The hidden engineering of airport runways: Engineered Materials Arresting Systems
The Hidden Engineering of Runways
[Note that this article is a transcript of the video embedded above.] September 2025 was an unusually bad month for runway overruns in the US.Wesley Crump (Practical Engineering)
like this
spit_evil_olive_tips
in reply to spit_evil_olive_tips • • •direct link to the video embedded in the article: (18m39s)
if you want to just read Wikipedia: en.wikipedia.org/wiki/Engineer…
- YouTube
www.youtube.comNeatNit
in reply to spit_evil_olive_tips • • •Same video on Nebula: nebula.tv/videos/practical-eng… (16m36s, presumably because it skips a sponsored segment)
I'm actually surprised he doesn't look to Nebula from the blog post version of the video.
Practical Engineering — The Hidden Engineering of Runways
NebulaMelodiousFunk
in reply to NeatNit • • •A friend of mine reached out to a couple of Nebula creators to ask them if it was more beneficial financially for people to watch their stuff on Nebula or YT. Neither had a cut and dried answer, saying that YT views are important for long term discoverability that was hard to quantify vs getting a direct cut of the Nebula money/YT ads. So I'll sometimes watch shorter-form videos on YT and save the deep dives/binging for Nebula.
Edit because I forgot the point I was responding to: Grady linking to YT might be a case of needing that engagement either short or long term.
√𝛂𝛋𝛆
in reply to spit_evil_olive_tips • • •Anyone here ever driven in a runaway trap system?
I was mildly scared of them when I was getting my commercial driver's license ages ago. I was looking at potential jobs involving cranes or an excavator and lowboy. When a typical tractor trailer is fully loaded, you only have 3-4 full hard presses on the brakes before you lose them. Air brakes are inverted. The unpowered brakes state is fully engaged. The pneumatics are holding back the shoes; unlike typical cars that are pressing the friction material into a surface using hydraulics. When a truck fully engages the brakes, it lets all the air out. Then the reserve is used to refill the system to disengage. The engine's compression is a primary component of the braking system. However, it is a manual transmission. Unlike manual cars, these do not have synchromesh (small clutches that spin up the secondary gear shaft to match the primary shaft speed). If you miss a shift, you only have around a 50-75 RPM window where shift will mesh at all. On top of that, the engine only revs 2k-3k RPM, so the transmission is usually an 8 spe
... Show more...Anyone here ever driven in a runaway trap system?
I was mildly scared of them when I was getting my commercial driver's license ages ago. I was looking at potential jobs involving cranes or an excavator and lowboy. When a typical tractor trailer is fully loaded, you only have 3-4 full hard presses on the brakes before you lose them. Air brakes are inverted. The unpowered brakes state is fully engaged. The pneumatics are holding back the shoes; unlike typical cars that are pressing the friction material into a surface using hydraulics. When a truck fully engages the brakes, it lets all the air out. Then the reserve is used to refill the system to disengage. The engine's compression is a primary component of the braking system. However, it is a manual transmission. Unlike manual cars, these do not have synchromesh (small clutches that spin up the secondary gear shaft to match the primary shaft speed). If you miss a shift, you only have around a 50-75 RPM window where shift will mesh at all. On top of that, the engine only revs 2k-3k RPM, so the transmission is usually an 8 speed with 2-3 splitters. That means there are 16-24 speeds total, and for any given speed, only one little shift window exists. I was scared of big downhills. When a truck is fully loaded, going down hill, and you've got to shift for engine braking, it can feel about like someone is fully depressing the accelerator in a regular car. That shift window passes super fast. One can rev match the engine to a small extent, but it is still easy to miss in an unfamiliar rig. You are more focused on staying in the lane when every visual indication you're used to in cars is missing. Like you feel much larger than the lane and you only have around half a meter of extra margin split on both sides of the truck when driving minimum width lanes. So you miss the gear mesh, now you hard press the brakes to get the speed somewhere low where you are able to find a gear. Miss like that 3 times in a few minute span, and you're likely to run out of air. That slams on the brakes, but that is not enough to stop a fully loaded truck on grades steeper than 5-6%. It is why the signs exist warning about the grade. You must use the engine AND brakes at these grades, managing the air levels in concert with the RPM and gear selected.
Anyone here ever fucked that up, or been in to a runaway ramp or engineered stopping surface?
sem
in reply to √𝛂𝛋𝛆 • • •eightys3v3n
in reply to √𝛂𝛋𝛆 • • •√𝛂𝛋𝛆
in reply to eightys3v3n • • •Powderhorn
in reply to spit_evil_olive_tips • • •