Drone footage of Seattle's new 57 foot SR 99 tunnel [video] | Hacker News Reader

Drone footage of Seattle's new 57 foot SR 99 tunnel [video]

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86 pointscurtis56 comments

I just looked and can't find it. Big Bertha had stopped and it came up on Slashdot. Having some familiarity, I was the resident expert. So, I tracked down all the project info and was able to find the person who'd modeled the traffic - id known him for years but he died before the project was completed.

I can't find this at Slashdot. I went on for hours and answer a ton of questions. A couple of days later, I was still answering questions. More and more info piled in and we were able to find online documents squirreled away in strange places.

It was a neat write up and a bunch of people helped and asked questions. I'd link it, but it seems to have gone missing.

Either way, it was a hell of a project. I had nothing to do with it. I do know some of the folks involved but was retired before this and I mostly worked East of the Mississippi.

Ah well... There is a lot that goes into infrastructure. It was awesome getting to see it. My favorite work was field work. I'd escape the office and do field work out of dinghy hotels. Someone has to collect the data.

So, I've seen them tunnel, blast, pave, line, and more. I've helped sign crews and driven a grader. None of that was actually a part of my job, but I am a five year old.

Either way, boring holes is tough and things break a lot. Equipment is often single use or rented. It's pretty fancy stuff. It is really just a bunch of men with heavy equipment playing in the dirt and mud - which is as awesome as you might imagine.

I used to get a police escort as I'd drive our data car down the highway. The reflectometer grabbed the data from the lane markings and stored them in the computer in the trunk. I can do that for hours. But, I digress...

You can watch documentaries and see how they bore tunnels. That's like watching a cooking show. If you get to go see it in person, that is pretty sweet.

I wish I could find my previous writeup. Oh well...

The gist of it is, it is loud, dangerous, smelly, and appears to be pretty hard work. I was never allowed to touch the machine, which is for the best. It's like a monster that we've commanded to eat a hole in a mountain. That's pretty impressive.

So, if you are thinking you're burning out, maybe you can go work for the highway department for a few years. They will teach you to drive some pretty awesome stuff.

Really quite cool to read about. Thanks for posting!

The Tunnel Boring Machine is called Bertha, not Big Bertha.

You'll have to take that up with the media. I can only go by what they were calling it and what we called it during the fun phase of learning why it broke, who was involved, and how far over budget it just might go.

I had zero to do with the project. Google tells me you're right, but Google also tells me the media called it Big Berth. Don't blame me, blame them.

I'm guessing it's 57 feet in diameter, not 57 feet long. At first I was slightly confused.

It is 2 miles long.

#metoo. Length is kind of the default dimension for a tunnel. Seeing one unspecified number, that's what we automatically assume it describes.

Seems crazy to spend as much as they did and only get 2 lanes each way. I'd love to see better road and rail infrastructure, but road construction, unlike road maintenance, doesn't seem to be WSDOT's thing -- I think due to how the plans have to be approved directly by voters. (Their pass-clearing operations on I-90, etc. are amazing, though.)

> I think due to how the plans have to be approved directly by voters.

Virtually no major road projects are put to the voters around here. (Highway 99 is the exception because it was so controversial.) You're thinking of transit projects in Puget Sound which usually have to go through two or three rounds of voting to get fully funded...

To wit, the bill that authorized Sound Transit to hold its most recent vote included several billion in not-subject-to-a-popular-vote road projects. I actually prefer that our representatives control the budget; that's what we elect them to do. But this double standard of "roads are fine but transit...pfft, well, that must be ratified" is obnoxious.

What about convincing voters to build low-speed maglev?

https://youtu.be/c8SqDVUdMtY

https://youtu.be/uqobD2XUAJU

Genuine question: what's the point of low-speed maglev? Seems like you could just use a regular electric train.

When have you ever seen a regular train used within a city for short distance travel?

Do you mean light-rail or a subway? Much faster and much quieter.

