Hong Kong's Famous Bamboo Scaffolding Hangs on (For Now) | Hacker News Reader

Hong Kong's Famous Bamboo Scaffolding Hangs on (For Now)

nytimes.com

205 pointsperihelions63 comments

Unpaywalled - https://www.nytimes.com/2025/05/24/world/asia/hongkong-bambo...

Former Australia scaffolder here: The bamboo scaffold is used to hold people mainly and to act as fall protection not support weights like steel scaffold (i.e They won't be storing I-Beams on it temporarily or shifting wheel barrows full of cement). Weight difference in people. When I was scaffolding in Australia, I was 70Kg and 178cm tall. I was working with people who were 100-120kg+, Those people would have been carrying 4-5 steel boards about 80-100kgs on their shoulder, I was carrying 3-4 steel boards 60-80kgs. Light duty scaffold, is 2 boards wide (450mm) and 3m long bays. I could pass another person my weight, but some one who is 100-120Kg+ I would struggle on scaffold. Most of it is build at heavy duty steel which is 5 boards wide + 2 board hop ups and 2.4m long (Standards say it should be 1.8m long). After 45M high, scaffold has to restart again and they use I beams inside the buildings and U heads under the screw jacks before they start building again. I prefer buildings 4 storeys high (1 ground + 3 levels), that is you get the sun in the winter and if the shit hits the fan even if you jump from that high you may break bones but you should still be able to live depending on what you land on.

You never know who you'll meet on Hacker News. I recall a comment thread where someone challenged another's assertion about a mathematical concept by saying that only a recipient of certain mathematical award would be qualified to make that point, and it turned out they had. Busted!

The Putnam incident: https://news.ycombinator.com/item?id=35079

Exactly!

I was in Hong Kong several years ago and saw some of the scaffolding up close.

As a former Boy Scout with a lot of experience in knots/lashing etc, I was VERY curious to see what kind of ropes, knots and lashing they use.

Turns out it's just some flat nylon ribbon and mostly a couple quick wraps and overhand knots.

Really is amazing that it all stays together. I imagine the friction between the ribbon and the wood surface of the bamboo must be high enough to be "sticky".

> mostly a couple quick wraps and overhand knots.

"The toughest part of the job, though, is tying a proper knot to secure bamboo poles, which can take years to master"

Cool sketches of the knots - https://multimedia.scmp.com/infographics/culture/article/318...

I'm sure the years to master includes where and which way to do the knots.

> some flat nylon ribbon

Over 0.5 kN per strip, blah blah boring specs for the scaffolding which at 25 pages would be... 100 times shorter than the EU?

Any who, my bamboo wilted after cutting, you have to treat it it seems... so not even close to the knot stage, but did find the spec'ed lashes, then remembered I hate knots, like just the basic reef knot ones... screw years. Zip ties FTW

Knots and construction with poles and rope lashing was always my favourite part of scouts. The sketches of the knot looks cool on the surface but don't tell me much about how they are tied or what other lashings they are similar to. Not much detail and the second image has three running ends?

Years to master a knot? I understand it's critically important that they be tied properly, but years to master a knot just doesn't seem possible.

It can't be right. I could understand architected the scaffolding itself on a large scale would take a long time though, to be safe and reliable.

The post below got flagged, but they the link they shared has some really nice visualizations of the scaffolding:

https://multimedia.scmp.com/infographics/culture/article/318...

Wrapping a rope under tension for several turns around a cylinder can make very strong assemblies. Relevant concept:

https://en.wikipedia.org/wiki/Capstan_equation

Note that the exponent is proportional to the number of turns.

It's a simple square pole lashing knot (also known as a japanese square lashing). It works well with almost any kind of cordage. The knot holds the poles in a 90-degree orientation and the finish of the knot tightens the main cord to lock it in place. Natural fiber actually locks better than nylon as it has more 'tooth'. The use of nylon is mostly to resist the elements, adds a bit more strength, is cheaper to manufacture and easy to cut for disassembly.

Nylon degrades relatively quickly under UV exposure tho. It's a well known thing in climbing/mountaineering to not trust the gear that's been sitting in the sun for a while and people have died ignoring this advice (famously, Dan Osman). Interesting choice for outdoors setting...

It's only about 60% degraded after 36 months exposure. The scaffolds aren't up for that long (they're taken down immediately once work is complete). The nylon joint is several times stronger than it needs to be to keep the poles together (2.5 kN per joint; point-loaded beam is spread between two joints, so 5 kN; max rated beam load is below that).

Just fyi, the guy who did the analysis of Dan Osman's failed rope (Black Diamond's QA manager) concluded the rope was not affected by UV or weather exposure. (https://groups.google.com/g/rec.climbing/c/gW92OrNs7_o?pli=1)

You might be inclined to peruse The Ashley Book of Knots (ABOK).

keep in mind that for tying around things and binding, that the knot is really there to maximize the friction of the line against the thing - and to do so under various circumstances. Ideally the knot itself is holding very little load.

