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U.S. Army Corps of Engineers Bay Model
- WillAdams 5mo agoIt's a shame that there isn't a series of articles on such models --- saw the Chesapeake Bay model (mentioned in a footnote) on a field trip when I was much younger (and it was still in active use for research I believe, yes, as my kids constantly tell me, I'm old). Simulation used to be essentially impossible, something one dreamed of, or had to pay for time on a Cray or similar supercomputer/cluster. Apparently, the Chesapeake Bay model was built just as that was becoming feasible: https://easternshorebrent.com/2017/11/30/doomed-progress-the-chesapeake-bay-hydraulic-model/ https://easternshorebrent.com/2017/11/30/doomed-progress-the... and has since been dismantled and a business park built on the site.
- DonHopkins 5mo agoAhoy crewmembers! Are you old enough to remember Captain Chesapeake and Mondy the Sea Monster? Captain Chesapeake WBFF TV45 https://www.youtube.com/watch?v=a3kjJt_7zw4 https://www.youtube.com/watch?v=a3kjJt_7zw4 Ahoy! - The Captain Chesapeake Story https://www.youtube.com/watch?v=8QUGMVYIHvA https://www.youtube.com/watch?v=8QUGMVYIHvA Did you know that Traffic Jam Jimmie was also Mondy the Sea Monster?!?
- deleted 5mo ago[deleted]
- redm 5mo agoThese are the kinds of interesting engineering challenges that were solved with human ingenuity and grit; I wish we were talking more about them to our youth to inspire imagination about what's possible.
- nkrisc 5mo agoThe distortion is interesting and something I didn’t realize the model included. I assume that it’s necessary because the effects of surface tension and the viscosity of water (and other effects?) change its behavior at this scale relative to the features of the model?
- WillAdams 5mo agoYes. Another technique was to use alcohol rather than water since it has lower surface tension, but that was only workable for smaller models (which were usually enclosed).
- nkrisc 5mo agoI think a model this size full of alcohol would also be quite hazardous for several reasons.
- btrettel 5mo agoEven if it wasn't a large size, it likely wouldn't be great. During my PhD on sprays, I did some (unpublished) experiments using isopropyl alcohol to reduce the surface tension. The nozzles I used were around 1 mm in diameter as I recall. I did not anticipate that the room would fill up with isopropyl alcohol vapor and (probably) tiny droplets. I wore a mask and maybe left the room while each trial was running. Breathing that likely wasn't great for my lungs.
- lstodd 5mo agoYou just get drunk from the vapour way faster than it can have a measurable impact on the lungs. (you can actually drink it if it's reasonably pure. it's even less toxic than ethanol, but the hangover is terrible)
- deleted 5mo ago[deleted]
- lorenzohess 5mo agoIf I recall correctly, at an undistorted scale, the water would be so shallow that surface tension and viscosity would dominate, so the depths are exaggerated to keep the flow realistic. More specifically, tidal flow obeys Froude similarity, not Reynolds. Matching the model's Froude number to the real Bay's requires enough depth for gravity waves and tides to scale correctly, which the vertical exaggeration provides. But the distortion makes the flow too efficient, so copper strips are added throughout to achieve the right frictional resistance.
- contingencies 5mo agoThe fellow who lived next door to me told me of a similar model system used to model Sydney Harbour which he worked on in the 1970s. IIRC it was instrumented with electronics and linked to a VAX or similar early machine.
- emmelaich 5mo agoThe Aus Navy had a computer simulation of Sydney Harbour, dating from the 70s or maybe 80s. One particular feature of the system was a disk drive about 1m in diameter with about 12 heads. Cost a bomb, but I guess it was worth it. When I saw a demo, they had an easter egg of a Loch-Ness type monster in it. There's also a topographical map of the harbour at St Ives showground but it's purely non-hydrographical. But it's almost disappeared now through neglect.
- cucumber3732842 5mo ago>The Aus Navy had a computer simulation of Sydney Harbour, dating from the 70s or maybe 80s. One particular feature of the system was a disk drive about 1m in diameter with about 12 heads. Cost a bomb, but I guess it was worth it. Meanwhile the Soviets probably found a little inlet somewhere that was "close enough", evicted anyone who lived there and excavated it to match. Some junior engineer probably had to wake up at 1am to take a kayak out to "Little Kotlin Island" to change the tape in the recording equipment in time for the tide change.
- contingencies 5mo agoInteresting about the St Ives showground map. Where is it exactly? They have a nice orchid show. Usually it seems to be mostly a bunch of HK dudes playing with RC cars.
- emmelaich 5mo agoI think it is under heritage order now. I looked for it last time I was there; maybe it's covered up ready for restoration? It's actually a topographical map of the whole Sydney basin. This article has a pic: https://www.neighbourhoodmedia.com.au/post/st-ives-showground-a-military-training-camp-in-wwii https://www.neighbourhoodmedia.com.au/post/st-ives-showgroun... [edit: Seems to be where the RC cars race!]
