It might seem like a bit of a trollish question, but I'm wondering the same thing. I am trying to think of benefits to wooden ladders; they are heavy, easier to damage, harder to make. Probably an incredible challenge to make extendable ones too.
The one upside beyond cosmetics I can think of is they probably don't get hot the way metal does.
edit: OK, I finished watching the video, I understand now. So it's not that they are necessarily better than metal, but they are necessary in SF.
See the article at http://articles.sfgate.com/2007-06-25/bay-area/17249021_1_wo... - They don't conduct electricity like aluminum or wet fiberglass ladders do....Aluminum or fiberglass, when it gets too hot, it gets soft; it will actually fold over without any warning."
wood is far more safer when exposed to heat than metal. while wood starts to burn on the outside it turns into coal, which effectively seals the remaining wood core from oxygen - preventing (for a while) further structural loss. this is taken into consideration when sizing wooden structures in buildings.
metal on the other hand loses structural integrity when exposed to heat shockingly fast. the wtc towers showcased this effect quite publicly.
experienced firefighters prefer to deal with fire in wooden structures than in metal ones. they can predict how long a wooden roof structure will take till collapse quite well, while a metal structure is a nightmare.
so, flammability and structural integrity under heat are two different things. non-intuitive for most non-engineers, hence the retarded wtc discussions.
in SF's case they use wood because of its function as an isolator.
>>metal on the other hand loses structural integrity when exposed to heat shockingly fast. the wtc towers showcased this effect quite publicly.
but isn't that at extremely high temperature? Wouldn't that same amount of heat burn wood far faster than it would damage metal?
The wtc towers were exposed to jet fuel and beaten by a jetliner slamming into the building. Also, the metal beams in the wtc towers were made of steel while ladders are made of aluminum.
For a straight-up failure test, yes. Try exposing wood and metal to fire, then cool it, then expose it again, etc. You can tell visually when the wood is likely to fail much easier than the metal.
Aluminium also melts before it glows red from being hot. It's why it's relatively difficult to weld, and why there were a lot of failures in early aluminum-frame bikes.
If you build it from right type of wood prepared the right way - those things are incredible. They are insulators - helping with electricity AND heat. They are predictable...
Wood is an awesome material - but it takes time and expertise to do it right - thus making it expensive. But nevertheless the highest quality and style items are still made of wood - it just ain't cheap. Think: furniture, insulation, windows, doors, floors, stairs... Hell wooden shingle roofs can and do last over hundred years if prepared properly.
I didn't spot where it said why the SFFD themselves manufacture the ladders (as opposed to buying them from somewhere). Should it really be the job of the SFFD to build ladders from raw materials?
I think it's the only method to ensure that all the ladders are of perfect quality. If you outsource the production to the lowest-bidder, then you get lowest-bidder quality.
It's a way different thing to build a ladder that your colleagues (and friends) are going to climb, than to build something on an constantly more restrained time schedule for somebody you don't even know the name of. The latter encourages shortcuts, the former encourages avoiding them.
There are a lot of life safety devices which are made by someone other than an end user, after competitive bidding.
You either need to do testing of every article delivered, or set up something like ISO 9000/9001 quality management and accept that you will be paying a premium for a documented, repeatable process.
Counterfeit parts getting into the supply chain (which might be visually identical, and may even appear identical to testing) are a problem, but that's where having documented/audited suppliers comes in.
Flying is statistically much safer than driving. They may not ensure quality in many of their amenities, but their safety standards are as high as they come.
That's not exactly an apples to apples comparison the space shuttle's record sit's between cars and commercial aircraft in deaths per passenger mile. 14 deaths in 20k orbits * 7 people @ 42k miles per orbit. = 1 death per 420 million miles vs commercial aircraft which sit at 1 death per 2,000 million miles vs cars at 1 death per 80 million miles. But, the shuttle is not exactly a safe ride.
Now, if you line things up by trip, it's car's then aircraft then the shuttle.
I wonder what it does to workmens-comp and liability insurance when you build the equipment your employees use as opposed to something bought from a vendor.
When a ladder breaks and a firefighter breaks a leg, the department can't really sue itself, can it?
