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The San Franciso Fire Department makes its own wooden ladders by hand

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Re: The San Franciso Fire Department makes its own wooden ladders by hand

#161

Post by pm24601 »

LeifCarrotson wrote: post #50
lisper wrote: post #22

Earlier quoted context omitted.

> one can't help but suspect that sheer tradition is a somewhat significant factor Only if you didn't read the article. "There's a city-specific reason why San Francisco has stuck with wood rather than swap over to metals, and the answer lies in looking up. The high-voltage cables and wires that guide the city's (oft-maligned) public transport system Muni, and trolley cars crisscross above nearly every street, mean t…

And only if you're also about 40 years behind ladder tech - notice the stepladders in the "A view of the main repair facility" photo? They're nonconductive fiberglass. They're stronger than wood, lighter than wood, don't need to be oiled/varnished, don't require cutting down old-growth trees, and aren't susceptible to moisture damage. You can buy them exhaustively tested, mass produced, in whatever quantities you req…

I would bet another advantage of wood is they fail gracefully.

From article:

"We had one ladder here that was fully involved in a fire for 25 minutes, and the whole tip of it—six feet—was crispy. It looked like a log you pull out of a campfire," Braun says. "That can't go back in service but we were curious, so we put a new halyard [rope used to hoist ladders] on it for a load test. Even in that condition, it passed."

Re: The San Franciso Fire Department makes its own wooden ladders by hand

#163

Post by jerf »

sbov wrote: post #91
HillaryBriss wrote: post #69

Earlier quoted context omitted.

a retired police officer once told me that the quantity of officers citywide goes through a repeated cycle from low to high to low again. when the number of officers is too low and there's too much crime, the people demand that the government hire more. so government does that. and crime goes down. then the public notices all these police officers "doing nothing" and complains about wasted government resources. so, n…

This is a common phenomena, and I'm not sure if there's a general term for it. E.g. people prematurely stop taking antibiotics because they feel better, or people go off their meds because they feel fine, etc.

I'd say this is best described by the concepts from control theory. In this case it really reminds me of bang-bang control: https://en.wikipedia.org/wiki/Bang%E2%80%93bang_control and in particular, the failure state that it can result in when applied in the real world: "depending on the width of the hysteresis gap and inertia in the process, there will be an oscillating error signal around the desired set point value (e.g., temperature), often saw-tooth shaped." In this case, there is a ton of hysteresis and inertia in the process, and by golly, the sawtooth is what you get... more officers this year, more officers next year, more officers after that, maybe it tops out a bit, and then BANG big cut.

It doesn't perfectly apply because technically, the system does not merely have two states, but the failure state is still very reminiscent of what is described here.

As kcorbitt points out in a sibling comment, differential equations are also a very powerful mechanism for understanding these phenomena, even when they are continuously approximating a discrete function like "number of police officers". Unfortunately, the standard treatment of this incredibly practical and important topic in college is terrible, and people come out with no understanding of how important it is to understanding the real world. As a really simple example, anywhere you can find a -dx^2/dt^2 term, you are almost certain to experience oscillations; they can be drowned out but it takes a lot, to put it in intuitive terms. With so many such terms in the world, there's a lot of oscillations that you simply can't avoid. I tend to believe our economy oscillations more than it absolutely has to for various reasons, for instance, but the idea I've sometimes seen proposed that it shouldn't oscillate at all is impractical. Too many terms like that in the world.

Re: The San Franciso Fire Department makes its own wooden ladders by hand

#164

Post by mike12345 »

hinkley wrote: post #119
_bxg1 wrote: post #102

Earlier quoted context omitted.

My takeaway is that there are benefits to in-housing your own tools, not that everybody should. There's also a middle-ground available in the software industry: reading the code of the open-source tools you use. You can understand how your tools work without rebuilding them from scratch. Also, if you're using open-source (which most people do these days), the "cheaper" argument doesn't apply.

Those smoke jumpers aren’t making their own nuts and bolts, ropes, cloth, or felling their own trees. They’re making tools by assembly. Many of us work the same way. From what I understand every master craftsman has a small quantity of tools they either made themselves or at least modified to purpose. Tools with bits added on or ground off (eg, wrenches ground thin for tight spots, or magnetized). I class jigs as a s…

A software equivalent to jigs, might be something like specialized project templates available in IDEs and the like.

Re: The San Franciso Fire Department makes its own wooden ladders by hand

#165

Post by zrobotics »

analog31 wrote: post #159
legitster wrote: post #2

If you get a chance to visit a Smokejumper base, I highly recommend it. One of the things you learn is that everyone on the team is required to make all of their own equipment by hand. So all of these highly trained, ex-military guys spend days on end doing nothing but sewing clothes and packing parachutes. The reasons described: - Cheaper than contracting out everything - They have a better idea of the exact specifi…

A related anecdote: There was for a long time, a history of students in certain disciplines such as physics and some areas of chemistry, making their own tools and equipment. My dad had to build an NMR as part of an analytical chemistry course. I built an exceptional amount of gear for my graduate research project. Of course there's the bit about using cheap labor. But a side result is that you have a chance of actua…

That might have more to do with 1)students being cheap & 2)researchers often needing custom equipment that is unavaliable commercially. I know the justification given for undergrad chemists learning glassworking was the expectation that as professionals it would be a required skill.

Re: The San Franciso Fire Department makes its own wooden ladders by hand

#166

Post by jmiserez »

hinkley wrote: post #119
_bxg1 wrote: post #102

Earlier quoted context omitted.

My takeaway is that there are benefits to in-housing your own tools, not that everybody should. There's also a middle-ground available in the software industry: reading the code of the open-source tools you use. You can understand how your tools work without rebuilding them from scratch. Also, if you're using open-source (which most people do these days), the "cheaper" argument doesn't apply.

Those smoke jumpers aren’t making their own nuts and bolts, ropes, cloth, or felling their own trees. They’re making tools by assembly. Many of us work the same way. From what I understand every master craftsman has a small quantity of tools they either made themselves or at least modified to purpose. Tools with bits added on or ground off (eg, wrenches ground thin for tight spots, or magnetized). I class jigs as a s…

Utility functions and small self-contained libraries. Nice thing about software jigs is that copying them is free, so often they’re open-sourced.

Re: The San Franciso Fire Department makes its own wooden ladders by hand

#168

Post by malbertife »

kcorbitt wrote: post #125
sbov wrote: post #91

Earlier quoted context omitted.

This is a common phenomena, and I'm not sure if there's a general term for it. E.g. people prematurely stop taking antibiotics because they feel better, or people go off their meds because they feel fine, etc.

Also a common pattern in biological ecosystems. Great weather one year leads to lots of fresh grass around, so more rabbits than usual survive to adulthood. An abundance of rabbits leads to more foxes than usual surviving. But the next year the increased fox population over-hunts the rabbits, crashing their population, and the next winter the underfed fox population crashes in turn, allowing more rabbits to survive t…

The Lotka-Volterra equations are a simple and popular mathematical model of this kind of dynamics:

https://en.wikipedia.org/wiki/Lotka%E2%80%93Volterra_equatio...

Re: The San Franciso Fire Department makes its own wooden ladders by hand

#169

Post by TimTheTinker »

chadwilken wrote: post #162

Of course they do, that is the hipster capital of the world and hipsters need everything to be retro.

Retro is not automatically bad because hipsters like it. Also, "hipsters" did not exist prior to 10 years ago. They've been doing this for a whole lot longer than that.
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