Show HN: Build a Lisp in Swift https://ift.tt/3j2jWlF

Show HN: Build a Lisp in Swift https://ift.tt/3rYIq25 August 21, 2021 at 05:56AM

Then and Now: Keeping the Cable Cars on the Move

Then and Now: Keeping the Cable Cars on the Move
By Jeremy Menzies

When Andrew Hallidie’s first cable car climbed Nob Hill on Clay Street in August 1873, the cars were a brand-new technology to replace the horse-drawn streetcars used at the time. Little did he know that 148 years later, cable cars would still be scaling the steep slopes of Nob Hill.

Many of the methods used to maintain and operate the cars to this day harken back to the golden era of cable cars in the late 1800s. As we ramp up for the return of revenue service on San Francisco’s beloved cable cars, check out the images below for a look at just some of the behind-the-scenes work keeping the system running, both then and now.

Keeping up the Cars
Maintaining the cars on a regular basis is vital to keeping them safe, operable and looking good for the tens of thousands of people who ride them. At the Cable Car Division shops, mechanics, carpenters and painters perform routine maintenance, make repairs and brighten up worn out paint to keep the cars in shape.

Then: Two painters work on California Street Cable Car 15 in the paint shop at California Cable headquarters in 1952 (once located on the SW corner of Hyde and California Streets).

Now: A painter lays down masking tape to paint striping on the side of Powell St. Cable Car 22, which was rebuilt in 2017.

Minding the Cable
Without cables and the machinery used to move them, there would be no cable cars. Today the age-old work of cable splicing, a method of attaching one end of the cable to the other, is done by hand, the same as it has been done for over 100 years. Another critical job is maintaining the winding machinery used to move the cable and cars through the streets.

Then: cable splicing in 1947 involved hand tools, skill and a bit of brute force, much the same as 10, 20, or 50 years earlier. 

Now: This 2014 shot looks about the same as its 1947 counterpart, minus the hats and cigarettes!

Major Overhauls
When a car is too old or damaged to operate safely, it is rebuilt by teams of skilled craftspeople. The metalworkers in our Special Machine shop are responsible for building new metal parts used throughout the vehicle – from heavy wheel and suspension assemblies to decorative parts of the passenger grab bars. Carpenters rebuild the entire car, while painters and mechanics finish getting the car looking its best and ready to roll.

Then: Two mechanics stop for a photo in 1958 with an overhauled cable car truck in the heavy repair shops once located on Ocean and San Jose avenues (present day location of Muni’s Green Division).

Now: A welder cuts up an old cable car truck using a torch at the Special Machine Shop, which handles building brand new trucks from scratch. In addition to using traditional methods, the shop is truly a 21st century operation with computer-controlled machines that can make parts from technical drawings that were painstakingly uploaded into modern machining software.

Tracks to Run On
Today, as throughout the past 100+ years, track crews are responsible for keeping the track system up and running. Unlike regular rails used in our streetcar and subway systems, the cable car rails include complex pieces to not only guide the cars but also move the cable up and over hills and around bends.

Then: A track crew works to replace a depression beam and bumper bar on Powell Street in this 1971 photo.

Now: In this 2019 shot, a track crew replaces an old depression beam just blocks from the 1971 photo. Depression beams are used to push against the cable to keep it from hitting the channel in which it runs wherever the road dips.

The maintenance and restoration efforts of SFMTA's cable car barn staff speak to their unparalleled background skills and their mastery of age-old trades that help keep our very own national landmark on the move. 

Catch a ride on the cable cars for free throughout the month of August and look for them to return to revenue service in September. 
 

Published August 21, 2021 at 04:57AM
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Show HN: Duedilly.io – Accuracy of Reddit Trading Ideas https://ift.tt/3sBHZen

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Show HN: FreeBoardGames.org – FOSS platform for publishing boardgame.io games https://ift.tt/2W92N0z