In London. The south doesn't have much in the way of tube trains.

Also, TFL has taken over some of the regular lines and re-branded them The Overground. These run regular trains.

I've often commuted a couple of stops from London Bridge to Charing Cross, it's short enough that on the way back from work I would often walk or use a Boris bike.

I preferred that route to taking the Underground as it's just nicer travelling above ground, I can't say that it made a difference to the travel time.

These are regular trains at the end of longer routes to the South.

The trip is less than 2 miles and takes 18 minutes?

https://www.londondrum.com/transport/train-journey.php?from=...

It’s hard to compare but the maglev seems to operate much quicker: http://www.chinadaily.com.cn/china/2017-06/15/content_297514...

“The maglev line will have eight stations stretching over 10.2 kilometers and will run at a maximum speed of 100 kilometers per hour. The whole journey will take about 20 minutes, including the time for passengers to get on and off”

Sorry if I wasn't clear enough, I meant - why would one choose a maglev for low-speed transportation, rather than a non-maglev vehicle that runs on rails? (Fill in whatever terms you want in your mind, light rail, subway, tube, underground, tram, streetcar, EMU, I don't care.)

I answered with “it’s much faster and much quieter”.

Here’s a 360 degree video of the gotthard base tunnel: https://youtu.be/i0kdT5oEN2Q In contrast to the Seattle project there are two tunnels running side by side. More information: https://en.m.wikipedia.org/wiki/Gotthard_Base_Tunnel

Total cost $4.25 billion for those wondering.

$2b per mile (vs $5-10m for a regular Highway). I wish tunnels were cheaper and faster to build.

What a waste. If they just demoed it it would create a new neighborhood and everyone would just switch modes.

For the project:

https://en.m.wikipedia.org/wiki/Alaskan_Way_Viaduct_replacem...

Why did they reduce the viaduct from six lanes down to four? If you're going thru the trouble for boring a tunnel, do it proper and either keep the same lanes or add (even a convertible lane --disabled vehicle/rush hour lane) But reduction? Except for earthquake proofing the roadway, this does not improve upon the traffic on SR-99.

It reminds me of the Caldecott Tunnels --they had to bore a new one to carry all the traffic --but at least you can forgive that because traffic volume was lower when they orig built them.

For what it's worth the project eliminates the downtown exits which is where a lot of people on the existing viaduct are either coming from or headed. Combined with a toll, I expect traffic over this section of roadway to improve. It's the other nearby roads that are concerning.

I see where they are just trying to alleviate things for thru traffic, but that leaves the side roads to make up for the traffic off-load --making it worse for the commute.

My complaint is that if you're going to invest a few billion into boring a tunnel, at least make it wide enough to carry all the orig traffic given that adding marginal width is a small fraction of overall cost of building a tunnel.

At 32 feet, it does seem like they have plenty of width for 3 lanes each way with no shoulder. 12 foot lanes are the standard for 60-70 mph interstates, but Aurora's top speed limit is like 45 mph or something and I think it's even lower in the current tunnel. So 10.6 foot lanes seem pretty reasonable.

Take a look at the sides of the I90 E tunnels. Tunnel walls tend to jump out at Seattle drivers. Gotta give people some breathing room and I'm sure there is some consideration for leaving space for emergency vehicles to squeeze by. I am also hoping they increase the speed limit inside the tunnel since there are no ramps. I think there is probably consideration for making it easy for buses to navigate as well.

I think you have a good point about emergency vehicle access.

I-90 is a much higher speed road, though. (Assuming they don't take your suggestion of increasing the speed limit in the tunnel.) Freeway standard is 12 feet per lane (and even the 1940-era Mt Baker tunnels have 12 foot lanes[0]), but again, Aurora isn't a freeway.

Meanwhile, buses are about 8.5 feet wide[1] and easily fit in a 10 foot lane. Most Seattle streets are narrower than that.

