I'm scratching my head as to why my Jump Stabilisation Ship is tracted at a meager 342 km/s. Is there a penalty at some point if the masses of the two ships are vastly different? 
My Tug is 10,000 tons and has a speed of 2400 km/s. My Bïfrost JSS has a base speed of 333 km/s. So what gives? 

There are two important rules here:

• A ship under tow does not contribute its own engine power to the speed of the fleet.
• The speed of a tug plus a ship under tow is determined by the tug's engine power and the total mass of both the tug and the towed ship.

Given this, you have a total of 480 engine power on the tug, and a total of 70,000 tons (tug 10,000 + station 60,000) or 1,400 HS. 480 EP / 1,400 HS * 1,000 = 342 km/s, so the numbers check out correctly.

I'm scratching my head as to why my Jump Stabilisation Ship is tracted at a meager 342 km/s. Is there a penalty at some point if the masses of the two ships are vastly different? 
My Tug is 10,000 tons and has a speed of 2400 km/s. My Bïfrost JSS has a base speed of 333 km/s. So what gives? 

TG-01 Sheperd 001  (Sheperd class Tug)      10 000 tons       114 Crew       360.5 BP       TCS 200    TH 480    EM 0
2400 km/s      Armour 1-41       Shields 0-0       HTK 47      Sensors 5/0/0/0      DCR 1-1      PPV 0
MSP 132    Max Repair 100 MSP
Tractor Beam     
Lieutenant Commander    Control Rating 1   BRG   
Intended Deployment Time: 3 months   
● Recreation Room-25    ● Library-25    2x ● Escape Pod-5    ● Security hardpoint-5   

Honeywell Aero Nuclear Thermal Engine C80 (6)    Power 480    Fuel Use 10.06%    Signature 80    Explosion 5%
Fuel Capacity 850 000 Litres    Range 152.1 billion km (733 days at full power)
Refuelling Capability: 50 000 litres per hour     Complete Refuel 17 hours

Silas-Nein Small Thermal Sensor 1-5 (1)     Sensitivity 5     Detect Sig Strength 1000:  17.7m km

This design is classed as a Commercial Vessel for maintenance purposes
This design is classed as a Tug for auto-assignment purposes

JSS-01 Bifröst 001  (Bifröst class Jump Stabilisation Station)      60 000 tons       197 Crew       1 384.8 BP       TCS 1 200    TH 400    EM 0
333 km/s      Armour 1-136       Shields 0-0       HTK 52      Sensors 5/0/0/0      DCR 1-0      PPV 0
MSP 24    Max Repair 1 000 MSP
Commander    Control Rating 2   BRG   AUX   
Intended Deployment Time: 3 months   
Jump Point Stabilisation: 180 days
● Large Crew Lounge-100    ● Onboard Hospital-50    ● Recreation Room-25    2x ● Security hardpoint-5    9x ● Escape Pod-5    3x ● Medium Hydroponics-50    ● Promenade-50    ● Fitness Center-50    ● Library-25    ● Small Armory-5   

Honeywell Aero Nuclear Thermal Engine C80 (5)    Power 400    Fuel Use 10.06%    Signature 80    Explosion 5%
Fuel Capacity 1 400 000 Litres    Range 41.7 billion km (1449 days at full power)
Refuelling Capability: 50 000 litres per hour     Complete Refuel 28 hours

Silas-Nein Small Thermal Sensor 1-5 (1)     Sensitivity 5     Detect Sig Strength 1000:  17.7m km

This design is classed as a Commercial Vessel for maintenance purposes
This design is classed as a Stabilisation Ship for auto-assignment purposes


Does anyone know the calculation for the current base temperature of a system body?
I suspect it's a simple matter of star brightness and current distance from star.

Prior to eccentric orbits, the base temperature of a body never varied, so I could just use the value of FCT_SystemBody.BaseTemperature.
But that value seems not to vary over time.

Have to ask, there are Troops actually aboard said ship?

Asking from experience...

Yes yes there were troops aboard 

I figured out the issue, I had to create a colony before, Jesus Christ.

Have to ask, there are Troops actually aboard said ship?

Asking from experience...