Re. technical domains you may not know exist: airplane flatware logistics.
When you want to look at something optimised, start with things that are expensive to run. Airports are expensive in nearly every sense of the word, so it's a place where you find things being optimised to hell and back. Outgoing passenger flights may need clean, fresh flatware. The window in time allocated to unload dirty flatwar and load a clean batch is small; that cart of flatware needs to be in exactly the right place at the right time, or there will be delays, which will cost a lot of money to someone.
So, naturally, the strategies on how to get flatware onto airplanes is an area of deep study.
I talked to a friend of a friend at a party about this, since it was their subject of study. They thought they were studying the most boring thing in the world and I couldn't make them understand why it fascinated me.
Native Brit here. Never come across the word flatware before. It appears to be a US term. Or maybe I'm just ignorant.
1. utensils, as knives, forks, and spoons, used at the table for serving and eating food. 2. dishes or containers for the table that are more or less flat, as plates and saucers (source: the internet)
Native Brit here. Never come across the word flatware before. It appears to be a US term. Or maybe I'm just ignorant.
I'm from the US, and while I'm sure I've heard it before, I never really noticed it until this last November when I was planning a dinner party for the first time. As I understand it Silverware, Flatware, and Plasticware are all categories of utensils.
In the U.S. I encounter it used by businesses that sell and rent knives, forks, etc., but I rarely hear it used outside the context of buying and renting. Ikea has a "flatware" category on their web site[1], for example, and our biggest local rental company[2] does as well, but I've never heard anybody at a restaurant or a house party ask where to find the flatware. In those contexts we use the word "utensils".
plates, dishes, saucers in a sense "shallow; smooth-surfaced" + ware (n.). Originally as distinguished from hollow ware; U.S. sense of "domestic cutlery" recorded by 1895.
Native Brit too - I think it's more of an "industry" term, across food service companies, whereas is in general use in the States. Might be an Americanism though, but have heard it pretty commonly here when in food prep circles.
In the U.S., "silverware" is probably even more common (is that what you say in the UK?), but HN readers probably tend to be the type reluctant to use such an obviously wrong term, since the knives, forks, and spoons included in the category are only in very rare cases actually made of silver. :) "Flatware" is more technical/industry, and the next most common if you don't like "silverware"; plus the general "cooking show" trend of everyone wanting to use industry terms to seem like food industry insiders.
Is flatware logistics really a separate field? I get that the general logistics of handling "cabin consumables" is a big deal, but it seems to me that most flatware is integrated in the food carts?
Semi-relevant anecdote: I once rebooked last minute on to a flight and as I was boarding perhaps 15 minutes later as one of the last passengers, a guy in a high-viz vest came half-running down the jetway and handed the cabin crew a box with one single premium economy meal. I was rather impressed by the operation, and a bit apprehensive about declining the meal once in the air.
Unfortunately, I don't remember too many specifics, but a web search for "ground handling operations technical perspective" seems to bring up an overview with pretty graphs which might serve as a decent starting point for further research.
> It's such a big world out there, so much to know.
I love this type of articles, there really is so much out there to learn.
I always found myself thinking, while waiting for the green light:
* Who makes these traffic lights?
* What software controls the traffic system?
* Are all traffic systems controlled by the same organizations?
* Can they get hacked? Of course they can… Are they difficult to hack?
* How can someone land a job to work on this type of SCADA systems?
I am right now sending my resume to McCain [1] they are currently looking for .Net, Java and Embedded engineers. If I don't get any of these jobs, at least I know where to continue looking. My dream have always been to work in projects like that, someone people consider them boring, I find them very interesting.
Had similar a long time ago whilst I watched some workmen working on the traffic lights of a 6 way junction. It was being controlled by temporary lights, and they were winding up the job.
One guy with a laptop plugged into the central cabinet, and another over at the control box for the temporary lights. Temporary guy fiddled with something, put all the lights to red, and eventually everything came to a halt. Big thumbs up from him, and the cabinet guy pressed what seemed to be 'Enter' on the laptop, at which point the main lights all lit red, and then began the cycle.
We take shutdowns and startups for granted in our world, but we also expect traffic lights to work 24/7. I'd just witnessed the crossover of these two expectations, and was fascinated :-)
I once spent a slow weekend watching YouTube videos about elevators. There's a surprisingly large community of elevator nerds out there. Many fascinating videos out there on how elevator programming works (especially love the ones about old relay-based elevators https://www.youtube.com/watch?v=_xjXdjj2m5Q )
One such software is SCOOT, which has been around since 1979. The name is an initialism for Split Cycle Offset Optimization Technique. All of these are traffic light jargon: the red/green split, the cycle length, and the green phase offset.