The video says that nobody has been injured on these wooden ladders - nobody has fallen off. It's implied that none of them have broken in action. Probably worth it to them.
I don't think it's just a quality concern. The video mentions a 15-year "maturation period" for the wood to acclimate to the humidity in San Francisco. If that's a requirement, I doubt there's much of a market (and space) for manufacturing to take place out in the city itself.
Maybe wood used for wine barrels? Doesn't seem like much of a market.
That isn't unique to ladders - wood for any project should acclimate to its environment (humidity) before starting construction and it doesn't take 15 years.
Actually, the time it takes is roughly dependent on the thickness of the wood and the delta in humidity from the place where it was cut and the place where it will be used.
Typically you want to avoid wood used for ladders drying out after the ladder is put together because it will loosen the joints.
OK. And it doesn't take 15 years for the moisture content of wood in the thickness they are using for those ladders to come to equilibrium. And that is assuming that the moisture content is asymptotically approaching some target humidity. Since the humidity in San Francisco varies quite a lot the target ambient humidity is not constant.
So although they may make fine ladders, it's not because they have the wood sitting around for over a decade.
The longer you acclimate the wood, the tighter the joints are. You also are able to spot flaws in the wood. This is one of the reasons why people recover wood from old barns -- a farmer I worked for in high school was offered a substantial amount of money for wood in a Dutch barn built in the 1600's.
These guys are old-school craftsman who are obsessed with quality. Refreshing in this age of disposability.
The reason old wood is valuable is because it has characteristics that are not available in lumber harvested today. These include grain, width of planks and density. Not because its moisture content has had several centuries to change.
When you have a plank, post or beam that has stood in place in an unheated barn for 400 years, it has been subject to the vagaries and every permutation of hot & cold, damp & dry.
These cycles bring out the best and worst of the wood. Obviously you are recovering old wood in a barn for other reasons as well, but in the ladder scenario, they want top notch wood that will last. Since SFFD has ladders that have been in active service since 1919, they obviously have that down.
Undoubtedly the astrological sign of the wood is also a factor in how the wood has responded to its life experiences, but that is all irrelevant for making a ladder as long as the wood's moisture content has stabilized suitably for its target environment.
a). it is a tradition
b). they want to keep the tradition
c). they like building the ladders to ensure safety for their fellow firefighters
d). why even question whether they should keep doing it or not. leave them to continue their traditions and handiwork.
Because SF has low hanging power lines and because the weight makes them more stable in windy situations. Why not? It's not like if they had firemen do ladders in their free time. They have a different department where only 2 people work making ladders.
I don't know how well this is going to be accepted here, but I marveled at the cultural value of making and using your own wooden ladders in this day and age. In our practical, efficiency-obsessed style of doing things, people generally don't care about these details anymore. But those ladders are beautiful. I wished someone had pointed that out, because I'd never noticed it in SF.
But in a city that can't keep its budget priorities in line, this seems like another instance of a lot of money without any real data that the money produces better results.
It's hard to say for sure that you could get a fair assessment since peoples' lives are on the line.
If the ladders are twice as much, but due to the peculiar electrical and atmospheric (wind) conditions in SF, could it be argued that these ladders increase the safety of the firefighters?
TCO would also have to be measured to be certain that this is worth it or not. If aluminum ladders are half as much, but last a quarter of the time… then it's arguable that the wooden ladders are cheaper.
I'm close to people who work in the public sector, and this sort of thing is not where the real waste is. This is two or three guys in a shop somewhere. At least they're making stuff. You know that Despair.com catchphrase, "None of us is as dumb as all of us?" Well it's like that. You need some serious mass before you can start moving money and influence. Real waste comes from political graft.
Imagine a whole branch of a municipality where more than half the people are managers sitting around and doing nothing. They're all making upwards of 100k, and they're all covering each other's asses. Their propaganda machine is bigger than yours. Now before all you Republicans and Libertarians get all smart-ass, I should add that it happens plenty often in the military-industrial complex too with the contractors who do the majority of the real work. Same stories, different people.
> Now before all you Republicans and Libertarians get all smart-ass, I should add that it happens plenty often in the military-industrial complex too with the contractors who do the majority of the real work.
