Lift, pull, “bang!” Lift, pull, “bang!”

As most of San Francisco sleeps, a crew of Muni employees — splicers — work overnight to repair the underground 1-1/4 inch cable that carries San Francisco’s iconic cable cars up and down some of The City’s steepest hills.

Christopher Chong, 63, firmly grips a line and holds on tightly as he hits the mallets against the cable again, again, again. He stops, breathes, and waits for his team to move back a few feet before again grasping the cable tightly. Chong thumps the mallets together again; they clang loudly.

For Chong and the other 11 splicers on his shift, this is just another 9 to 5 at the office — that is, 9 p.m. to 5 a.m.

Chong, a cable car maintenance worker for 30 years, says about the night shift:

“On graveyard, you’re actually doing the work. I feel a sense of pride in what I do … I’d rather get in there and actually do the work on the cables so I think that’s actually the fun part.”

Chong begins his night around 7:30 p.m., driving from his home a few blocks from Golden Gate Park to the Cable Car Barn and Museum at Washington and Mason streets. The museum houses all three cable lines, and provides shelter for The City’s 40 historic cable cars during the overnight hours.

Chong arrives by 8:00 p.m., enters the office and checks a log that shows the work performed during the previous shifts that day. If Chong notices any issues from previous shifts, he talks to the splicer from that shift. Problems with the cable may require Chong to refocus his repair plan for the night.

Other splicers working the night shift filter in until 10:00 p.m. He assigns small tasks to trainees for them to conceptualize and learn how to do certain jobs:

“When they see what we do, they think anyone can do it. … But there’s a certain skill set that goes along with this job that’s very demanding … so we try to get them to get the feel[ing] of using the tools in the correct way.”

Around 11:30, Chong gives the splicers time to rest and eat:

“[At] one o’clock, that’s when the heavy work starts.”

After the last cable car rolls into the barn, the cable lines shut down and the workers check the splices – “the weakest point of the cable.”

This night, Chong and his crew implement a new splice.

They start by tightening a clutch to keep the same tension throughout the cable, then they get to work. Their job tonight focuses on 96 feet of cable coming from one cable car line. Using heavy equipment, splicers cut the cable in two places to more easily work on two separate pieces of cable – each 48 feet long.

Chong says:

“We cut out half the old splice. … We take the damaged area [of the cable] out and replace it with new wire.”

Explaining the repair process, Chong adds that the cable is made up of six strands (or wires) and a core, “the backbone of the cable.”

Chong says:

“… splices [are] held together by tails (ends of the cable) interwoven back into the core, so what we do is we pull those tails.”

Then, they strip out the damaged strand from the larger cable. The splicers must get the strand back “into profile,” meaning that they need to straighten the strand for it to be as uniform and shapely as the rest of the cable.

To straighten the cable, a group of splicers grab hold of the strand, gripping it tightly, while one worker takes hold of two large mallets and repeatedly hits them against the out-of-profile section.

Then, they “weave in a new set of wires onto the strand.” Workers remove the core and replace it with the new set of interwoven wires – the new core. By 4:15 a.m., they have reattached the two pieces of cable and put the newly reformed cable back into operation, just in time for cable cars to begin rolling again around 5 a.m.

The cable car system in San Francisco is the only one of its kind in the world, so splicers must fabricate their own tools and implement a specific system to complete their repair work. The work is very physically demanding, and it is not automated – the process is almost entirely driven solely through the workers’ labor.

Chong likes the job because, while he and the other splicers work as a team, he finds working by himself is easy to do:

Chong says with a chuckle: