Logistics in the Pacific during WW2

[locarno24]

Well - we don't really know from that perspective. Depends who's doing the blockading, and what your perception of traveller sensors tech is. Wide baseline sensors (orbital 'emplaced' sensors and system wide sensor buoys networked together will have orders of magnitude more sensitivity than anything slung off the hull of a combat-capable battlewagon.


Picking up a ship accelerating hard on IR is probably not that hard as its reactor must be running hot. Matching velocity well enough to board or exchange extended fire....different requirement.

There's also the question of whether there's a 'jump flash' - when a ship jumps, it essentially creates a pocket universe, inflates it, and floats off in its own little soap bubble - said jump bubble will probably also catch its fair share of backdround radiation plus the exotic particles that are mentioned in passing in some descriptions I've seen of traveller jump physics. All of these will get dumped into the destination system when you jump in and the bubble 'pops'.


But yes, logistics and tankage capability, along with self-repair capability will be vital for traveller fleets. Given that it takes a week for news to arrive, and another for supplies to be sent back, plus no ship with meaningful combat ability can carry two decent-range jumps worth of fuel due to giving up half its volume to tankage space, supporting tankers, fuelling ships, spares freighters, etc, will be vital - especially for things like frontier cruisers and strikerons using strike cruisers and strike battleships to drop in 'behind the lines' using jump-5+ ships.

 

[Rick]

Yes indeed, for an Imperial fleet that has to be able to hit any system.

Now consider a less well-equipped fleet. Assume it picks a target system with a gas giant (or more) - its first target will be to fight for control of the gas giant(s), at which point it doesn't need extensive tanking, has a bridgehead in the target system and a base to expand from.
The opposition, on the other hand, has just found out jump fuel is a limited resource and needs all it can lay its hands on - even to the point of seizing fueled-up civilian ships, or pressing them into service if they're armed.

 

[locarno24]

Now consider a less well-equipped fleet. Assume it picks a target system with a gas giant (or more) - its first target will be to fight for control of the gas giant(s), at which point it doesn't need extensive tanking, has a bridgehead in the target system and a base to expand from.

True - plus it's probably easier to secure a 'bit' of a gas giant - a gas giant's 100d region is so damn huge, and usually their local region is so complex with rings, moons, etc, that the idea of any sort of fixed defence is not going to work.

The counter to that is that it's one of the easiest places to 'hide' defenders - the idea of SDBs playing U-Boat by either hiding in the upper atmosphere of landed on smaller planetoids and ambushing refuelling ships is a classic traveller tactic; whilst a gas giant is one of the most tactically useful bits of space to take (aside from the mainworld), it's also one of the most dangerous to try and exploit.

 

[Condottiere]

With a gas giant, fuel is not a limited resource.

Access to fuel depends on how much the defending system government is willing to invest on defence forces deployed there.

The moons could have deep site meson guns, with the SDBs provide uptodate targetting information.

 

[phavoc]

This line of discussion begs the long-requested answer to the issue of 'high guard', and the stated vulnerability of a ship doing refueling. Combat in the atmosphere of a gas giant has never been well explained, nor has function of the HIgh Gaurd, other than supposedly stooging above the section of the gas giant that other ships are doing their refueling in.

Fleet trains, with their often extensive supply and repair capabilities, would accompany major fleets into enemy territory. Or they would set up shop in a nodal system that other fleets would return to for resupply and repairs.

All of these questions belong in a naval module, if anything just for players to have the background on fleet ops. TCS didn't really get this far.

 

[Rick]

With a gas giant, fuel is not a limited resource.

Access to fuel depends on how much the defending system government is willing to invest on defence forces deployed there.

The moons could have deep site meson guns, with the SDBs provide uptodate targeting information.

So, how long does it take to find a supplier, raise the cash and buy the guns, build the gun sites, along with all associated targeting infrastructure, increase the size of your SDB fleet and do all that between finding out that a neighbouring system wants to invade, to its fleet's turning up guns blazing (metaphorically speaking). If the systems aren't actually at war or shooting at each other, the most a system will probably have to deal with is pirates; for which massed meson guns and wall-to-wall SDB's might seem to be an expensive over-reaction. No - most systems, unless they're living with the constant threat of invasion, probably wouldn't have extensive defences like that.

 

[Condottiere]

To reiterate, it depends on how much a government wants to invest in system defence, which includes denying access to easy sources of fuel.

The smallest meson gun costs a base two trillion schmuckers, but has to be taken out first or at least it's eyes and ears, otherwise dedicated tankers will be obliterated, while warships have to risk combat damage, without being able to reply.

 

[Rick]

To reiterate, it depends on how much a government wants to invest in system defence, which includes denying access to easy sources of fuel.

The smallest meson gun costs a base two trillion schmuckers, but has to be taken out first or at least it's eyes and ears, otherwise dedicated tankers will be obliterated, while warships have to risk combat damage, without being able to reply.

