I don't know if you can tractor with multiple ships or not.

But if you want to know how much grunt you need to drag something around at the speed you want, there's a little bit of math you can do to know for sure before you get started.

You have a barge, the century class, at 518k tons. You have a tug that masses 25k tons, and puts out 4*175EP, 700EP, for a speed of 1400km/sec.

So, the math. You can calculate how fast you will go, speed=EP/tons*50000, or speed=EP/HS*1000, i'll stay in tons here.

So lets check your tug first, just to see. 700/25000*50000 = 1400, just as aurora said.

Now lets see about when its towing the barge. 700/(25000+518000)*50000 = 700/543000*50000 = 64.5km/sec

How far can that go in two years? (days in aurora year)*(seconds in aurora day)*speed = 360*86400*64.5 = 2.006b km. Or a little more than Earth to the far side of saturn's orbit.

If you want to know how much engine you need to hit a given speed, you can rearrange it: speed/50000*tons = EP Again, lets look at the tug to see it. 1400/50000*25000 = 700 EP, and it has 700 EP

So lets say you wanted to get to pluto in 2 years, that's 7.4b km. on average distance/360/86400=km/sec, 7,400,000,000/360,86400=237.9km/sec. So we need 238km/sec, minimum.

How much EP do you need to move the barge and tug at 238km/sec? 238/50000*543000 = 2585EP

On Nuclear Pulse, how much engine is that? 50 hull size 0.5 power engines are only 200 EP, so 13 of them for 2600EP. 32,500t just in engines.... but that's heavier than we did the math for....we need more engine, or a smaller barge.

Make your tug 60,000t and you'll need 2751EP, 14 of Nuclear Pulse size 50 power 0.5 will give you 2800EP, for a towing speed of 242km/sec. You'll need 35000t in engines, leaving you 25,000 tons of ship to go with them for the cargo portion.

On Ion, you can get your needed speed on just 2/3 the engine, 10 size 50 power 0.5 ion drives get you 300EP each, 3000 total, and 25000t in engines. for a 60kt tug towing the barge, thats a speed of 260km/sec, 8.1b km in 2 years.

btw, don't do all this by hand for each new design, spreadsheets every aurora player's best friend, lol.