[0]: http://www.seattleasce.org/committees/hh/LaceyBridgeReport.p...

[1]: https://cptdb.ca/wiki/index.php/New_Flyer_Industries_XDE60

Maybe interesting datum: the existing Battery Street Tunnel has two lanes with a total width of 25 feet[0].

> The SR 99 roadway width narrows to 25 feet with two lanes in each direction through the BST

> The existing lane width varies from 10.5 feet to 11 feet, and there are no existing shoulders only a gore stripe adjacent to the curb... The existing posted speed is 40 mph.

So there's no real reason we couldn't keep the 10.5 foot lane size, 40 mph speed limit, and do three lanes. The new tunnel has better sight lines and curve radius than the BST. And there's separation between directions, which is better than the Aurora bridge (which also has pretty narrow lanes):

> Many aspects of the existing horizontal and vertical curves do not meet today’s roadway design standards for the posted speed limit. When compared to current design standards for stopping sight distance, horizontal curve radius, and vertical curve length, about two-thirds of the horizontal and vertical curves would coincide with a design speed of less than 40 mph.

[0]: http://www.scatnow.com/DesignDev3Grade.pdf

Is three lanes at 40mph higher throughput than two at 60?

Trick question! "mph" is not a direct measure of throughput. Cars per second (passing a given measurement point) is.

If the spacing of the cars is the same between the two, then a 60 mph lane is moving more cars per second than a 40 mph lane. The spacing never is the same, though, unless these are autonomous cars.

Also, throughput is limited by bottlenecks. If an upstream bottleneck has throttled things to one car every ten seconds, it doesn't matter whether the downstream lane is 30 mph or 60 mph.

Fine points but in this case posted MPH isn't an output, it's an input. So is the number of lanes.

Spacing is a function of speed. Even with autonomous cars spacing is not constant because there are on and off ramps so some will be accelerating or decelerating. We don't even know how those cars will work, maybe you can pay more to drive faster!

The question here is which configuration of the tunnel will maximize throughput.

I can't find any explicit statement of the planned speed limit but I did find a document [1] that implies there will be variable speed limits much like other highways in the area.

[1]: http://www.wsdot.wa.gov/Projects/Viaduct/Media/Default/-NewD...

Really good points. I was suggesting the need for a shoulder so people don’t just drive into the walls like they do on I90.

And what, put in a car elevator to get from the tunnel to first avenue? The tunnel is 200 feet underground at the location of the current ramps.

It's my understanding the first tunnel plans were for a six-lane tunnel. I have not seen the elevation/depth info on the tunnel, but even at 200f, you just need a longer ramp to ascend.

But you have to build that subterranean ramp. The tunnel cost billions already without the ramp, how much more would it cost with that added complexity? There will still be surface streets where the viaduct is located.

I'm not a transit engineer but I do think this is one of the drawbacks in the kind of radical democracy we push in Washington. Everything goes up to a public vote, even things the public can't really fully be experts on.

Seattle is very limited with the amount of land available. It's not feasible to build the 18 lane ultra freeway required to allow everyone to drive to their destination.

For better or worse Seattle city planners have taken a car-hostile approach to try and force people onto public transit. Unfortunately they also can't figure out how to pay for enough buses and trains to get everyone where they are going.

Also, my understanding is that there will be a surface street where the current viaduct is which combined with the tunnel will allow downtown access and increase capacity beyond what we have today.

> Seattle is very limited with the amount of land available.

Tunnels don't use land.

The ramps to get in and out of them do though. Also tunnels do occupy space. Seattle already has a bus tunnel and a rail tunnel to avoid. On top of being built on Jell-O.

This is an important point, and one you can see in practice in downtown Boston walking above the I-93 tunnel - lots of land is still used for off-ramps and on-ramps, which tends to have high-speed traffic, whose presence is dangerous and discourages walking, which is the lifeblood of the city.

