What do you have on the Alaska to Russia, bridge/tunnel, and how long is the tunnel? Overview of the Alaska-to-Russia Bridge/Tunnel Proposal. The concept of a physical connection between Alaska (USA) and Russia across the Bering Strait has been floated for over a century, primarily as a bridge or tunnel for rail, road, cargo, and potentially energy or fiber optic lines. It would link the Chukotka Peninsula in Russia's Far East with Alaska's Seward Peninsula, creating a land route between North America and Eurasia. The strait itself is about 82 km (51 miles) wide at its narrowest point, with depths averaging 30-50 meters (98-164 feet) and extreme Arctic conditions including ice, earthquakes, and tectonic activity along the boundary between the North American and Eurasian plates. The idea dates back to at least 1890, when Colorado Governor William Gilpin proposed a global railway system including a Bering Strait bridge. Early 20th-century plans, like a 1904 Siberian-Alaska railroad tunnel pitched to the Russian Empire, were rejected due to costs and invasion fears. In the Cold War era, a "Kennedy-Khrushchev World Peace Bridge" was briefly discussed as a symbol of détente. Modern proposals gained traction in the 2000s:2007 TKM-World Link (Transcontinental Railway): A Russian-led plan for a 6,000 km rail network from Siberia to Alaska, including oil, gas, and electricity transport. Approved by Vladimir Putin in 2008 as part of Russia's 2030 development plan, but stalled due to the global financial crisis. 2011 Russian Green Light: Russia committed to a $65 billion project, emphasizing economic ties with Asia and North America. Chinese Involvement: In 2014, engineers proposed a Beijing-to-Alaska high-speed rail via a 200 km tunnel, tying into China's Belt and Road Initiative. As of October 2025, the project remains hypothetical and unfunded, with no construction underway. However, recent geopolitical shifts have revived discussions, particularly following a Putin-Trump summit in Anchorage, Alaska, on August 15, 2025.Recent Developments: The "Putin-Trump Tunnel." In October 2025, Kirill Dmitriev, CEO of Russia's Direct Investment Fund and a Kremlin envoy, proposed a "Putin-Trump Tunnel" as a symbol of US-Russia unity. Key details: Structure: An underwater rail and cargo tunnel under the Bering Strait, potentially including roads, pipelines, and fiber optics. Builder: Suggested collaboration with Elon Musk's The Boring Company for tunneling expertise. Cost and Timeline: $8 billion total, completable in 8 years, funded by Russia and international partners. Purpose: Unlock joint Arctic resource exploration (e.g., rare earth metals in Alaska using Russian tech), boost trade, and foster post-conflict economic ties. Dmitriev highlighted it as a "New Deal" for Russia's Far East-Arctic region. Trump's Response: During a White House briefing, Trump called the idea "interesting," amid talks of a broader "US-Canada-Russia-China" rail line (e.g., from Harbin, China, via Russia and Alaska to San Francisco, ~13,000 km at 350 km/h). Challenges: Geopolitical tensions (e.g., Ukraine war), sparse infrastructure in Chukotka and rural Alaska, environmental risks, and high maintenance costs in permafrost and seismic zones. Critics note it could reduce Europe's strategic importance, shifting global trade dynamics. Dmitriev launched an AI video challenge (#putintrumptunnel) for visualizations, with prizes including trips to the region or a "first ride" if built. Tunnel Length. The proposed tunnel length varies slightly by plan but consistently exceeds 100 km to account for a safe underwater path (deeper than a direct surface bridge to avoid ice and currents). Common figures: Proposal/Source: Length Notes TKM-World Link (2007) 103 km (64 miles) Longest proposed tunnel globally; via Diomede Islands for ventilation. Wikipedia/Bering Strait 103 km (64 miles) Undersea rail from Chukotka to Seward Peninsula. Kremlin "Putin-Trump" (2025) 112 km (70 miles) Rail/cargo focus; Dmitriev's estimate. InterContinental Railway 100 km (62 miles) Dual-gauge rail; includes shafts on Big/Little Diomede. Inhabitat (2011) 105 km (65 miles) Twice the Channel Tunnel's length. A direct strait crossing is ~82 km, but engineering requires curvature for stability, pushing it to 100+ km. Bridge alternatives (e.g., via Diomede Islands) would total ~76 km but face ice floe risks.Public and Expert Sentiment (from X/Twitter)Recent