Top all-time · #879
Grady Hillhouse
Personal blog · practical.engineering/blogsciencehardware
Grady Hillhouse writes Practical Engineering, a personal blog at practical.engineering about science and hardware. Since 2021, 74 different Hacker News readers have linked it 158 times, most often “Repairing Underground Power Cables Is Nearly Impossible”. It is still writing: the last post was on 2026-10-20, and you can follow it by feed.
Sometimes recommended · 8 of 40 sampled comments recommend it?
Why HN links it
HN readers link Practical Engineering's civil engineering explainers, transcribed from Grady Hillhouse's videos, on topics such as roads, dams, bridges, landfills and power grids, plus his book.
- Recommended for · 8 comments
- Called a good basic explainer and really good, interesting and worth a look; one commenter says to start reading here; the book is called fantastic and worth pr
Summarised by Claude from a sample of 40 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
Entertaining, educational engineering projects and topics by Grady Hillhouse.
Most-linked posts?
- Repairing Underground Power Cables Is Nearly Impossible6 people · 6 mentions · first linked 2021-09-21
- The Dangers of Low Head Dams (2019)6 people · 6 mentions · first linked 2021-06-06
- The Engineering of Landfills5 people · 5 mentions · first linked 2024-09-03
- When Kitty Litter Caused a Nuclear Catastrophe5 people · 5 mentions · first linked 2025-04-15
- What Is a Black Start of the Power Grid?4 people · 4 mentions · first linked 2022-12-07
- Every US Electrical Outlet Explained3 people · 3 mentions · first linked 2026-09-15
- /book3 people · 3 mentions · first linked 2022-07-21
- Was Starship’s Stage Zero a Bad Pad?3 people · 3 mentions · first linked 2023-06-23
- Whatever Happened to Fire Escapes2 people · 2 mentions · first linked 2026-10-20
- /2 people · 2 mentions · first linked 2025-12-23
What Hacker News says?
One of the largest time components can be due to soil compaction. This period can look like no work is being done, but is a vital step. That's not to say that sometimes no work is being done because of scheduling, equipment, funds, or any number of other reasons. This video/article does a good basic job explaining why it can take so long: https://practical.engineering/blog/2020/6/1/why-does-road-co... edit: I think…
Comment linking /blog/2020/6/1/why-does-road-construction-take-so-long
on “Road resurfacing during the daytime without stopping traffic [video]”Submitted How French Drains Work as a story · 755 points
HN discussionA cool recent one for large-scale infrastructure is "Engineering in Plain Sight": https://practical.engineering/book
Comment linking /book
on “Making Software”Submitted The Engineering of Landfills as a story · 521 points
HN discussionIt's also a communication problem, because labels like "100-year/1000-year event" are easily misunderstood. * they're derived from an estimated probability of the event (independently) happening each year. It doesn't mean that it won't happen for n years. The probability is the same every year. * the probabilities are estimates, trying to predict extreme outliers. Usually from less than 100s of years of data, using…
Comment linking /blog/2025/9/16/an-engineers-perspective-on-the-texas-floods
on “Ryanair flight landed at Manchester airport with six minutes of fuel left”Submitted Is the world really running out of sand? as a story · 514 points
HN discussionThis looks pretty cool. I wonder how much sand it contains! We use plastics in non-structural building material replacements already. Fencing, railings and decking all have plastic variants, or plastic + wood. Mixing it with sand might turn it into mechanically stabilized earth? The load is born by the sand, and the plastic keeps the sand from shifting. https://practical.engineering/blog/2016/5/15/mechanically-st...
Comment linking /blog/2016/5/15/mechanically-stabilized-earth-aka-mse-reinforced-soil
on “Kenyan recycles plastic waste into bricks stronger than concrete”Submitted Why Bridges Don't Sink as a story · 358 points
HN discussionIts very hard to repair and keep track of underground. https://practical.engineering/blog/2021/9/16/repairing-under...
