# The $29BN Megaproject in the Heart of a Mountain ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain.webp]] **Creator:** The B1M · **Published:** 2025-12-10 · **Length:** 28:41 · [Watch on YouTube](https://www.youtube.com/watch?v=NFrr-L_BcC4) > Caption source: YouTube **manual English (UK)** captions (`en-GB`), downloaded with **yt-dlp** on the first attempt with the default client. The track reads like the edited script plus verbatim interviews and covers the whole video, including the Straight Arrow News sponsor read (9:31–10:41) and the closing sponsor line. It has a few rough spots: "Gottard" for Gotthard (4:11), "Mont Canis" (4:22) next to the correct "Mont Cenis" (5:41), "Tunnel European Lyon Turin" for TELT (11:02; the description says Tunnel Euralpin Lyon Turin), "the harbour mountain" (9:39, probably "the heart of a mountain"), "You've shown content" (10:04), "it's not going to start that" (2:04, meaning "stay that way") and "raised boring machines" for raise boring machines (22:13). TubeAlfred was not used (0 credits). **Companion article:** [Inside Europe's New Mega-Tunnel Under The Alps](https://www.theb1m.com/video/inside-the-lyon-turin-mega-tunnel) on theb1m.com, by **Adam Savage** (10 December 2025; "Video hosted by Fred Mills. This video contains paid promotion for Straight Arrow News."). It follows the script under its own headings (Next-door neighbours, Fast track, Bang-up job, The scale of the task, The (not so) boring method, Laying the foundations, Going exploring, A breath of fresh air, Forza Italia, The price tag, Long way to go). It names the interviewees **Alexander Heim** (project manager, Implenia), **Matteo Calorio** (geologist, TELT), **Thomas Deviese** (tunnel construction manager, Eiffage Génie Civil) and **Emmanuel Humbert** (TELT construction director for France), and captions a photo of Fred with **Guillaume Lefrere** (site manager, VINCI Construction/Webuild). On cost it differs from the narration: the article prices the **cross-border section at just over EUR 11BN (about USD $13BN)**, funded **40% EU, 35% Italy and 25% France**, and gives **EUR 25BN / USD $29BN** for the whole railway, with the national approach sections paid by each country with up to 50% EU co-financing. The YouTube description adds the same clarification. The article leaves out the sponsor read, Fred's road trip and cathedral reactions, the gantry, Viviana tour and control-cabin exchanges, and the closing "proud" quotes. Figures were cross-checked against TELT's own releases on [Viviana](https://www.telt.eu/en/highlight/viviana-is-ready-the-mechanised-excavation-restarts-in-the-maurienne-area) ([baptism release](https://www.telt.eu/wp-content/uploads/2025/04/20250401_TELT_CS_BATTESIMO_TBM_TORINO-LIONE_EN.pdf)), the [July 2024 cost update](https://www.telt.eu/wp-content/uploads/2025/11/TELT_nota-stampa_allineamento-costi_EN.pdf) and its [reply to the 2025 European Court of Auditors report](https://www.telt.eu/en/highlight/telt-replies-to-the-2025-eu-court-of-auditors-report). YouTube chapters are used as section headings and line up with the captions. Screenshots come from the 720p stream (format 136). Host: **Fred Mills**. On-screen interviewees: **Alexander Heim** ("Project Manager, Implenia"), **Xavier Bernardin** ("Technical Manager, Implenia"), **Guillaume Lefrere** ("Site Manager, VINCI Construction/Webuild"), **Matteo Calorio** ("Geologist, TELT"), **Thomas Deviese** ("Tunnel Construction Manager, Eiffage Génie Civil") and **Emmanuel Humbert** ("Construction Director (France), TELT"). Paid promotion: **Straight Arrow News** (9:31–10:41, plus a closing reminder). The B1M's own plugs (description): **Get Construction Talking** and *The World's Best Construction Podcast*. Additional footage and images (from the description): Tunnel Euralpin Lyon Turin (TELT), Euronews, No Comment and VOA. On-screen material includes animated maps of the Lyon–Turin route and the base-tunnel profile, a "1,000,000 tonnes of CO2" graphic, landslide footage, a Modane ventilation-shaft diagram and the text of **Commission Implementing Decision (EU) 2025/1715 of 30 July 2025** on implementing the Lyon-Turin cross-border section of the Mediterranean corridor. ## Outline ### 0:00 Intro - **0:00** Fred Mills: "I'm currently standing in a massive tunnel deep beneath the Alps." When finished it will stretch **more than 50 km** and bring two major European countries closer together. - **0:17** The tunnel is the main section of a new railway that will **cut journey times in half**, and in a few years it will be the **longest single rail tunnel in the world**. - **0:30** "But how exactly do you build a train line through a mountain range?" Fred has come to one of the world's biggest construction projects to find out ("We're digging through the middle of a mountain"), and to see its impact on the wider continent. - **0:55** "Whoa, look at this!" (a preview of the cathedral cavern). "This is quite literally my **deepest dive yet** into one of this planet's biggest mega-builds." ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t0004.webp]] ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t0056.webp]] ### 1:16 The Lyon-Turin Route - **1:26** On a road trip from **Lyon** to **Turin**, the quickest current route, Fred points out what the map doesn't show: the **Alps** sit between the two cities. It's a beautiful drive but takes about **four hours**, the same as the train. - **2:04** That won't last much longer: teams are building a new railway under this natural border, "with a **record-breaking tunnel**". - **2:17** **France** and **Italy** are two of the largest economies on the planet and both in the **EU**, yet moving people and goods between them isn't straightforward. **92%** of freight between Italy and France goes **by truck**, which is worse for the environment and slower than rail. - **2:55** The existing Lyon–Turin railway dates from the **1800s**, is full of winding curves and steep slopes, and is threatened by **landslides**: the one in **2023** shut the line for **a year and a half**. ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t0090.webp]] ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t0150.webp]] ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t0195.webp]] ### 3:38 The Base Tunnel - **3:24** Modern trains can cross terrain that wasn't possible in the 19th century, largely thanks to new tunnelling techniques. In the Alps engineers have perfected **base tunnels**, which burrow through the **base of a mountain** so tracks can be laid almost flat, enabling faster trains. - **4:05** The **Mont Cenis Base Tunnel**, halfway between Lyon and Turin across the border, will stretch **57.5 km**, a fraction longer than Switzerland's **Gotthard Base Tunnel**, which, though almost a decade old, remains one of the only base tunnels completed anywhere. - **4:22** Lyon–Turin travel time: **3 h 47 min → 1 h 47 min**. - **4:35** Road and rail shares should become **50-50**, taking about **a million heavy vehicles** off the road a year and cutting **a million tonnes of CO2**, roughly what **400,000 homes** produce in 12 months. - **5:03** Freight trains will carry **2,000 tonnes** instead of **700**, and passenger services rise from **six to 22** long-distance trains a day. - **5:15** The line fills a crucial gap in the **Mediterranean Corridor** of the **Trans-European Transport Network** (TEN-T), easing east–west travel across Europe. ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t0232.webp]] ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t0300.webp]] ### 5:40 Drill and Blast - **5:41** At the French start of the tunnel, trains will enter through a rectangular **cut-and-cover** section and then a **3 km** stretch of particularly tough geology: tests found **fractured and sheared rock**. - **6:10** So this section uses the traditional **drill and blast** method: drill holes in a circle, fill them with explosives, "hit a big red button", clear the rubble by truck, add **steel ribs**, spray with **shotcrete**, and repeat, step by step. "You actually get to see your adversary... the mountain that you're battling." - **7:06** Alexander Heim (Implenia): this part had **550 m** of loose-ground excavation before drill and blast continued; outside and inside works, special foundation works, and a final **140 m cut-and-cover** section. - **7:29** "This right here is where you really feel like you are digging through the heart of a mountain", among cold, craggy rock walls stabilised with shotcrete. ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t0350.webp]] ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t0438.webp]] ### 7:48 Reinforcement - **7:48** Converting the craggy surface into a conventional tunnel. Xavier Bernardin (Implenia): the **gantry** took a couple of months to design and manufacture, "a **prototype**... quite unique in the world". They pour a **10 m bay every day, five days a week**. - **8:15** The sequence: **waterproof membrane**, then brownish-red **steel reinforcement**, then a thick **concrete** slab, laid **10 m a day** for **3 km** in this section alone, "a mere fraction of the journey from France to Italy". - **8:49** Water is everywhere before waterproofing. Heim: water ingress "is normal" in the Alps and even welcome, because wet roadways keep down **dust**, "a severe problem for health and safety"; excess water is pumped to a **treatment plant**, recycled and reused at the face. - **9:31** *Sponsor segment:* **Straight Arrow News**, pitched on hearing objectors' voices; its **Media Landscape** feature groups sources from left to right by bias rating (to 10:41). ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t0480.webp]] ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t0515.webp]] ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t0545.webp]] ### 10:44 The New Railway - **10:44** The railway will be **270 km** long, **70%** in France and **30%** in Italy, in three parts: the **cross-border section** (the base tunnel plus links to the existing railway) and the two approach sections to the cities, which include several much shorter tunnels. - **11:02** The cross-border section is overseen by **TELT** (Tunnel Euralpin Lyon Turin), the public promoter in charge of construction and management, owned **50-50** by the French and Italian states. - **11:20** It includes **162 km** of galleries and tunnels, with access shafts and safety bypasses; **over a quarter**, nearly **50 km**, is complete. - **11:34** The base tunnel runs from **Saint-Jean-de-Maurienne** to **Susa**: **45 km** in France ("or rather *in* French soil") and **12.5 km** in Italy, in **two tubes** (north and south). Around **4,000 workers** at peak. - **12:08** Saint-Jean-de-Maurienne will be the last of France, and of daylight, that Lyon–Turin passengers see; its station will be replaced by a much bigger **international** one, and the same will happen at the Italian end. ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t0655.webp]] ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t0735.webp]] ### 12:47 Tunnel Boring Machine - **12:47** Drill and blast covers only about **a quarter** of the tunnel. The rest uses **seven tunnel boring machines** working at the same time. - **13:04** The first, **Viviana**, began in **September 2025** to dig **9 km** between **Saint-Martin-La-Porte** and **La Praz**, linking existing access tunnels. - **13:38** On board with Guillaume Lefrere: "our first TBM on the project, launched six weeks ago", a **hard-rock TBM**, **10.4 m** excavated diameter, **2,000 tonnes** "in nominal mode", half of it at the front. - **14:07** The **cutterhead** has **61 cutters** and is fixed to the **shield**. It was brought into the tunnel at **90 degrees** to its direction of travel and rotated before the rest of the TBM was attached. - **14:34** Behind it, the machine lays **concrete lining segments**: the target is **100,000**, each **50 cm** thick and reinforced with **rebar**, with **eight per ring**. "If you need eight in a ring, but you're making 100,000? That's crazy." - **15:08** Trailers and a **conveyor belt** carry spoil out; **more than half** is reused in tunnel linings, embankments and the new stations. "A giant **mobile factory**" run by **15 people**. - **15:51** In the **control cabin**: guidance monitors and **jack pressures**, low now in **ring-building mode** and high when the jacks push off the lining to drive the cutterhead through tough ground. - **16:28** **Cross passages every 333 m** link the north and south tubes for maintenance and **emergency evacuation**. ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t0775.webp]] ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t0820.webp]] ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t0855.webp]] ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t0960.webp]] ### 16:48 The Geology - **16:48** The big problem with such a long, deep tunnel is **uncertain geology**: even with today's tech you can't be sure what soils, rocks and **fault lines** lie ahead, and a surprise could cause delays, endanger teams or stop the project. - **17:18** So teams spent years digging **exploratory tunnels**; one was completed in **2022**. - **17:34** Matteo Calorio (TELT): "each phase of excavation it can present some new surprise". The tunnel passes **80 geological domains**, from **alluvial deposits** at the French entrance to **gneiss**, "one of the oldest rocks in the Western Alps", each responding differently to excavation. ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t1030.webp]] ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t1055.webp]] ### 18:07 The Cathedral - **18:08** "Whoa, look at this! The size of this space!" The crew told Fred to "get ready for **the cathedral**", and now he sees why. - **18:33** He is now **halfway** along the base tunnel. This drill-and-blast cavern ends at a concrete face where a TBM will bore **17 km** across the border to Italy. - **19:05** **Seven huge caverns**, up to **22 m high** and **23 m wide**, give access to the base tunnel; TBMs will be assembled inside and dig from the centre to the Italian border. - **19:29** Thomas Deviese (Eiffage Génie Civil): this will be a **gripper TBM**, designed for hard rock, with **no precast segments**; depending on the geology, the ground will be supported with **shotcrete**, **bolts** or **steel frames**. - **20:04** Fred found it "seriously daunting": at points **600 m** of solid rock overhead, the height of **Merdeka 118**, "the world's second tallest building". Workers are **counted in and out** and wear **location tags**; the rock "hasn't seen the world since its formation, nearly **half a billion years** ago". - **20:54** "It's remarkable... There's men and women working away to connect two countries, boost economies and change the world. It's epic, epic stuff." ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t1092.webp]] ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t1170.webp]] ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t1215.webp]] ### 21:13 Ventilation - **21:14** Further along, boring machines drill **straight down**: **four vertical shafts** from the surface, **1,300 m above sea level**, to the tunnel, for **ventilation** for workers and for any evacuation once the tunnel is in service. - **21:51** Method: a **pilot hole** about **40 cm** across is bored down, a long metal bar is slotted in, **cylindrical metal formwork** fills any cavities with concrete, then a **cutting head** attached at the bottom excavates back up. These **raise boring machines**, a technique borrowed from mining, are "a kind of vertical TBM". - **22:20** The first shaft is dug and temporarily lined using a new type of **robot** placed inside. - **22:27** Work is ramping up in **Italy**: facilities for making tunnel segments and processing spoil, and a new junction on the elevated highway at **Chiomonte** for site access. ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t1290.webp]] ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t1325.webp]] ### 22:53 Opposition and Cost - **22:53** The project is happening in a "breathtakingly beautiful, peaceful and serene valley", and many locals oppose it. Protest groups have fought it from the start; in **2023** more than **3,000 demonstrators** came to the area, and both participants and **police** were injured. - **23:24** Objectors cite **environmental damage** and argue the existing railway makes the new one unnecessary, despite its speed, green benefits and lower **landslide** vulnerability. - **23:44** Cost: about **EUR 25BN**, roughly **USD $29BN**. **Almost half** is EU-funded, and **Italy** pays the larger share of the rest because it committed more funding up front and its side is more complex: tougher terrain and access, though shorter. (Description: the $29BN covers the whole railway; the cross-border section is **EUR 11.1BN / $13BN**.) ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t1385.webp]] ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t1420.webp]] ### 24:16 Remaining Work - **24:16** Today it's "a mega-build in full swing", but there have been **delays**, opposition from politicians and protesters, and **budget gaps**. - **24:32** In **July 2025** France, Italy and the EU approved a joint document setting out the actions and timetable. It confirmed commissioning of the base tunnel by the **end of 2033** and, for the first time, EU funding for **all segments** of the railway. - **24:56** Almost **three quarters** of the tunnelling remains, but with all civil works contracts (worth several billion euros) awarded, excavation should speed up. - **25:22** Emmanuel Humbert (TELT): all construction contracts are awarded in France and Italy, the final global **equipment** contract is being awarded, and alongside regulatory and construction difficulties "there is a **human challenge** also". - **25:52** A decade from now the region will be busier; by then "we should hopefully know whether sacrificing some of that tranquility so the whole of Europe can prosper was the right call". ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t1480.webp]] ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t1525.webp]] ### 26:10 Conclusion - **26:12** Humbert: proud to work on a project that benefits future generations and the environment "and that will also serve Europe". - **26:30** Fred: "truly blown away". Questions remain about impact and value, but "this project is going to change our world". - **26:56** Xavier Bernardin: "when the tunnel will be open, I hope I will take the **TGV** and get to say 'I worked on this site.'" - **27:11** It will bring two countries closer, cut journey times and take almost a million trucks off the road. "This project really does speak to the **best of construction**... whenever this industry is confronted with something that feels impossible, we prove the world wrong." - **27:48** Closing thanks to **Straight Arrow News**, and a subscribe call for "the channel that takes you into some of the world's longest tunnels". ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t1600.webp]] ![[images/The-29BN-Megaproject-in-the-Heart-of-a-Mountain-t1690.webp]] ## Things mentioned ### The Lyon–Turin railway and Mont Cenis Base Tunnel - **Lyon–Turin railway**: **270 km**, 70% France / 30% Italy; cross-border section plus two national approach sections - **Mont Cenis Base Tunnel** (*tunnel de base du Mont-Cenis*): **57.5 km**, twin tubes, **Saint-Jean-de-Maurienne** to **Susa** (45 km France, 12.5 km Italy); set to be the world's longest single rail tunnel - Cross-border section: **162 km** of galleries and tunnels, nearly **50 km** done; cross passages every **333 m**; **4,000** workers at peak - Benefits: **3 h 47 → 1 h 47**; 50-50 road/rail split; about **1M** heavy vehicles and **1M tonnes of CO2** a year (≈ 400,000 homes); freight trains **700 → 2,000 t**; passenger services **6 → 22** a day; fills a gap in the TEN-T **Mediterranean Corridor** - New **international stations** at Saint-Jean-de-Maurienne and on the Italian side - Existing **1800s** Lyon–Turin line (curves, steep slopes) closed by a **2023 landslide** for about 18 months - Timetable: **July 2025** France–Italy–EU commitment; commissioning by **end-2033**; almost three quarters of the tunnelling still to do. Not in the video: the July 2024 cost update moved delivery of the equipped cross-border section from **end-2032 to late 2033** ([TELT](https://www.telt.eu/wp-content/uploads/2025/11/TELT_nota-stampa_allineamento-costi_EN.pdf)). ### Construction methods and machines - **Drill and blast** (explosives, steel ribs, **shotcrete**) for fractured, sheared rock; **cut-and-cover** sections (including a **140 m** one) and **550 m** of loose-ground excavation - Lining: waterproof membrane, rebar, concrete in **10 m** bays poured by a **prototype gantry** - Water ingress managed by pumping, a **treatment plant** and reuse at the face - **Seven TBMs**; **Viviana**: hard-rock TBM, **10.4 m**, **2,000 t** "in nominal mode", **61 cutters**, segment erector, conveyor, **15** crew; **100,000** segments (50 cm, rebar, **8 per ring**); 9 km between **Saint-Martin-La-Porte** and **La Praz**. Not in the video: TELT gives Viviana as **180 m** long, **2,300 t**, **8,100 kW** and **10 trailers**, advancing **300–450 m a month**; it was built by **Herrenknecht** in Schwanau, Germany, named after the wife of TELT's first director general **Mario Virano**, and baptised on **1 April 2025** by ministers **Matteo Salvini** and **Philippe Tabarot**; the lot (CO 6/7) is held by **VINCI Construction Grands Projets** (lead), **Webuild**, **Dodin Campenon Bernard** and **Campenon Bernard Centre Est** ([TELT](https://www.telt.eu/en/highlight/viviana-is-ready-the-mechanised-excavation-restarts-in-the-maurienne-area), [release](https://www.telt.eu/wp-content/uploads/2025/04/20250401_TELT_CS_BATTESIMO_TBM_TORINO-LIONE_EN.pdf)). - **Gripper TBM** (no precast segments; shotcrete, bolts or steel frames) to bore **17 km** to Italy from the "cathedral" cavern - **Seven caverns** up to **22 m** high and **23 m** wide - **Exploratory tunnels** (one finished in **2022**); **80 geological domains**, alluvial deposits to **gneiss** - **Four ventilation shafts** from **1,300 m** above sea level, dug with **raise boring machines** (pilot hole about **40 cm**, cavity formwork, upward reaming), lined by a new **robot** - Spoil reuse (over half) in linings, embankments and stations; Italian segment and spoil-processing plants; new highway junction at **Chiomonte** ### Cost, funding and politics - Whole railway: about **EUR 25BN / USD $29BN** (video and companion) - Cross-border section: **EUR 11.1BN / $13BN** (description); companion funding split **40% EU, 35% Italy, 25% France**; approach sections national with up to **50%** EU co-financing. Not in the video: the estimate rose from **EUR 8.6BN** (2015) to **EUR 11.1BN**, both