X discussions (as of October 21, 2025) mix excitement, skepticism, and geopolitics:Optimism: Users see it as a "game-changer" for trade and peace, with Trump as a "builder" and Musk's involvement appealing. Doubts: Concerns over costs, Russia's reliability (e.g., historical border disputes), and low population density making it uneconomical. Broader Vision: Some tie it to a pan-Eurasian rail, reducing NATO's role and elevating Arctic routes. Overall, while visionary, the project hinges on US-Russia thaw. No firm commitments exist, but 2025 buzz suggests it could progress if summits yield deals. ________________________________________________________ How would Musk's tunneling company bore this, and keep it level? __________________________________________________________________ Hypothetical Approach to Boring the Alaska-Russia TunnelThe Boring Company's involvement in the proposed "Putin-Trump Tunnel" across the Bering Strait is conceptual, as no construction has begun, and the company has no prior experience with undersea projects. However, based on their existing technology and general tunneling practices, the process would adapt their Prufrock-series Tunnel Boring Machines (TBMs) for this ~100-112 km underwater route. This would draw from innovations in urban tunnels like the Vegas Loop, combined with established subsea techniques similar to the Channel Tunnel. The project would require international collaboration, with estimated costs around $8 billion and a timeline of 8 years, emphasizing remote operation for safety in harsh Arctic conditions. opentools.ai Challenges include seismic activity, permafrost, ice, and water pressure, necessitating specialized adaptations for feasibility. opentools.ai Boring Process Using The Boring Company's Methods. The Boring Company would likely deploy advanced Prufrock TBMs (e.g., Prufrock-4 or later iterations), which are designed for high-speed, continuous mining in soft soil—relevant to the Bering Strait's sedimentary seabed. boringcompany.com Here's a step-by-step overview: Preparation and Launch (Porpoising): The TBM arrives on a truck at a launch site on the Alaskan or Russian side. It tilts downward and begins boring directly into the ground within 24 hours, eliminating the need for deep pits or cranes. boringcompany.com For undersea sections, entry points would be coastal shafts, with the machine transitioning underwater gradually. Excavation: The rotating cutter head at the front thrusts into the soil/rock, using disc cutters, tungsten carbide bits, and drag picks to chip away material (muck). encardio.com Prufrock's key innovation is continuous mining: it excavates while simultaneously installing precast concrete tunnel liners behind it, avoiding stops every 5 feet like traditional TBMs. boringcompany.com This targets speeds over 1 mile per week—6x faster than older models. boringcompany.com Muck is removed via conveyors or, for undersea, mixed with slurry and pumped to the surface. encardio.com Undersea Adaptations: For watery, soft ground, they'd use a Slurry Shield or Earth Pressure Balance (EPB) TBM variant. encardio.com Slurry Shield: Pressurized slurry fills the cutter head to balance water/earth pressure, preventing collapse or flooding; spoil is pumped out for separation and reuse. encardio.com EPB: Excavated material is plasticized with foam/slurry and removed via screw conveyor, maintaining face stability without full slurry. encardio.com These handle high water pressure (up to 7+ bars) in granular or soft sediments. encardio.com The Boring Company would customize Prufrock for immense pressures and instabilities, potentially with reinforced shields and seismic-resistant liners. opentools.ai Zero-People-In-Tunnel (ZPIT) Operation: The entire process is remote-controlled from an Operations Control Center, enhancing safety in remote, hazardous Arctic/undersea settings—no humans enter during normal boring. boringcompany.com Completion and Retrieval: At the end, the TBM "porpoises" out onto a trailer (e.g., "The Monster") for transport to the next site or reuse. boringcompany.com Multiple TBMs could bore from both ends, meeting midway like the Channel Tunnel. The tunnel would be smaller-diameter (~12 feet) for efficiency, reducing material removal, and include rail, pipelines, and fiber optics. capitaly.vc Vertical integration (in-house design/manufacturing) keeps costs low, targeting <$8M per