Each carried two 76 mm main guns, an Oerlikon 20mm autocannon for anti-aircraft defence, as well as two twin 45 cm torpedo tubes.

Combined with a reasonable speed of 25 knots (46 km/h) and excellent manoeuvrability this enabled the Trygg class vessels to operate effectively both in cooperation with other naval units and on their own.

In 1932, the Norwegian Labour Party made public a proposal crafted by Fredrik Monsen, that the armed forces be dissolved entirely and replaced by a "civil guard".

The civil guard would include 18 Trygg class vessels, with the armament of two 76 mm main guns and two twin 45 cm torpedo tubes retained.

[4] Olaf Kullmann and Erik Anker Steen had contributed to the "civil guard" concept with advice from a naval perspective.