As I lived in HK back in the 1970's I'm pretty sure that was not flat nylon ribbon at all in those days, but simply strips of split bamboo or shavings from the surface of a broken pole. It would make sense to transition to nylon, since that could be made on a spool rather than having to be created on site.

I've got used to how scanty UK scaffolding is now but at first it worried me that it would not be robust enough.

I find the single apartment scaffolding to be the most amazing. These guys turn up at the door of your 30th floor apartment with a bunch of bamboo poles and nylon strips and a couple of hours lated the entire side of the apartment is scafolded, like a spider's nest hanging off the side of the building.

To begin, one guy hangs out the window, drills a few holes in the outer concrete wall, and bolts a piece of L shaped steel to support the initial bamboo "floor". After that he's outside balancing on the first piece while he drills more and extends along the wall. Someone on the feeds the poles through the window.

He usually has a rope attached to a waist harness, which is initially held by someone inside, and then clipped to the braces outside... most of the time.

The whole thing is amazing to watch.

It's necessary every time you need to service something outside, like replacing or repairing aircon.

Isn’t the side of your building full of holes then? I guess they can re-use the brackets if they need to do it again for some reason.

It is, but they fill them with silicone when they remove it. The brackets I was referring to are about 70cm wide, so no chance of leaving them there.

I have a bamboo "balcony" outside my 22nd floor living room window until tomorrow Monday, as they've just installed a new air con unit. It really is quite amazing. And, frankly, not a job for me...

bamboo scaffolding might be one of those examples of where a superior local solution gets replaced by an inferior, yet more scalable generalisable solution. Bamboo is organic, therefore non-standard, therefore harder to track, measure, quantify, maintain - everything you want to do in health and safety, organic material will frustrate. So even though it is better solution in so many ways (cheaper, lighter, flexible, green, man-portable etc) because it is non-standard it ends up being considered unsafe

I dunno. Framing lumber is organic, yet we have systems to grade it and charts to show how strong it is (taking into account random imperfections).

Yeah, since they use so much bamboo, it might be feasible to grade the pipes by thickness and/or some other objective measure of strength. Heck, they probably already do, informally.

As for imperfections, the bamboo masters seem to know how to (over)compensate for them, i.e. they build the scaffolding to withstand several times the expected load. As would any good engineer.

> Heck, they probably already do, informally.

I feel like I'm seeing more and more of this kind of conjecture on HN about things that are quite easy to verify.

It also surprises me that anyone would assume they're either operating without any standardisation or that they'd only be doing it informally. It's China, first of all, and it's the 21st century.

The guidelines from the local government are available here: https://www.bd.gov.hk/doc/en/resources/codes-and-references/...

The bamboo is specified by genus, age, drying time, thickness etc. with exact tolerances given for variation.

Hell, even in the 5th century or before, they'd have had enough experience to know that bamboo of certain size would be appropriate or not. Sure, they might not now the exact tensile strength in Netwons or lbs/in or whatever unit, but they'd have enough experience to know that to make a bridge for an ox to cross would need certain sizes of bamboo. Even if that knowledge came from losing an ox or two, it would have been learned quickly enough.

    > It's China

No, Hongkong is not China. It has totally separate civil construction and worker safety rules.

Two systems, one country.

Is there a reason you make the distinction, i.e. a reason to believe that Hong Kong is more likely to practice safety standards on at best an informal basis?

Apparently

> It has totally separate civil construction and worker safety rules.

That doesn't logically imply that the separate rules are operating on an ad hoc and informal basis. I linked to the regulations in my initial comment.

There are separate civil construction and worker safety rules in the United Kingdom for example, but that doesn't mean there's no formal system in the UK.

Yes the standards are different. Also true for restaurants and sanitation.

I believe you're touching on the idea of 'legibility'. The topic is explored in the book Seeing Like A State (https://en.wikipedia.org/wiki/Seeing_Like_a_State).

I think that there are ways to standardize organic components. One of the links provided in another comment to the south china morning post has a good write up on the scaffolding. They show the minimum thickness of the wood as well as the minimum diameter. We know that wood of specified dimensions have the necessary strength. Sure, these components might not be "straight", but as long as they have the minimum specs, they can be considered standardized. Hell, go to your local big box hardware store, either the blue one or orange one, and look at all of the non-straight standardized lumber they offer. People build houses out of that crap

A shame that only zipties are mentioned with no discussion of traditional rope materials. It was interesting to see the Cantonese theater discussed. There is a very active Bangkok Chinese cultural and financial support for Cantonese theater. Every year, around Chinese New Year time, numerous stages are constructed (sometimes with forecourt gates) across the city and Cantonese opera performers are flown in from mainland China. Catch it while you can.

If you look at the pictures where it says "zip ties", they clearly are not zip ties. They are long strands of bamboo.