mile. boringcompany.com Component Function Undersea Relevance Cutter Head Rotates to excavate with discs/bits; transfers muck to conveyors. Pressurized to counter water ingress in slurry/EPB modes. encardio.com Shield/Grippers Anchors for thrust; protects workers (though ZPIT minimizes this). Stabilizes against pressure; EPB uses soil for balance. encardio.com Trailing Gear Conveyors/slurry pumps remove spoil; installs liners. Handles slurry transport in watery conditions. encardio.com Maintaining Level and Alignment TBMs like Prufrock must stay precisely on course over long distances to avoid deviations that could cause structural issues or missed connections. The Boring Company would use advanced navigation systems, adapted for underwater where GPS is unavailable. ingenia.org.uk Guidance Systems: A total station laser theodolite provides a continuous beam reference, detected by targets on the TBM. ingenia.org.uk Real-time displays show position, attitude (tilt/skew), and alignment vs. the planned path. ingenia.org.uk The operator (remote in ZPIT) adjusts hydraulic rams to correct thrust and direction. ingenia.org.uk Leveling Tools: Optical levels ensure horizontal accuracy. ingenia.org.uk Gyro theodolites provide orientation relative to true north, compensating for no GPS. ingenia.org.uk Inertial navigation or wire-guided systems could supplement for underwater precision. For Long/Curved Sections: Prisms on tunnel walls deflect the laser around curves, reducing errors from refraction or heat. ingenia.org.uk Stations are periodically reset with surveys tied to surface points via shafts. ingenia.org.uk Computers integrate data for 3D modeling, ensuring the tunnel stays level (e.g., minimal grade variations) and aligned, even in seismic zones. This precision was key in projects like the Channel Tunnel, where lasers and computers aligned bores from opposite sides. quora.com For the Bering Strait, additional seismic monitoring and flexible liners would maintain integrity if minor shifts occur. Overall, while ambitious, The Boring Company's focus on speed, cost, and automation could make this viable, but it demands innovations beyond their current land-based tunnels. opentools.ai ___________________________________________________________________ OK, so, in boring the Channel Tunnel, and the proposed Alaska to Russia tunnel, and considering all the "Length Notes" you provided on other tunnel projects, how, exactly do they take into consideration the earth's curve over all those lengths? For example, the approximately 70 mile length for the Alaska tunnel would include a 3267.61 feet drop, and similar curve drops for all the existing tunnels at 8 inches per mile squared. There would necessarily have to be a continuous curving cut rather than an actual horizontal, or "level" bore hole, correct? _______________________________________________________________________ Accounting for Earth's Curvature in Long Tunnel ConstructionTunnel engineering for projects like the Channel Tunnel (also known as the Eurotunnel) and hypothetical ones like the proposed Alaska-Russia (Bering Strait) tunnel must indeed consider the Earth's curvature to ensure precise alignment, structural integrity, and functionality. The user's calculation of a ~3267-foot "drop" over 70 miles is based on the approximate formula for the curvature drop from a tangent line to the Earth's surface: roughly 8 inches per mile squared, or h ≈ (d² × 8) inches, where d is distance in miles (converting to feet gives your figure). This is a valid approximation for the vertical offset over that distance on a spherical Earth with a radius of about 3959 miles. However, in tunnel boring, this doesn't mean a massive "drop" that needs to be dug out; instead, it's integrated into the design and surveying process to create a path that's "level" relative to gravity, which inherently curves with the planet.In short: Yes, long tunnels require a continuously curving path rather than a perfectly straight (Euclidean) borehole to remain functionally level. A straight-line bore (a chord through the Earth) would deviate from the intended depth or alignment due to curvature, potentially causing the ends to misalign or the midpoint to be too deep/shallow. Engineers account for this through geodetic surveying, where "level" follows the Earth's geoid (an equipotential surface shaped by gravity, approximating mean sea level). This results in a gently