A government that's interested only in defence is going to be spending the minimum amount it can. Why buy Meson guns if you've only ever had to deal with pirates and low level threats up to this point? They'll have some SDB's that can double up as outlying customs/patrol vessels, a few agile, fast interceptors to deal with anything that gets through the SDB's and probably satellite defences around the main world, possibly some around the Gas Giant(s) as well if their Navy can exert enough pressure on the government.

 

[locarno24]

Indeed.
SDBs are more flexible in that they can be essentially over-gunned customs vessels and do any of the other jobs a system fleet might need (rescue, cartography, hell - even supply runs between orbital installations).

The problem is that even the best SDB is unlikely to match up to a jump-capable warship, because by the time you expend cruiser or battlecruiser money on a hull, you might as well make it jump-capable and actually have some ability to project power. They should be able to make mincemeat of fleet train ships, though.

Deep-site meson guns are hella expensive, but provide very impressive fixed defence around a given area. The problem is the sheer volume of space you're trying to protect - 'covering' a mainworld with a gun is one thing, but covering a gas giant from one of the gas giant's moons is quite another.

 

[phavoc]

Indeed.
SDBs are more flexible in that they can be essentially over-gunned customs vessels and do any of the other jobs a system fleet might need (rescue, cartography, hell - even supply runs between orbital installations).

The problem is that even the best SDB is unlikely to match up to a jump-capable warship, because by the time you expend cruiser or battlecruiser money on a hull, you might as well make it jump-capable and actually have some ability to project power. They should be able to make mincemeat of fleet train ships, though.

Deep-site meson guns are hella expensive, but provide very impressive fixed defence around a given area. The problem is the sheer volume of space you're trying to protect - 'covering' a mainworld with a gun is one thing, but covering a gas giant from one of the gas giant's moons is quite another.

Interesting idea - siting meson guns on the moons of a gas giant. I wonder what it would be like for an incoming fleet to simply target moons and blindly fire their meson weapons to try and disable/destroy deep sited guns. Probably not very efficient, and it really depends on the size of the moon. Hiding your power source would probably be more of an issue.

According to the original rules, SDB's lurking in a gas giant's atmosphere could play holy hell with refueling ships, not just the tankers. Which is where the term High Guard came about. But just how and why a refueling ship is more vulnerable has never been published.

 

[Condottiere]

Like I said, it's a question of investment.

You might see this if the primary world is an asteroid belt; they'd certainly be interested in protecting their gas station.

 

[Rick]

Indeed.
SDBs are more flexible in that they can be essentially over-gunned customs vessels and do any of the other jobs a system fleet might need (rescue, cartography, hell - even supply runs between orbital installations).

The problem is that even the best SDB is unlikely to match up to a jump-capable warship, because by the time you expend cruiser or battlecruiser money on a hull, you might as well make it jump-capable and actually have some ability to project power. They should be able to make mincemeat of fleet train ships, though.

Deep-site meson guns are hella expensive, but provide very impressive fixed defence around a given area. The problem is the sheer volume of space you're trying to protect - 'covering' a mainworld with a gun is one thing, but covering a gas giant from one of the gas giant's moons is quite another.

Again, why on earth would you go to the expense of buying meson guns if you don't expect to ever need them? If you've only faced threats that SDB's can handle, why would you think you need meson guns? Meson guns are the weapons you buy if you are either completely paranoid or realistically under threat by jump capable big fleets - it'd be like Jamaica buying nuclear missiles 'just in case' Haiti got a bit aggressive! :twisted:

 

[Condottiere]

'Cos if you know or suspect the other guy has got mesons up his sleeve, you have to really commit enough forces to overwhelm it.

Otherwise, you'll have to go around it, because a battle of attrition will favour the defender.

 

[PsiTraveller]

Locarno24: "The problem is that even the best SDB is unlikely to match up to a jump-capable warship, because by the time you expend cruiser or battlecruiser money on a hull, you might as well make it jump-capable and actually have some ability to project power. They should be able to make mincemeat of fleet train ships, though."

I'll argue the point on the other side of this. I think that defense has a lot more advantages and a system can spend money very smartly to create a real problem for attackers, by several methods.

The challenge for ships as currently built by the Navy is that a Jump 4 warship built to project power loses 50 percent of its volume to engine and fuel. An SDB of the same tonnage has just as many hardpoints but can have more armour (if the Jump ship did not max out armour, again, it depends on which build you are using). So a 10 000 Ton Jumpship has 5000 tons of fuel and engines whereas a 10 000 SDB monitor can have 5000 tons of extra large bays, or a launch tube full of drones or fighters and staterooms for pilots to increase missile volley number and weight. 5000 tons is a lot of space to pack extra nastiness.
Not having a Jump engine on a 10 000 ton ship saves 15000 MCr to spend on attack and defensive capacity for the same hull, or planetary defense platforms to deter attackers.

If you don't mind giving up 20 percent of the tonnage but saving a lot of money per ton you can go planetoid and get 2 armour upfront. The cost drops by a factor of 12.5 for planetoid ships. You might be able to afford 2 ships for the price of 1 attacker. As per Condottiere pointed out about an asteroid based primary. They may well have cheap rocks to throw engines in and defend their turf.