Funny that you mention Libertarians when they're hardly defenders of the military-industrial complex.
Amazing. An old tradition that has completely failed to change in response to new technology.
You wouldn't want to use an aluminum ladder near power lines, of course. So how about fiberglass ladders? After searching on "firefighter fiberglass ladder" you get http://www.fireladder.com/fiberglass.html
There's no 50 foot model, like the one talked about in the video, but there's a 40 foot version. Costs half as much, and weighs half as much. It's non-conductive, and most importantly, it's made by a civilian contractor, so you don't have to run your own ladder building shop.
"The San Francisco Fire Department has been "green" since before it was a fad"
I fail to see how making your own ladders is "green". Is the carbon footprint of employing two guys that maintain ladders, heating a shop, etc more-so then that of a company that can manufacture ladders at a larger scale? etc?
I live across the bay from SF, but if I was a resident of San Francisco, I would seriously consider this an inefficient use of public funds unless they had data to prove that wood ladders are economically superior to fiberglass ladders.
They mention that their data actually admits the opposite, that they're less economical, costing about $100/foot. They don't mention what the alternative ladders cost, but it sounds like their argument is because wood ladders gain them advantages that others don't: nonconductive material, heavier weight against winds, etc.
They also say that they last several times as long. Considering they have a large stock to begin with spending buying a 30' ladder @ 100$ / foot vs 30$ a foot X 3 replacements works out to about the same amount of money.
I work on decade old aluminum ladders on a daily basis, I fail to see how wooden ladders last longer under regular conditions.
An aluminum ladder conducts electricity, but also conducts heat. I let a ladder on a black shingle roof one day in the middle of summer and I had to get gloves to hold it long enough to literally throw it off the roof.
> "You don't want to use a 50-foot lightweight aluminum ladder in heavy winds -- it's too dangerous," Cohane said.
Can and do, but fixing the feet and using tie-offs isn't exactly practical for firefighters.
> The largest ladder they make is 50 feet, weighs 350 pounds and takes six firefighters to lift.
Compare this to the largest ladder we use, which is IIRC 40 feet and is easily moved by one man if done properly (we've had guys fall with them before).
> advantages that others don't: nonconductive material, heavier weight against winds, etc.
There are other large US cities with wind, one is even known as the "Windy City" (although it isn't the windiest). All of them need nonconductive and heat resistant.
Wood is not just a poor electrical conductor, it's also a poor conductor of heat. That means that a wood ladder resting on a wood building will not become hot enough to ignite the structure on which it is resting.
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[ 4.6 ms ] story [ 150 ms ] threadThe one upside beyond cosmetics I can think of is they probably don't get hot the way metal does.
edit: OK, I finished watching the video, I understand now. So it's not that they are necessarily better than metal, but they are necessary in SF.
metal on the other hand loses structural integrity when exposed to heat shockingly fast. the wtc towers showcased this effect quite publicly.
experienced firefighters prefer to deal with fire in wooden structures than in metal ones. they can predict how long a wooden roof structure will take till collapse quite well, while a metal structure is a nightmare.
so, flammability and structural integrity under heat are two different things. non-intuitive for most non-engineers, hence the retarded wtc discussions.
in SF's case they use wood because of its function as an isolator.
but isn't that at extremely high temperature? Wouldn't that same amount of heat burn wood far faster than it would damage metal?
The wtc towers were exposed to jet fuel and beaten by a jetliner slamming into the building. Also, the metal beams in the wtc towers were made of steel while ladders are made of aluminum.
http://www.burnsstainless.com/yieldstrength.aspx
So you need a ladder that can cope with such problems.
If you build it from right type of wood prepared the right way - those things are incredible. They are insulators - helping with electricity AND heat. They are predictable...
Wood is an awesome material - but it takes time and expertise to do it right - thus making it expensive. But nevertheless the highest quality and style items are still made of wood - it just ain't cheap. Think: furniture, insulation, windows, doors, floors, stairs... Hell wooden shingle roofs can and do last over hundred years if prepared properly.
Kindly put a warning in the title when you post videos. Especially when they
They said sales of wooden ladders doubled in the 5 years prior to when the article was written.
