The big problem of late Honorverse

Theemile wrote:Compensators actually work on a volume of space, not an actual mass. It's just a ship of x mass fills said volume. Empty or full, everything inside the volume is compensated.

This is described in ACD, where we see the Sub-optimal havenite designs with spin sections, and slower speeds are accepted for a wider compensated volume.

The reason for the mass statements is the Great Resizing, where mass was the only dimension kept from the early books to the latter books.

Ok, so when we hear that 9 or 10 million tons is the current upper practical limit for a ship's size, it's not due to the mass of the ship actually being that size, it's because a ship of the maximum practical size typically has that mass. That is, ships tend to keep to an average density across all volumes.

I'm not sure this makes sense. I'd expect the biggest portion of the mass of a ship to be its hull, especially the armour for a warship. Given the square-cube law, you'd expect that the fraction of mass dedicated to the armour to decrease as the volume of the ship increases. Internal spaces start to take a bigger proportion and those have much smaller density. Even missile and other ammunition shouldn't mass as much as armour. The only thing I can think of that could even come close to that density is highly-compressed hydrogen -- if you can use gravity to compress it to fusion, you can compress it to less than fusion and just pack a lot of it.

It's more likely it's like Jonathan_S said and the mass assumes a constant density for historical reasons which may not apply anymore. Let's take these figures:

Jonathan_S wrote:I don't think you're right about the freighters being listed as their loaded weight. I'm using the numbers of the Starhauler class listed in the SITS books. A small modular freighter for Silesian trade is a 1.9 mton design, 767 m long, 128 m across, and 119 m tall.

Assuming an elliptical cross-section and modelling the entire ship as a cylinder, that would give an a volume of 767*128*119*π = 36.7 million m³ and an average density of ~47 kg/m³ (less than half as dense as wool, slightly more than polyurethane foam). Those numbers only make sense if the volume is mostly air (1.225 kg/m³ at STP) or even vacuum. In turn, if the 1.9 MT is mostly hull and the hull material clocks at 10,000 kg/m³ (more dense than iron), volume occupied by the hull is 190,000 m³. That's 0.5% of the total volume. Or, again assuming our perfect cylinder, it would mean the hull is between 8.5 and 9 m thick.

That makes sense to me.

Now, of course, a warship's armour is likely to be thicker and denser than a freighter's hull.

David has said in multiple places they are using liquid hydrogen, which has a density 1/14th as much as water. Liquids don't compress well.

Hydrogen gas has a density of .084 kg/m3. So at 12 bar it's at 1kg per cubic meter. So at 12,000 atmosphere it's as dense at water. And water is neither a cryo fluid nor explodes violently when you poke a hole in the tank like say a 12,000 bar tank of hydrogen will. A SCUBA tank is typically at 200 bar, and will cause some serious damage when it fails. Kind of like this one: https://jalopnik.com/what-a-car-looks-l ... -706539520

Theemile wrote:Compensators actually work on a volume of space, not an actual mass. It's just a ship of x mass fills said volume. Empty or full, everything inside the volume is compensated.

This is described in ACD, where we see the Sub-optimal havenite designs with spin sections, and slower speeds are accepted for a wider compensated volume.

The reason for the mass statements is the Great Resizing, where mass was the only dimension kept from the early books to the latter books.

I'm not convinced you could fill an 8 mton freighter with 30 or 40 mtons of lead ingots and not affect its acceleration.

In warships I agree they're never dense enough for mass to mater; it's all volume. But I still believe the early statements in the books that mass can also matter -- I just think it only happens with pretty high densities where you've got a lot of mass concentrated in a relatively little volume.

ThinksMarkedly wrote:I'm not sure this makes sense. I'd expect the biggest portion of the mass of a ship to be its hull, especially the armour for a warship. Given the square-cube law, you'd expect that the fraction of mass dedicated to the armour to decrease as the volume of the ship increases. Internal spaces start to take a bigger proportion and those have much smaller density. Even missile and other ammunition shouldn't mass as much as armour. The only thing I can think of that could even come close to that density is highly-compressed hydrogen -- if you can use gravity to compress it to fusion, you can compress it to less than fusion and just pack a lot of it.

Actually reading the armor essay in the anthology 'In Fire Forged' Honorverse armor doesn't sound all that high density - certainly far less so that the armor of a 20th century battleship.

It's apparently made up of a Boundary layer of silica carbide/tungsten carbide sometimes mixed with iron; then fairly broad layers of aerogel like material "in the lowest possible density" make of lighter elements as energy scattering materials, backed by the structural battlesteel. (Actually on heavier warships I think you get a layercake of boundary / scatter / boundary / scatter until you reach the hull.

Sounds like a warships hull+armor would actually be less dense, on average, (but much thicker) than a freighters because the freighter would just be high strength steel or whatever while the warship also has thick layers of low density energy absorbing materials within its armor.



