Specifications for elephant-resistant steel poles

[Baluncore]

Since I am testing the repellent effects of chemicals from scent marks I cannot add any extra repellents to the setup.

Are the repellents you are testing attracting the elephants and triggering the destructive behaviour. Do you have posts with cameras as controls, that are not attacked as often by elephants?

If you regularly provided a reward for elephants on the posts, could you train elephants to not destroy the reward bearing posts. Do not provide more reward if the post is damaged. Take the camera, but leave the damaged posts so elephants will learn that damaging posts is not rewarding.

 

[Peter Apps]

Are the repellents you are testing attracting the elephants and triggering the destructive behaviour. Do you have posts with cameras as controls, that are not attacked as often by elephants?

If you regularly provided a reward for elephants on the posts, could you train elephants to not destroy the reward bearing posts. Do not provide more reward if the post is damaged. Take the camera, but leave the damaged posts so elephants will learn that damaging posts is not rewarding.

There are no repellents there as yet - I am running with no scent as a control. In any case the scent will not be at the cameras; it will be in dispensers 5 m from two of the cameras at each array and 15 m from the other two. In an earlier study elephants took no special notice of the repellent.

As I said in an earlier reply; training a whole population of elephants is utterly impractical. In any case, the training protocol you propose would not work with any animal that I can think of.

 

[anorlunda]

@Peter Apps ,

I think that your problem is fun. We are very willing to help. But putting my engineer's hat on, I must say the following.

Your requirements are so fuzzy and ill defined, and your numerical estimates so crude, that the very idea of calculating the minimum size post is preposterous. It wastes your time and our time to even try. Given the uncertainties, you should get something 10x times stronger than you think. (maybe 50x)

If you insist on the minimum size, then spend your time sharpening your requirements and validating your estimates. Calculating the answer before the problem is well defined is not productive.

 

[Peter Apps]

@Peter Apps ,

I think that your problem is fun. We are very willing to help. But putting my engineer's hat on, I must say the following.

Your requirements are so fuzzy and ill defined, and your numerical estimates so crude, that the very idea of calculating the minimum size post is preposterous. It wastes your time and our time to even try. Given the uncertainties, you should get something 10x times stronger than you think. (maybe 50x)

If you insist on the minimum size, then spend your time sharpening your requirements and validating your estimates. Calculating the answer before the problem is well defined is not productive.

Well, thank you for your inputs. I disagree that the problem is "fun" - elephants damaging equipment and pushing cameras out of alignment are a serious drain on resources and productivity is an under-resourced project with a very serious aim; to find new ways of managing large predator behaviour so that we can limit their impacts on livestock agriculture and thereby reduce the human-wildlife conflict that is the single major cause of declines in large predator populations all over the world.

If the dimensions of a steel square tube 1m long that can recover after having a 500 kg mass hung on the end in cantilever loading is fuzzy I am not sure what would consider to be exact. I do not have the luxury of working in a field where problems are well defined in an engineering sense - but I do the best I can with the resources available. Fortunately some other posters have been helpful enough to work with my crude numbers, and have come up with pole sizes that were somewhat larger than I expected; 75mm square instead of 50 mm square, but certainly not 10 times or 50 times larger as you suggest. Forgive me for being blunt but what is preposterous here is your suggestion that I use 500 mm square for a 10 times margin or 2.5 m square for 50 times - I am camera trapping in the African bush, not building advertising hoardings alongside a highway. Doubtless with your engineer's hat on you can suggest that I go for solid instead of tube, but I do not have heavy machinery to move it around.

Contrary to you claim about calculating before the problem is well defined, other posters have been able to produce sensible and useful answers working from my crude estimates for loading. How on Earth do you suggest that I go about "validating my estimates" - equip poles with strain gauges and wait for wild elephants to push against them ? Do you seriously think that anyone would fund that ?

 

[anorlunda]

Contrary to you claim about calculating before the problem is well defined, other posters have been able to produce sensible and useful answers working from my crude estimates for loading. How on Earth do you suggest that I go about "validating my estimates" - equip poles with strain gauges and wait for wild elephants to push against them ? Do you seriously think that anyone would fund that ?

What I suggested more than once, is that you stop calculating and compensate for uncertainty by adding huge safety factors and oversize it.

And I was not all negative, I provided you with a link to tables where non-engineers could simply look up an answer.

 

[jack action]

I'm surprised that it wasn't suggested earlier, but I would use 4 angles driven in the ground in a square arrangement, with other angles bolted to them to form 'X' braces. The bigger the square, the more it will resist torsion and bending.

On the upside, the camera can be put inside the square, thus it doesn't give a lever to the elephant to twist the angles.

If you also cover the assembly with bolted pieces of plywood or sheet metal, it will prevent the elephant from using the 'X' braces as handle to twist or pull the angles. Heck, if you use thick enough plywood, the 'X' braces might not even be necessary.

 

[Baluncore]

A better shape might be a cone made from a sheet of memory plastic, shaped like a “witches hat”. Apex angle might be about 60°. Bury and pin the skirt down in soil with sticks or rocks on skirt to keep it fixed and hidden. Camera is in a steel box which is bolted to the internal surface of cone. Lens looks through a small hole near the top of the cone. There need to be a number of small air holes, including some near the top above the camera box to allow thermal air circulation for cooling during the day in hot sun.

An elephant would have trouble gripping the closed cone. If the cone was crushed, then the plastic would slowly stand back up once the elephant had gone and the cone warmed up in the sun.

Problems: The smell of remaining plasticiser, pick the right material and vent it in the sun. Cost of roto-molding.
Advantages: Light weight, stacks well, memory-plastic can be driven over by a truck, then reused.
Available in any colour, or cover with cheap glue and throw local soil at the surface once installed.

Multiple use, can be made of white plastic, or painted white and used to mark an airstrip. Sales cover the cost of manufacture and research.