The exits, entrances, and ops building uses surface land.

There is limited subterranean land as well.

So, planners there are car-hostile but are still spending billions to deliver as many total lanes as currently exist, counting both the tunnel and the surface street?

If that's the definition we're using, then I'd like someone to show hostility to an interest of mine by spending billions on it.

The comment I replied to was suggesting a second tunnel may need to be constructed to handle increasing traffic volume. My comment was pointing out that this is difficult for a number of reasons including the geographic reality of Seattle. The comment also assumed a car-first approach where roads have to meet increasing demand which is also not a priority in Seattle in 2017.

When the project is complete capacity will be the same or slightly larger than the capacity of a roadway built in the 1940s. Seattle has doubled in population since then. The current viaduct barely serves our needs and the new tunnel and surface street combo will not solve the transportation problems alone. We need fewer single occupant vehicles.

Cars are not given top priority in project planning. Just because one tunnel and one road are being put in place does not change that. There are transit corridors downtown that do not allow cars. Most downtown streets are a maze of one ways that make navigation difficult. Parking requirements for new construction are continually relaxed, reducing available parking across the city. Car tabs are expensive to fund for transit and discourage driving. Seattle has a lot of anti-car policies.

Planners here would like to spend more on building out our light rail and increasing bus/bicycle ridership than they would on adding subterranean exit ramps to a bypass tunnel.

e: Seattle's public transit system is largely bus-based so new road construction tends to take that into consideration with reserved lanes and stops and little attempt to serve the volume of cars.

Also, I don't think anyone claimed the tunnel project was supposed to solve traffic problems. The issue is that the viaduct itself is old and unstable. The tunnel is a combination of a safety improvement to a state highway and a subsidy for Olympia's favorite construction companies.

Tunnels digging costs are roughly proportional to the square of their diameter, if we take Elon Musk's word for it.

So a six lane tunnel probably cost more than twice of four lanes.

That's a great point, I failed to realize. This is a two-deck tunnel, so the price increase might not have been as steep.

In any event, some of the original proposals were for six lanes --wished they'd carried that out.

It was also already the world's largest tunnel boring machine.

Even a 4/3 multiplication of the diameter would have ~doubled the cross-section surface.

> Tunnels digging costs are roughly proportional to the square of their diameter

Given a constant length and homogeneous ground composition (conditions that apply to the current discussion)... It makes a lot of sense that the cost is proportional to the volume being removed.

There has to be more to it than just homogenous ground composition. Surely drilling into granite is harder than clay or something? Also my understanding was that the SR99 tunnel is through both fill and clay.

http://www.wsdot.wa.gov/Projects/Viaduct/About/Tunneling

I may not have used the best phrasing:

For a given tunnel length and ground composition, the cost is proportional to the area of the cross section.

Adding lanes doesn't reduce traffic. It's called induced demand. In 1 year new capacity (supply) creates 50% in demand and in 5 years it is 100%. You want less traffic? Stop giving roads away for free.

I wonder how it was flown such a long distance without GPS? Also for consumer DJI drones the signal range in the tunnel would not be sufficient I think.

Urm, most drones are controlled by a person holding a remote. Said person could've just ... walked along?

There were quite a few cuts as well, so I don't see any challenge there

It's almost certainly being piloted manually. It's moving slowly and there's a lot of cuts, so the controller probably just walked along with it.

There's a point where it switches from a lower level to a higher level, seemed pretty clearly manual to me.

Oh, the magic of editing.

True story: I loved the movie Cocktail with Tom Cruise. I set out to learn all his bar tricks from the film, including lighting a match with one hand. Took me two months and many burned fingers before I mastered it. Then, I re-watched the movie to make sure I was doing it right, only to realize it was an editing trick and he never really did it. Oh well. I learned a skill for life.

I like Jackie Chan’s philosophy w.r.t that sort of thing, I’m sure he would have spent the time, and that means a lot when the scene plays :)

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