Also remember that as you scale up warship you also begin adding additional internal armor belts; such as the ones around the core hull that BCs and some CAs have. And then with the latest SD(P)s a 3rd armor belt armoring the walls of the pod bay. So the cube square law doesn't help you as much as you might first think because the ship designers keep using that interior volume to add more interior armor.
Also warships also have lots more passage ways, crew quarters, and maintenance areas around equipment than freighters. That's lots of mostly air to reduce their density - whereas once you fill a freighter's hold there's not much free area left because freighters are mostly hold.

Jonathan_S wrote:Also remember that as you scale up warship you also begin adding additional internal armor belts; such as the ones around the core hull that BCs and some CAs have. And then with the latest SD(P)s a 3rd armor belt armoring the walls of the pod bay. So the cube square law doesn't help you as much as you might first think because the ship designers keep using that interior volume to add more interior armor.
Also warships also have lots more passage ways, crew quarters, and maintenance areas around equipment than freighters. That's lots of mostly air to reduce their density - whereas once you fill a freighter's hold there's not much free area left because freighters are mostly hold.

I would expect that the larger the ship, the more full of air it would be. The problem is that we keep being told of how cramped the conditions are for junior officers and enlisteds.

Take an Invcitus, at 1394 m long, 202 m in beam and 188 m draught. If we model it on a simple cylinder 188 x 1394 m, it would have a total volume of 154.8 million cubic metres. As it "masses" , its average density is 51.4 kg/m³. Let's assign all its 8.77 million tons of mass to armour and let's say that armour has a density one tenth that of steel. That accounts for only 6.5% of the total volume. That leaves us with 144.6 million cubic metres of internal volume unaccounted for.

That actually supports the hypothesis that the mass of the ship is its completely unladen weight, no bunkerage, no missiles, probably not even any air inside. But there's still a lot of unaccounted-for volume.

Apparently all modern spaceships in the honorverse structurally are constructed from battlesteel, civilian or military. It's an extremely strong carbon nano-composite.

ThinksMarkedly wrote:The problem is that we keep being told of how cramped the conditions are for junior officers and enlisteds.

It's plot. Like the total inability to carry a squad of marines on the Roland's while they each have the offices and quaterers to operate and house a squadron command staff.

kzt wrote:

ThinksMarkedly wrote:The problem is that we keep being told of how cramped the conditions are for junior officers and enlisteds.

It's plot. Like the total inability to carry a squad of marines on the Roland's while they each have the offices and quaterers to operate and house a squadron command staff.

The Rolands have so much internal volume that their tiny crew couldn't play hide-and-seek because finding anyone would be impossible. And it must be worse in a Wolfhound, with just 97 crew. (Just imagine what mischief the crew of the GNS Francis Mueller could cause if they were aboard a Roland)

No, the reasons they have so few embarked Marines were that the RMMC was having staffing difficulties and that they didn't need Marines to complement the Navy crew during damage control. When fighting Haven during the second war, there weren't almost any boarding actions in hostile territory and Rolands didn't operate independently. This was a shortcoming that wasn't realised until Tenth Fleet dispersed in tiny packets that still kicked SLN ass.

Jonathan_S wrote:

Theemile wrote:Compensators actually work on a volume of space, not an actual mass. It's just a ship of x mass fills said volume. Empty or full, everything inside the volume is compensated.

This is described in ACD, where we see the Sub-optimal havenite designs with spin sections, and slower speeds are accepted for a wider compensated volume.

The reason for the mass statements is the Great Resizing, where mass was the only dimension kept from the early books to the latter books.

I'm not convinced you could fill an 8 mton freighter with 30 or 40 mtons of lead ingots and not affect its acceleration.

In warships I agree they're never dense enough for mass to mater; it's all volume. But I still believe the early statements in the books that mass can also matter -- I just think it only happens with pretty high densities where you've got a lot of mass concentrated in a relatively little volume.

ThinksMarkedly wrote:I'm not sure this makes sense. I'd expect the biggest portion of the mass of a ship to be its hull, especially the armour for a warship. Given the square-cube law, you'd expect that the fraction of mass dedicated to the armour to decrease as the volume of the ship increases. Internal spaces start to take a bigger proportion and those have much smaller density. Even missile and other ammunition shouldn't mass as much as armour. The only thing I can think of that could even come close to that density is highly-compressed hydrogen -- if you can use gravity to compress it to fusion, you can compress it to less than fusion and just pack a lot of it.

Actually reading the armor essay in the anthology 'In Fire Forged' Honorverse armor doesn't sound all that high density - certainly far less so that the armor of a 20th century battleship.

It's apparently made up of a Boundary layer of silica carbide/tungsten carbide sometimes mixed with iron; then fairly broad layers of aerogel like material "in the lowest possible density" make of lighter elements as energy scattering materials, backed by the structural battlesteel. (Actually on heavier warships I think you get a layercake of boundary / scatter / boundary / scatter until you reach the hull.

