Commercial Engines for Military Ships

[liveware (OP)]

Traditionally I have used military engines exclusively for all military ships. However, in my recent game I have decided to use a different approach. Instead of building commercial supercarriers to move around my military like I have done previously, I have built several jump-drive equipped stations and positioned them around jump points I want to connect to my empire. This strategy has actually been working out quite well for me, as it allows non-jump ships to easily transit to other systems in my empire, without resorting to jump point stabilization. Along with the jump stations, I have begun equipping some my military ships with commercial engines as this allows for much greater cruising/patrol range. Below is my standard cruiser design which is currently in use throughout my empire. These cruisers serve two roles: to provide PPV to keep colonies in check and to provide some defensive capability in case of alien attack. As such, they are slow, heavily armed, and have quite excellent range for their low engine tech (high efficiency nuclear drive = improved nuclear pulse drive tech).

Code: [Select]

Havana class Missile Cruiser (P)      10,000 tons       185 Crew       1,228.9 BP       TCS 200    TH 250    EM 450
1250 km/s      Armour 3-41       Shields 15-450       HTK 64      Sensors 0/0/0/0      DCR 10      PPV 52.42
Maint Life 8.16 Years     MSP 1,168    AFR 80%    IFR 1.1%    1YR 31    5YR 467    Max Repair 96.6 MSP
Magazine 352   
Captain    Control Rating 1   BRG   
Intended Deployment Time: 24 months    Morale Check Required   

TMG P125.00-50C High Efficiency Nuclear Drive (2)    Power 250    Fuel Use 8.94%    Signature 125    Explosion 5%
Fuel Capacity 226,000 Litres    Range 45.5 billion km (421 days at full power)
TMG Beta S15 / R450 Force Shield Generator (1)     Recharge Time 450 seconds (0 per second)

Twin TMG R200-67.00 Magnetic Accelerator Cannon Turret (1x4)    Range 20,000km     TS: 16000 km/s     Power 0-0     RM 20,000 km    ROF 5       
TMG R22-TS16000 (70%) MAC Turret Targeting Computer (1)     Max Range: 21,760 km   TS: 16,000 km/s     54 8 0 0 0 0 0 0 0 0

TMG Size 24 SLGM Cannister (8)     Missile Size: 24    Hangar Reload 245 minutes    MF Reload 40 hours
TMG Size 12 SLGM Cannister (8)     Missile Size: 12    Hangar Reload 173 minutes    MF Reload 28 hours
TMG Size 6 SLGM Cannister (8)     Missile Size: 6    Hangar Reload 122 minutes    MF Reload 20 hours
TMG Size 1 SLGM Cannister (16)     Missile Size: 1    Hangar Reload 50 minutes    MF Reload 8 hours
TMG FC23-R1 (70%) SLGM Targeting Computer (1)     Range 23.1m km    Resolution 1
TMG FC107-R100 (70%) SLGM Targeting Computer (1)     Range 107.3m km    Resolution 100
TMG FC49-R10 (70%) SLGM Targeting Computer (1)     Range 49.8m km    Resolution 10

TMG AS10-R1 (70%) DRADIS (1)     GPS 72     Range 10.7m km    MCR 963.4k km    Resolution 1
TMG AS23-R10 (70%) DRADIS (1)     GPS 720     Range 23.1m km    Resolution 10
TMG AS49-R100 (70%) DRADIS (1)     GPS 7200     Range 49.7m km    Resolution 100

This design is classed as a Military Vessel for maintenance purposes

A side benefit of using commercial engines on my military ships which I have not yet fully developed is that I can deploy jump stations with substantially larger commercial jump drives than I can military jump drives, due to the expense of researching large military jump drives. This means I could in theory field much larger military ships than would otherwise be possible using military jump drives and military engines.

Does anyone else use this approach? If so, what are some pitfalls you've come across? I imagine ship speed will become an issue at some point, however I hope to mitigate this by using commercial-engined carriers to support my fast front-line military ships.

