Construction of large naval vessels ... useless?

[rlbell]

Oh, no, neutrino detectors are canon, and there's at least one novel that made a handheld neutrino detector (although that ignored the Explorer Corps statement that neutrino detectors couldn't be fitted to ships smaller than cruisers). They're just not going to be supported any more because their capabilities are too out of sorts with other BT sensors.

The rules say they can spot and track individual fusion engines of any size throughout their range. That means once a neutrino detector adapts to a star system (supposedly taking a couple of weeks), it can watch every fusion engine - 'Mech, personal car, DropShip, etc - at 10AU.

Considering most other BT sensors have trouble seeing objects at 0.01AU, the neutrino detector hasn't been reprinted since Explorer Corps.

My bad!  TPTB not supporting neutrino sensors is what I meant.

Hand held neutrino sensors imply so much technomagic that the BT universe could not be as we recognize it.  A one kilogram mass of heavy water in a 6cm radius sphere could pick up thirty solar neutrinos in a year (detection rate is based on path length and density)-- IF you can shield the device from all other energetic particles .  So, a handheld device includes portable shielding that stops all X-rays, gamma rays, and cosmic rays-- mount a larger version on mechs and ships and they have nigh invulnerable shields against lasers and PPC's.  How they fare against large kinetic bolides is any guess.  The shielding problem can be mitigated by mounting the neutrino detector inside a detector for generic high energy particles and reject any event that excites both sensors, but still leaves the problem of not detecting many neutrino events.  They only way around that is to present a very large, dense and (if you want to know where the neutrino came from) transparent mass, so a handheld detector incorporates both transparent degenerate matter and antigravity fields.

As for descriminating all of the various neutrino sources on a planet, there is the wicked problem that all beta decays release neutrinos (why Fermi proposed their existence, to account for an apparent violation of conservation of energy), so rocky planets may be a large, diffuse sources of them.  Depending on how many neutrino events can be detected per unit time, it may take weeks of observations to seperate a stationary source from that background.  Tracking a moving source requires capturing multiple neutrinos from it as it moves, which requires a detector of huge mass, or rediculous amounts of raw magic.

[Marwynn]

Whew. I just finished creating a series of fusion-powered subs and forgot all about the neutrino detectors! Thankfully, they're being swept under the rug.

Back to Wordpad and TacOps!

[Flameblade]

As noted in the construction forum thread..

I personally would look at the mobile building rules to create a large blue navy warship to get around the items restriction.

[FedComGirl]

Using the super heavy vehicle construction rules allows you to use every vehicles under 100 tons can. They go up to 500 tons.

[Fireangel]

Using the super heavy vehicle construction rules allows you to use every vehicles under 100 tons can. They go up to 500 tons.

The problem with super-heavy vehicles constructed under the combat vehicle rules is that they are little more than powered barges; with a suspension factor of 30, you need some pretty big engines, even using XXL and Large engines, limiting them to a top speed of 1/2 or 2/3 MP (for the smaller ones; fastest possible 2/3 would be a 265-tonner with a 500-rated XXL Large Engine that weighs in at 231.5 tons!  :o).

Basically, if you want to build a naval unit larger than 265 tons that goes faster than 1/2 MP, your ONLY choice is to use the support vehicle construction rules. Also keep in mind that even that unit is boasting a full-on Large XXL engine,making it prohibitively expensive for what is essentially a barge for local use.

[FedComGirl]

I was wrong they go up to 555 tons, unless that's been changed in the PDF since there isn't an engine rating that big.

The 500 XXL Engine is 154.5 tons but you're right they're really expensive. Still it would let you pack in a lot of cruise missile launchers at 1 slot each and mount different kinds of armors. It'd make an expensive sea turtle.  ;D

[Moonsword]

The 500 XXL Engine is 154.5 tons but you're right they're really expensive. Still it would let you pack in a lot of cruise missile launchers at 1 slot each and mount different kinds of armors.

You're right that that's the number in the book but the large engines don't waive the need for shielding.  Fireangel's 231.5 ton figure is off by a half-ton for a combat vehicle mounting such an engine (my math gives 232 tons).