It's a way different thing to build a ladder that your colleagues (and friends) are going to climb, than to build something on an constantly more restrained time schedule for somebody you don't even know the name of. The latter encourages shortcuts, the former encourages avoiding them.
You either need to do testing of every article delivered, or set up something like ISO 9000/9001 quality management and accept that you will be paying a premium for a documented, repeatable process.
Counterfeit parts getting into the supply chain (which might be visually identical, and may even appear identical to testing) are a problem, but that's where having documented/audited suppliers comes in.
http://www.sfgate.com/webdb/sfpay/index.shtml
I think there must to be more to it than that.
Or airlines are making their own airliners now? :)
Now, if you line things up by trip, it's car's then aircraft then the shuttle.
When a ladder breaks and a firefighter breaks a leg, the department can't really sue itself, can it?
The department doesn't sue, the firefighter does.
Department-made equipment means that the city is the only party on the other side of the lawsuit.
Then what about their trucks, their hats and coats, their hoses, and so on?
Maybe wood used for wine barrels? Doesn't seem like much of a market.
Typically you want to avoid wood used for ladders drying out after the ladder is put together because it will loosen the joints.
The varnish helps with this as well.
So although they may make fine ladders, it's not because they have the wood sitting around for over a decade.
These guys are old-school craftsman who are obsessed with quality. Refreshing in this age of disposability.
These cycles bring out the best and worst of the wood. Obviously you are recovering old wood in a barn for other reasons as well, but in the ladder scenario, they want top notch wood that will last. Since SFFD has ladders that have been in active service since 1919, they obviously have that down.
Although it would be a good idea to check the income and pension deals the shop staff have to make sure they're sane.
No doubt about it. I was just answering the question "why even ask".
If the ladders are twice as much, but due to the peculiar electrical and atmospheric (wind) conditions in SF, could it be argued that these ladders increase the safety of the firefighters?
TCO would also have to be measured to be certain that this is worth it or not. If aluminum ladders are half as much, but last a quarter of the time… then it's arguable that the wooden ladders are cheaper.
Imagine a whole branch of a municipality where more than half the people are managers sitting around and doing nothing. They're all making upwards of 100k, and they're all covering each other's asses. Their propaganda machine is bigger than yours. Now before all you Republicans and Libertarians get all smart-ass, I should add that it happens plenty often in the military-industrial complex too with the contractors who do the majority of the real work. Same stories, different people.
Funny that you mention Libertarians when they're hardly defenders of the military-industrial complex.
You wouldn't want to use an aluminum ladder near power lines, of course. So how about fiberglass ladders? After searching on "firefighter fiberglass ladder" you get http://www.fireladder.com/fiberglass.html
There's no 50 foot model, like the one talked about in the video, but there's a 40 foot version. Costs half as much, and weighs half as much. It's non-conductive, and most importantly, it's made by a civilian contractor, so you don't have to run your own ladder building shop.
In a high-wind city like San Francisco, being too light is a bug, not a feature.
I live across the bay from SF, but if I was a resident of San Francisco, I would seriously consider this an inefficient use of public funds unless they had data to prove that wood ladders are economically superior to fiberglass ladders.
http://www.duosafety.com/price_list.html
Update: check starpilot's link here: http://news.ycombinator.com/item?id=1854136, which has a lot more information on the reasoning behind the use of wood.
An aluminum ladder conducts electricity, but also conducts heat. I let a ladder on a black shingle roof one day in the middle of summer and I had to get gloves to hold it long enough to literally throw it off the roof.
> "You don't want to use a 50-foot lightweight aluminum ladder in heavy winds -- it's too dangerous," Cohane said.
Can and do, but fixing the feet and using tie-offs isn't exactly practical for firefighters.
> The largest ladder they make is 50 feet, weighs 350 pounds and takes six firefighters to lift.
Compare this to the largest ladder we use, which is IIRC 40 feet and is easily moved by one man if done properly (we've had guys fall with them before).
There are other large US cities with wind, one is even known as the "Windy City" (although it isn't the windiest). All of them need nonconductive and heat resistant.
So, what makes SF's ladder needs unique?