The article spans a naval-base campus and several distinct rock facilities. In 1939 Älvsborg Radio was built at Nya Varvet, a staff rock room was blasted in Billingen's east side around 1942, and the short-wave station received a separate rock room on Hängesten. In the early 1950s Billingen was extended west for stores, workshops and a two-storey staff/command space. Later sections have greater ceiling height; old sections are mould-affected because ventilation was reduced. The naval staff moved out in the 1960s because cover was insufficient, the site was not nuclear-safe and it was too urban. No protected area, excavation volume, portal count or system capacity is published. The entire Nya Varvet site was sold in 1986 for SEK 10.3m; that is not a construction cost.

inner_structure: Billingen: eastern staff rock room, later westward expansion for stores, workshops and staff/command use.; Hängesten: separate rock room for the short-wave station.; Later Billingen sections have materially greater ceiling height, but no measurement is given. | levels: count: 2 | scope: early-1950s Billingen staff/command space | evidence: Explicitly reported; does not describe Hängesten. | other: 1910 campus accommodation plan: 300 coastal artillery personnel plus 330 naval personnel; not cavern capacity.; Early 1950s campus workforce: over 1,000 temporary/permanent staff; not cavern capacity.; About 40 boats at peak; a naval-base activity metric, not facility geometry.

amount_sek: 10300000 | price_year: 1986 | scope: sale price for the whole Nya Varvet area to two companies | note: Land/asset transaction, not original construction cost and not the value of any single rock facility.

Naval command/staff and communications functions in Billingen.; Stores and multiple workshop types in the expanded rock complex.; Short-wave radio function at separate Hängesten rock room.; Ventilation; reduced operation contributed to mould in older Billingen sections.; No generator, water, protection-door or communications-equipment quantities are published.

Billingen cavern expansion, support and two-level inner program.; Stores/workshops versus headquarters fit-out.; Hängesten radio cavern and mission electronics.; Ventilation, moisture control and protected utilities.; Scope boundary between fortified minimum and entire naval base/shipyard.

Three linked cost subjects must remain distinct: the inclusive documented-fortified Nya Varvet scope, Billingen as a component, and separate Hängesten/Älvsborg Radio. Campus personnel, boats and sale price do not describe one cavern.

Indeterminate

Measured plans/sections and portals for Billingen and Hängesten.; Cavern excavation and support quantities.; Inner-building/shop/store areas and structural quantities.; Radio/communications, power, HVAC and protection equipment inventories.; Explicit inclusive-parent roll-up logic and scenario-consistent child aggregation.; Defined boundary for documented fortified scope versus whole naval base.

The complete source map correctly links three dossiers; the initial sources_full internal_dossier_urls listed only Hängesten.; The article's title and bulk of geometry concern Nya Varvet/Billingen, while Hängesten receives one sentence.; The inclusive Nya Varvet base estimate is lower than its stated included Billingen child base, indicating inconsistent scenario/roll-up logic.; The SEK 10.3m figure is a whole-site sale price, not construction or replacement cost.