Sounds like a warships hull+armor would actually be less dense, on average, (but much thicker) than a freighters because the freighter would just be high strength steel or whatever while the warship also has thick layers of low density energy absorbing materials within its armor.



Also remember that as you scale up warship you also begin adding additional internal armor belts; such as the ones around the core hull that BCs and some CAs have. And then with the latest SD(P)s a 3rd armor belt armoring the walls of the pod bay. So the cube square law doesn't help you as much as you might first think because the ship designers keep using that interior volume to add more interior armor.
Also warships also have lots more passage ways, crew quarters, and maintenance areas around equipment than freighters. That's lots of mostly air to reduce their density - whereas once you fill a freighter's hold there's not much free area left because freighters are mostly hold.

Actually, I think with a freighter filled with lead, you have the opposite problem, the mounted nodes are not powerful enough to move the given mass, regardless of the compensation factor. you have two systems working in concert here, the compensator, whose field strength limits the maximum acceleration compensated, and the drive nodes, who project a wedge of sufficient power to accelerate the mass.

We already know the compensator field extends some meters from the actual hull, at least enough for the spikes of Grav arrays to be compensated, and this allows for pods and small craft to be tractored near the hull and be compensated; it isn't until they fall behind the ship, out of said field, that they become a significant drain on the ship's accel. In AAC we saw SDs tractor 400 pods - at least a million tons - to their hulls without losing accel. Some ships were designed for Pod towing with extra heavy wedges - Like the Mars B. However, we know that all warships are overpowered (to some degree) for battle redundancy, so it makes sense that an SD would have 12% extra wedge power to carry such a load.

ThinksMarkedly wrote:The Rolands have so much internal volume that their tiny crew couldn't play hide-and-seek because finding anyone would be impossible. And it must be worse in a Wolfhound, with just 97 crew. (Just imagine what mischief the crew of the GNS Francis Mueller could cause if they were aboard a Roland)

No, the reasons they have so few embarked Marines were that the RMMC was having staffing difficulties and that they didn't need Marines to complement the Navy crew during damage control. When fighting Haven during the second war, there weren't almost any boarding actions in hostile territory and Rolands didn't operate independently. This was a shortcoming that wasn't realised until Tenth Fleet dispersed in tiny packets that still kicked SLN ass.

The exterior measurements of the ship don't tell you that much about the habitable volume inside the pressure hull. Sure, a Roland has more internal volume per crew member than previous designs, but a lot of that internal volume is eaten up by two magazines full of 60 Mk 16's each, counter missile magazines, massive battlecruiser grade graser implacements, point defense clusters, impeller rooms, etc.

As for the shortcomings of not having Marines: it's not that they weren't aware of the down side of that decision, it was that they felt the trade off between losing that capability to get the maximum tonnage of warship out into space as fast as humanly possible took precedent. They were planning for a much longer war than they actually got.

Galactic Sapper wrote:

ThinksMarkedly wrote:The Rolands have so much internal volume that their tiny crew couldn't play hide-and-seek because finding anyone would be impossible. And it must be worse in a Wolfhound, with just 97 crew. (Just imagine what mischief the crew of the GNS Francis Mueller could cause if they were aboard a Roland)

No, the reasons they have so few embarked Marines were that the RMMC was having staffing difficulties and that they didn't need Marines to complement the Navy crew during damage control. When fighting Haven during the second war, there weren't almost any boarding actions in hostile territory and Rolands didn't operate independently. This was a shortcoming that wasn't realised until Tenth Fleet dispersed in tiny packets that still kicked SLN ass.

The exterior measurements of the ship don't tell you that much about the habitable volume inside the pressure hull. Sure, a Roland has more internal volume per crew member than previous designs, but a lot of that internal volume is eaten up by two magazines full of 60 Mk 16's each, counter missile magazines, massive battlecruiser grade graser implacements, point defense clusters, impeller rooms, etc.

As for the shortcomings of not having Marines: it's not that they weren't aware of the down side of that decision, it was that they felt the trade off between losing that capability to get the maximum tonnage of warship out into space as fast as humanly possible took precedent. They were planning for a much longer war than they actually got.

There wasn't a rush, it as a finished design. Bu-ships just designed a stripped down warfighter; a design that packed the most in the smallest hull while endangering the fewest crew. And as a fighting unit, it was much more capable than anything before, at an economical cost, while risking the smallest crew possible.

They just took that concept too far. In peace time, they would have slowly built a handful, deployed them, then realized the design couldn't do 1/3rd of the normal destroyer/cl jobs, then redesigned the rest. But building in wartime, they built a bunch and got exactly what was needed, while finding their peacetime limitations.

What most of us have been saying for years is why was the commodore space not be designed to be multifunctional, with the space able to be modified for a squad of Marines and equipment when the Ship isn't used as a flagship.