Why do San Francisco firefighters keep using wooden ladders at the fire site?

by Thomas Hawk

Wooden ladders are used at the fire department in California / San Francisco, USA. A wooden ladder is made by a craftworker belonging to a fire department by hand, and it seems that it is used for 100 years with the old one. At first glance I get worried that if I use a wooden ladder at the fire site I will be burning, but there was a reason for that to be used for a long time.

Inside San Franciso's Fire Department, Where Ladders Are Made by Hand
https://gizmodo.com/inside-san-francisos-fire-department-where-ladders-are-1552279252

All of the tree ladders used in the San Francisco fire department were created by craftsmen in the San Francisco fire department. We do all the assembly and repair by ourselves. The lumber used for fire ladders is luxury goods and bamboo pine on the American West coast is used. The tree grows slowly, and so that the density of the annual rings becomes high, I use things that were growing on the east slope of the mountain. Mr Brown says that there must be nine annual rings per inch (about 2.5 cm). Also, the inclination of the annual ring and its shape are important in making a ladder.

Wood that clears these stringent conditions first gets used to the San Francisco climate of about 13% humidity in the warehouse. The craftmen will drive the electrodes at both ends of the wood and measure whether the wood has been well adapted to the climate as a material of the ladder by flowing current.

Once the wood adapts to the climate, we process it immediately and make a ladder. All the parts of the ladder will be decided while measuring the processed wood with the machine, after painting the linseed oil twice, apply a powerful varnish like that used for the leisure boat a couple of times. It seems to be a simple task at first sight, but work so that it does not distortion and assembles it uniformly and paints varnish equally, based on the structure of the tree so as not to be damaged immediately under severe conditions Craftsmanship.

The ladder for fire fighting is designed to be reassembled even after disassembling. Mr. Brown says, "We are an environmentally friendly organization in San Francisco and we do not want to waste wood." Thirteen kinds of wooden ladders are made in total, and it is said that there are 50 feet (about 15 meters) high ones, but in the unlikely event of being broken, they are processed into ladders of different heights by reassembling It is also possible to do so.

The reason that the San Francisco fire department uses wooden ladders rather than aluminum alloy ladders is because wooden ladders are more elastic and durable than aluminum ladders that are commonly used. According to Mike Brown, head of fire department managers in San Francisco City, the longevity of aluminum alloy ladders is at most 7 to 8 years, but wooden ladders should continue to be used for a long time while reworking It is possible.

by torbakhopper

It is a relatively new ladder that is shown on the left in the image below and it is repaired about 1 or 2 times. The thing on the right is a ladder used about 60 years ago, he said he is reworking five or six times. The ladder on the right also has burned traces in varnish. Ladders older than new ladders are deeply shaded because they are painted over and over again.

Also, as the trolley bus runs in San Francisco, a lot of electric wires are stretched around the town. For that reason, I prefer using a wooden ladder rather than a metal ladder with high conductivity.

However, since wooden ladders for fire fighting are very expensive compared to those made of aluminum alloy, it seems that it is hard to be used in fire stations in other towns. Mr. Brown says, "In California where there is San Francisco there are only two places making ladder, the San Francisco fire department is one of them We are only making our own ladder we use It is precise, just by maintaining the ladder that we have. "

Jerry Lee who worked as a maintenance craftworker in the San Francisco fire department for 28 years and retired in 2017 said "After retirement, I was really surprised that my ladder was" beautiful. "For me, It is simply a functional thing. " In addition to Mr. Jerry Lee, he also engaged in the sculpture of an eagle sitting on a bell attached to a fire truck besides the ladder for fire, saying, "Not only ladders but almost all of the things used in the San Francisco fire department We were making and repairing with them. "

by Todd Lappin