Floor Area · reported
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The archive documents F 9 Säve Nya berget as an aircraft rock hangar in a rock cavern. Construction is recorded from early 1950s to 1955. Its documented role was nuclear-resistant storage, servicing, arming and rapid launch preparation for an entire fighter wing.
Floor Area · reported
Published date and precision preserved
Published date and precision preserved
Unit-attributed · 7 more or shared in the original article
Functional recreation of the documented facility in Sweden using current construction methods and 2026 prices, preserving the documented capacity, protection, autonomy and redundancy. Ex VAT; excluding land, financing, remediation, classified mission equipment and data-centre hardware.
Provisional audited central concept screen; expected-risk calibration is pending. It is not yet a risk-adjusted expected cost.
Method, scope and confidence →15 photographs sourced from the original article, with captions where available.
Published, calculated and proxy dimensions are deliberately separated. Missing evidence stays visible instead of becoming zero.
Rock in place removed before bulking; the excavation-pricing quantity.
Internal airspace; not the amount of rock removed.
Blasted material after bulking; the haul and disposal quantity.
These cubic metres are not interchangeable.
Usable, floor or footprint area; the label is preserved because these are not always interchangeable.
Floor Area · reported · Publisher articleRock in place removed before bulking; the quantity used to price excavation.
Reported facility floor/shelter area is used as the screening usable-area basis. Archetype cavern-envelope factor is 5 design m³ per usable m². · Prior model input reviewed by auditInternal air or chamber volume. It is not solid excavation without overbreak, access and support geometry.
No usable quantity in the reviewed source · Evidence gapBlasted material after bulking, or its handled mass. No swollen cubic metres are inferred when only tonnes are modelled.
Reported facility floor/shelter area is used as the screening usable-area basis. Archetype cavern-envelope factor is 5 design m³ per usable m². Mass uses an assumed Swedish hard-rock density of 2.65 t/m³. · Reviewed mass-handling modelLength alone is insufficient; a costable tunnel also needs width, height or cross-sectional area.
Main Tunnel Length · Publisher articlePublished chamber or arch geometry used to test volume and support assumptions.
No usable quantity in the reviewed source · Evidence gapRock surface requiring bolts, mesh or shotcrete, preferably measured in square metres.
No support-area quantity is published · Audited excavation scopeCounts and dimensions of access, transfer, utility and emergency interfaces.
The horseshoe tunnel has western and eastern approaches. · Reviewed base modelCast inner structures and linings, kept separate from excavated rock and reinforcement mass.
Reported facility floor/shelter area is used as the screening usable-area basis. Archetype concrete factor is 0.5 m³ per usable m². · Reviewed base modelGroundwater, inflow, drainage, pumping and moisture-control evidence affecting construction and operation.
No usable quantity in the reviewed source · Evidence gapThe headline answers the current replacement question. Historic cost, CPI and construction-index comparisons remain separate because they answer different questions.
Different specifications receive different estimates; they are not used as the upper and lower limits of one answer.
Preserves documented capacity, protection, autonomy and redundancy using current construction methods.
Requires a modern structural, fire, protection and supplier performance brief.
Requires IT load, cooling topology, grid capacity, redundancy and autonomy. Server hardware is excluded.
No representative facility construction cost selected
General purchasing-power comparison—not a construction quote
Broad BKI proxy—not a bunker-specific rebuild price
Scope lock. Functional recreation of the documented facility in Sweden using current construction methods and 2026 prices, preserving the documented capacity, protection, autonomy and redundancy. Ex VAT; excluding land, financing, remediation, classified mission equipment and data-centre hardware. Named F 9 Säve 'Nya berget' aircraft rock hangar completed in 1955, with 22,000 m² / 236,806 ft² floor area, a 407 m horseshoe main tunnel, approximately 20 m entrance width, about 30 m rock cover and capacity for at least 60 aircraft. It includes turntables,…
Audit revision sweden-replacement-audit-2026.08.15. The central WBS below incorporates the 61-article review. The former deterministic low/base/high cases remain available only as sensitivities and revision history.
Direct works + owner / design / investigation + legacy concept contingency
Central quantities × current installed-rate screen.
Not yet probability-weighted. The current legacy concept contingency remains separate.
