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Underwater Chain Saws

stanleyinfrastructure.com

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Re: Underwater Chain Saws

#81

Post by mindslight »

unwind wrote: post #39
anjel wrote: post #21

While gas / electric chainsaws are unlikely to work underwater, I can't imagine a reason why a hydraulic chainsaw wouldn't work on dry ground with its superior weight to power ratio and lack of blue smoky exhaust. Probably quieter too.

Forestry harvesting equipment (those all-terrain vehicles with long booms) uses hydraulic chainsaws for the felling step. Of course then the hydraulic pump is on the massive vehicle so portable in that way.

https://limbsaw.com/ for a consumer version. Although I don't really get the niche - by the time a branch is high/big enough that you can't use a hand held pole saw, I would think managing the break/fall would be more important.

Re: Underwater Chain Saws

#82

Post by benj111 »

I'm most surprised that Stanley actually makes professional tools.

Why do all these tool companies make actual good tools, and then license their names off to sell sub par rubbish trading off a name that used to be known for quality.

Re: Underwater Chain Saws

#83

Post by wlesieutre »

amelius wrote: post #74
dig1 wrote: post #43

Earlier quoted context omitted.

I can imagine why these things are expensive, as someone who occasionally cleans the local Olympic pool using an underwater vacuum cleaner (just a side gig to get free diving time). Salty or chlorinated water (and public pools usually use heavily chlorinated water) will dissolve almost anything over time - I've seen chlorinated water eat through plastic or neoprene in 2-3 years of use. Account to that mentioned vacuu…

Yes, and it's not just the chlorinated water, but also the atmosphere in a swimming pool that causes problems. https://www.hse.gov.uk/foi/internalops/sims/cactus/5_02_18.h...

Ductwork collapse in Colorado earlier this year https://www.sportskeeda.com/pop-culture/what-happened-gaylor...

Re: Underwater Chain Saws

#85

Post by theamk »

MichaelZuo wrote: post #60
theamk wrote: post #38

Earlier quoted context omitted.

I worked at the company which used a proprietary compiler, IDE including debugger.. It was few thousands $ I believe. plus about the same amount for their proprietary JTAG adapter. Worst software I ever used. Crashy, slow, critical features missing (example: debugger can show thread list... but not the stacks of other threads). So no, I would not expect expensive commercial software to be better. It might generate 2%…

But at least the vendor would guarantee, in writing, some minimum baseline of performance?

At most, it would be something like "our examples work, and we can provide support". I've never seen things like "IDE does not crash" written into contracts.

Re: Underwater Chain Saws

#86

Post by m3047 »

itishappy wrote: post #78
crdrost wrote: post #28

Earlier quoted context omitted.

For the first question, according to [1] gasoline uses 9000L air per liter of gas and a liter of gas runs a chainsaw for an hour ish, something like 150 L/minute. This is an order of magnitude higher than humans or so, so a scuba tank that lets you dive for an hour would only let you chainsaw for maybe 5-10 minutes? [1] https://news.ycombinator.com/item?id=9504215#9505263

And that's at atmospheric pressure! 100ft would be 4x the pressure at the output, requiring 4x the flow rate to do the same work. (Assuming you don't have some sort of magic low-pressure high-volume chainsaw "rebreather" apparatus.)

> requiring 4x the flow rate to do the same work.

I strongly suspect that this is incorrect. A given amount of oxygen and fuel releases the same amount of energy at any (reasonable?) pressure. 4x oxy (and fuel) --> 4x energy... this is the principle of turbochargers and superchargers (although the limiting factor is compression).

Interestingly, and paradoxically, I suspect that at an appreciable depth you mitigate the "air pump" effect and you don't need the compression stroke (or as much of one) to achieve a particular fuel mixture density prior to ignition so you'd lose "compression braking" and gain some efficiency.

(I also suspect that what happens if your vessel implodes and you're suddenly subject to 6,000psi is that the now superheated oxygen reacts with any oxidizable material at hand in an explosive exothermic reaction.)

Re: Underwater Chain Saws

#87

Post by otabdeveloper4 »

MichaelZuo wrote: post #60
theamk wrote: post #38

Earlier quoted context omitted.

I worked at the company which used a proprietary compiler, IDE including debugger.. It was few thousands $ I believe. plus about the same amount for their proprietary JTAG adapter. Worst software I ever used. Crashy, slow, critical features missing (example: debugger can show thread list... but not the stacks of other threads). So no, I would not expect expensive commercial software to be better. It might generate 2%…

But at least the vendor would guarantee, in writing, some minimum baseline of performance?

Ha ha. Oh boy.

Re: Underwater Chain Saws

#88

Post by qchris »

jeffrallen wrote: post #48
theamk wrote: post #38

Earlier quoted context omitted.

I worked at the company which used a proprietary compiler, IDE including debugger.. It was few thousands $ I believe. plus about the same amount for their proprietary JTAG adapter. Worst software I ever used. Crashy, slow, critical features missing (example: debugger can show thread list... but not the stacks of other threads). So no, I would not expect expensive commercial software to be better. It might generate 2%…

Leonard's Law: Software will be as bad as it's users can tolerate, and no worse. VHDL compilers are catastrophically bad, because electrical engineers have to tolerate them and make tape-out. FADECs don't normally crash airplanes because pilots don't like when that happens.

Is there an article/primary source on this that you can point up? I spent a few minutes searching but couldn't seem to find anything.

Re: Underwater Chain Saws

#89

Post by dayOneFatally1 »

Daub wrote: post #12
CBLT wrote: post #2

From the user manual on that page: > Maintain proper footing and balance at all times. Is this not supposed to be used in deep water? Or am I just swimming wrong?

Former chainsaw operater speaking. I cant imagine easily using a chainsaw underwater for the every action has an equal and opposite reaction thing. However, I notice that the front spikes on the saw are noticably big. When these are dug into the timber, they offer a fulcrum using which the operator can apply force onto the timber. This could lessen though not negate the issue. I gave up chainsawing the day I accident…

All I'm hearing is, you were a chainsaw operator for one day: the same day you got your boots.

Re: Underwater Chain Saws

#90

Post by dayOneFatally1 »

Noumenon72 wrote: post #75
ordu wrote: post #32

Earlier quoted context omitted.

> Just that morning I had put on a pair of steel toecap boots for the first time. Saved my toes. Amazing coincidence. Cannot help but think that it was not a coincidence, but you feeling your toes safe because of toecaps.

Perhaps he bought the boots realizing he was about to attempt things where his toes were at risk.

I think he only had the job for one day.
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