If the attacking Navy went to Drop Tanks things change and the attacking ships could be within 10 percent of the hull capacity, minus whatever they kept as a reserve for emergency Jump fuel. I am writing up such a squadron right now for the TAS program. It is not done yet, but I have been noodling around with SDB vs Jumpship combat. There are some very interesting implications for a ship being jump capable.

 

[Rick]

'Cos if you know or suspect the other guy has got mesons up his sleeve, you have to really commit enough forces to overwhelm it.

Otherwise, you'll have to go around it, because a battle of attrition will favour the defender.

All you've done is dodged the question and talked straight past me again.
I agree with you in that, if a system knows it's likely to be attacked by a rival system then it does make sense to invest in meson gun sites, if said rival system was stupid enough to broadcast its intentions far enough in advance that the target had time to build them.
But the question I've been trying to get you to answer is if a system doesn't feel it is under threat of attack, has only had to deal with pirates in the past, why would it feel the need to build meson gun sites?

 

[PsiTraveller]

A system might feel the need if the geography of the Main made it necessary for a system to have a very strong defense. It may not even be a system level decision, but could be way up the chain geographically. The Central Navy command analyses the trade and travel patterns and decides system X is a strategic location and needs to be defended to keep logistical lines open. The Sector coughs up the money and the Meson site, and a bunch of SDB's are carried into the system.

Planets that are chokepoints along a Main are ripe for heavy defense of all sorts. It denies freedom of movement to the enemy and allows ease of movement to your forces.

 

[Rick]

A system might feel the need if the geography of the Main made it necessary for a system to have a very strong defense. It may not even be a system level decision, but could be way up the chain geographically. The Central Navy command analyses the trade and travel patterns and decides system X is a strategic location and needs to be defended to keep logistical lines open. The Sector coughs up the money and the Meson site, and a bunch of SDB's are carried into the system.

Planets that are chokepoints along a Main are ripe for heavy defense of all sorts. It denies freedom of movement to the enemy and allows ease of movement to your forces.

True again, but then the meson guns will be sited to cover the navy base and refuelling posts, be bought by the Imperium and have little to do with the system main world.
But lets assume that these are 2 relatively remote systems, away from the main hub of the Imperium and the major trade routes; after all, who's going to invade another system when the Imperial Navy is breathing down your neck? System A is more aggressive and wants to invade system B, which is unaware of the plans for the moment. System A could start a massive fleet building and meson gun emplacement program, but this will tip off system B, who will start doing the same, no doubt, as they'd have a realistic expectation of aggression and/or invasion. But if system A was clever and built up its forces covertly, then why would system B feel the need to have meson guns?

 

[PsiTraveller]

Also true. Covert plans may allow an element of surprise.

In the end it will be up to the GM to develop and justify whichever action they decide to take. Arguments can be made for both sides.

 

[Nathan Brazil]

But the question I've been trying to get you to answer is if a system doesn't feel it is under threat of attack, has only had to deal with pirates in the past, why would it feel the need to build meson gun sites?

The Virus Novels have that as an ongoing fear. They are known relics of the Third Imperium. The world (Promise, I think), on which Sandman resides is far from the borders of the Imperium. But it was built pre-Virus. So who were they built to defend against?

My suggestion is as defense for big things like The Civil War, or because the novel was in Diaspora Sector, maybe the Solomani or Zhodani in other areas. The Meson sites are not generally for anti-piracy. They are overkill as you suggest if it is JUST anti-piracy. I suggest they are there for the big stuff like existential threats to the Third Imperium.

Since this started as a WWII thread, think of them as more useful outposts, but at least not a Maginot Line :roll: .

 

[phavoc]

Maginot line...in spaaaaaccccceeeee! not sure what the stellar equivalent of a forest should be.

Fixed defenses make sense if you have a risk to the planet. In the general imperium they would be hard pressed to justify more than a token defense of a planet using fixed defenses - unless they were potentially in range of raiders from anothe major space polity. Planets along the Solomon Rim could be justified in having them. Likewise important planets in the Marches, or near the Aslan. But in general credits would be better spent on mobile system defenses that could also function in other areas - much like the described function of SDB's.

But getting back on topic a bit, logistically navies in the 52nd century seem to have relatively short legs. While you can frontier refuel and extend your operating radius, I don't see any of the published designs wirh much cargo storage for food, parts, supplies, etc. Some of which could be handled by a fleet train, but since logistics isn't sexy we really don't see much of this anywhere in the materials.

I know some argue that tech allows them to recycle the aur, water and even food, and with 3D printing they just recycle parts and print new ones. All reasonable assumptions for the 52nd century, but not practical when you take a step back from it all. If tech is that good, why the continual need for expansion and exploitation of other systems? I'm pretty sure they would have solved the people problem if they solved the resource problems too.

I think that none of this was thought about, which is reasonable since it's supposed to be an RPG, and I have to admit I've never met someone who wanted to role play an economist or central banker...