22% applied to the direct-work screen.
Raw model SEK 2.32bn · rounded for Confidence D.
Transitional limitation. SEK 394,256,250 is still a blanket concept contingency, not probability-weighted expected risk. This is why the amount is labelled provisional. The audited hangar rock WBS remains the central scope ledger.
Inclusive protected hangar complex; separately published fuel and KC records are component views.
74/100 article-geometry completeness. Detailed source extraction is available in the original-article audit.
Confidence D · geometry completeness 74/100
Do not add this blindly to related records. Inclusive parent of se-f9-save-new-berghangar-fuel and se-f9-save-new-berghangar-KC.
Largest active lines in the audited central component schedule.
The workbook publishes one revised central schedule. Its prior low and high stress cases are retained only under sensitivities; no line-level probability distributions are implied.
Hydrogeology, drainage, pumping and moisture control · SEK 66,000,000
Hydrogeology, drainage, pumping and moisture control · SEK 66,000,000
Integrated testing, commissioning and public-safe documentation · SEK 26,125,000
| Change | Scope | Audited base | Quantity / rate basis | Provenance |
|---|---|---|---|---|
| Retained | 01Large-cavern excavation and supportCivil Rock | SEK 825,000,000 | 110,000 Solid Design m³ × SEK 7,500 / Solid Design m³Derived From Published quantity · Assumption rateReported facility floor/shelter area is used as the screening usable-area basis. Archetype cavern-envelope factor is 5 design m³ per usable m². | Existing archive WBS |
| Retained | 02Rock mass handlingMass Handling | SEK 29,150,000 | 291,500 T × SEK 100 / TDerived From Published quantity · Derived rateReported facility floor/shelter area is used as the screening usable-area basis. Archetype cavern-envelope factor is 5 design m³ per usable m². Mass uses an assumed Swedish hard-rock density of 2.65 t/m³. | Existing archive WBS |
| Retained | 03Concrete floors, barriers and inner structuresStructural | SEK 77,000,000 | 11,000 m³ × SEK 7,000 / m³Derived From Published quantity · Assumption rateReported facility floor/shelter area is used as the screening usable-area basis. Archetype concrete factor is 0.5 m³ per usable m². | Existing archive WBS |
| Retained | 04Installed reinforcementStructural | SEK 19,250,000 | 550,000 Kg × SEK 35 / KgDerived From Published quantity · Assumption rateReported facility floor/shelter area is used as the screening usable-area basis. Archetype concrete factor is 0.5 m³ per usable m². Archetype reinforcement intensity is 50 kg per concrete m³. | Existing archive WBS |
| Retained | 05Hangar, workshop and fire-system fit-outBuilding Services | SEK 280,500,000 | 18,700 m² / 201,285 ft² × SEK 15,000 / Usable m²Derived From Published quantity · Assumption rateReported facility floor/shelter area is used as the screening usable-area basis. Fit-out factor is 0.85 times the reference scale. | Existing archive WBS |
| Retained | 06Protection and resilient utilitiesProtection | SEK 132,000,000 | 7.33 Project × SEK 18,000,000 / ProjectAssumption quantity · Assumption rateOne protection package per 3000 usable m² / 32,292 ft², subject to a 2-package minimum. | Existing archive WBS |
| Retained | 07Heavy portals and escape interfacesSite And Access | SEK 12,000,000 | 2 Project × SEK 6,000,000 / ProjectDerived From Published quantity · Assumption rateThe horseshoe tunnel has western and eastern approaches. | Existing archive WBS |
| Retained | 09Aircraft-support mission systemsMission Systems | SEK 110,000,000 | 7.33 Reference Package × SEK 15,000,000 / Reference PackageAssumption quantity · Assumption rateOne mission package per 3000 usable m² / 32,292 ft², subject to a 2-package minimum. | Existing archive WBS |
| Added | R009Hydrogeology, drainage, pumping and moisture control | SEK 66,000,000 | 8% of supported-rock scope as a class-screening allowance | Class assumption — site investigation/RFQ required |
| Added | R010Integrated testing, commissioning and public-safe documentation | SEK 26,125,000 | 5% of MEP/protection/mission-system scope | Class assumption — commissioning plan required |
Active base WBS SEK 1,577,025,000 · owner/design and contingency are added in the scenario cards above · 12 removed rows across the archive remain visible as change history.