Show HN: FreeBoardGames.org – FOSS platform for publishing boardgame.io games Hello HN, I have started FBG some years ago when I moved to the Bay Area and could not find a simple, cross-platform, no-registration way to play board games with my friends back in my home country. I also wanted to make it simple to create multiplayer board games online for developers in their free time. Shortly after, I found out about boardgame.io with similar goals and decided to join forces with them. It became the engine of our board games, and we focused on publishing/serving them. To be fair with everyone and inspired by Wikipedia, we made the project a non-profit with GPLv3 Affero license. Since then, the project has gotten many amazing contributors that developed really cool board games, added translations, helped with infra, etc (see https://ift.tt/3glVHNr ...). My focus has been on the infrastructure (scaling, adding text chat, etc). During the pandemic, we saw a large 30x increase in usage, and it also became more useful for me, as I started using it at work for (now virtual) fun team meeting events. Please check it out and give any feedback! I've been postponing submitting on HN for a long time because I always felt it "wasn't ready enough" as there are a ton of rough edges, but I came to the realization that this feeling might never go away. August 20, 2021 at 11:44PM

Show HN: Cassyni – Relaunching Academic Seminars https://ift.tt/3y5b3fh

Show HN: Cassyni – Relaunching Academic Seminars Hi, this is Andrew (arhpreston) and Ben (benjyk) from Cassyni ( https://cassyni.com ). We both completed PhDs in physics before going on to found Publons and Kopernio, companies that were acquired by -- and became a part of -- Web of Science, a product researchers on HN may be familiar with. It is well known how important academic seminars are for networking, promoting your research, and keeping up with latest developments. But the scale is under-appreciated: by our estimates more than 1 million academic seminars were happening every year. And then Covid came along... As a result many seminar series are now online and recorded using solutions that cobble together tools like Zoom, Google Sites and Sheets. This all more or less works but is painful and time consuming to operate. Our co-founders, researchers at Imperial College London and Texas A&M, experienced this firsthand. With their input we set out to build a tool to take the pain out of organising a seminar series. The idea is that in just a few minutes you can set up a professional looking seminar series and begin inviting researchers. We take care of the tedious process of setting up an online presence and working with speakers to find a time slot that works for them, collect their bio, abstract, promotion and more. We’ve been operating in beta for several months now. You can see some of the seminar series that are up and running on our homepage. These range from your standard departmental series (ABI Tuesday Seminars: https://ift.tt/3mi7RL0 ), to a series about a specific tool for scientific simulations (PyFR: https://ift.tt/3zbj2ZS ) through to a journal that brings in authors to talk about influential papers (J. Comp Phys.: https://ift.tt/2UDmk98 ). Note that you can click on the archive tab of each series to watch recordings of previous seminars. As you can see, these are not just standard departmental seminars; the shift to online has removed geographics barriers, enabling different types of seminar series to develop. What they all have in common is that they are helping communities to form around different kinds of research topics, and they all give you information and nuance you wouldn’t find by reading the related publications alone. On the attendee side, we’ve done some nifty work to integrate with Zoom so the live experience is better (instead of a name in a Zoom meeting you can see the profile of people in the room and participate in a live Q&A: https://ift.tt/3ml5G9t ). In the longer term we think Cassyni can help to make seminars and their recordings a searchable (e.g., check out the slides we’ve automatically extracted from the video and search for “flux” here: https://ift.tt/3D5RkA3 ) and citable (as you can see from the previous link public seminars on Cassyni get a DOI and are indexed in CrossRef) part of the sphere of human knowledge -- a complement to the published literature. We thought we’d share what we’ve built with HN in the hope of getting some feedback about what we can improve. If you are a researcher please do take a look and let us know what you think. And if you’re interested in setting up a seminar series drop us a line (help@cassyni.com) to let us know where you came from and we’ll organise an HN discount for you. August 20, 2021 at 08:33PM

Breaking #FoxNews Alert : Biden defends handling of botched Afghanistan withdrawal, says can't guarantee outcome

Breaking #FoxNews Alert : Biden defends handling of botched Afghanistan withdrawal, says can't guarantee outcome

— R Karthickeyan (@RKarthickeyan1) Aug 20, 2021

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August 21, 2021 at 12:16AM
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Breaking #FoxNews Alert : WATCH LIVE: Biden to address Afghanistan evacuations after reversing course to stay in DC amid crisis

Breaking #FoxNews Alert : WATCH LIVE: Biden to address Afghanistan evacuations after reversing course to stay in DC amid crisis

— R Karthickeyan (@RKarthickeyan1) Aug 20, 2021

from Twitter https://twitter.com/RKarthickeyan1

August 20, 2021 at 11:21PM
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