Modular Subsystem designed for interchangeability on a wide variety of Imperial Navy starship designs. The SI402 -C1 (Shield, Imperial, Year 4402), also known by its code-name 'Barricade' is a first-generation, fully self-contained, modular Capital-class Starship Shield Modulator. The design is based on the UAS/UTN (Old Federation) standardised Cluster Crystalline Tetramatrix Shield Generator design, with significant enhancements in efficiency afforded by Imperial Engineers. The C1 'Barricade' is a C-Type subsystem, only able to be supported by Capital-class power-delivery systems on Battlecruisers or some heavier cruiser-class warships such as the Thunderhead-class.
Despite newer, upgraded models of the C2 and C3 designation becoming available shortly after C1 units were phased into Imperial Service, the 'Barricade' remains in service due to the unit's low cost of production, ease of maintenance and wide availability of spare components. The C1 'Barricade' shield generator is most notably installed in the auxiliary shield bays of ED-class Battlecruisers in several quad-unit arrays, while newer warships of the class were fitted with C2 or C3, second and third generation Modulators in their primary bays.
One of the notable improvements to the Imperial-series of Shield Modulators was the inclusion of Polarytic Catalyst Radiators, visible around the outside of the unit. Previous designs relied on electromagnetic fields to modulate a passive Polarytic crystal field. Imperial Engineers tasked with bringing Old-Federal and slightly upgraded New-Federal Era Shield Generators up the standard required by AIN service pioneered the PCR system by directing the Polarytic Crystals directly from the core into the electromagnetic field, greatly improving energy transfer efficiency and allowing for significantly faster recovery from shield collapse.
Due to the direct exertion of Polarytic energy discharge, the magnetic sinks fitted to existing starship shield bays (such as existing Endeavour Series 5As being retrofitted for Imperial Service under ED-class designation) required extensive upgrades to direct the flow of P-radiation without interfering with sensitive electronics.
Despite C2 and C3 upgrades to 'Barricade' modulators, the Imperial Navy has expressed no interest in de-classifying the subsystem for civilian or paramilitary use, likely to the highly advanced nature of the PCR Field Modulator upgrade, as such, it remains strictly controlled.