I’m joining the EV club

Are you in the hurricane path?

Bob Wilson

 

Congrats on your first EV...

 

Congratulations on your new (for you) electric car!

You've piqued my curiosity: What island was it purchased on, and what island is it going to?

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A ferry ride, that explains it. I was wondering how you could "drive" from one island to another, since I (apparently correctly) inferred from your comment there were no bridge connections.

 

Disclaimer: The "napkin math" analysis below has been made by someone who has never even visited New Zealand. Some of my assumptions may therefore be entirely wrong.

Keep in mind that's for a single lane of traffic going each direction. How much throughput would that allow, and would that create a daily traffic jam? What would be a realistic transit time of the tunnel during a typical rush hour, given the number of people trying to use it every day?

Let's say, for the sake of argument, that a car enters/ exits the system once every 1.25 seconds. (Based on my personal driving experience, that's a realistically close -- although quite unsafe -- average spacing of cars traveling in dense traffic.) Let's assume a 1.75 hour window for "rush hour" traffic. (90 minutes might be more realistic, but let's err on the side of being generous.) One car every 1.25 seconds for (60 x 60 x 1.75) 6300 seconds yields 5040 cars.

The population of New Zealand's north island was estimated at 3.67 million in 2017; the population of the south island was estimated at 1.038 million back in 2011. I see per Wikipedia that the two major cities in New Zealand are both on the North Island. I therefore conclude -- perhaps wrongly, but it seems a reasonable conclusion -- that most of the industry and commercial buildings are on the north island, and that therefore the percentage of people traveling from the north island to the south island to work, and back north to go home, is probably a fairly low percentage of the north island's population. Therefore I'm going to ignore that portion of the traffic, assuming it at least won't be any greater than that going the other way. I'm going to consider just the traffic originating from the south island; presumably a larger percentage of people living there would be commuting to the north island for work, and back south to go home.

So, how many cars are there on New Zealand? Mr. Google says there were 3,858,000 vehicles in New Zealand in 2015. I'm going to make another assumption, which again is almost certainly not accurate: I'm going to assume the distribution of cars between the north and south islands is the same as the population distribution. If 77% of the cars are on the north island, that means ~34% are on the south island, or ~1,327,000.

5040 cars yields 0.38% of all the cars on the south island.

Sorry, Gooki, but unless I've made a serious mistake in my reasoning or math somewhere, then just one lane of traffic ain't gonna cut it. 10 "Boring Co." tunnels, yielding 10 lanes of traffic, would get you up to a capacity of ~3.8% of the cars on the south island... which I would guess still wouldn't be even close to being adequate to handle rush hour traffic.

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Addendum:

On the other hand, Wikipedia's article on the "Interislander" ferry service at New Zealand says the ferries handle about 230,000 vehicles per year, which averages only 630 per day, and that would be going both ways. Compared to that, a tunnel able to handle 5040 cars per day going north in the morning, and the same number going south in the evening, would be much more than adequate.

I guess the real question is just how much having a traffic tunnel between the islands would increase traffic. From my brief reading about the service, it looks like ferry fees are pretty steep, so at least in theory, the ability to drive from one island to the other would increase traffic dramatically, unless the tolls for using the traffic tunnel were similarly exorbitantly high.

 

As a tunnel gets longer, the ability to bring in fresh air and exhaust, hot, unbreathable air becomes more difficult. Something like a 'moving sidewalk' or 'carrier of cars' makes more sense. For heat engine cars, a reasonable cool-down interval makes a lot of sense.

There is a reason why the Chunnel uses electric trains with car carriers:


As long as you don't 'Bexit' yourselves, it makes a lot of sense. Given the population size, I could even envision a single train and service tunnel solution with multiplex trains for the half-hour travel each way. A double-wide section midway would allow trains/carriers to pass each other as surface trains do in the USA sharing a single track. Of course I didn't consider the depth between the two islands which could be a big show stopper.

Bob Wilson

 

The channel tunnel (chunnel) cost about $21 Billion, and it had severe cost over runs. Granted it was a little longer (45 KMs), was a rail link and there was a lot of unknowns, I cannot see this tunnel as being less than $3-4 billion even using modern construction practices and a very close management of costs. Just transportation of equipment will cost a lot. Then there are associated facilities at either end. Things add up. Instead of tunnel, a bridge may be cheaper or some sort of combination. There are some very long sea bridges including the under construction Hong Kong–Zhuhai–Macau Bridge (HZMB). The sea portion is about 30 KMs. Again, not sure how the deep the crossing is and if there are cyclones or typhoons (what are they called in that area?) there.

