4 ms·

I liked your analysis, but it hinges on the $150 million per mile figure. Is there any data to back that up, or any reason you chose that figure? Is there any r

by apeace 9y ago

I liked your analysis, but it hinges on the $150 million per mile figure. Is there any data to back that up, or any reason you chose that figure? Is there any reason to believe that Boring Co's technology could lower the cost?

tzury 9y ago
I am looking at projects record in my region and seeing around $60m per kilometer for a “simple cars” road tunnel. And this is when the Chinese have done it. Perhaps for an high tech tunnel such as this one, $150m per mile is a modest estimate
lobster_johnson 9y ago
I don't buy the parent's arguments, but the $150m figure isn't too far from what Musk has pitched [1]: > Currently, tunnels are really expensive to dig, with some projects costing as much as $1 billion per mile. In order to make a tunnel network feasible, tunneling costs must be reduced by a factor of more than 10. So, a factor of 10 is $100m, but we don't know what "or more" means at this point. [1] https://www.boringcompany.com/faq/ https://www.boringcompany.com/faq/
JumpCrisscross 9y ago
OP's method [1] works better backwards. Assuming 250 miles (l) financed interest-free for 50 years, we find an implied ticket price (p) of the cost per mile (c) divided by the quantity 73 times daily ridership (c / 73 r). Generalised, we get (l c) / (18250 r) = p. New York City and Washington, D.C. are 229 miles apart [2]. The Acela has ridership of 3.47 million per year [3], or about 951 on average per day. Acela tickets cost no less than $99 [4]. Plugging in we find the cost per mile can be no more than $7.5 million. That is 30% the cost per mile of the cheapest tunnel, the Shanghai River Crossing, and 5% the cost per mile of the median tunnel in Figure 5 [5]. On the other hand, the Falcon 9's list price [6] per pound to low-earth orbit is about $1,230. That's approximately 70% to 85% cheaper than the competition [7]. Naturally, you'd charge less than $99 and hope for more than a thousand daily riders. The trick is finding routes for which the price elasticity of demand is high, i.e. where reducing the ticket price by 1/2 generates more than a 2x demand boost. [1] https://news.ycombinator.com/item?id=15519733 https://news.ycombinator.com/item?id=15519733 [2] https://www.travelmath.com/drive-distance/from/New+York,+NY/to/Washington,+DC https://www.travelmath.com/drive-distance/from/New+York,+NY/... [3] https://en.wikipedia.org/wiki/Acela_Express https://en.wikipedia.org/wiki/Acela_Express [4] http://www.nbcwashington.com/news/local/Amtrak-Lowers-Acela-Express-Fares.html http://www.nbcwashington.com/news/local/Amtrak-Lowers-Acela-... [5] https://tunneltalk.com/TunnelTECH-Apr2015-Arup-large-diameter-soft-ground-bored-tunnel-review.php https://tunneltalk.com/TunnelTECH-Apr2015-Arup-large-diamete... [6] http://www.spacex.com/about/capabilities http://www.spacex.com/about/capabilities [7] http://4.bp.blogspot.com/_VyTCyizqrHs/S9IabKEr1nI/AAAAAAAAHbc/2qXZ169gNgE/s1600/space1.jpg http://4.bp.blogspot.com/_VyTCyizqrHs/S9IabKEr1nI/AAAAAAAAHb...

by apeace 9y ago

tzury 9y ago

I am looking at projects record in my region and seeing around $60m per kilometer for a “simple cars” road tunnel. And this is when the Chinese have done it. Perhaps for an high tech tunnel such as this one, $150m per mile is a modest estimate

lobster_johnson 9y ago

I don't buy the parent's arguments, but the $150m figure isn't too far from what Musk has pitched [1]: > Currently, tunnels are really expensive to dig, with some projects costing as much as $1 billion per mile. In order to make a tunnel network feasible, tunneling costs must be reduced by a factor of more than 10. So, a factor of 10 is $100m, but we don't know what "or more" means at this point. [1] https://www.boringcompany.com/faq/ https://www.boringcompany.com/faq/

JumpCrisscross 9y ago

OP's method [1] works better backwards. Assuming 250 miles (l) financed interest-free for 50 years, we find an implied ticket price (p) of the cost per mile (c) divided by the quantity 73 times daily ridership (c / 73 r). Generalised, we get (l c) / (18250 r) = p. New York City and Washington, D.C. are 229 miles apart [2]. The Acela has ridership of 3.47 million per year [3], or about 951 on average per day. Acela tickets cost no less than $99 [4]. Plugging in we find the cost per mile can be no more than $7.5 million. That is 30% the cost per mile of the cheapest tunnel, the Shanghai River Crossing, and 5% the cost per mile of the median tunnel in Figure 5 [5]. On the other hand, the Falcon 9's list price [6] per pound to low-earth orbit is about $1,230. That's approximately 70% to 85% cheaper than the competition [7]. Naturally, you'd charge less than $99 and hope for more than a thousand daily riders. The trick is finding routes for which the price elasticity of demand is high, i.e. where reducing the ticket price by 1/2 generates more than a 2x demand boost. [1] https://news.ycombinator.com/item?id=15519733 https://news.ycombinator.com/item?id=15519733 [2] https://www.travelmath.com/drive-distance/from/New+York,+NY/to/Washington,+DC https://www.travelmath.com/drive-distance/from/New+York,+NY/... [3] https://en.wikipedia.org/wiki/Acela_Express https://en.wikipedia.org/wiki/Acela_Express [4] http://www.nbcwashington.com/news/local/Amtrak-Lowers-Acela-Express-Fares.html http://www.nbcwashington.com/news/local/Amtrak-Lowers-Acela-... [5] https://tunneltalk.com/TunnelTECH-Apr2015-Arup-large-diameter-soft-ground-bored-tunnel-review.php https://tunneltalk.com/TunnelTECH-Apr2015-Arup-large-diamete... [6] http://www.spacex.com/about/capabilities http://www.spacex.com/about/capabilities [7] http://4.bp.blogspot.com/_VyTCyizqrHs/S9IabKEr1nI/AAAAAAAAHbc/2qXZ169gNgE/s1600/space1.jpg http://4.bp.blogspot.com/_VyTCyizqrHs/S9IabKEr1nI/AAAAAAAAHb...