PH, I need your help! (polar expeditions/metal fabrication)
Discussion
For those that don't know me, I've been loitering around PH since the olden days. I also lead polar expeditions for a living - in 2004 I became the third in history to reach the North Pole solo and on foot (a 640-mile camping trip that Reinhold Messner called “ten times as dangerous as Everest”).
No one has been able to repeat the journey since. I had a bash at doing it from the Canadian side last spring (and setting a speed record in the process) but was foiled by a broken ski binding. And here's where I need some help...
The binding is called a Salomon SNS X-Adv BC:
And my boot has a corresponding groove and a bar across the front that clips into the binding:
And (after stepping onto the binding) it works like this:
Flip lever (1) down, slidey bit moves back (2) and clamps the bar of the sole against a plate (circled).
So far so good. Here's what I was doing with them:
(at -45ish, probably a little more than the designers had in mind
but they're the strongest bindings on the market and they've worked well for me on three previous expeditions and nearly 1,000 miles)
Last spring, however, one of 'em broke. Here it is after dismantling:
The metal plate that mates with the bar of the boot (1) snapped, along with two screws that mount it to the ski (2).
So, the question is, how can I stop this happening again? My guess is to have this plate remanufactured in a stronger (and perhaps thicker by a few mm) metal - Titanium, perhaps, and to find some super-strong screws. But where to start? They're some sort of steel, but I know nothing about metallurgy or the bespoke fabrication of small parts like this.
Here's another pic of the offending parts:
This might sound trivial, but it scuppered a £150k expedition that took me two years to train for and finance, and I'm keen to find a solution. So, over to you lot. I'll think of a prize for the winning solution(s)...
Thanks!
No one has been able to repeat the journey since. I had a bash at doing it from the Canadian side last spring (and setting a speed record in the process) but was foiled by a broken ski binding. And here's where I need some help...
The binding is called a Salomon SNS X-Adv BC:
And my boot has a corresponding groove and a bar across the front that clips into the binding:
And (after stepping onto the binding) it works like this:
Flip lever (1) down, slidey bit moves back (2) and clamps the bar of the sole against a plate (circled).
So far so good. Here's what I was doing with them:
(at -45ish, probably a little more than the designers had in mind
but they're the strongest bindings on the market and they've worked well for me on three previous expeditions and nearly 1,000 miles)Last spring, however, one of 'em broke. Here it is after dismantling:
The metal plate that mates with the bar of the boot (1) snapped, along with two screws that mount it to the ski (2).
So, the question is, how can I stop this happening again? My guess is to have this plate remanufactured in a stronger (and perhaps thicker by a few mm) metal - Titanium, perhaps, and to find some super-strong screws. But where to start? They're some sort of steel, but I know nothing about metallurgy or the bespoke fabrication of small parts like this.
Here's another pic of the offending parts:
This might sound trivial, but it scuppered a £150k expedition that took me two years to train for and finance, and I'm keen to find a solution. So, over to you lot. I'll think of a prize for the winning solution(s)...
Thanks!
Edited by polar_ben on Thursday 8th January 11:07
I spoke to Salomon - they'd never seen this before, but the market for thses types of bindings is tiny and they seem reluctant to help, partly as I doubt any manufacturer would guarantee their product for this sort of abuse.
And yes, I was attacked by a polar bear in 2001, but that's another story
And yes, I was attacked by a polar bear in 2001, but that's another story
The screws didn't break though it was just them metal plate?
I can't tell you were to get it made of what material to use but I would suggest that there are some sharp (inner) corners in the stamping near where it broke, these corners particularly on stamped part can lead to "crack propogation" also if it is a stamped part it will have been cold worked and unless heat trated afterwards it will have changed the characteristics of the metal.
Stamping is used as it is cheap and quick for mass production but for something this important you would be better off having it macchined from cast metal (so not to cold work it) and not have any sharp corners used the biggest radii possible.
People will probably add to this, I'm more of a stamping based engineer just pointing out what appears to be the flaws in the original design.
I can't tell you were to get it made of what material to use but I would suggest that there are some sharp (inner) corners in the stamping near where it broke, these corners particularly on stamped part can lead to "crack propogation" also if it is a stamped part it will have been cold worked and unless heat trated afterwards it will have changed the characteristics of the metal.
