An 18,000-ton carrier for a Nordic federation

Could a Nordic federation build an 18,000-ton, 30-knot carrier for convoy-protection groups with about 42 aircraft?

Yes. An 18,000-ton ship could resemble a larger light fleet carrier, with its additional displacement available for machinery or protection. The TSR requirement needs a 1930s or later context.

The proposed carrier displaces 18,000 tons standard, makes 30 knots, and carries 42 aircraft: 18 fighters and 24 torpedo-spotter-reconnaissance aircraft. Those requirements are judged plausible for a large light fleet carrier, using the later Colossus class as a comparison of scale. The extra displacement above a smaller light fleet carrier could support better machinery or protection. The proposed convoy group also contains a capital ship, two cruisers, and a destroyer flotilla. The aircraft terminology needs a date qualification because torpedo-spotter-reconnaissance aircraft belong to the 1930s development of naval aviation.