in 2012 euros, after all civil-works contracts were let in 2023 ([TELT](https://www.telt.eu/wp-content/uploads/2025/11/TELT_nota-stampa_allineamento-costi_EN.pdf)); TELT repeated the EUR 11.1BN and end-2033 figures in its January 2026 reply to the **European Court of Auditors** ([TELT](https://www.telt.eu/en/highlight/telt-replies-to-the-2025-eu-court-of-auditors-report)). - **TELT** (Tunnel Euralpin Lyon Turin): binational public promoter, owned 50-50 by France and Italy - **Commission Implementing Decision (EU) 2025/1715** of 30 July 2025 (shown on screen) - Local opposition and protests: more than **3,000** demonstrators in **2023**, injuries to protesters and police ### Comparisons - **Gotthard Base Tunnel** (Switzerland), currently the longest - **Merdeka 118** (Kuala Lumpur), "the world's second tallest building", as a measure of the **600 m** of rock overhead - **TGV** high-speed trains ### Figures - Tunnel **57.5 km**; railway **270 km**; galleries **162 km** (≈ 50 km done) - **92%** of freight by truck today; **4 h** drive; **3 h 47 → 1 h 47** - **1M** vehicles, **1M t CO2**, **400,000** homes; **700 → 2,000 t**; **6 → 22** trains - Viviana **10.4 m**, **2,000 t**, **61** cutters, **15** crew, **100,000** segments; TBM run from cathedral **17 km** - Caverns **22 × 23 m**; overburden up to **600 m**; shafts from **1,300 m**; pilot hole **40 cm** - Cost **EUR 25BN / $29BN** (whole line), **EUR 11.1BN / $13BN** (cross-border); commissioning **end-2033** ### People and organisations - **Fred Mills** (host); **Adam Savage** (companion article author) - **Alexander Heim** and **Xavier Bernardin** (Implenia); **Guillaume Lefrere** (VINCI Construction/Webuild); **Matteo Calorio** and **Emmanuel Humbert** (TELT); **Thomas Deviese** (Eiffage Génie Civil) - **TELT**; **Implenia**; **VINCI Construction**; **Webuild**; **Eiffage Génie Civil**; **European Union** / European Commission - Footage: TELT, **Euronews**, **No Comment**, **VOA** ### Places - **Lyon**, **Turin**, the **Alps**, **Maurienne** valley: **Saint-Jean-de-Maurienne**, **Saint-Martin-La-Porte**, **La Praz**, **Modane** (shaft diagram); Italy: **Susa**, **Chiomonte** ### The B1M and sponsor - **Straight Arrow News** (paid promotion; Media Landscape feature) - **Get Construction Talking**; *The World's Best Construction Podcast* ## Biographies ### Fred Mills Co-founder and on-camera host of **The B1M**. He presents this long on-location documentary himself, from a Lyon–Turin road trip, the French tunnel faces, the Viviana TBM and the "cathedral" cavern, calling it his "deepest dive yet" and ending on the line that the industry "proves the world wrong". ### Adam Savage Writer at **The B1M** and author of the companion article *[Inside Europe's New Mega-Tunnel Under The Alps](https://www.theb1m.com/video/inside-the-lyon-turin-mega-tunnel)* (10 December 2025). Not to be confused with the *MythBusters* presenter. The article follows the script, names the interviewees and corrects the cost framing by separating the cross-border section from the whole railway. ### Alexander Heim **Project manager** at the Swiss contractor **Implenia** on the French drill-and-blast section. He describes the 550 m of loose-ground excavation, the inside and outside works and the final 140 m cut-and-cover, and explains why water ingress helps control dust. ### Xavier Bernardin **Technical manager** at **Implenia** (per the on-screen caption). He explains the prototype lining gantry that pours a 10 m bay a day, and closes the film hoping one day to ride the TGV through the tunnel and say "I worked on this site". ### Guillaume Lefrere **Site manager** for **VINCI Construction/Webuild** (per the on-screen caption and the companion photo caption). He shows Fred around Viviana, explaining its diameter, weight, segment target and control-cabin systems. ### Matteo Calorio **Geologist** at **TELT**. He explains the 80 geological domains the tunnel crosses, from alluvial deposits to ancient gneiss, and how each phase of excavation can bring a new surprise. ### Thomas Deviese **Tunnel construction manager** at **Eiffage Génie Civil**. In the cathedral cavern he describes the gripper TBM that will head for Italy, supporting the ground with shotcrete, bolts or steel frames rather than precast segments. ### Emmanuel Humbert **TELT's construction director for France**. He confirms that all civil works contracts are let and the final equipment contract is being awarded, highlights the regulatory, construction and human challenges, and speaks of pride in a project that benefits future generations and Europe.