Stamping is used as it is cheap and quick for mass production but for something this important you would be better off having it macchined from cast metal (so not to cold work it) and not have any sharp corners used the biggest radii possible.
People will probably add to this, I'm more of a stamping based engineer just pointing out what appears to be the flaws in the original design.
polar_ben said:
in 2004 I became the third in history to reach the North Pole solo and on foot (a 640-mile camping trip that Reinhold Messner called “ten times as dangerous as Everest”).
No one has been able to repeat the journey since. I had a bash at doing it from the Canadian side last spring (and setting a speed record in the process) but was foiled by a broken ski binding. And here's where I need some help...
Can't help, but followed the diary of that trip day by day and was gutted for you when that happened! Really hope that someone here can help No one has been able to repeat the journey since. I had a bash at doing it from the Canadian side last spring (and setting a speed record in the process) but was foiled by a broken ski binding. And here's where I need some help...
Whilst I suspect that minimizing weight on your trip might be something of a priority, would carrying a spare be feasible?
How much testing of a new component are you going to be able to do? I think I'd rather consider swapping a part (if that's possible in the environment) than relying on something knocked up in a shed.
How much testing of a new component are you going to be able to do? I think I'd rather consider swapping a part (if that's possible in the environment) than relying on something knocked up in a shed.
From the internet:
Stainless Steels.
Cryogenic (Low Temp.) Resistance
Cryogenic resistance is measured by the ductility or toughness at sub zero temperatures. At cryogenic temperatures the tensile strengths of austenitic stainless steel are substantially higher than at ambient temperatures. They also maintain excellent toughness.
Ferritic, martensitic and precipitation hardening steels should not be used at sub-zero temperatures. The toughness of these grades drops significantly at low temperatures. In some cases this drop occurs close to room temperature.
I take it the material you have their is magnetic (i.e. ferritic)?
Stainless Steels.
Cryogenic (Low Temp.) Resistance
Cryogenic resistance is measured by the ductility or toughness at sub zero temperatures. At cryogenic temperatures the tensile strengths of austenitic stainless steel are substantially higher than at ambient temperatures. They also maintain excellent toughness.
Ferritic, martensitic and precipitation hardening steels should not be used at sub-zero temperatures. The toughness of these grades drops significantly at low temperatures. In some cases this drop occurs close to room temperature.
I take it the material you have their is magnetic (i.e. ferritic)?
polar_ben said:
Thanks chaps. Callan, yes - they look like they were stamped. The screws snapped as well, I think as a direct result of the plate snapping.
Sounds like machining is the way forward. Can this be done with stainless steel (apologies if these are numpty questions)...
Yes. Just has to be done slowly. Stainlees will have much better properties so although what Callan says is correct it will be far less critical at the low temps.Sounds like machining is the way forward. Can this be done with stainless steel (apologies if these are numpty questions)...
Why don't you just email Ran Fiennes and ask him what skis he uses?
G'kar said:
Whilst I suspect that minimizing weight on your trip might be something of a priority, would carrying a spare be feasible?
Potentially, though I had no way of removing the screws that had snapped (flush with the surface of the ski) and therefore no way of replacing the binding.Ben, have you tried speaking to any Universities about this? It would probably make a good project for someone/somewhere.
If you don't have any luck on here, I'll try to have a word with one of the material engineering (or whatever the hell it is called) guys when I go back on Monday. The department does work with Williams F1 team and various other motorsport companies so I'm sure looking at a footbinding wouldn't be too much of a problem.
If you don't have any luck on here, I'll try to have a word with one of the material engineering (or whatever the hell it is called) guys when I go back on Monday. The department does work with Williams F1 team and various other motorsport companies so I'm sure looking at a footbinding wouldn't be too much of a problem.
Olf said:
Why don't you just email Ran Fiennes and ask him what skis he uses?
Because he's never managed to get there on foot. He lost his thumb and a few fingers trying in 2000 
There's one other system that a couple of Norwegians have used successfully, but that doesn't seem bomb/foolproof either.
Edited by polar_ben on Thursday 8th January 11:27
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