Engine Tech Questions

[Kaiser Kirk]

Hmm ok questions first, long winded reason for questions second.

Since ICE tech has been dropped, I encountered several questions :
1_  There was recently a discussion that seemed to resolve that VTE engines are not limited to the year categories or SHP ratings in the Naval Propulsion tech as they are not Turbines.

Diesels are also not turbines. Are Diesels constrained by year and SHP?

2) The vessels I was tinkering with were coming out at ~4400shp. Previously the largest Diesel I could make was 3000shp. Since thats been scrapped, there shouldn't be an issue with larger engines, correct?  Further there is the logic bit that with a Diesel electric set up one can simply feed 3 x 1500shp into the electrical system driving the shaft.

So... are there still 3,000hp limits on Diesels, and if so,  does feeding through a turbo-electric system change that?

3) Lastly, the ICE tech used to offer an alternate route to the Naval Propulsion tree.  Once you hit 1920, there were no HP limits, so you could freely use Diesels in place of Steam plants, with the exception of needing a bonus tech for Capital ships. This also meant there was a chance you could skip the steam turbine tech line. I was more advanced in diesels than in steam turbines.

So, how does the future of large maritime diesels look now?

Background : So, I had a concept of a motor gunboat in a semi MAS role, essentially combining many light combatant roles. Gun for sinking small vessels and shore bombardment, torpedoes for larger ships, possibly mine rails. Electric batteries for silent night ops. Perhaps carry a raiding squad. Coal fired ships can throw sparks at night, so oil burning. Steam plant are not quick to react to power changes, and then there is that nasty habit of boilers to vent scalding steam when punctured, so Diesel-electric is the way to go.

Interestingly, reading on wiki, it seems non-petroleum fuels were something Mr. Diesel was exploring, and working steam engines running on Peanut oil were shown at the 1892 Paris expo. 

Bavaria has no oil, this might be a route to follow. I can see it now: " Enemy Soldier : Sir, I think I smell...yes, I do, I smell bacon !, Enemy Captain- thats thier engines, it's the Bavarians, sound the alarm!"

[Korpen]

Hmm ok questions first, long winded reason for questions second.

Since ICE tech has been dropped, I encountered several questions :
1_  There was recently a discussion that seemed to resolve that VTE engines are not limited to the year categories or SHP ratings in the Naval Propulsion tech as they are not Turbines.

No and yes. The engine tech governs the engine year for all kinds of  engines, but only turbines are limited in power by it.
At least that is how things are written, and all VTE/ICE designs I have seen so far seems to follow that.

Diesels are also not turbines. Are Diesels constrained by year and SHP?

Yes and No. Limited in year but not SHP. However the old ICE tech did limit engine size, and I think it might be motivated to put in some limit on ICE engines again. One thought could be that if one wants more then 8000shp ICE engines one would need the diesel drive tech (to give that tech a reason for existing). 

Background : So, I had a concept of a motor gunboat in a semi MAS role, essentially combining many light combatant roles. Gun for sinking small vessels and shore bombardment, torpedoes for larger ships, possibly mine rails. Electric batteries for silent night ops. Perhaps carry a raiding squad. Coal fired ships can throw sparks at night, so oil burning. Steam plant are not quick to react to power changes, and then there is that nasty habit of boilers to vent scalding steam when punctured, so Diesel-electric is the way to go.

Leaving aside that electric engines should (but not in spring sharp) be quite a bit heavier the geared ones, it should be noted that while electric engines are quiet the same can not be said about the diesel. A diesel makes allot more noise then a turbine, especially at high power, and it is also far less reliable then a turbine during extended operation. If rapid power changes are asked for, I would not rule out a petrol engine, as they respond better to power changes then a diesel used to do.
Not that diesel are a bad idea, I just do not find them to be a clearly superior choice either.

Batteries I do not think is all that good an idea as they give of toxic gases and can start fires if they get wet, and explode of not well-maintained or if damaged. IN addition, to get any realistic runtime (even at fairly low speed) on them you would need quite a few batteries.