[Dawa1147]

I usually use Commercial Engines on:
Carriers (where Speed is not much of an issue, and weight savings for fuel allow more Hangar Space)
Orbital Weapon Platforms (So they can relocate on their own, one engine is usually enough)
and importantly
Stealth Ships:
Since Stealth is important, high power (and thus high thermal) is counterproductive.
Being much, much cheaper than similar Military Engines (esp. with the thermal redouction) allows me to build more faster for less cost
(that last one especially: you use far less precious gallacite)
The reduced cost eases MSP costs of engineering failures and saves space on fuel

In the past I've run my main missile fleet on civ engines, and found the time savings on research kinda ok. The main benefit to me was unified preproduction of components, massive fuel savings, and having the supply ships easily keep pace with the main fleet. If you run them as the backbone of invasion fleets, the  slow speed felt like less of an issue: even if enemies were faster (and my select fast ships couldnt deal with them), the enemy always has something of value you can advance on, forcing them to react to you. Just keep some faster ships to deal with flankers.

[liveware (OP)]

Good point on the stealth aspect, I have not yet developed that capability but it is in the works.

Commercial engine carriers are on the drawing board once ion drive engine tech is available.

A single commercial engine on each jump station might be worth-wile, as then I can forgo using tugs.

Also a good point on the 'initiative' side of things. If I can force the enemy to engage my slow ships at an even slower target of my choosing (such as a colony), I can still maintain a tactical advantage.

[Jorgen_CAB]

There are always some trade-off you will need to do no matter what you do. In my opinion everything is relative. It depends on your strategic, tactical and practical needs.

I generally find that some type of ships don't need as much speed as other types of ships. I might not build commercial engines and I usually like to keep the engines military though with a lower power settings at times as that makes the engines more affordable to research and mount on the ship if I can accept the loss in speed.

If I want to build a really big fast fleet carrier I might need to also build a large powerful engine with thermal reduction and those engines usually are extremely expensive to research. If you also play on a severely reduced tech rate such engines research times will feel even more of an issue. But there can still be times where you wan't a 125% power 5000t engine with a 75% thermal reduction.

In general my escort carriers usually are equipped with commercial or lower power military engines and have the speed to match the rest of my military supply and logistics ships. I'm not overly concern of the fuel usage of my fleet in general as military ships mostly go somewhere when they really need to and you can also use fleet tugs to move them strategically between naval bases in peace time to reduce fuel usage anyway.

My main reason for building cheaper engines are research not fuel or cost as those I think are not that critical in comparison to the shortcoming of lower speed or less mission tonnage on the ships. If most capital ships usually have a range of 15-25bkm then the volume of fuel on the ship is never in question for a large capital ship.

So, for me it is a matter of research cost and general need for those ships in an operational or grand scale manner.

[liveware (OP)]

Strategic thinking is definitely relevant in this consideration. For me, I am developing a relatively 'young' (<300 years old) empire. I almost always impose a 10-20% research speed malus on my empires. So I am in the process of laying the strategic ground work for future tactical considerations. Among those considerations are the relative merits of military and commercial engines. Currently I have deployed 10k ton military jump stations and 50k ton commercial jump stations. I picked these numbers somewhat arbitrarily. The size of the jump engines on the jump stations directly impacts the composition of any future military fleets, as they will be constrained to the limits of the established jump stations, except in times of extreme peril.

At this 'early' stage, I desire to minimize micromanagement of my fleets, so it is desirable to have larger ships with longer range. This will likely change when I start encountering NPRs, and I will start developing carriers with faster parasite craft. My hope is that my cruisers can still offer some utility by launching a large salvo of missiles at the onset of combat and then retreating, allowing faster craft to engage hostiles at short range.

[Michael Sandy]

Commercial engines on either long ranged missile combatants, or mid range missile combatants with a lot of point defense is quite a workable design.  The theory of commercial engined missile ships is you go with cheaper and bulkier components and missiles in general.  A 2-stage 6 MSP missile with a cheap, not high power engine 1st stage and a 3 MSP 2nd stage is going to cost only slightly more to build than the 3 MSP 2nd stage.  So you substitute volume in magazines a bit to get your kill power, which you can do because your fleet cost per magazine is relatively low.

In a missile duel, the engines of a commercial engined missile ship take a lot of punishment compared to their cost.

A commercial engined missile ship would then transition into becoming a fleet collier role, as it has the endurance to economically transport lots of missiles.

I would go with somewhat bigger commercial engined ships, if you can.  Figure out what the smallest commercial jump engines you can build are, and build jump stations (with their own engines) to go with them, and design your early fleet around them.