Overview The Transilien Line J is one of the most complex and structurally rich suburban/regional rail networks in the Paris region. Operating from Paris-Saint-Lazare, it forms a true multi-branch railway system connecting dense inner suburbs, peri-urban areas, river valleys, rural territories, and regional towns across Île-de-France and the Normandy border. Rather than being a single line, Line J functions as a Hub-and-Spoke Network organized into specific track groups ("Groupes"), making it uniquely suited for a modular Train Sim World DLC structure. This makes Line J ideal for simulation: High service density: Up to 28 trains per hour at peak times. Parallel Running: Fast regional trains overtaking local suburban trains. Mixed stopping patterns: Direct, Semi-Direct, and Omnibus. Complex timetables: Interaction between Transilien, RER A, and Intercités. Operational variety: From urban density to rural single-track operations. ️ Historical Context & Era Setting Proposed Era: Modern Transition (c. 2015 – 2022) Setting the DLC in this specific timeframe allows for the simultaneous operation of two distinct generations of rolling stock, maximizing gameplay variety before the older fleet is fully retired. The infrastructure originates from the 19th-century railway expansion west of Paris, connecting the capital with Normandy. The Line J identity groups these western routes into a unified network operated by SNCF. ⚡ Electrification & Power System System: 25 kV AC / 50 Hz Electrification type: Overhead catenary Coverage: Fully electrified network Substations: Distributed along trunk and branches Signalling & Safety Systems Primary signalling: BAL (Bloc Automatique Lumineux) Train protection: KVB (Contrôle de Vitesse par Balises) Traffic Management: IPCS (Installations Permanentes de Contre-Sens): Many sections allow bidirectional running on a single track during disruptions—a massive gameplay feature for TSW scenarios. NExT: Modern operation centers managing dense flows. Gameplay Implication: Realistic braking discipline, signal anticipation, and "wrong-way running" scenarios via IPCS. Speeds & Performance Maximum speeds: Urban sections: 60–90 km/h (37 - 56 mph) Suburban sections: 100–120 km/h (62 - 75 mph) Regional outer sections: up to 140 km/h (87 mph) [Group V] Gradients: Max ~12‰ (1.2%), typically 4–8‰. Terrain: River valley alignments (Seine), urban viaducts, and steep branch divergences. ️ Network Structure & Track Groups The line is organized by "Groupes" at Paris-Saint-Lazare to manage traffic flow. Central Hub: Paris-Saint-Lazare All branches originate here. The station throat is a complex interlocking puzzle. Branch 1 — Paris → Vernon-Giverny (via Poissy) Track Group: Groupe V (Fast Lines) Total Length: ~80 km (50 miles) Route: Paris-Saint-Lazare Houilles–Carrières-sur-Seine (Major interchange) Poissy (Interchange with RER A) Villennes-sur-Seine Vernouillet–Verneuil Les Clairières de Verneuil Les Mureaux Aubergenville–Élisabethville Épône–Mézières Mantes-Station Mantes-la-Jolie Rosny-sur-Seine Bonnières Vernon-Giverny (Normandy Region Border) Profile & Gameplay: High Speed: Fastest section of the network (140 km/h). Shared Traffic: Shares tracks with RER A (Nanterre to Poissy) and Intercités (Paris-Normandy fast trains). Mix: Long-distance suburban services and regional freight. Branch 2 — Paris → Mantes-la-Jolie (via Conflans) Track Group: Groupe VI Total Length: ~56 km (35 miles) Route: Paris-Saint-Lazare Asnières-sur-Seine (Often skipped by fast trains) Argenteuil (First major stop for most services) Note: Inner stations (Bois-Colombes, Colombes, Le Stade) are bypassed by this branch. Val d’Argenteuil Cormeilles-en-Parisis La Frette–Montigny Herblay Conflans-Sainte-Honorine (Junction Node) Conflans-Fin-d’Oise (RER A Interchange) Maurecourt Andrésy Chanteloup-les-Vignes Triel-sur-Seine Vaux-sur-Seine Thun-le-Paradis Meulan–Hardricourt Juziers Gargenville Issou–Porcheville Limay Mantes-la-Jolie Profile & Gameplay: Semi-Direct Operations: Racing past local stops in the inner suburbs. Seine Valley: Scenic, winding route along the north bank of the river. Branch 3 — Paris → Gisors Track Group: Groupe VI (Shared trunk with Branch 2 until Conflans) Total Length: ~69 km (43 miles) Route Divergence: From Conflans-Sainte-Honorine: Éragny–Neuville Saint-Ouen-l’Aumône – Quartier de l’Église Pontoise (Major Terminus) Osny Boissy-l’Aillerie Montgeroult–Courcelles Us Santeuil–Le Perchay Chars Lavilletertre Liancourt–Saint-Pierre Chaumont-en-Vexin Trie-Château Gisors (Normandy Region Border) Profile & Gameplay: Rural Immersion: Transitions from city to deep countryside. Single Track: Sections of single-line working require precise timetable adherence. Branch 4 — Paris → Ermont-Eaubonne Track Group: Groupe IV Total Length: 14.2 km (8,8 miles) Route: Paris-Saint-Lazare Asnières-sur-Seine Bois-Colombes Colombes Le Stade Argenteuil Sannois Ermont-Eaubonne Profile & Gameplay: The "Omnibus" Experience: Serves the stations skipped by the longer distance trains. High Frequency: Short, intense commuter runs. Traffic Interaction: Runs parallel to the faster Group VI trains, creating visual interest. Rolling Stock (Line J Specific) By setting the DLC in the Transition Era, both iconic trains are active simultaneously. 