Interestingly, reading on wiki, it seems non-petroleum fuels were something Mr. Diesel was exploring, and working steam engines running on Peanut oil were shown at the 1892 Paris expo. 

Bavaria has no oil, this might be a route to follow. I can see it now: " Enemy Soldier : Sir, I think I smell...yes, I do, I smell bacon !, Enemy Captain- thats thier engines, it's the Bavarians, sound the alarm!"

Well rapeseed oil is more likely then peanut oil in the case of Bavaria, but apart from it being several times more expensive then petroleum I see no reason why bio-diesel could not work. :)

[Guinness]

We mods are conferring. Expect clarification soon.

(queue the Jeopardy music)

[Guinness]

Ok, first on the subject of SHP limits:

SS2 uses the same weights for turbines, electric and diesel (or any combination thereof). This means the only propulsion type with a built-in disadvantage is VTE. So we are unanimous that the engine year SHP limits should apply to turbines, electric, and diesel (or combinations thereof). VTE engines continue to be unlimited in maximum SHP, though in almost all cases, their higher weight would make use in high SHP designs unattractive.

I'm going to clarify the ruleset to that effect today.

It's worth noting that after 1920, we don't yet have an SHP limit, but SS2 still has it's own limit.

Also, previously on the subject of diesel propulsion, I wrote this:

SS2 gives no advantage to diesels in either weight or range, so it seems like a good idea to have one less rule to cover them. Capital ship diesel engines stays in, as does electric propulsion, for role playing purposes.

So we want to allow diesels on "non-capital" ships, while still keeping the capital ship diesel tech viable. We could make a rule to codify that, but I think for the time being, unless we really really need a rule, let's just keep diesel implementation on small ships sane. So something under 2000 tons can certainly be exclusively diesel powered, I think, for instance. But if you think your ship falls under the "Capital Ship" category, which to me is anything over 10,000 tons, but we have not codified that in a rule as yet, you should develop the Capital Ship Diesel tech.

The 2000 ton displacement number was a guess on my part. I think we'd need to look at the design to see if it makes sense. This is somewhat uncharted territory so far. I don't personally understand the propulsion item in the tech tree to be turbine specific (though it certainly looks written that way). A question that we'll need to discuss is if we want that to cover all propulsion techs (since to SS2 they are all the same anyway), if we want the separate diesel and electric techs to simply enable their use, or something else.

Not good answers, I know, but this is the first time anyone has expressed an interest in diesel powered small and medium fast combatants that I know of.

[Guinness]

I updated the rules to say this:

Naval Propulsion
1895 Baseline(0): Complex Reciprocating Engines, Engine Year 1900
1902 Advanced (+1): Engine year 1905, Max. non-VTE power 5,000 HP/Shaft,
        Direct-drive Turbines
1905 Cutting Edge (+3) Engine year 1909, Max. non-VTE power 12,000 HP/Shaft
1909: Engine year 1912, Max. non-VTE power 20,000 HP/Shaft
1913: Engine year 1916, Max. non-VTE power 35,000 HP/Shaft
1917: Engine year 1920, Max. non-VTE power 40,000 HP/Shaft, Engine year = year laid down.

[P3D]

VTE power is limited by SpringSharp to 20000SHP, anyways.

And a note, please update the coastal fort rules.

[Kaiser Kirk]

Leaving aside that electric engines should (but not in spring sharp) be quite a bit heavier the geared ones, it should be noted that while electric engines are quiet the same can not be said about the diesel. A diesel makes allot more noise then a turbine, especially at high power, and it is also far less reliable then a turbine during extended operation. If rapid power changes are asked for, I would not rule out a petrol engine, as they respond better to power changes then a diesel used to do.
Not that diesel are a bad idea, I just do not find them to be a clearly superior choice either.

My dim recollection is the USN found that the turbo-electric system ran about 10% heavier, but allowed easier compartmentation, full power reverse and other little things. Though part of it was then you didn't have to cut gears.

