conventional start, commercial engine only fleets

[Michael Sandy (OP)]

A lot of the campaign stories I love have situations where a new size class of ship is built, and it can't be deployed outside the solar system or jump network because there is no jump ship big enough for it yet.

So why not have the starting ship designs built with commercial engines, size 25+ engines with 50% reduced power?  Build them about 60% engine or so, and they will be as fast as conventional ships with 30% engine, with cheap efficient engines.

Maybe a meson tech fleet too, which goes for a robust engines as armor philosophy, since they can't shield or armor against mesons, they build systems that can take a few hits.

They could then not need military jump engines developed until they were contemplating jump assaults, and conventional start empires aren't going to be contemplating jump assaults early.  If they are assaulting another system early, the other guys probably haven't developed jump theory yet.

The smallest effective design they could make would be about 1,700 - 2,000 tons, 1 size 25 engine with 9-15 HS left over (not including armor, crew, maintenance).  They would probably have multiple size 25 engines on the smaller designs, to allow for some mobility if an engine was hit.  They would need to build larger shipyards for the same ship payload, and being larger, they would be more vulnerable to active sensor detection.

But only needing one jump ship design, and one that could be built in civilian shipyards at that might be worth it.

I think I would name the jump ship class "Dragoon", or some other mounted infantry name.  Some unit that rides to battle, but fights on foot.  And I am wracking my brain for a 15-16th century German unit name for the soldiers assigned to hold the horses for their fellow mounted infantry.

[NuclearStudent]

Wait, what?

I was under the impression commercial jump drives wouldn't work for military units anyhow.

I am, generally, just really really confused as to what you are trying to talk about.

[Michael Sandy (OP)]

K, my understanding is that there is a distinction between "commercial engines" and "civilian ship for the purpose of maintenance" definitions.

A commercial engine jump ship cares only about the engines, and does a jump that scrambles the sensors for longer.

"Civilian ship for the purpose of maintenance" means no military systems, and no sensors large than one hull space.

[83athom]

Commercial Jump drives may only jump ships marked as "commercial" while military ones can jump any within its limit.

[Michael Sandy (OP)]

Yes, but is "commercial" solely defined by the engines, and is it different from "civilian" which is about whether the ship qualifies for cheap maintenance?

[Iranon]

I like to build most ships with 55-80% engine tonnage (high end: 0.5 power commercial designs that would otherwise be military, slow military ships that use them as damage sinks). Some analysis backing this up: http://aurora2.pentarch.org/index.php?topic=9146.0

For fast ships, building more of these bulky ships instead of fewer compact ones is only slightly more expensive and saves considerable fuel.
For slow ships, around 50% engines is cheaper as well as more fuel-efficient, up to 80% is worth considering because we gain interior HTK for very little cost. Better than armour in some ways.

[Michael Sandy (OP)]

I remember doing the math a decade ago for freighters and colony ships, that the optimum engine ratio for maximizing cargo*distance/time per build cost was different.  The more expensive the cargo system, the higher the engine ratio was optimum.  So for really cheap cargo holds, you went cheap on the engines.  For more expensive cryo tanks, the optimum ratio was significantly more engines per cryo tank.

This is actually kind of a problem in that the colonists are likely to arrive before the infrastructure.

Also, the shorter the haul, the more important cargo handling systems were over engines.

Might be fun revisiting the math on survey ship size too.  What is the ideal ratio for a survey ship spent traveling vs time spent surveying?

[Iranon]

It all depends on what you hold fixed.
My analysis in the linked thread assumes a fixed speed requirement. Yours apparently assumed you have a fixed engine type.

Keeping neither fixed and cost-optimising your civilian haulers, you end up with around 50% engine size for all craft, but different power multipliers (lower for freighters, higher for colony ships).

[83athom]

Yes, but is "commercial" solely defined by the engines, and is it different from "civilian" which is about whether the ship qualifies for cheap maintenance?

Commercial and civilian are two different things. Civilian ships are classed as commercial, but you own your own commercial ships. They are not only defined by engines, but a number of other modules and settings. If the design screen says "Classed as commercial for maintenance..." at the bottom, a commercial jump drive can jump it. If its marked as military, only a military drive can jump it.

[Iranon]

I'm fairly sure I remember commercial jump drives being able to jump military ships with commercial engines.

[Gyrfalcon]

That's an easy one to test - create a new game, whip up a commercial jump ship and a military ship with commercial engines, SM that you know where the jump points are and attempt to jump the military ship through.

[Titanian]

Commercial jump drives have no problem moving military ships as long as those are powered by commercial engines.

[Jorgen_CAB]

Yes... the Jump Drive system ONLY care about what drives is installed.

A military Jump Drive can jump any ship, if memory serves. Commercial Jump Drives can only jump ships equipped with Commercial Engines, it does not matter if the ship itself is flagged as a military ship or not.

[Michael Sandy (OP)]

So given that is it possible, is it a good idea?  Early on, simply not having to retool a shipyard to build a military jump ship seems to really help.  With military ships having the same fuel efficiency as freighters, escorting freighters is less of a fuel drag.

The drawbacks seem to be in the shipyard capacity and sensor footprint areas, if at all.  That, and with minimum size 25 engines, size creep is more of a problem.  If you are shooting for a particular fleet speed, you can't just edge the ship up a tad in size with an extra engine.

[Titanian]

In one of my games I have a fleet that uses size 50 engines with 40% power in their military ships of Size 107 (5350t).   Yes, half of those ships is the giant engine, but they are quite cheap to build and you won't need hundreds of fuel harvesters to feed your fleet.  You won't get FACs equipped with these engines, but I wouldn't build smaller ships if I didn't use commercial engines, so increased sensor footprint isn't an issue for me,  as I can always put the stuff into multiple smaller ships.  Sure, at some point I will probably want to have bigger ships due to efficiency, but that is not much different when using more powerful engines.