So we've got 333 (332.5 by his math) tons accounted for by the engine and the internal structure alone.  The smallest possible cruise missile installation (a CM/50 with one round) is 80 tons, so you can fit two of them.  What you could do is mount an impressive Long Tom battery with a decent ammo load.

[FedComGirl]

Oh yeah Oops! silly me  :D

Yep. Could be fun  ;D

[Fireangel]

You're right that that's the number in the book but the large engines don't waive the need for shielding.  Fireangel's 231.5 ton figure is off by a half-ton for a combat vehicle mounting such an engine (my math gives 232 tons).

 ???
Hm... Large 500 base weight is 462.5 tons.
XXL divides by three; 154.166~
Vehicle shielding multiplies by 1.5; 231.25
Round up to nearest half ton; 231.5

I have no problem rounding up to 232 for purposes of this thread  ;), but how did you come up with 232? (just curious) 

[A. Lurker]

???
Hm... Large 500 base weight is 462.5 tons.
XXL divides by three; 154.166~
Vehicle shielding multiplies by 1.5; 231.25
Round up to nearest half ton; 231.5

I have no problem rounding up to 232 for purposes of this thread  ;), but how did you come up with 232? (just curious)

Per the Advanced Engine Master Table on TacOps p. 308, the weight of a large 500 XXL is in fact 154.5 tons, and that times 1.5 yields 231.75 rounding up to 232. Whether you're really supposed to effectively round up to the nearest half ton twice (since that table obviously already did it once) is an interesting question...

[Fireangel]

I was wrong they go up to 555 tons, unless that's been changed in the PDF since there isn't an engine rating that big.

TO pp. 378 states that the SF of super heavy combat naval units equals (Tonnage / 10, rounded up to nearest 5)*. A 555-ton super heavy combat naval unit has an SF: 56, requiring a 499-rated engine, but since these don't exist in canon, a 500-rated Large engine must substitute.

Still, such large "combat vehicles" are impractical due to the enormous size of the engines required; the cheaper engines are simply too heavy (a 500 ICE weighs in at 925 tons! :o) or simply too expensive (XL + Fusion) for the 1/2 MP maximum they can achieve.

Not that I can't see some extremely specialized niches, but honestly, there is a reason why template B & C large naval support vehicles exist; the 555-ton combat barge might have the slots to spare, but it lacks the spare tonnage to fully take advantage of it.

(NOTE: the following is NOT a design; just a numbers exercise)

A 555-ton naval combat unit has (at best):

232 tons of engine (for 1/2 MP performance)
55.5 tons of internal structure (10%; TO pp. 378)
28 tons of control equipment

So far we have used up 315.5 tons out of 555, leaving 239.5 tons for everything else... and only 10 item slots to fit it in.

It can sport a maximum of 1982 points of armour, spread out over 6-8 locations (6 base plus1-2 turrets). This translates as an average of 330 per facing in a non-turreted barge, 283 in a barge with one turret and 247 in a barge with two turrets. All this armour weighs in at 123.5 tons (for Std. Armour).

So maxed out in armour (needed, given its practical immobility) there are 116 tons left for 10 item slots.

Of course, one might consider trading armour protection for the ability to submerge (55.5 tons)... or not...

Funniest thing is that the smaller the barge, the larger the payload:

A 550-ton naval combat unit has (at best):

203 tons of engine (495 XXL Large) (for 1/2 MP performance)
55 tons of internal structure (10%; TO pp. 378)
27.5 tons of control equipment

Total: 285.5 tons (25 more tons available than the 555-tonner).

Of course, there is a point of reversal, but it will still go at a whooping 1/2 MP.


* You are not the only one who misremembered the rule: SF: 30 applies only up to 300-ton naval (combat) units.  :-[

[Moonsword]

I have no problem rounding up to 232 for purposes of this thread  ;), but how did you come up with 232? (just curious) 

As A. Lurker noted, it was a 150% multiplier off of the listing for the 500 XXL fusion engine, which is 231.75 tons.  I figured you were going by a formula at some point in the process instead of reading it out of the book I did which I would note is a legitimate option since you may be using fractional accounting.  However, the question didn't specify, so going by the minimum set of optional rules necessary for the concept, it's supposed to be 232 ton.

