Help with jump drives

[drayath (OP)]

I'm having an issue where i can't get my ships to transit a jump-point, can anyone see the issues with ship design or orders?

Orders: Move to jump-point (definitely at location), Standard transit of jump-point.

Message: 30th March 2037 07:40:51,Empire,Sol,Sol Transport cannot carry out its standard transit order as at least one ship is larger than the ship with the highest jump rating.  No friendly or allied jump ships are available for escort

At jump-point is a Hermes class Jump Tender (80500t jump capacity, 3 ship limit)
'Sol Transport' contains 1 Transit MkII class Cargo Ship (79100t)

Tried waited a day to ensure jump drive not on cooldown.
Tried doubling size of jump drive.
Tried adding both ships to same task-force and doing squadron jump.
Taskforce containing 1 Pathfinder class Scout Carrier does work.

-------------------------------

Hermes class Jump Tender    30 450 tons     132 Crew     534. 2 BP      TCS 609  TH 400  EM 0
656 km/s    JR 3-25(C)     Armour 1-86     Shields 0-0     Sensors 5/6/0/0     Damage Control Rating 1     PPV 0
MSP 11    Max Repair 256 MSP
Intended Deployment Time: 3 months    Spare Berths 6   

JC80K Commercial Jump Drive     Max Ship Size 80500 tons    Distance 25k km     Squadron Size 3
Civ Low Power (2)    Power 200    Fuel Use 0. 94%    Signature 200    Exp 2%
Fuel Capacity 1 000 000 Litres    Range 628. 1 billion km   (11081 days at full power)

Civ IR Scanner (1)     Sensitivity 5     Detect Sig Strength 1000:  5m km
Civ EM Scanner (1)     Sensitivity 6     Detect Sig Strength 1000:  6m km

This design is classed as a Commercial Vessel for maintenance purposes
<commercial drive>

-------------------------------

Transit MkII class Cargo Ship    79100 tons     241 Crew     894 BP      TCS 1582  TH 2000  EM 0
1264 km/s     Armour 1-164     Shields 0-0     Sensors 5/6/0/0     Damage Control 1     PPV 0
Maintenance Capacity 7 MSP
Cargo 50000   Spare Berths 14    Cargo Handling Multiplier 50   Tractor Beam     

Civ Low Power (10)    Power 200    Fuel Use 0. 94%    Armour 0    Exp 2%
Fuel Capacity 1 000 000 Litres    Range 242. 0 billion km   (2216 days at full power)

Civ IR Scanner (1)     Sensitivity 5     Detect Signature 1000: 5m km
Civ Ship Scanner (1)     GPS 1600     Range 9. 6m km     Resolution 100
Civ EM Scanner (1)     Sensitivity 6     Detect Strength 1000: 6m km


This ship is classed as a commercial vessel for maintenance purposes
<commercial drive>

--------------------------------

Pathfinder class Scout Carrier    8 000 tons     87 Crew     695 BP      TCS 160  TH 400  EM 0
2500 km/s     Armour 1-35     Shields 0-0     Sensors 1/1/0/0     Damage Control Rating 2     PPV 0
Maint Life 4. 72 Years     MSP 1109    AFR 256%    IFR 3. 6%    1YR 82    5YR 1223    Max Repair 100 MSP
Intended Deployment Time: 60 months    Flight Crew Berths 96   
Hangar Deck Capacity 3000 tons     

Civ High Power (1)    Power 400    Fuel Use 5. 3%    Signature 400    Exp 5%
Fuel Capacity 1 000 000 Litres    Range 424. 5 billion km   (1965 days at full power)

This design is classed as a Military Vessel for maintenance purposes
<commercial drive>

[83athom]

The ship with the jump drive has to be bigger than the things it is jumping. And commercial jump drives shouldn't be able to jump military ships but something is up with the code.

[drayath (OP)]

Is there a specific design reason for this, seems a bit odd than you improve the performance of a jump tender by bolting cheap & heavy stuff to it (in my case 25% thrust, tech 1 Nuclear Pulse enginesx21 giving 50kt for just 160 cost) rather than with the jump drive design. 