arced tunnel that matches the planet's curve, ensuring water drainage, rail gradients, and meeting points from dual-end boring align correctly.Key Concepts in Curvature Consideration"Level" vs. Straight: In engineering, "level" means perpendicular to local gravity (measured by plumb lines or levels), not a flat plane. Over long distances, gravity directions converge toward the Earth's center, so a truly level tunnel naturally curves downward relative to a straight line in space. If bored as a perfect straight chord:The midpoint would sag toward the Earth's center by the sagitta (h ≈ d² / (8R), where R is Earth's radius in miles). For a 70-mile tunnel: h ≈ 70² / (8 × 3959) ≈ 4900 / 31672 ≈ 0.155 miles ≈ 817 feet deeper at the midpoint compared to the ends (if ends are at the same radial distance from Earth's center). Your 3267-foot figure is the full tangent-to-surface drop over 70 miles (h ≈ d² / (2R) ≈ 0.619 miles), which applies more to line-of-sight or horizon calculations. For tunnels, the relevant deviation is the smaller sagitta, as the path is subsurface. Why It Matters: Ignoring curvature could lead to misalignment (e.g., tunnels from opposite ends missing each other by meters), uneven depths (affecting pressure or geology), or structural stresses. For east-west tunnels like the Channel or Bering, there's also a lateral effect: meridians converge, so "north" shifts slightly over distance, requiring bearing adjustments. General Process in Tunnel Boring:Geodetic Surveying: Before boring, the path is mapped using spherical geometry. Tools like GPS (for surface references), gyro-theodolites (for underground orientation independent of magnetic fields), and total stations measure positions relative to the geoid. Calculations incorporate Earth's radius and local variations (Earth is an oblate spheroid, not a perfect sphere). Tunnel Profile Design: The tunnel isn't flat; it's profiled with gentle grades (e.g., descending then ascending in undersea tunnels) to follow stable geological layers, which themselves curve with the Earth. Software models the arc to maintain constant "level" or depth. During Boring: Tunnel Boring Machines (TBMs) use laser guidance systems, inertial navigation, and real-time sensors to stay on the curved path. Lasers project a reference beam, adjusted for curvature via periodic surveys tied to surface benchmarks. Gyroscopes maintain direction, compensating for any geoid undulations. Alignment from Both Ends: For long tunnels, boring starts from both sides. Curvature corrections ensure they meet: e.g., vertical and horizontal offsets are pre-calculated and monitored. Specific to the Channel Tunnel (50.46 km / 31.35 miles total undersea length)Curvature Integration: The tunnel's service and rail bores gently curve up/down (maximum gradient 1.1%) and left/right to follow the stable chalk marl layer, which parallels the seabed's natural curve. ice.org.uk Engineers explicitly accounted for Earth's curvature in alignment, using advanced surveying with gyro-theodolites and lasers. tandfonline.com Tidal effects, gravitational variations (from sun/moon), and the geoid were modeled to ensure the British and French sides met precisely in 1990 after 15.6 km each of boring. everything-everywhere.com Drop Calculation: Over 31.35 miles, the tangent drop is ~655 feet (using 8 in/mi²), but the actual sagitta for a chord is ~164 feet. The tunnel's profile dips to a maximum depth of 75 m below sea level, incorporating this curvature to avoid deviations. Example Adjustment: Similar to London's Crossrail (26-mile tunnels), where ignoring curvature would have offset the endpoint by 20 mm laterally due to meridian convergence. ianvisits.co.uk The Channel Tunnel used similar corrections, amplified by its length and undersea nature. Specific to the Proposed Alaska-Russia (Bering Strait) Tunnel (~100-112 km / 62-70 miles)Curvature in Proposals: While still conceptual (no construction), plans like the 2007 TKM-World Link or 2025 "Putin-Trump" tunnel emphasize engineering feasibility in Arctic conditions, including seismic zones and permafrost. debuglies.com Curvature would be handled similarly to the Channel Tunnel: geodetic modeling to curve the bore along the geoid for level rail/pipeline grades. The Diomede Islands (midway) could serve as ventilation/access points, breaking the tunnel into segments where curvature adjustments are easier. en.wikipedia.org Drop Calculation: For 70 miles, as noted, sagitta ~817 feet. The tunnel would arc gently to maintain ~30-50 m depth under the strait, following seabed geology. interbering.com Proposals don't detail exact curvature math publicly, but standard practice (as in other long tunnels) would use the same surveying tools. Additional Challenges: The Bering region's tectonic activity requires flexible, earthquake-resistant designs, but curvature handling remains standard. debuglies.com If involving The Boring Company (as suggested), their Prufrock TBMs would adapt guidance systems (lasers, gyros) for the curve, similar to urban projects but scaled up. Comparison with Other Long Tunnels (from Provided Length Notes)Using the sagitta approximation for chord deviation:Tunnel/Proposal Length (miles) Approx. Sagitta (feet) Curvature Notes Channel Tunnel (undersea) 31.35 ~164 Curved profile follows geology; geoid-based surveying ensured alignment. ice.org.uk TKM-World Link (Bering) 64 ~513 Hypothetical; would arc to match geoid for rail stability. Putin-Trump (Bering) 70 ~817 As above; Diomede shafts aid segmented curving. InterContinental Railway (Bering variant) 62 ~481 Similar geodetic adjustments. Inhabitat 2011 (Bering) 65 ~529 Focus on undersea stability includes curvature modeling. In all cases, the bore is curved to remain level per gravity, not straight. This is standard in civil engineering for any project over ~10-15 km where curvature becomes measurable. quora.com +1 For math: The exact profile uses spherical trigonometry or finite element modeling, but the 8 in/mi² rule guides initial estimates.This approach has been proven in tunnels worldwide, ensuring they function as intended without "fighting" the planet's shape. _____________________________________________________________________ OK, what about Musk's proposed 3,400-mile underwater tunnel connecting London and New York? 3,400 miles means a 1,372.48 mile drop during boring, under the Atlantic ocean. . . _______________________________________________ Overview of Elon Musk's Proposed Transatlantic TunnelElon Musk, through The Boring Company, has publicly proposed or endorsed concepts for a transatlantic tunnel connecting New York City and London, spanning approximately 3,400 miles (5,472 km) across the Atlantic Ocean. This idea gained traction in late 2024 and early 2025, with Musk claiming his company could build it for around $20 billion—dramatically lower than expert estimates of $19-20 trillion, which he dismissed as inflated by suggesting it could be done for "1,000 times less money." thebrighterside.news +2 The tunnel would incorporate hyperloop or vactrain technology: pressurized pods or trains traveling through near-vacuum tubes to eliminate air resistance, enabling speeds over 3,000 mph (4,828 km/h) and reducing travel time to about 54 minutes—faster than many urban commutes and comparable to a Boeing 737's cruising speed. thebrighterside.news +1 This would revolutionize global trade, tourism, and connectivity, potentially running on renewable energy for lower emissions than air travel. thebrighterside.news The proposal builds on Musk's 2013 hyperloop whitepaper and The Boring Company's urban tunneling expertise, but it's still highly conceptual—no detailed engineering plans, funding, or international agreements exist. newsweek.com Experts like Oxford University's Bent Flyvbjerg see Musk as the "best hope" for feasibility due to his track record in cost reduction and innovation, though he rates success as "high-risk" and far below 100%. newsweek.com Challenges include regulatory hurdles, international cooperation, and immense technical barriers like seismic activity along the Mid-Atlantic Ridge (a 1.8-mile-high volcanic rift where tectonic plates diverge). dailymail.co.uk Construction Method: Not a Traditional Bored TunnelUnlike shorter undersea projects like the Channel Tunnel (bored through bedrock), the transatlantic proposal isn't envisioned as a single straight bored tunnel due to the impracticality of such a long, linear excavation. Instead, it would likely combine methods: thebrighterside.news +1 Submerged Floating Tunnel (SFT) for Deep Sections: The primary approach involves buoyant, vacuum-sealed tubes anchored to the ocean floor with cables or tethers, floating at a controlled depth (e.g., 50-100 meters below the surface to avoid ships and storms). This "archimedes bridge" design uses positive buoyancy from