- LucasLanglois 5mo agoIf you don't know Tom Scott, he has done a great video 4mn vide on the model where you can see it in action: https://www.youtube.com/watch?v=i70wkxmumAw https://www.youtube.com/watch?v=i70wkxmumAw
- MontagFTB 5mo agoYes, that’s a great video. The Mythbusters used the same model to understand Bay Area current flows during their Alcatraz escape attempt episode.
- rbanffy 5mo agoSomeone should do a follow up episode with a person dressed up as Godzilla.
- NoSalt 5mo agoI am ... confused by your statement.
- rbanffy 5mo agoTo simulate a Godzilla incursion and check if the movie where Godzilla attacks San Francisco makes an accurate depiction of what would happen. For science.
- hnav 5mo agoThe real question is would a Godzilla incursion be good for property values (novelty, tourism attraction, remove some housing stock) or decimate them (safety concerns, change the spirit of neighborhoods).
- gumby271 5mo agoDepends on the cost of Godzilla insurance, which currently is quite low. Lock in now!
- carderne 5mo agoJohn McPhee talks about a similar model for the Mississippi River in “The Control of Nature” Well worth a read. Fun stories about Hawaii and Los Angeles too, iirc.
- Robdel12 5mo agoThis is neat to see. US army crops of engineers is a negative “word” to me after growing up in FL and they destroyed so many ecosystems. And the entire Everglades. They’re still at it now. My family has basically spent the past 30 years fighting a ware they put in on our natural creek. It killed the creek, it shrunk the flow to the size of the culvert. So, It’s neat to see something competent! Imagine if they modeled what cutting off the natural draining to the Everglades would do :p
- bumby 5mo ago>It’s neat to see something competent! The existence of negative externalities or tradeoffs does not inherently imply incompetence. I remember reading that the USACE said the NOLA levees would not adequately protect against a category 5 hurricane but the powers that be didn’t think the added cost for a more robust design was worth the risk. If true, it doesn’t imply USACE was incompetent but that we live in an uncertain world with tough tradeoffs.
- reaperducer 5mo agoUS army crops of engineers is a negative “word” to me after growing up in FL That you were able to grow up in Florida at all is largely because of the Army Corps of Engineers.
- mattlong 5mo agoI highly recommend a visit. It’s only a beautiful ferry ride and nice walk along the waterfront away from San Francisco. A refreshingly retro and analog experience.
- obvioustourist 5mo agoSee also the Mississippi River Basin model built by German engineer POWs during WWII: https://en.wikipedia.org/wiki/Mississippi_River_Basin_Model https://en.wikipedia.org/wiki/Mississippi_River_Basin_Model
- supertroop 5mo agoDon’t show something good the government has done or the POTUS will cancel it!!!
- eezing 5mo agoThis is a hidden gem in the Bay Area. Go check it out if you live near by.
- youngtaff 5mo agoWhy do the Army Corps of Engineers get so involved in civil infrastructure in the US - thinking of the Mississippi in particular? In other countries the government would be involved but it would be a civilian rather than military role
- bumby 5mo agoNot sure about the exact thrust of your question but a few points: - flood management is not easy to monetize so there is not much incentive for private industry. The timelines for design decisions (100 year, 500 year) often don’t mate well with private incentives - it crosses many property boundaries which makes it hard to manage unless you have the rights of a government - much of the work is still done by private companies but managed by the government, just like other infrastructure works like roads, bridges etc.
- DonHopkins 5mo agoFlood management in the Netherlands even influenced the country's style of government decision-making: the "Polder Model" of consensus-building. The idea is that if everyone shares the same dikes and drainage systems, they have to cooperate regardless of political differences. A flood doesn't care whose land it is. https://en.wikipedia.org/wiki/Polder_model https://en.wikipedia.org/wiki/Polder_model >The polder model (Dutch: poldermodel) is a method of consensus decision-making, based on the Dutch version of consensus-based economic and social policymaking in the 1980s and 1990s. It gets its name from the Dutch word (polder) for tracts of land enclosed by dikes. https://en.wikipedia.org/wiki/Maeslantkering https://en.wikipedia.org/wiki/Maeslantkering >The Maeslantkering 'Maeslant barrier' is a storm surge barrier on the Nieuwe Waterweg, in South Holland, Netherlands. It was constructed from 1991 to 1997. As part of the Delta Works, the barrier responds to water level predictions calculated by a centralized computer system called BOS. It automatically closes when Rotterdam, especially the Port of Rotterdam, is threatened with flooding. https://en.wikipedia.org/wiki/Delta_Works https://en.wikipedia.org/wiki/Delta_Works >The Delta Works (Dutch: Deltawerken) is a series of construction projects in the southwest of the Netherlands to protect a large area of land around the Rhine–Meuse–Scheldt delta from the sea. Constructed between 1954 and 1997, the works consist of dams, sluices, locks, dykes, levees, and storm surge barriers located in the provinces of South Holland and Zeeland.
