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Also from 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
by exegete 8y ago
Also from 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 that ladders made of conductive elements are generally just too dangerous to use.
>"I think there's a lot of fire departments that went aluminum and wish they could go back to wood but it's too expensive," Braun says. "There's only two ladders manufacturers in the states—and we're one of 'em. We only make our own ladders and can barely even keep up with what we have."
- gsnedders 8y agoHow do other countries with OHLE cope? AFAIK, most use metal ladders. Just rely on quickly getting the wires isolated?
- VectorLock 8y agoI think when the electrical service wires have insulation it isn't as much of an issue as opposed to the electricity driven trollies needing bare conductors.
- gsnedders 8y agoOHLE is specially overhead equipment like that used for trams, trolleybuses, etc. Most places I was thinking of don't have electrical supply wires overground.
- rickycook 8y agomelbourne has probably the worlds most extensive tram network, with exposed overhead wires and our fire department uses metal ladders
- VectorLock 8y agoHaving never been to melbourne how close to they run to multi-level structures? In San Francisco the wires powering trollies are practically feet from dwellings.
- mdorazio 8y agoI don't understand this. Fiberglass is non-conductive, so that's not really a reason to not use non-wood ladders. It is also generally stronger and more durable for the same weight.
- tw04 8y agoEvery fiber glass ladder I've seen has aluminum caps at both ends and aluminum steps.
- function_seven 8y agoAs long as those steps and caps are connected with fiberglass sides, what’s the issue?
- maxbond 8y agoAt high voltages the electricity may be able to arc between the steps. Electricity will do some pretty incredible things at high voltages. Check out this video of some idiots turning a powerline into a Jacob's ladder. https://www.youtube.com/watch?v=-yBTHrXEK4U https://www.youtube.com/watch?v=-yBTHrXEK4U
- function_seven 8y agoThat video was awesome. I'm guessing that the types of ladders SFFD are using aren’t going to be anywhere near power lines of that high a voltage.
- raldi 8y agoI can't tell what, if anything, they were doing besides filming.
- jquast 8y agoi think a weight tied to thin uninsulated wire, thrown like a baseball over the lines