The problem with the curve in this entire question is the fact that large engines are ridiculously inefficient.  The larger stock engines (most pointedly the 400-rated engines) are already moving that way, after all.  The large engines take the ball and run over the horizon with it.

[Fireangel]

Ah! that explains it. I was working off a .doc that lists the base weights of Large engines only.

Yeah. Inefficiency of Large engines is one cast-iron sandy beach. It's almost as if TPTB put them out just to shut up those clamoring for higher-rated engines and not have to worry about unbalancing the game.

[Moonsword]

Well, as I said, the 400-rated engines are already pointing that way if you look at the numbers.  The smaller large engines are sort of passable, but the engine tonnages seem to work on an exponential calculation of some sort and it really kicks into high gear around 420 or so.  (I may not be correct there, of course.)

As far as the document, it might be descended from the MaxTech engine list, which didn't calculate things out fully the way the TacOps chart did.

[A. Lurker]

Well, strictly speaking the TacOps chart also isn't quite complete. It fails to list the weights for XXL engines rated 400 and below, so for any hypothetical vehicles using those you're forced to ponder "1/3 normal, +50%, now where was I supposed to round up to the nearest half ton again?" anyway. ;)

Personally, I'd favor doing any rounding purely at the end, keeping fractions until then. Introduces the least error from a mathematical point of view, and there's occasional precedent for it elsewhere in the rulebooks. But as in our case here, applying a straight formula on the one hand and using the actual tables on the other won't always give the same results if we do that, and that's not something I'm really comfortable with either. (It doesn't help that, as far as I know, the formula used to derive standard engine weights -- if one even exists and the first numbers weren't just pulled out of thin air and massaged until they felt right -- hasn't ever been published in the first place.)

[FedComGirl]

It can sport a maximum of 1982 points of armour, spread out over 6-8 locations (6 base plus1-2 turrets). This translates as an average of 330 per facing in a non-turreted barge, 283 in a barge with one turret and 247 in a barge with two turrets. All this armour weighs in at 123.5 tons (for Std. Armour).

Can be lightened with other armors though or made heavier with more effective points with hardened armor. Still, even with standard armor that's a lot of points.  It's also more than a support vehicle. If I did it right a Support ship the same weight can only have 189 points of armor. That's 12 tons of tech D armor. If I did it right.

So far we have used up 315.5 tons out of 555, leaving 239.5 tons for everything else... and only 10 item slots to fit it in.

Um...Combat vehicles have 5 critical slots plus 1 for ever 5 tons the vehicle weighs. I come up with 116 slots.

Funniest thing is that the smaller the barge, the larger the payload:

Funny how that works.

I think it comes down to whether you want a heavily armed and armored sea turtle or a lighter armed faster dolphin.

[Fireangel]

Can be lightened with other armors though or made heavier with more effective points with hardened armor. Still, even with standard armor that's a lot of points.  It's also more than a support vehicle. If I did it right a Support ship the same weight can only have 189 points of armor. That's 12 tons of tech D armor. If I did it right.

It needs the protection; at 1/2 MP it can't really get away from an area; once spotted it can be attacked with impunity by the enemy. Of course, if it gets a motive hit, that's the end of it.

Um...Combat vehicles have 5 critical slots plus 1 for ever 5 tons the vehicle weighs. I come up with 116 slots.

Shows how often I design big combat vees.  :D

Funny how that works.

I think it comes down to whether you want a heavily armed and armored sea turtle or a lighter armed faster dolphin.

Basically, yes.But it's more complicated than that; a super heavy combat barge is practically useless for everything except its narrow combat role and even then it's unlikely to survive its first battle. That's a lot of wasted resources. A larger (and in all likelihood, faster) support vehicle, even if identically armed, can remain on-station longer, can travel farther and can be used for a broader range of missions than the turtle.

[FedComGirl]

It needs the protection; at 1/2 MP it can't really get away from an area; once spotted it can be attacked with impunity by the enemy. Of course, if it gets a motive hit, that's the end of it.