The three inputs most likely to move the current screen.
These deterministic stress cases simultaneously vary quantities, rates, scope allowances and contingency. They are not confidence intervals and no longer serve as the headline answer.
Links support a rate, scope boundary or method. Context-only sources are not represented as quotations.
Gryaab February-2024 long-tunnel benchmark: SEK 5,513/design m³ for excavation plus support. Low case is lightly currentized; base/high add small, constrained, non-repetitive bunker uncertainty.
Gryaab February-2024 long-tunnel benchmark: SEK 5,513/design m³ for excavation plus support. Low case is lightly currentized; base/high add small, constrained, non-repetitive bunker uncertainty.
Skanska's Ostlanken order value is SEK 240m for handling 2.0m tonnes of rock and 0.4m tonnes of soil, excluding options. The base is the observed blended benchmark; bounds are assumptions.
Public ready-mix material check only; installed underground rates require RFQ.
Public retail material check only; cutting, bending, fixing, waste and underground logistics require RFQ.
Public material establishes specialized systems but no prices. Package values are assumptions and must not be read as classified equivalence.
Nuclear-resistant storage, servicing, arming and rapid launch preparation for an entire fighter wing.
Excavation of the new hangar began.
B004Hangar class modernized with reinforced shock doors, protected fuel/weapon stores, turntables and fixed preparation positions.
B011New rock hangar completed.
B009,B040Primary protected fighter-hangar role.
B009,B010,B040New F 9 rock hangar completed.
B004Protected aircraft-hangar operation with later aircraft, fuel-system and command changes.
B004,B009,B010,B012Bas 60-era reduced role, wartime storage/maintenance and wider defence stores after F 9 closure.
B041,B043,B044Command centre moved inside after the Wennerström disclosure; exact date not stated.
B012Associated motorway reserve road base completed.
B015Reserve road base downgraded to reserve takeoff strip.
B015F 9 wing closed; hangar shifted toward storage roles.
B043,B044Command centre last used during a major one-week exercise in the hangar.
B012Säve wartime airbase closed when the Air Force left.
B044Short continued use for aircraft dismantling before later non-operational/museum context.
B044Hangar used for several more years to dismantle Saab 37 Viggen aircraft.
B044Aeroseum used the new hangar.
B007Museum use by Aeroseum.
B00748 reviewed claims. Evidence locators resolve against the stored article hash or archived snapshot.
| Subject | Claim | Value | Date | Evidence | Certainty |
|---|---|---|---|---|---|
| milestone | Event | Excavation of the new hangar began. | early 1950s | B004 | Reported |
| milestone | Event | New rock hangar completed. | 1955 | B009,B040 | Reported |
| milestone | Event | Hangar class modernized with reinforced shock doors, protected fuel/weapon stores, turntables and fixed preparation positions. | late 1950s | B011 | Reported |
| milestone | Event | Associated motorway reserve road base completed. | 1964 | B015 | Reported |
| milestone | Event | Reserve road base downgraded to reserve takeoff strip. | 1967 | B015 | Reported |
| milestone | Event | F 9 wing closed; hangar shifted toward storage roles. | 1969 | B043,B044 | Reported |
| milestone | Event | Säve wartime airbase closed when the Air Force left. | 1999 | B044 | Reported |
| milestone | Event | Hangar used for several more years to dismantle Saab 37 Viggen aircraft. | after 1999 | B044 | Reported |
| lifecycle summary | Event | Primary protected fighter-hangar role. | 1955–1960s | B009,B010,B040 | Reported |
| lifecycle summary | Event | Bas 60-era reduced role, wartime storage/maintenance and wider defence stores after F 9 closure. | 1960s-1999 | B041,B043,B044 | Reported |
| lifecycle summary | Event | Short continued use for aircraft dismantling before later non-operational/museum context. | post-1999 | B044 | Reported |
| quantitative observation | Entrance Width | 20 m | — | B004 | Reported |
| quantitative observation | Floor Area | 22,000 m² / 236,806 ft² | — | B004,B009 | Reported |
| quantitative observation | Main Tunnel Length | 407 m | — | B004 | Reported |
| quantitative observation | Installation Depth | 10–12 | — | B009 | Reported |