- hirpslop 5mo agoThe bay’s first LLM (large liquid model) was invented in the 1950s.
- DonHopkins 5mo agoAdvection Is All You Need On the Dangers of Stochastic Parrotfish: Can Large Liquid Models Understand the Bay? The Brackish Lesson: Scale Beats Insight in Large Liquid Models Large Liquid Models are Few-Drop Learners Schooling Laws for Tidal Liquid Models No Silver Mullet
- e40 5mo agoTook my son there when he was young (6?) and we all loved it. What a great day trip.
- msisk6 5mo agoI haven't been there in awhile. Back in the 90's the Autodesk tech office was next door to the Bay Model and we'd occasionally pop over for lunch and tour the place. Great to see it still around and open to the public.
- dieselgate 5mo agoWas it displayed at the Civic Center or did Autodesk have an office location in Sausalito? I had never heard of this Bay Model and believe to only have seen a model at the (new location) of the Exploratorium - this was over a decade ago so don't quite recall
- hnav 5mo agoAutodesk was founded in Marin and later moved down. This model is 10km^2 so it's not moving anywhere.
- gregschlom 5mo agoNitpick: the model is 100m x 100m roughly, so 10,000m^2 which is 0.01km^2
- dieselgate 5mo agoYes, the Marin Civic Center in Terra Linda is what I'm referring to. Edit: above said "next door" so I'm curious how literal they meant this
- msisk6 5mo agoLiterally next door. Maybe one other building between Autodesk and the Bay Model. When I started in 1990, most of engineering at Autodesk was in 2320 and 2330 Marinship Way in Sausalito. Later I moved down the street across from Mollie Stone in 3 Harbor. The infamous every-Friday "Beer Bust" was in 1 Harbor during those years. Ted Nelson had a house boat not far way, too. Wild times. A few years later we moved up to the new HQ on McInnis Parkway in San Rafael. We also had several buildings on Civic Center Drive and several floors of 4000 on top of the hill. I think I had an office in all of those at one time or another except the HQ building -- I managed to escape that and the new fangled "open office space" they put in that one.
- karlgkk 5mo agoI’d gone here as a young child in school, and then went as part of a team building afternoon. Massive Deja Vu in front of all of my coworkers
- Lammy 5mo agoBig fan of this thing. It's one of my favorite places to take friends who visit the Bay Area. Something that's not mentioned in the article is that the building they occupy is a former warehouse of Marinship, a World War Ⅱ shipyard that made Liberty Ships and T2 oil tankers used to supply fuel in the Pacific Theater: https://en.wikipedia.org/wiki/Marinship https://en.wikipedia.org/wiki/Marinship The Bay Model building has a Marinship museum in a front room. For anyone who wants to see Marinship's full story in motion, here's my HEVC encode of ‘“Tanker” — 1942–1945 War Time History of Marinship Corporation’ https://mega dot nz/file/lgtmlKIA#asrzuwGOxi6l8I5BmgyAxfKkm1zFcxvY4SYS1SxqtZk See also Marin City, which is the remains of Marinship's on-site worker housing: https://en.wikipedia.org/wiki/Marin_City,_California https://en.wikipedia.org/wiki/Marin_City,_California e: the Bay Model building is the big square one that is center-frame starting at 04:30 in the video, Marin City at 09:23, and some beginnings of modern-day international oil politics at 12:28.
- nonethewiser 5mo agoI went to SF once for a few days and this is one of the things my friend showed me in my limited time there. I remember it from time to time. It's pretty cool. Im trying to reflect on why it was so memorable. I thought it was interesting at the time but it wasnt mind-blowing or something. I think it is just just such a unique oddity and a relic of the past. There was so much effort and space devoted to this. You'd never do something like that today.
- Wistar 5mo agoI used to live in Tam Junction, close to Sausalito. I had lived there at least a year before I discovered the Bay Model and was amazed when I visited it. It is huge.
- vlad-asis 5mo agoTheir models HEC-HMS and HEC-RAS are really great hydraulic models. Unfortunately, with Windows native interfaces...
- taco_emoji 5mo agoThere's a similar model for the entire Great Lakes watershed at Discovery World in Milwaukee. You can even press a button to make it rain!
- ThreatPortSec 5mo agogood
- bigbrained124 5mo agoDid this use this to model operation sea-spray?
- protocolture 5mo agoEveryone knows that Hydraulic models aren't for bays, they are for the British economy. https://en.wikipedia.org/wiki/Phillips_Machine https://en.wikipedia.org/wiki/Phillips_Machine