Yes, in part because it involves forgetting all of the dramatized baloney that you've seen on television. It's not done from a wireless laptop in the back of a moving car magically giving the protagonists a green wave at the opportune time with zero notice and preparation.
For starters, in some places around the world much of this infrastructure was interconnected long before WiFi was even invented. There will be telecommunications lines to a central control office, and it is there that one would attack the system. Think of the original Italian Job movie, where a replacement tape at the control centre subverted the system. One would also attack it at these various roadside cabinets.
(This is not to say that no systems use radio. Several do, and their vulnerabilities are appalling. But this is not universal. And the vulnerabilities lie in things like operating systems that were invented long after computer-managed traffic light systems for cities themselves were, meaning that said operating systems are not universal either.)
Thanks for your kind words. You might like the rest of my blog. Other recent articles have discussed the price of dried maggots as a protein source, naming conventions in the Saudi royal family, the Turkish and Hebrew translations of “Joe Blow”, how plutonium-powered pacemakers work, and why you can say “redden”, “whiten”, and “blacken” but not “greenen”.
(The Bay Area contingent of HN can answer that!) Traffic lights (typically red/green only) at the bottom of on-ramps that rate-limit ("meter") traffic onto the freeway, typically during rush hour. You drive up to a red, stop, it turns green and you go. (Sometimes a sign indicates that 2 cars get to go per green given.) There are usually sensors embedded in the rightmost lane of the freeway shortly before the merge point, and on a good day, it feels like it gives you a green timed with a gap. (Although I think it also sometimes just times out and lets you go, in which case, no gap.)
The ones here have an HOV lane and a non-HOV lane, usually; typically they just force the HOV lane to come to a near stop before turning green; I think that's more to slow the HOV traffic down to avoid collisions with the adjoining non-HOV lane should their light also turn green, but it feels like a weird formality when driving it. Some days the cops sit on the ramp pulling people cheating in the HOV lane.
It is one of the two things I warn family visiting that have never visited before. (In the majority of the US, you just get on the highway, there isn't a traffic light at the bottom of a ramp, that'd be absurd, since you're wanting to accelerate to ~70mph.) (The other is lane splitting: motorcycles will (ab)use the dividing line, particularly between lanes 1 & 2, to pass.)
> Did you know that the long pointy triangle thing is called a “gore”?
> Well, you might survive, because there is a thing there that is designed to crush when you hit it. It might be a QuadGuard Elite Crash Cushion System
Or it might be the traditional solution, which is a bunch of rubbermaid garbage pails filled with water.
(Not that long ago, I was trying to let someone merge in front of me, but they couldn't make up their minds and ended up slamming their brakes into the gore. I bet they had fun getting out of there.)
I skimmed the comments here before reading the article and was curious what a "gore" looked like. After a seconds pause, I decided I should get on with reading the article instead of searching for "highway gore" :)
Some customers have indicated that common deicing
and dust control chemicals that are used on the
highway make excellent choices for antifreeze
agents. These include:
In the NYC area, we also have some on-ramps with red/green traffic lights. However, these are only active during peak traffic times, and are otherwise turned off.
They are similarly active only during peak hours in CA.
Usually, at the entrance to the ramp from whatever road feeds it, there's also a sign that lights up flashing to tell you the metering is on, so you know you can expect to stop ahead.
At 5AM, as I sit waiting for a traffic light on a deserted stretch of road during my morning commute, glaring tempestuously at the nearby redlight camera, I wonder how we've gotten to driverless cars before getting to 'smart' intersection signaling systems that know there is a lone commuter patiently waiting to pass.
It has to do a lot with reliability and cost. A smart car has a lot of expensive sensors and an expected life of a few years with regular maintenance. There's also a huge market opportunity around smart cars. Those cabinets can last decades, in all conditions, with minimal upkeep. Adding sensors decreases reliability and increases maintenance cost. There isn't usually an appetite to put traffic signal upgrades or extra maintenance headcount in city budgets for non-critical infrastructure upgrades, so the financial incentives to innovate are more limited as well.
Thanks - interesting. I know traffic pattern/flow models and studies can be extremely complex. However, from the perspective of a 'dumb' commuter, it seems like the investment in smarter traffic signals would be offset by global savings from/economic benefits of reduced congestion (e.g. idle bus transit fuel/maintenance savings or generally increased standard of living and economic imprivements due to increased traffic flow).
It is useful to talk about both inefficiency (the thing you point out) and exploitability (the ability for any individual actor to make useful amounts of money out of fixing the inefficiency.)
