San Francisco's Fire Department is one of the few left in the United States that still uses wooden ladders. Each is made by hand at a dedicated workshop. Some have been in rotation for nearly a century. We'll get to the why and how, but hang on: Wouldn't a wooden ladder burn? Yes. They go up in flames.
That sounds like a terrifying safety hazard, but these ultra-durable climbing tools aren't constructed from run-of-the-mill kindling. I visited the SFFD's in-house ladder studio and main repair facility in SF's industrial Bayview neighbourhood, where every single fire apparatus cycles through when it needs to get fixed up. My guide, Mike Braun, has been on-site for the past 20 years, and has run the whole show for 16 of those.
The proud motto of the SFFD workshop.
Wood is resilient in ways which aluminium -- now standard for fire department ladders -- can't even compare. "You know if you take an empty coke can and bend it three or four times and it tears really easy? That's what aluminium ladders will do," Braun says. "They have a seven to eight year lifespan, after which they need to be replaced."
Wooden ladders, on the other hand, can last indefinitely. "You can stress wood right up to its failure point a million times; as long as you don't go beyond that, it will come right back to where it was. They can be involved in a fire for a pretty long time; after that, it's just a matter of sanding off the top coat of material then inspecting the wood. If it's good we'll re-oil it, revarnish it, and put it back in service."
A panorama of the ladder shop.
Now lest you think this is just a quick fix for your own failing apparatus, the shop is starting out with an exceptionally high grade of lumber. Ladder rails are all made from West Coast Douglas Fir, which Braun says is harvested from the eastern slope of a mountain: That side gets less sunshine; which means the trees grow more slowly; resulting in rings that are closer together and an all-around more resilient material.
"There have to be nine rings per inch -- minimum," Braun tells me. "You don't want them spread too far apart because that makes it weaker. Plus, the grain pattern can't vary more than 15 degrees off of vertical, with no knots, no inclusions, no funny marks."
This is marked up to show which part of the wood will be used for rails based on the SFFD's exacting standards. Anything that doesn't make the cut will be turned into cross-beams or pulls.
The Waiting is the Hardest Part
If it passes the ring density test, then it's time to fully acclimate the wood to San Francisco's climate, which is about 13 per cent moisture, before it's ready for action. Each piece is left in the workshop for years until it hits the right ratio -- at one year per inch of thickness, it's quite a wait! Testing is done by pounding a probe into each end of the wood and sending a current between the two points.
Here's where the wood sits for years, acclimating to the moisture level in SF's climate. The darker pieces on the top have been around for longer -- "Some are 50 years old," Braun says -- while the boards on the bottom still have a ways to go.
Never a Wasted Rung
OK, so now the wood is properly aged -- what next? "Our ladders were designed to be disassembled and reassembled," Braun says. "We use machinist level measurements so all the rungs are spaced properly and precisely." Each ladder gets two coats of linseed oil, then two or three coats of marine spar varnish.
That incredibly precise craftsmanship is obviously imperative to making damn certain these things will withstand the most extreme conditions and incredible wear and tear, but there's an important mix-and-match component to that design decision -- one that's central to the way the workshop and repair facility approach their work.
"We're all pretty eco-friendly around here," Braun says. "We don't like to waste." This could be their second motto. To wit: Elements from every ladder -- all 13 different styles, the tallest of which is 50 feet -- can be repurposed in a newer incarnation, should the original need to be taken out of service for any reason.
Here you can see old rungs -- made of Hickory or Ash -- being used on new rails. "Those were from a bigger ladder; we just turn the ends, and put 'em in the next size down."
Each ladder gets two coats of linseed oil, then two or three coats of marine spar varnish.
Have a look at the ladders above. "See what happens? You have a sharp edge right there on the left -- that's a brand new ladder that's been refinished once or twice. That one on the right is probably 60 years old, and has been refinished five or six times. That one in the middle is ready to be taken out of service because it's getting too thin. We may load test it and keep it as a spare -- one of those just-in-case ladders. But you can see as they get older the wood gets darker from the finish."
In fact, the whole center is like an ultra-high-efficiency hub for upcycling; almost everything is salvageable in some way. "Anything that we can reuse to save money for the city, we'll reuse it. The idea is always to economize how we can by utilising component parts -- especially because we've already paid for them."
Police car doors and tires, ready for a second life.
More supplies, future TBD.
If Wood's So Great, Why Don't More Fire Departments Use It?
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 aluminium 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."
For 28 years, a man named Jerry Lee built and restored all of San Francisco's ladders -- he retired last year, and finished his reign with a stint as the artist-in-residency at Workshop Residence. After all that time, showing his handiwork to a new audience offered an entirely new perspective. "I was so surprised when people referred to the ladders as 'beautiful.' For me they have always just been functional," he told me.
Functional is an understatement.
"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."
Here are some more pics from my visit:
A view of the main repair facility. "We fix literally everything. The only thing we don't do here is Muni -- they have their own facility -- and some of the water department stuff." Each of the portable lifts beneath the raised vehicles can hold seven-and-a-half tons.
Not every day you can step beneath a massive Fire Department vehicle -- unless you work here.
One of the ladders in its natural habitat.
Braun holds up a battering ram he helped design.
"These are from the olden days when they used horses had to pick up bales of hay," Braun says. "But the guys still carry these because they use them for grabbing junk out of a fire."
This eagle is a Jerry Lee original -- hand carved, and the only one of its kind. "Anything that says SFFD on it, we made it." The "old" bell, says Braun, "has been on a couple rigs."
The machine shop is... cluttered.
And finally: This may have been my favourite part of the tour. "Pete has collected all these different doughnuts over the years. They're all real, and covered with lacquer so they won't go bad. Some of these are ten years old."