How big would a Tug have to be to move that 51,000 ton Orbital Mining Platform ? For me there would be in game time constraints in building a Shipyard large enough for the Tug and working out what engines I would need to provide the moving power / Fuel allowances etc.
I am only using the basic Nuclear Thermal powered Engines at present.
DavidR
Technically, fifty tons.
But that would still be speed 1 km/s, and you want at least 50 km/s to catch planets, and 500 km/s for comets.
The correct answer for tugs is "as fast as you can practically make them within your size, cost, and mineral restraints" -- and all of that depends on your technology, wealth, production, minerals, officers and governors.