3D technical engineering drawing of an underground EDF utility tunnel beneath Paris, in clean blueprint style. The tunnel is shown in perspective with precise geometry, straight lines, and a clear vanishing point. Include cable trays, pipes, and industrial lighting in a simplified technical style. In the foreground, a vertical shaft ("chatière") is shown as a perfect cylinder descending from the tunnel floor. The opening is a clean ellipse in perspective, with visible slab thickness. The ground is displayed as a cutaway section, showing limestone layers (calcaire) using simple hatch patterns and technical shading, not realistic textures. Style: engineering blueprint, black and white or blue background with white lines, vector-like, clean linework, minimal shading, high precision. Include annotations, arrows, and labels (in French): "Galerie EDF", "Chatière", "Calcaire", "Coupe du sol". Orthographic-meets-perspective technical illustration, highly structured, professional infrastructure diagram, CAD-like rendering. Chatière diagonal sur 6m prof Mehr sehen