National history of protected railway traction-power supply rather than a single facility. It traces reserve sidings and timber shelters through concrete shelters and rock caverns, and reports approximately 25 protected reserve sites, nearly 15 protected ordinary converter stations, and 134 rail-mobile converter sets before the end of the 1970s. No site dimensions or construction costs are given.

other: value: 25 | unit: sites | scope: national reserve-supply system at peak | note: Approximate count of protected reserve sites across concrete shelters and rock caverns; not a count for one facility.; value: 15 | unit: stations | scope: national ordinary traction-power system | note: Nearly 15 ordinary converter stations in concrete or rock; separate from the approximately 25 reserve sites.; value: 134 | unit: rail-mobile converter sets | scope: SJ fleet before the end of the 1970s | note: Equipment fleet count, not facility geometry.

Rail-mobile rotary converter, transformer and switchgear wagons; Rail sidings at three-phase-grid crossing points; Weather shelters in timber or sheet metal, later concrete shelters and rock caverns; Grid connection and traction-power conversion to railway single-phase supply; Periodic proof operation with cabling checks and at least one day of energized service

Chosen site typology and protection level; Rock excavation or reinforced-concrete shelter construction; Rail siding and grid-connection length; Heavy mobile electrical equipment and handling clearances; Ventilation, drainage, cabling and access; Portfolio-wide testing, maintenance and eventual sealing

National railway-resilience program spanning several facility classes and a mobile-equipment fleet. The reported counts must not be applied to one representative unit or added together as though they described one site.

Indeterminate

A selected focal site or representative typology; Floor area and clear dimensions; Siding length and trackwork; Cavern or shelter quantities; Portal, ventilation and drainage details; Electrical equipment capacity and inclusion boundary; Historic construction accounts

No linked dossier exists, consistent with the lack of a single facility subject.; The source record classifies the article as Civilförsvar, but the content is civil railway traction-power resilience/total defence rather than a civil-defence command facility.; Approximately 25 reserve sites and nearly 15 ordinary stations are distinct portfolios; combining them would overstate a program total.; Later sealing left rails, creosote sleepers and electrical remnants in place at some sites, so remediation is a separate lifecycle scope.