Unless an area is both inefficient and exploitable, it is plausible that it will go unfixed for a long time.
When you start viewing it in those terms, you find obvious inefficiencies everywhere.
If you were on a motorcycle instead of in your car, you could watch as those "smart" systems go through a few cycles for the vehicles travelling in the other directions without ever once giving you the green light.
Fortunately, the state I live in (Indiana) finally passed a "dead red" law a couple years ago, meaning that I can now disregard that red light and proceed through the intersection anyways (assuming it's all clear and safe to do so).
Sensors are common, ranging from basic induction loops in the road to microphone arrays that can tell you what type of vehicle is on each page of an intersection from the tire noise.
Sadly there are laws that require each light to be green for a minimum period, so all these really do is keep one phase of lights on longer at rush hour.
I wonder if the transition from human-driven vehicles to
self-driving will bring a resurgence of traffic circles
in the US as an intersection that can readily support any
mixture of self-driven and human-driven.
Traffic circles where I live are a complete boondoggle. They are seen by city planners as a wonderful, progressive, very forward-thinking concept. And I have no problem with them in theory. But when they convert a normal "four-way" intersection to to a traffic circle it always seems to take about a year, is built far larger than necessary, requires annexation of pieces of private property around the perimeter, and features a large center island with trees and ornate landscaping.
I can't see a reason it should take more than a few weeks to round out an intersection and remove the stoplights/stop signs.
There are reasons to make roundabouts with large radii. Ironically, some of them involve traffic-light controlled roundabouts, where traffic queued at a red light queues back around the roundabout. The consideration here is that one makes the circumference of the roundabout greater in order to provide more queueing room before the queue for one junction backs up beyond the preceding one.
The government just upgraded a traffic-light-controlled roundabout where I live, and enlarging the circumference in order to provide more queueing space was one of the considerations mentioned in the public consultation doco.
Also bear in mind how large, possibly articulated, vehicles have to navigate roundabouts versus how they can navigate box junctions, especially since the approaches to roundabouts by design slew approaching traffic to one side. (This is a consideration that for smaller vehicles brought about the idea of the mini-roundabout, and is also behind having overrun areas around reduced central islands.)
when I was a kid (a long time ago) those cabinets were full of electro-mechanical relays, you could hear them clicking.
I discovered that by thumping against the box hard the traffic lights would suddenly change so I could cross.
I did this exactly once because while no one had an accident the traffic got a bit hairy for a minute as lights changed early without a yellow phase ....
I'm not sure just how accurate it was, but I still remember the first season MacGyver episode "Thief of Budapest" where he adjusted the settings to create a traffic jam.
In case anyone is wondering very similar cabinets are also used for telecom in major cities. Shaw has sidewalk mounted cabinets throughout Vancouver for part of their fiber and cable TV network, and there's Telus pedestal/junction cabinets as well.
I have seen models very similar to traffic control system cabinets used for patch panels for fiber + 1RU sized routers and switches, medium sized UPS, etc.
Once you're used to looking at electrical enclosures they all sort of start to look the same. What you're describing in your photos are similar to what my company designs for all forms of industrial domains: agriculture, wastewater, oil & gas, mining, telecom, power, etc.
Elsewhere in this thread someone talks about "optimization" and electrical enclosures are no different. There's various levels of certification that they need to meet in regards to the different environments they're installed to work in, it only makes sense that a standard style of design emerges instead of specifically engineering something per task.
(EDIT: I should mention I do not work for hammond, I just linked their site because I know we use their enclosures a lot)
This post is one of the many reasons I love HN. In depth discussion of obscure (but very interesting) topics; and the personal websites that host them.
I only found out about these a few months ago because there was always a cop leaning against one outside a ballpark before and after games with a radio plugged into it.
I asked what he was doing and he gladly showed me that he was just manually cycling the lights, basically on a longer delay where required to clear jams and work with another cop directing traffic.
I've always wondered why those cabinets are so big. Traffic light controls seem like the kind of thing that could be reduced to a much smaller package given greater computing power combined with smaller and more efficient hardware. What does all the hardware inside actually do?
Maybe one box needs to communicate with a network of other boxes to keep traffic in sync over a wider area. I'm guessing that the bottom rack with the yellow cables plugged into it is some kind of networking gear.
Also, the equipment has to switch some fairly high-power loads - until the recent adoption of LED-based traffic lights, I'd guess that traffic light bulbs probably drew a few hundred watts each, and there can be many lights in a large intersection. You can see a row of 15A and 20A circuit breakers in the box in the photo, on the left side of the second rack from the top, with a 50A main breaker below them. The equipment below that rack looks like power-switching modules.