lightweight materials, counterbalanced by anchors, allowing the structure to flex with currents and earthquakes. thebrighterside.news Sections would be prefabricated onshore, towed into position, and assembled underwater using submersibles or robots. Bored Segments Near Coasts: The Boring Company's Prufrock TBMs could bore entry/exit tunnels on land or shallow seabed near New York and London, transitioning to the floating system offshore. newsweek.com +1 This hybrid avoids deep boring across the ocean. Vacuum and Maglev Integration: Tubes would be airtight for near-vacuum conditions, with magnetic levitation (maglev) for frictionless propulsion. Prototypes like China's T-Flight (387 mph tests) and SpaceX-backed pods (288 mph) inform the tech. dailymail.co.uk No full-scale tests exist for this scale, and construction could take decades (or centuries at Channel Tunnel paces), though Musk's innovations aim to accelerate it. thebrighterside.news Accounting for Earth's Curvature and the "1,372.48 Mile Drop"Your calculation of a 1,372-mile "drop" over 3,400 miles uses the approximate formula for the vertical offset from a tangent plane to the Earth's surface: h ≈ d² / (2R), where d is the arc distance (3,400 miles) and R is Earth's radius (3,959 miles), yielding ~1,460 miles (close to your figure; slight variance may come from using a different R or the 8 inches per mile squared approximation: h in feet ≈ (2/3) d², then converted to miles as ~1,459). This represents the "bulge" or maximum deviation if viewing the path as a straight line tangent to the Earth at one end—the far end would appear "dropped" below the horizon by that amount.However, for the transatlantic tunnel:It's Not a Straight Bore: A perfectly straight (chord) tunnel through the Earth would indeed deviate massively due to curvature. The sagitta (midpoint depth relative to the ends) is s = R (1 - cos(d/(2R))), exactly ~356 miles deeper at the center for d=3,400 miles (using θ = d/R ≈ 0.859 radians). This would plunge the tunnel ~580 km into the Earth's mantle (crust is only 8-50 km thick), exposing it to extreme heat (up to 1,000°C+), pressure, and molten rock—utterly impossible with current technology. dailymail.co.uk Curved Path Following the Geoid: Instead, the tunnel would be designed to gently curve parallel to the Earth's surface (geoid), maintaining a roughly constant depth below the ocean floor or sea level. This ensures it's "level" relative to gravity—perpendicular to local plumb lines, which converge toward Earth's center. The structure arcs with the planet's radius, avoiding deep penetration. thebrighterside.news For SFT Sections: Tubes are assembled in curved segments, contoured to the ocean's natural bathymetry (seabed profile), which already follows Earth's curve. GPS, sonar, and geodetic surveys map the path; sections are positioned with sub-centimeter accuracy using underwater robotics. The gentle arc (radius ~3,959 miles) means no sharp bends—over 3,400 miles, the total "drop" is distributed as a smooth curve, with local grades <1% for stability. For Any Bored Parts: Near-shore boring would use the same methods as the Channel Tunnel: geodetic surveying with GPS, gyro-theodolites, and lasers to adjust for curvature in real-time. TBM guidance systems (e.g., total stations) maintain alignment along the planned arc, resetting via surface benchmarks. Software models spherical geometry to ensure ends align without deviation. Ocean-Specific Considerations: The Atlantic's varying depths (average 2 miles, max ~5 miles in trenches) and features like the Mid-Atlantic Ridge require the tunnel to undulate vertically (e.g., dipping under ridges). External pressures (up to 1,000+ atmospheres) are countered by reinforced tubes and vacuum internals; curvature isn't a direct pressure factor but is integrated into stress modeling. dailymail.co.uk The SFT's flexibility allows it to adapt to minor geoid variations or tectonic shifts. In essence, the "drop" isn't excavated as a vertical plunge; the tunnel's path is engineered to curve continuously with Earth, making it functionally level over the distance. This is standard for long infrastructure (e.g., pipelines, bridges) but amplified here by scale. While visionary, the project remains speculative, with experts doubting near-term realization due to costs and geology. newsweek.com ______________________________________________________________________________