| quantitative observation | Rock Cover | 30 m | — | B007,B009 | Reported |
| quantitative observation | Minimum Aircraft Capacity | 60 aircraft | — | B010 | Reported |
| quantitative observation | Original Turntables | 4 turntables | — | B011 | Reported |
| quantitative observation | Surviving Turntables At Article Time | 2 turntables | — | B011 | Reported |
| quantitative observation | Backup Generators | 2 ship diesel generators | — | B017 | Reported |
| technical system | Aircraft Flow | Horseshoe main tunnel supported one-way towing, side-tunnel storage, turntables and preparation positions at the exit. | — | B007,B011 | Reported |
| technical system | Aircraft Servicing | Electricity, fuel, weapons and ammunition connections supported preparation, service and repair. | — | B005,B012 | Reported |
| technical system | Power | Two Nohab ship diesels could supply the entire hangar and airfield on grid failure. | — | B017 | Reported |
| technical system | Integrated Support | Command centre, squadron spaces, accommodation, workshops, stores and fuel depot were incorporated. | — | B010,B014 | Reported |
| protection | Rock Cover And Depth | Fully below ground with roughly 30 m rock cover. | — | B007,B009 | Reported |
| protection | Reinforced Shock Doors | Two massive reinforced-concrete doors protected the main tunnel against limited nuclear-blast effects. | — | B004 | Reported |
| protection | Qualified Nuclear Claim | Modern hangars were designed for limited nuclear attack; the article explicitly says none was fully protected against blasts above one megaton. | — | B010,B037 | Reported |
| protection | Emergency Egress | Marked exits and luminous floor lines supported evacuation during blackout/smoke. | — | B017 | Reported |
| milestone | Event | New F 9 rock hangar completed. | 1955 | B004 | Reported |
| milestone | Event | Command centre moved inside after the Wennerström disclosure; exact date not stated. | after 1963 | B012 | Reported |
| milestone | Event | Command centre last used during a major one-week exercise in the hangar. | 1990s | B012 | Reported |
| milestone | Event | Aeroseum used the new hangar. | archive era | B007 | Reported |
| lifecycle summary | Event | Protected aircraft-hangar operation with later aircraft, fuel-system and command changes. | 1955 onward | B004,B009,B010,B012 | Reported |
| lifecycle summary | Event | Museum use by Aeroseum. | archive era | B007 | Reported |
| quantitative observation | Shock Door Mass | 80 tonnes | — | B003 | Reported |
| quantitative observation | Rock Depth Or Cover | 30 m | — | B003 | Reported |
| quantitative observation | Floor Area | 22,000 m² / 236,806 ft² | — | B004 | Reported |
| quantitative observation | Backup Generators | 2 ship diesel generators | — | B006 | Reported |
| quantitative observation | Original Turntables | 4 turntables | — | B009 | Reported |
| quantitative observation | Turntables Remaining At Archive Date | 2 turntables | — | B009 | Reported |
| technical system | Aircraft Readiness | Aircraft in the western/eastern approaches could stand fuelled, armed and connected to tow vehicles for rapid launch. | — | B004,B005 | Reported |
| technical system | Power | Two ship diesels could supply hangar and airfield during grid loss. | — | B006 | Reported |
| technical system | Climate And Structure | Partly freestanding inner structure with dehumidified air gap and concrete rock anchors. | — | B007,B008 | Reported |
| technical system | Fuel And Fire | Leaking floor fuel lines were addressed; sectional asbestos curtains and water/foam sprinklers controlled fire spread. | — | B010,B011 | Reported |
| technical system | Command | KC inside hangar remained connected but non-operational at archive time. | — | B012 | Reported |
| protection | Rock And Heavy Doors | Publisher calls the facility atom-bomb-safe, but this is an unqualified historical claim rather than a certified rating; heavy doors and nearly 30 m of rock are reported. | — | B003 | Reported |
| protection | Redundant Aircraft Approaches | Western and eastern approaches offered alternate aircraft routes, though either could be blocked by attack. | — | B005 | Reported |
| protection | Emergency Egress | Personnel emergency exit and luminous escape markings supported blackout evacuation. | — | B005,B006 | Reported |