The ribbons don't look to me like bamboo. Another commenter here (alexpotato) says the ones he observed up close were nylon.

It's nylon, and safety measures are a joke. You will see often workers shirtless/no helm/no safety harness up there.

I think safety measures always end up like that for things that can go well for years before having someone crash down. Most workers would probably go their entire career without experiencing a fall, with or without safety equipment.

And life is cheap in China and India - the 2 most populous region in the world. There's also the work culture where workers will actually protest against safety measures - some safety measures like helmet or vests in construction are disliked because wearing these on hot and humid climates make the workers extremely uncomfortable. Some workers also see it as "molly coddling for sissies" because "in their experience they've only seen very few work injuries or death, and those who do get injured are 'idiots' who don't follow instructions".

I was in Hong Kong (first time) a week ago.

The bamboo surprised me, so I took a look. I didn't see any zip ties. It looked like it was lashed together with the nylon ribbon that is often used in packing.

Really amazing to see it on 20 story buildings.

Cantonese, from mainland China?

Guangdong is mainland China.

Yes. The Cantonese culture as well as the language are very much alive and kicking in Gwongdung and in Gwongsai – the homeland of the Cantonese culture. Both are part of mainland China. The wider area, that also includes Hong Kong and Macau, is known as Lingnan.

As a former construction worker, I marveled at this when I was in Hong Kong a few years ago. We spent so much time rigging scaffolding in the US - these guys just grabbed a bunch of bamboo, some rope, and built platforms tout de suite.

Bamboo scaffolding is also very prevalent in Indian cities. Actually before seeing this article, I thought it was an Indian technique.

Bamboo scaffoldings have been used in China and India since ancient times. It is not a new technique.

Here is a video produced by MillMILK, which is IMO one of the best Hong Kong YouTube channels. They documented how giant bamboo scaffoldings are built on the cliff. I have verified the auto translated Eng subtitles are pretty good. https://youtu.be/ndf1QcBmQiM

Related, and worthwhile for the source article:

Why Hong Kong uses bamboo scaffolding, and meet the spider-men who climb it - https://news.ycombinator.com/item?id=42665355 - Jan 2025 (2 comments)

Bamboo Scaffolding in Hong Kong - https://news.ycombinator.com/item?id=42820011 - Jan 2025 (3 comments)

Grew up in HK. In typhoon season the bamboo scaffolding has a little give and flex that metal scaffolding doesn’t, and you’d be glad for that.

Japan does not use bamboo scaffolding and experiences plenty of typhoons. Same for East Coast US.

> Traditionally, workers learn their craft by shadowing one master with knowledge passed down through generations.

I love it when white collar people try to have perspectives on blue collar life.

> But Ms Pak learned any way she could, working with different bosses to broaden her skills and techniques, and overcoming taunts about her ability as a novice and her 5-foot-1 stature.

That's literally every construction job anywhere ever.

> “It would be a shame if the tradition dies in our hands,” she said.

There's no reason the tradition has to die. You just can't legitimately use it anymore for complex and large scale building projects. Profits are not more important than lives.

What a bizarre perspective this article puts forward.

If you think that Hong Kong doesn't have complex and large scale building projects (complete with bamboo scaffolding), then you're mistaken.

It's being phased out. That's the entire point of the article.

I lived in Hong Kong for nearly a year and our building underwent renovation on the facade at the time.

We could open our windows and go up to the roof on the scaffolding.

Good times.

https://archive.ph/DYVba

Those giant building-sized curtains with bamboo scaffolds look like a building fire's wet dream

“the rest of China pivoted toward metal amid an overproduction of steel.”

So the steel is cheaper than bamboo?

The truth is: it is simply not as safe as metal. E.g. bamboo scaffolding has been outlawed in Shenzhen since 1994 [0] due to safety concerns.

[0]: https://www.sz.gov.cn/zfgb/2008/gb622/content/post_4950758.h...

It doesn't say bamboo is inherently unsafe, it says due to a shortage of bamboo meeting the required standards (4 years old, 7.5cm for vertical and 9cm for horizontal supports) and construction sites using substandard bamboo as substitute have resulted in collapses in heavy weather conditions.

It's easier just to require steel than to play bamboo police.

Is no one playing steel police?

Might be nitpicking, but the Chinese text is actually saying it's for both (a) shortage of good bamboo, AND (b) safety in hurricanes, etc. It did not imply that bamboo which met the required standards is safe enough for these conditions. But I agree with your conclusion: safety is kinda important when it comes to scaffolding, on which people would walk around...

I’m curious what the failure modes are. Is it because of the bamboo or because of the way they’re fastened? Or something else.

I was told a decade ago that bamboo is less likely than steel (or other metals) to resonate drilling/machine use on the other side of a beam such that it causes another person’s hand to spasm and lose grip. Is there any truth to this

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