I just made a game with a silly amount of starting tech to see if it was conceivable. Rather than make a ton of systems for an example I just slapped a standard cargo hold on it for weight to see if a warship can move fast enough. Range is a little low but I chose 3x engine power just for example. At 65000 km/s 46,000 tons is nothing to shake a stick at. I could outfit a pretty substantial warship even with early technology at that size. Obviously, some missiles can and will go over 65000 but you have space to work with.
Tribal class Cruiser 46,150 tons 615 Crew 30760.5 BP TCS 923 TH 60000 EM 0
65005 km/s Armour 1-114 Shields 0-0 Sensors 1/1/0/0 Damage Control Rating 1 PPV 0
Maint Life 0 Years MSP 417 AFR 17038% IFR 236.6% 1YR 249215 5YR 3738222 Max Repair 1500 MSP
Intended Deployment Time: 3 months Spare Berths 2
Cargo 25000
3000 EP Photonic Drive (20) Power 3000 Fuel Use 140.3% Signature 3000 Exp 30%
Fuel Capacity 10,000,000 Litres Range 27.8 billion km (4 days at full power)
This design is classed as a Military Vessel for maintenance purposes
For argument sake here is the same gig with a smaller ballast weight.
Tribal class Cruiser 21,100 tons 612 Crew 30476.5 BP TCS 422 TH 60000 EM 0
142180 km/s Armour 1-68 Shields 0-0 Sensors 1/1/0/0 Damage Control Rating 1 PPV 0
Maint Life 0.02 Years MSP 903 AFR 3561% IFR 49.5% 1YR 50519 5YR 757783 Max Repair 1500 MSP
Intended Deployment Time: 3 months Spare Berths 1
Cargo 5000
3000 EP Photonic Drive (20) Power 3000 Fuel Use 140.3% Signature 3000 Exp 30%
Fuel Capacity 5,000,000 Litres Range 30.4 billion km (59 hours at full power)
This design is classed as a Military Vessel for maintenance purposes
edit: I know, it is an unrealistic technology level. It's just a concept. Since I am on the absurd topic beam FC tracking speed maxes out at 100,000 so the latter example would be impervious to anything sporting beam FC. AT this tech level I should see what kind of speeds an AMM can pull...