Case 615. Abwehr documents - the Department of Intelligence and Counterintelligence of the OKW (Hovermap High Command): development of the Abwehr - assessment of information about Gibraltar - a selection of military information on the state of Gibraltar's defence.

Brief Summary of Case 615

Case 615 is an extensive German intelligence assessment of Gibraltar's defences, compiled on 16 November 1940 from agent reports and reconnaissance data. The document was prepared for operational planning connected with the proposed assault on Gibraltar.

Key contents include:

• A detailed estimate of the British garrison, including infantry, artillery, engineers, communications personnel, tanks, anti-tank weapons, and support troops. The total strength is estimated at approximately 10,400 personnel, compared with a peacetime strength of about 3,200.
• Comprehensive descriptions of Gibraltar's coastal and fortress artillery, identifying individual batteries, gun calibres, locations, firing arcs, and defensive roles across the Rock and harbour area.
• Analysis of the fortress's anti-aircraft defences, including battery locations and an assessment of the overall anti-aircraft network protecting Gibraltar.
• Information on command posts, machine-gun positions, fortifications, walls, bastions, galleries, and defensive strongpoints, including the Queen's Line, King's Line, Moorish Castle area, and Charles V Wall.
• Detailed examination of the northern approaches to Gibraltar, including the airfield, lagoon, anti-tank ditches, minefields, wire obstacles, electrically charged fences, and other defensive barriers.
• Analysis of the routes leading into the city, including walls, gates, tunnels, bridges, drawbridges, strongpoints, and the likely fire support covering each avenue of approach.
• Extensive reporting on Gibraltar's underground tunnel and gallery system, including ammunition depots, command facilities, communications installations, fuel storage areas, water tunnels, and internal transport links.
• Terrain assessments covering the Rock's slopes, climbing possibilities, observation advantages, and defensive value of key geographic features.
• Repeated observations that British forces were continuously strengthening Gibraltar's defences, working day and night on fortifications and construction projects.

Overall, the file is a comprehensive intelligence dossier designed to provide German planners with a detailed picture of Gibraltar's military defences, fortifications, artillery positions, access routes, and underground infrastructure before the planned Operation Felix.