It's also entirely possible that this equipment is 20 or 30 years old, built at a time when computer hardware was much bulkier. There would be little incentive to replace it with something smaller if it was still working reliably.
In fact, this being repairable in the field by a person with a soldering iron and a bag of parts is a consideration.
Sometimes you cannot just get a full module to swap.
This. Repairability and durability are two reasons a lot of 'old tech' is in use.
I have a friend who is an engineer with PG&E who is great to take to parties full of tech nerds. They're always horrified by the '100 year old tech' running the grid. My take is that they're right to be horrified by the fragility of the grid, but have the 'why' exactly backwards - it isn't the vats of oil that make it fragile.
IIRC, in some cities (Chicago for one) there is a radio broadcast timing signal for traffic lights. There is a receiver in each control box. Sort of a WiFi NTP for traffic signals. Probably totally insecure and subject to hacking also.
A previous post was correct. There width is a standard rackmount in 332-type cabinets. The 332 type cabinets were originally designed by the California Department of Transportation. A lot of the design of cabinet dates back to the 70's. Until just recently the industry started to look at shrinking things down. Going to LED signal indications has helped a lot. The devices used to convert the low voltage coming from the traffic signal controller to switch to the high voltage driving the old incandescent heads took up a bit of space. How you land all the wires from signals heads and sensors also takes up a bit of space.
Some day when we have connected vehicles, vehicles talking directly to the signal cabinet we should be able to shrink things down even more.
How you land all the wires from signals heads and sensors also takes up a bit of space
That's what I figured the most likely answer to be. Simply connecting one wire to another (in a manner that makes repair/replacement easier) can take up a surprising amount of space and most control panels have rows of terminals that exist just for that purpose.
I think I understand what variable message signs are, and I can guess at changeable lane control, but what are the sprinklers and pumps for? What is ramp metering?
Very interesting (as always with good geekery almost regardless of actual subject matter), but so frustrating that the part about pumps and sprinklers not being answered.
The linked-to PDF in the article (the one that the quote above comes from) doesn't mention sprinklers or pumps more than once, either.
I guess traffic intersections often have decorative planting which might need watering and it would make sense to make the already-present light controller handle that, too. That's my best guess, at least. Some basic googling didn't turn up anything useful.
There has been a followup if you go to the homepage
"DOTs in California and presumably elsewhere often have a need for erosion control on the steep inclines of earth surrounding their highway ramps. So any time you see a 45-degree incline covered in greenery, chances are it has a sprinkler system attached and carefully maintained by the DOT. Those same sprinklers are often within a few feet of the ramp's metering lights…"
You’d be amazed at how prevalent they are. I come across them at least a couple times a year when popping the lid off this thing or that. Generally older gear :). The most recent that comes to mind is a radio repeater.
I'm not sure about the US, but in Australia pretty much all traffic signals in metro areas are all linked and controlled over fibre networks. You need single mode fibre given the distances between cabinets etc. (hundreds of metres to kilometres).
And if you're doing that, may as well just use single mode internally too because the transceivers and patch cables aren't really much different in price and you can get better volume discounts.
Without seeing the ferrule to ferrule contact it's hard to say if the termination is really dirty. Yes the jacket is dirty. What they have done that is a cardinal sin is running the fiber between equipment through the center of a rack rather than around or above.
I hope whoever installed that has a good cletop, fiber scope, set of ferrule sleeve cleaning swabs, push click cleaning tool.
Also hard to say if it's dirty or bad without seeing the back/internal side of that patch panel. Knowing city governments it could be anything from a dreadful mechanical splice to a perfectly done core alignment fusion splicer with 0.01 loss.
Also possibly a connection to a central traffic control center that can override signals during emergencies or special events that generate abnormal traffic flows.
I mentioned SCOOT elsewhere in this discussion. With such systems, overriding is (I was told) the norm. The isolated controller on fixed timing is the fallback case.
When you want to look at something optimised, start with things that are expensive to run. Airports are expensive in nearly every sense of the word, so it's a place where you find things being optimised to hell and back. Outgoing passenger flights may need clean, fresh flatware. The window in time allocated to unload dirty flatwar and load a clean batch is small; that cart of flatware needs to be in exactly the right place at the right time, or there will be delays, which will cost a lot of money to someone.
So, naturally, the strategies on how to get flatware onto airplanes is an area of deep study.
I talked to a friend of a friend at a party about this, since it was their subject of study. They thought they were studying the most boring thing in the world and I couldn't make them understand why it fascinated me.