Comment linking /blog/2021/9/16/repairing-underground-power-cables-is-nearly-impossible
on “NTP at NIST Boulder Has Lost Power”Submitted What really happened at the Millennium Tower? as a story · 336 points
HN discussionThis is a problem on Hawaii where the combination of an island power grid (can't sell it to the next grid over) and optimal conditions for solar. They've added some grid scale batteries - https://www.asce.org/publications-and-news/civil-engineering... > Situated on 8 acres of industrial land, the Kapolei Energy Storage project comprises 158 Tesla Megapack 2 XL lithium iron phosphate batteries, which are about the si…
Comment linking /blog/2024/3/18/how-the-hawaiian-power-grid-works
on “Vermont replacing power plants with home batteries”Submitted What happens when a reservoir goes dry as a story · 323 points
HN discussionHear hear. The word "Technology" has also been redefined to mean computer or phone stuff. As a real (manly) engineer, this pisses me off no end! :-) To answer the OP, this Civil engineering blog / video site is really good. I always learn something new, and his enthusiasm is infectious. Well worth giving it a look: https://practical.engineering/
Comment linking /
on “Ask HN: What are the best engineering blogs with real-world depth?”Submitted Why Retaining Walls Collapse as a story · 271 points
HN discussionnot software engineering, but https://practical.engineering/
Comment linking /
on “Ask HN: What are the best engineering blogs with real-world depth?”Submitted Fern Hollow Bridge should have been closed years before it collapsed as a story · 263 points
HN discussionWhat you are missing is that this is an extremely complex version of a drowning machine — very good read here [0]. Under the water is turbulence that just traps a person and keeps them tumbling underwater. In addition the article points out that there are numerous rock outcroppings underwater against which an unfortunate person's head would likely get bashed, reducing or eliminating consciousness. I also notice that…
Comment linking /blog/2019/3/16/drowning-machine-the-dangers-of-low-head-dams
on “The Strid: The ‘deadliest stretch of water’”Submitted When Abandoned Mines Collapse as a story · 228 points
HN discussionPractical Engineering recently did an episode comparing human dams to beaver dams. Not really an apples to apples comparison because we build dams for very different purposes, but beaver dams are not only less disruptive to the environment - they are often a net positive. Although they do sometimes create a nuisance for human infrastructure. https://practical.engineering/blog/2026/8/18/are-beavers-act...
Comment linking /blog/2026/8/18/are-beavers-actually-good-at-dams
on “Artificial beaver dams saw juvenile coho salmon survival rates go from 8% to 60%”Submitted The Dangers of Low Head Dams (2019) as a story · 227 points
HN discussionThere's also a practical engineering video on it: The Los Angeles Aqueduct is Wild https://www.youtube.com/watch?v=PhW2BjFQCZM ( https://practical.engineering/blog/2026/3/17/the-los-angeles... for blog post transcript) In searching YouTube history for it, I see I also stumbled across this project too: Why Aqueduct Solar Solves 2 MASSIVE Problems https://youtu.be/EVBacmPfQ6E (about 9 minutes in it gets into the engin…
Comment linking /blog/2026/3/17/the-los-angeles-aqueduct-is-wild
on “What California is learning from solar panels built over irrigation canals”Submitted Myths about construction as a story · 223 points
HN discussionAuthor: Grady Hillhouse Videos: https://www.youtube.com/channel/UCMOqf8ab-42UUQIdVoKwjlQ Blog: https://practical.engineering/blog/ Feed: https://practical.engineering/blog?format=rss
Comment linking /blog?format=rss
on “Why Bridges Don't Sink”Submitted How long would society last during a total grid collapse? as a story · 218 points
HN discussionI think all of the blogposts are just transcripts of videos from his youtube channel. You could use the feed from youtube to tell when there's a new release. Wait, I just checked the page source after writing the above to confirm and it looks like it does have one: https://practical.engineering/blog?format=rss
Comment linking /blog?format=rss
on “Why Bridges Don't Sink”Submitted Why are Texas interchanges so tall? as a story · 211 points
HN discussionMany of these weirs are extremely dangerous to swimmers. When I was young there was an incident on a nearby weir (obsolete lowhead dam) where one person got trapped and drowned and then four people who jumped in to rescue him also drowned. https://practical.engineering/blog/2019/3/16/drowning-machin...
Comment linking /blog/2019/3/16/drowning-machine-the-dangers-of-low-head-dams
on “Dam removals are bringing fish back across the northeastern United States”Submitted Whatever Happened to Fire Escapes as a story · 204 points
HN discussion>However there's another company that buys cheap land from farmers in the Amazon, with cheaper labor, ships it up via freight, and sells it for marginally cheaper. The costs in the latter example are largely driven by transportation - and while cheaper, has a significantly larger carbon impact. How does this apply to recycling though? Landfills in developed countries have little, if any externalities, because they'r…
Comment linking /blog/2024/9/3/the-hidden-engineering-of-landfills
on “A laptop stand made from a single sheet of recycled paper”Submitted Which power plant does my electricity come from? as a story · 201 points
HN discussion
