by humans?
--
JHG
RE: Elephant Enclosures
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RE: Elephant Enclosures
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm
RE: Elephant Enclosures
I stated a little earlier that I found something indicating that you need to account for the max speed of the elephant running into the enclosure, which is approximately 20 mph depending on the type of elephant. This obviously increases the loading significantly if indeed it needs to be accounted for in that manner.
Bill A - Please keep us updated if you find out any valuable information from contacting the zoos.
RE: Elephant Enclosures
I need to call Rich Purnell in Astrodynamics.
RE: Elephant Enclosures
If you are looking for traditional physics equations to apply you might look at something like 1/2 M V^2. Also make sure you consider slowdown distance in your analysis.
RE: Elephant Enclosures
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm
RE: Elephant Enclosures
RE: Elephant Enclosures
The force should be something like (1/2MV^2)/D where D is the slowdown distance. See IRstuff post above.
RE: Elephant Enclosures
Given:
E=.5mv^2
W=Fd
1. Assume an initial d, set E=W and solve for F (and watch your units)
2. Apply that F to the proposed structural system and see what deflection it yields.
3. With that knowledge refine Step 1 and repeat Step 2.
4. Repeat to the level of accuracy desired.
I've had folks tell me this is not the correct approach but it's better than asking the elephants.
RE: Elephant Enclosures
1) determine KE to be absorbed by the barrier
2) Make some conservative assumptions about which part of the barrier will be engaged by an impact
3) Determine maximum strain which can be absorbed by the engaged portion(s) of the barrier before your failure criterion is reached (elastic or ultimate limits, etc)
The result of step 3 give you the D in F=W/D; you can then determine what the various forces are, and you're on your way.
Some of these parameters need to be factored, depending on your approach and how you build in safety factor.
This process is, of course, iterative; but it's one way to get there.
RE: Elephant Enclosures
http://www.eng-tips.com/viewthread.cfm?qid=431133
RE: Elephant Enclosures
I think we were semaphoring our messages from adjacent ships simultaneously. Hopefully the fleet admiral won't mind.
RE: Elephant Enclosures
Never seen that one before- but if anything, it serves to verify the the approach is sound ha ha.
One Internet high five for you, sir.
RE: Elephant Enclosures
RE: Elephant Enclosures
Even an enraged elephant will "bend and break things" (like its head and shoulders) and so each subsequent charge will be less than the first. Consider running lighter weight horizontal round tube steel between the 10 inch dia verticals. Each horizontal is built in an opened "U" shape so it will deflect at each hit, but the deflection absorbs the energy by buckling and yielding and bending further and further "out" (away from the corral) with each hit.
But the elephant will be hitting the hard steel horizontal each time. And the deflection of the sacrificial horizontal will require replacement, but keep the animal in. (Make the horizontals closer to the ground closer together to restrain the smaller calves and females.)
If you run the cable inside the horizontal tube steel between each vertical, through the vertical, out through the next horizontal, into the next vertical, out from that vertical into the next horizontal, you'll tie the whole fence together so the force is eventually spread out between 4 or 5 verticals, and all of the intermediate horizontals are also bending and yielding. Back it up with an alarm and intervention system so the fence doesn't have to stand continuous asault all night, but only for 5-15 minutes until an attendent/vet administers the "sleepy shot".
RE: Elephant Enclosures
RE: Elephant Enclosures
With that picture, you can see the thing has more than 150 straight shot at the fence.
RE: Elephant Enclosures
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http://be.linkedin.com/in/fusionpoint
RE: Elephant Enclosures
According to the internet "They can carry a vast weight but are very heavy. They can pull up to 9 tons - 1.7 times their normal body weight."
http://www.telegraph.co.uk/news/earth/earthpicture...
Therefore, i say design it to handle that force. The pushing power is probably equal, i wouldn't think stopping it from running into the fence is possible... plus with that 18,000# it would probably hurt the elephant if it tried.
RE: Elephant Enclosures
RE: Elephant Enclosures
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm
RE: Elephant Enclosures
RE: Elephant Enclosures
Did he smash his way out or was there a latch he figured out? Park Rangers in North American like to claim that there is an overlap between the stupidest tourists and the smartest bears.
Running headlong into an inanimate object is a good idea if you want out, you weigh seven tons, and the object has not been properly engineered to withstand impacts.
--
JHG
RE: Elephant Enclosures
I helped with design of a Bison pen some years ago, I believe that we ended up with 10" "I" beams driven 10' into the ground (and extending 10' above) on 36" spacing, with heavy wall 2.875 drill pipe welded horizontally every 24". Bulls would charge it at full speed, and the fence would flex a bit. If you were walking by it would scare you pretty good. Not very aesthetic, but worked.
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P.E. Metallurgy, Plymouth Tube
RE: Elephant Enclosures
My design has been in place for over 10 years and i havent yet read anything in the news about an elephant rampage!