Also as I recall from long ago readings (i.e. could be faulty), Diesels ran something like 25% heavier, but were 25% more fuel efficient. So you saw them on long patrols.  In this case a petrol engine would work just as well, although with greater fire hazard.

Batteries I do not think is all that good an idea as they give of toxic gases and can start fires if they get wet, and explode of not well-maintained or if damaged. IN addition, to get any realistic runtime (even at fairly low speed) on them you would need quite a few batteries.

I hadn't thought of the explosion hazard potential.  I was already leaning towards two types, one with a minelaying rig, the second with troop seating. I could limit the batteries to the second.

I was considering them with the idea of using them for the final approach to shore, shutting down the main engines (also a reason for a diesel or gas) and using electric for silence. This of course led to wondering just how much weight to devote to batteries, the one I was working with I tossed in 5t, but I haven't a clue what that means range/speed wise.

Interestingly, reading on wiki, it seems non-petroleum fuels were something Mr. Diesel was exploring, and working steam engines running on Peanut oil were shown at the 1892 Paris expo. 

Bavaria has no oil, this might be a route to follow. I can see it now: " Enemy Soldier : Sir, I think I smell...yes, I do, I smell bacon !, Enemy Captain- thats thier engines, it's the Bavarians, sound the alarm!"

Well rapeseed oil is more likely then peanut oil in the case of Bavaria, but apart from it being several times more expensive then petroleum I see no reason why bio-diesel could not work. :)


[/quote]

[Guinness]

And a note, please update the coastal fort rules.

Are you talking about this:?

Blooded noticed that the current Coastal Fort rules use SS2 cost as for cost figures (was left there during one of the rules changes unintentionally), not the component cost one, could it be updated to fit the current rules?

I.e. Turret weight in BP, twice that in $ (as armament), and again the turret weight for installation. So a 300t turret would cost $0.9 and 0.3BP.

http://www.navalism.org/index.php?topic=135.0

http://www.navalism.org/index.php?topic=3725.msg40044#msg40044

[Guinness]

Well rapeseed oil is more likely then peanut oil in the case of Bavaria, but apart from it being several times more expensive then petroleum I see no reason why bio-diesel could not work. :)

Maybe it's time for a "fried foods are good for you" campaign in Bavaria? :)

[The Rock Doctor]

I look forward to the opening of the first hamburgerkaiser.

[Kaiser Kirk]

We'll be adding a new unit to the army TO&E,

A battalion sized field kitchen unit with extra large BBQs and large fans to waft the food smells over enemy lines.  Mortars will launch leaflet bundles promising food to deserters.

Biodiesel warships will ply opposing inshore regions, undermining morale with the smell of bacon..


Forgot to reply to the piece I was trying to quote above. The diesel was considered over the gas  for several reasons.
First was I had been thinking of maritime diesels.
Second the gas engines are more fireprone.
Third, I expect in wartime that petrol stocks might be in demand for aircraft, armored cars, motorized transport, etc. There may be less demand on diesel, and with biodiesel as potential alternate the navy wouldn't be competing with the army for a scarce resource.

edit : comment on weight penalty of electric -
while IRL there was that penalty, there was also better damage control, and greater efficiency in cruising speeds, as you could run the engine at what suited it. Use of electric drive also lessened demand on gearcutting facilities, which for the US at least was a plus.  In SS none of that shows up, and here we add a tech for the mere option of clicking a box which has no effect in SS. So I am not worried about not compensating for the mild IRL weight penalty.

[maddox]

Biodiesel warships will ply opposing inshore regions, undermining morale with the smell of bacon..

Do so along the North African coast please.

[Kaiser Kirk]

ok maybe not the muslim inshore regions...

[P3D]

Are you talking about this:?

Yes. I just got no confirmation if it was noticed at all, that's why I asked.

[Guinness]

My plan has been to update that today, but I just haven't had time yet. I will ASAP.