1. BB 27300 + VB2N (Push-Pull Sets) Role: The workhorse of the 2000s-2010s. Configuration: Electric locomotive + Double-deck "Danseuse" coaches. Physics: Heavy haul feeling, slower braking response, high torque. Status: Essential for the "classic" Transilien feel before modern EMU dominance. 2. Z 50000 "Francilien" Role: The modern face of the line (SNCF/Bombardier). Configuration: Articulated EMU (Electric Multiple Unit). Physics: High acceleration, sharp braking, single-handle master controller. Status: Gradually replacing the VB2N during this era. Gameplay Depth for Train Sim World Driving Variety: Terminal Operations: Managing the 27-track throat at Saint-Lazare. Parallel Running: Driving a direct train on Group VI while watching a local train stop on Group IV tracks next to you. RER Interaction: Sharing the busy tracks with AI RER A trains between Nanterre and Poissy. RER A "Mi2n" Poissy - Nanterre IPCS Scenarios: navigating wrong-way running during maintenance or signal failures. Service Types: Omnibus: All stops (Groupe IV). Semi-Direct: Skipping inner suburbs (Groupe VI). Direct/Fast: Paris to Mantes/Vernon (Groupe V). Empty Stock Moves: Moving trains from depots to the terminus. Modular DLC Logic This network allows natural DLC structuring: Core DLC: Paris-Saint-Lazare → Mantes-la-Jolie (via Poissy/Group V) + Argenteuil. Expansion 1: The Conflans/Gisors Branch (Rural extension). Expansion 2: The Ermont-Eaubonne Branch (Dense urban extension). Why This Line Works for TSW ✔ Real Network Structure: Correct representation of the "Groupe" system (IV, V, VI). ✔ Traffic Variety: RER A, Intercités, and Transilien sharing corridors. Intercités Normandie "Regio 2n" at Paris Saint-Lazare ✔ Era Perfection: The transition period allows for both Locomotive-hauled and Modern EMU gameplay. ✔ Operational Realism: IPCS, complex junctions, and varied stopping patterns. ✔ Visual Contrast: From the massive Paris terminus to the rural fields of the Vexin and Normandy borders. Conclusion Thank you for taking the time to read through this detailed proposal! This marks my 7th suggestion on the forum, and I truly believe that Transilien Line J is one of the most promising candidates for a future French route. Its unique mix of heavy suburban traffic, high-speed sections, and scenic river valleys fills a specific gap in Train Sim World that the community has been asking for. I look forward to hearing your feedback and discussing this potential route with you all!
I'd love to get a french route with a Paris terminus ! St-Lazare network is indeed a really busy one with interesting services patterns, etc. That said, I feel like St-Lazare, Gare du Nord and Gare de Lyon involve too much work (the stations themselves and the surroundings). Maybe we should focus on something of a more reasonable scale (as Montparnasse in Trainz and Gare de l'Est in MSTS)... Btw, which route are you refering to by "rural single track" ? I don't remember single track sections on Pontoise - Gisors...
Thanks for your feedback! It’s true that Saint-Lazare is a huge technical challenge, much like Gare du Nord or Gare de Lyon. However, it is not entirely impossible, especially since Dovetail has already modeled large and complex hubs (such as the major London or German terminals). The idea of breaking the network into modules would help make the project more 'reasonable' at the start. Regarding the single track, you are absolutely right to correct me! The Pontoise-Gisors section is indeed double-tracked throughout. I must have confused it with an adjacent line during my research. That said, even with double tracks, this portion offers a striking contrast to the urban environment at the start, which remains very interesting for simulation. It is precisely this mix between the hustle and bustle of Saint-Lazare and the calm of the Vexin region that, in my opinion, makes Line J so charming. Thanks again for the clarification!
Well... The J is one of my favorite networks in France Think epitomizes the true soul of banlieue transport there! Personally, would love to see its central section recreated, from Saint-Lazare to Mantes (via Poissy/Argenteuil); will be the most obvious and realistic option! And then, expand it further maybe! Franciliens and VB 2Ns are a must to have here (transition period, as you said). Also think that TER traffic addition (PHDs etc.) could be a welcome "boost"! Again, excellent suggestion!
Absolutely, really lovely indeed. That's right, it is indeed the first suburban railway network in France, with its Standard DC EMUs (Z 1300/1400/1500) !!!
Thanks a lot for your comment! I couldn't agree more—the Line J really has that unique 'banlieue' atmosphere you can't find anywhere else. I actually take this line every single day between Vernouillet-Verneuil and Poissy (and sometimes Saint-Lazare), so I’m right in the heart of it! From my window, I see exactly what you’re describing: the constant ballet of Z 50000 and VB 2N sets, but also the impressive TER/Intercity trains (like the Omneo Premium) flying past us on the fast tracks. Starting with the Paris to Mantes-la-Jolie section (via Poissy) is definitely the most logical move. It would cover the most iconic part of the network and offer so much variety in terms of traffic and scenery. Having that mix of suburban stops and high-speed bypasses is exactly what TSW needs for a French route. Glad to see we share the same vision for this DLC!