(The Hong Kong–Zhuhai–Macao Bridge, is a 55-kilometre (34 mi) bridge–tunnel system consisting of a series of three cable-stayed bridges, an undersea tunnel, and four artificial islands. It is both the longest sea crossing[5][6] and the longest open-sea fixed link on earth. The HZMB spans the Lingding and Jiuzhou channels, connecting Hong Kong, Macau, and Zhuhai—three major cities on the Pearl River Delta. https://en.wikipedia.org/wiki/Hong_Kong%E2%80%93Zhuhai%E2%80%93Macau_Bridge )

 

The boring company has drilled 1 mile of 12' diameter sewer tunnel (took 2 years start to finish, and the planned length was cut in half) in perfect soil conditions (no ground water) and close to the surface, drilling a deep bore tunnel under ground water table, and through varied materials is a completely different experience. Having seen both he Chunnel project personally, as well as the Macao bridge/tunnel this is a completely different caliber of project. Let's see how the Chicago tunnel project goes for the Boring company, Elon tweeted they would start construction last fall, now a year late, I have not heard any construction updates. Maybe the project is actually a "no go"? Likewise the Washington DC project Elon even showed a hole on a vacant lot he called the "starting pit", 18 months and no updates? I venture to say there is no digging happening on either of these projects? Having been involved in several deep bore tunnel drives I can tell you the old earth is very unpredictable when you get under ground. No mater how many core samples you drill before hand, there are always surprises, and when you get below the water table the complexity increases by magnitudes.

 

Let us not bring Elon into this conversation please (request to all). If a bridge/tunnel etc is to be built between the north and south Islands of New Zealand, I am going to assume it will be done by a company that is well experienced and has a track record. Given that it is going to be very expensive for the reasons stated by @David Green, on second thoughts, I may be understating the costs and the real costs especially if you put a rail line for reasons stated by @bwilson4web. The real costs may be closer to $8-10 Billion. I do not know there is an appetite for such investments given the low volumes of traffic. So I am not sure it will be done in the next decade, given that there is a ferry alternative.

 

With the very high costs of building the tunnel or even a bridge, I doubt if the toll will be less than the ferry costs. The chunnel carries about 2.7 million cars, 1.7 million tucks and about 22 million passengers per year. You are not going to be any where close to those volumes in NZ and it is not cheap to cross the chunnel (more that 40 Pounds one way). Hence I cannot see how the investment will pay for itself unless prices are much higher. Or the government decides it is not a "commercial" venture but a "what is good for society venture" and massively subsidizes it.

 

Sorry, someone a few comments up suggested The Boring Company could possibly built it cheaper, I venture to say those thinking that do not understand the cost structure of building a tunnel, and the systems involved to operate, maintain it. Elon's little tunnel, is a toy, and has no safety, fire or egress systems. Tunnels open to the public has much higher standards. Elon offered on twitter rides in his bumpy tunnel for $1 each, I would fly down to check it out, but I guess those plans changed too...

 

Sure, a design like the England/France Channel Tunnel makes much, much more sense than the Boring Co.'s rather silly idea for a separate tunnel for each lane of traffic. And I completely agree about the need for an access tunnel in between the two traffic tunnels. For a tunnel this long, there will absolutely be a need for a maintenance tunnel, which also acts as an emergency escape route.

I hadn't considered the problem of ventilation. Generally, traffic tunnels have ventilation shafts run up to the surface at intervals, with a forced-air ventilation system used to keep the noxious fumes from ICEVs from building up to toxic levels inside the tunnel. But with the traffic tunnel running under the sea, the usual solution is closed off.

So yes, it would make far more sense to use electric trains to carry cars back and forth, rather than have them go thru the traffic tunnel under their own power.

 

That's how I see it, too. I just don't think there would be sufficient economic incentive in NZ to pay for such a project; not using a realistic design and a realistic estimate of construction costs. I don't consider the Boring Co.'s cost estimates to be at all realistic. Elon Musk talks about reducing tunneling costs by a factor of 10 as one of the goals for the Boring Co. But so far as I can see, they haven't actually made any progress at all on that front.

It looks to me like the Boring Co. started out as a half-joke -- the name itself is a joke -- and half very rich man's fantasy/ wishful thinking dabbling-in-a-hobby project. So far as I'm concerned, it still is and almost certainly never will amount to anything more than that. It really amazes me that so many people treat it as a serious concept.

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