Yep :)

Shows how often I design big combat vees.  :D

:) I don't that often either.

Basically, yes.But it's more complicated than that; a super heavy combat barge is practically useless for everything except its narrow combat role and even then it's unlikely to survive its first battle. That's a lot of wasted resources. A larger (and in all likelihood, faster) support vehicle, even if identically armed, can remain on-station longer, can travel farther and can be used for a broader range of missions than the turtle.

That's true. It does have narrow uses but it would require a lot of resources to be spent fighting it. Unless the attacker has Warships or uses nukes it could take a lot of others with it.

[Fireangel]

That's true. It does have narrow uses but it would require a lot of resources to be spent fighting it. Unless the attacker has Warships or uses nukes it could take a lot of others with it.

Not really. with an MP of 1/2, the super heavy barge simply can't go very far in a hurry; far fewer resources are needed to neutralize one as a threat than are needed for a faster vessel that can stay out at sea for weeks or months at a time.

[FedComGirl]

Except when one needs to go through that threat or that threat can reach out and swat you. Other than those situations though faster is better.

[truetanker]

Just curious, can one make a Catamaran - style hull in BT?

HSV-1 Joint Venture and HSV-2 Swift are examples of US Navy catamaran ships.

TT

[Fireangel]

Except when one needs to go through that threat or that threat can reach out and swat you. Other than those situations though faster is better.

Given the lack of mobility, one might consider a fixed emplacement instead. There are some very tight niches where a 1/2 MP naval unit might be just what the doctor ordered, but for 99.999% of applications it is just a target waiting to get sunk.

Just curious, can one make a Catamaran - style hull in BT?

HSV-1 Joint Venture and HSV-2 Swift are examples of US Navy catamaran ships.

TT

In BT, naval hulls come in three varieties: "displacement hull", "hydrofoil" and "submersible". The actual form it takes is irrelevant for game purposes; the number or arrangement of hulls is purely a matter of fluff. The 100,000-ton Luftenberg is a multi-hull arrangement as seen in its official art.

[FedComGirl]

truetanker like Fireangel said you can but it'd be a fluff only thing.

Given the lack of mobility, one might consider a fixed emplacement instead. There are some very tight niches where a 1/2 MP naval unit might be just what the doctor ordered, but for 99.999% of applications it is just a target waiting to get sunk.

yep

[truetanker]

Thanks Fireangel...

What would the maximum tonnage one can build a floating city? Say each " Ship " equals a city block?

Just curious is all, my books are packed away for the season.

TT

[Weirdo]

Go for a mobile structure. You don't track tonnage per se, but you can get some HUGE multi-hex units going, and they can be made submersible too if you want to go all out. 8)

[truetanker]

So what your saying is that I can build a Leviathan II as a submersible Mobile Structure, right?  ;)

TT

[Weirdo]

Yaknow...it might be possible.

You have a mission now.

[truetanker]

Well if I am going to create this monstrosity, a little help might be in order. First just how tall in levels should it be? And how am I going to create a massive enough enginespace to even move the damnable thing?

And can you even fire Naval energy weapons and Capital Missiles from just below surface level water ala Polaris?

TT

[Moonsword]

There's no exception to the general rule about not firing across the water line in the surface-to-orbit fire rules, so I'm going to have to say no, especially given the difficulties you already face firing across the space/atmosphere interface.

On a realistic level, missiles are probably doable (if possibly eating an accuracy penalty), but I have a feeling that trying to fire beam weapons through three different operating environments is going to jerk the penalties to the point the rules may say no for the sake of not having to say no with math that makes the shot impossible.

[FedComGirl]

Well if I am going to create this monstrosity, a little help might be in order. First just how tall in levels should it be? And how am I going to create a massive enough enginespace to even move the damnable thing?

Construction rules are in Tactical Operations. If you have it.

And can you even fire Naval energy weapons and Capital Missiles from just below surface level water ala Polaris?

Yes. The PDF Tactical Operations says, 

Fully submerged units may not attack units above the Water Line, unless they are equipped with Capital Missiles (see p. 103, SO), Cruise Missile (see p. 179) or multi-purpose missiles (see
p. 229, TW).