--------------------------
Hermes class Jump Tender    80 050 tons     360 Crew     890.  6625 BP      TCS 1601  TH 1312  EM 0
819 km/s    JR 3-25(C)     Armour 1-165     Shields 0-0     Sensors 5/6/0/0     Damage Control Rating 1     PPV 0
MSP 7    Max Repair 256 MSP
Intended Deployment Time: 3 months    Spare Berths 0   

JC80K Commercial Jump Drive     Max Ship Size 80500 tons    Distance 25k km     Squadron Size 3
Heavy Engine (21)    Power 62.  5    Fuel Use 0.  94%    Signature 62.  5    Exp 2%
Fuel Capacity 2 250 000 Litres    Range 537.  9 billion km   (7601 days at full power)

Civ IR Scanner (1)     Sensitivity 5     Detect Sig Strength 1000:  5m km
Civ EM Scanner (1)     Sensitivity 6     Detect Sig Strength 1000:  6m km

This design is classed as a Commercial Vessel for maintenance purposes
<Comercial Drive>

[db48x]

You could use fuel tanks instead, and have it double as a tanker.

[iceball3]

You could use fuel tanks instead, and have it double as a tanker.

Pretty much. Spam fuel storage if you want it to be a tanker, engineering spaces if you want it to be an ad-hoc maintenance ship. Using worse engines in large quantities just wastes fuel, honestly.
You could also pack armor or CIWS or both on it, if you want it to tank buttloads of missiles. Good when AMM spam is a big problem.

[drayath (OP)]

Needed to add 50kt to work with my existing set of civilian ships that are all at the 80k ton mark, that would be an awfall lot of fuel tanks. 

From the original
Using cheap engines cost an extra: 100 dur, 100 gal & 200 wealth
vs using very large fuel tanks that cost an extra: 1700 dur, 1700 brom and 3400 wealth (adds 50m liters of fuel storage)

Was not much concerned with fuel economy as the intention was for them to each have their own jump-point which they would not move from; But they will earth->a max distance jump-point (~2.  5b km) with just 10000 fuel.   The only reason they had a moderate fuel storage was as an emergency cache at every jump-point for when i forget to refuel something. 

Should also be noted these don't go anywhere near hostile forces, only have sensors as it my standard practice for all civilian ships.

[Iranon]

I like 55% low-multiplier (but current tech) engines, and devote the rest to fuel tanks.
OK-ish speed for reasonable cost, practically unlimited range, useful as a secondary tanker.

It may be worth to prioritise the minimum power tech line.
At 10% power, maximum-size drives cost the minimum of 5 per engine up to Internal Confinement Fusion, and you greatly cut your crew requirements - relevant as crew spaces are actually fairly expensive per ton compared to cheap bulk.
Tech investment is modest considering what you need for a decent jump engine, and it has other applications too - e.g. tugboats capable of hauling massive planet-built stations at a decent speed without undue fuel consumption.

If you absolutely don't want to spare the tech investment and have no secondary requirements for your mobile jump gates, low-tech low-power engines as in your current design make sense even though it's not pretty.

[db48x]

Should also be noted these don't go anywhere near hostile forces, only have sensors as it my standard practice for all civilian ships.

That gives me an idea for the one that does have to go into an unfriendly system; instead of some of the extra fuel, it could have a max-size passive sensor.

Anyway, the mistake with jump engines vs jump tender size is one that essentially everyone makes; the forum is littered with questions about it. There really ought to be a note about that in the jump engine design window.

[iceball3]

That gives me an idea for the one that does have to go into an unfriendly system; instead of some of the extra fuel, it could have a max-size passive sensor.

Anyway, the mistake with jump engines vs jump tender size is one that essentially everyone makes; the forum is littered with questions about it. There really ought to be a note about that in the jump engine design window.

Do note that passive sensors above size 1 count as military, i think, so maintenance can be a pain in the butt.

[drayath (OP)]

Have just found another use for it; There as so many large engines it can survive for several minutes vs 30 star swarm fighters. This may lead to a test of a squad Civilian Tank ships (80kt of engines and a size 1 active sensor vs size 750) leading the assault on a jump point and being decoys for my sensors-off combat ships.

[Iranon]

I've appreciated very-low-power engines to armour as damage sinks for quite some time, although mostly in the context of missiles ("cheaper to build than to shoot down").
Not fond of pure decoys as that just feels mean to the AI, but sometimes you can set up a Catch-22: When the cheap bulky easily-replaced stuff is actually a priority target while the more sophisticated/expensive vessels come into their own later in the engagement.

[drayath (OP)]

As an excuse, i have ion engines and ~level 2 tech and 2 8k military shipyards and the swarm have just expanded towards me from one of the two systems they have (each with nearly 1000 asteroids in!). In comparison their fighter have nearly 11kms speed and 180000km beam range, ignore the 2 hive ships they came with. My 12cm rail-guns need as much unfair assistance as possible, so the decoys will be bait at the jump-point with the only active sensors, and everything else (mostly fighters) will jump through once the enemy already have a target.