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Cooling the trains is a relatively easy problem to solve these days. It’s cooling the tunnels and stations that’s the true engineering challenge.
by JCM9 3y ago
Cooling the trains is a relatively easy problem to solve these days. It’s cooling the tunnels and stations that’s the true engineering challenge.
- rob74 3y ago...especially with such cramped stations and tunnels as the London tube!
- the_other 3y agoThe linked article touches on this. It explains that the new trains emit similar heat levels to older trains, and says there was no option to emit more heat without heating the tunnels. They made the running gear cooler (by installing less of it), and using that heat saving as the budget for the air cooling. As a software engineer who's not touched hardware design in 25 years, I found this heat budgeting really interesting.
- droopyEyelids 3y agoIf you're the kind of person who plays video games, you might enjoy Oxygen Not Included, managing heat is one of the game mechanics
- Cthulhu_ 3y agoAs is oxygen and waste; I never thought of it as an analog to the same problems that the tube has.
- droopyEyelids 3y agosame problems as life on planet Earth!
- rtkwe 3y agoWith the convenience of thermodynamically impossible heat deletion mechanics though. Steam turbines in that game delete heat for every bit of energy they produce.
- alex_duf 3y agoI'm hoping the aircon filters will start clearing the filthiness of the tube air. Something tells me they'll have to change them more often then think. Once you see it, you can't unsee it. There's this dark mist in the London underground, I find it very visible on the northern line, around elephant and castle. Just standing at one extreme of a platform and trying to look at the farthest part of the station, you'll realise everything is "foggy" by lack of a better term. One hour there would turn my snot black.
- morkalork 3y agoThere was a study on the TTC subway and they discovered the air quality was 10x worse than above ground and on par with Beijing. The accumulation of dusty linty particles on the walls has a cute name too "tunnel fur". I remember seeing workers going into the tunnels wearing N99 masks after that report was released.
- glompers 3y agoI always like the (grease?) smell in Montréal Metro stations but never thought about it in terms of particulate matter concentrations.
- morkalork 3y agoUnfortunately the only smell I can associate with the Montréal metro is piss
- VK538FY 3y agoI understood that the Montreal metro trains used wood breaks and peanut oil. Hard to say if that makes the same mess, but the rubber tires surely leave something. Also, the new rames may use different breaking technology.
- lbourdages 3y agoThey initially used different brakes, but they reverted to the good old peanut oil brakes because they had issues of some sort with dust. I'm struggling to find a source that tells the reason, but here you can see they chose wooden brakes. https://www.stm.info/sites/all/modules/custom/stm_import/imported_files/a-%20FicheMPM-10maquette_12.pdf https://www.stm.info/sites/all/modules/custom/stm_import/imp...
- JAlexoid 3y agoTunnels - sure, that's a challenge. But stations - that's a cost. Stations are connected to the surface by multiple shafts, or are already exposed.
- odiroot 3y agoNew Elizabeth Line's trains are quite pleasant though. Not sure if the stations have any better ventilation than e.g. Northern Line.
- ivix 3y agoCooling the stations is not an engineering challenge. It's a budget challenge. Installing and operating huge chillers is a solved problem.
- SideburnsOfDoom 3y ago> Cooling the stations is not an engineering challenge. Installing and operating huge chillers is a solved problem. Not correct in context. You cannot successfully chill air without having a place to vent the resulting waste heat. Where, in deep tube lines, to vent the waste heat, is _not_ a solved problem. It _is_ an unsolved engineering challenge. The heat has been accumulating there for decades. As detailed here https://en.wikipedia.org/wiki/London_Underground_cooling https://en.wikipedia.org/wiki/London_Underground_cooling https://news.ycombinator.com/item?id=38364027 https://news.ycombinator.com/item?id=38364027 https://news.ycombinator.com/item?id=38363476 https://news.ycombinator.com/item?id=38363476
- NegativeLatency 3y agoAt a certain point it seems like there'd be enough stored energy to justify some heat pumps for nearby building heating.
- SideburnsOfDoom 3y agoIf that was easy, it would have happened already https://news.ycombinator.com/item?id=38367176 https://news.ycombinator.com/item?id=38367176