Stainless Steel to the Rescue
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| Spike could live another 50 years thanks to the stainless steel cap being fitted here. |
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Elephant fitted with stainless steel tusk caps to prevent infection. By Dean Jobb
Nickel magazine, October 2002 -- When an elephant at the Calgary Zoo in Alberta, Canada cracked one
of its tusks, it took some mammoth dental work and a pair of custom-made stainless steel caps to put things
right. Instructors at the Southern Alberta Institute of Technology (SAIT) spent hundreds of hours designing
and crafting a new set of tusks for Spike, a 20-year-old Asian elephant, from bars of stainless steel S30403,
containing typically 10% nickel. In the process, they made history.
"As far as I know, as a cap for a broken or cracked tusk, it's the first time it's been done in stainless steel," says Rob Sadowski, who headed the team from SAIT's manufacturing and automation department that came to Spike's rescue. Although work elephants have been traditionally fitted with brass tusk caps and aluminum has been used to make replacement tusks, Spike's handlers and SAIT's millwrights and machinists agreed that stainless was the best solution. "Aluminum wouldn't be strong enough," Sadowski notes. "Because of Spike's sheer size, when he plays he can do a lot of damage."
Indeed, the 5.5-tonne creature already has, having cracked his left tusk earlier this year while roughhousing with one of his favourite toys -- a large tractor tire suspended by a chain. Veterinarians sawed off the broken section but found the crack extended toward the animal's jaw. Had it became infected, the result could be a massive toothache or even death.
The second tusk was cut off for balance, and zookeepers moulded wire mesh around the stumps to get rough measurements of the diameter and curvature of each one. SAIT instructor Roger Watson used the figures to create a three-dimensional computer model, and Spike was fitted with a wooden prototype to ensure a snug fit.
One of Sadowski's tasks was to track down the stainless steel. Corus Metals of Calgary was pleased to oblige, donating about $1,000 worth of 15-centimetre-diameter bar. "It certainly was an offbeat request," says Corus branch manager Girard Windle, who's more accustomed to supplying metals to the Alberta oil patch.
Elephants' tusks curve upward as well as inward and are not a uniform round shape, Sadowski explained, so the caps could not be bored to fit over the stumps. Two stainless bars were split lengthwise, hollowed out and machined to 13 centimetres in diameter and about 38 centimetres in length. SAIT welding teacher Art Cartwright then welded the two sides of each cap back together.
"There are other stainless steels that are easier to machine [for example, S30300 ], but they are not readily welded and have unreliable properties in the welded condition," Sadowski says. "We were also quite concerned that, once they were welded, that could distort them quite a bit and we may not be able to slide them on if there was a lot of distortion from the heat." Thus the choice of S30403.
The finished caps, each weighing about 14 kilograms, were fitted and secured with epoxy in an operation
that attracted international media attention. Spike could live another 50 years, and his shiny new tusks
should withstand any punishment he can mete out. "I can't see them breaking or denting," Sadowski says.
"They're certainly stronger than the ivory."
Dean Jobb is a freelance writer and lectures in journalism at Kings College in Halifax, N.S.
 Corus Metals 7805-51st Street, Calgary, Alberta, Canada T2C 2Z3 Tel: 1 403 236 1418 Fax: 1 403 236 0844 E-mail: corusmetals.calgary@corusgroup.com Website: www.corusgroup.com Southern Alberta Institute of Technology (SAIT) 1301 - 16th Avenue NW Calgary, Alberta, Canada T2M 0L4 Phone: 1 403 284 8473 Fax: 1 403 284 8884 Email: larry.lalonde@sait.ab.ca Website: www.sait.ab.ca |
