Invictus class weight questions

Weird Harold wrote:
(deletia)

That would be a question to ask RFC. FWIW, read up on the "Great Resizing" for the exact fluid used for figuring displacement of spaceships; it isn't water is all I remember.

The density of whisky is about .94, so you would have to take that into consideration.

Weird Harold wrote:So in the 44th century they classify ships by how much water they would displace? Why not just say Cubic meters?

That would be a question to ask RFC. FWIW, read up on the "Great Resizing" for the exact fluid used for figuring displacement of spaceships; it isn't water is all I remember.[/quote]

It is water by definition as he is using the SI system. 1kg is defined by water in earth's gravity.

As to why not say Cubic meters? Simple actually, because when he first started writing the series he started with mass... in kg... without a definition of volume/density. Then along came the observation that his ships were the density of smoke and that foopah. Then along came CLAC's/SD'P's/Tractored pods and why ships do not increase acceleration. To DIG HIMESELF out of the hole, he came up with compensator field which he had ALREADY semi defined in earlier books and then tied the compensator efficiency/field TO THE VOLUME, and not true "mass". Therefore the "mass" in said field just adds/subtracts "stress" on the impeller nodes.

Ultimately, the total mass, would eventually prove to great on the impeller nodes and here I would assume they would "burn out". For instance if you had a solid gold ship, it would be ~19X the true mass of a nominal 8M ton compensator field which is set at 250kg/m^3 which is actually fairly close to shipping tonnages for containers here on earth... 1 TEU = ~40 m^3 = ~10 tons So, for those who can't do the math... 10tons/40m^3 = 250kg/m^3 or EXACTLY what RFC set his ships density to... A standard TEU shipping container here on earth...

I seem to vaguely recall an RFC post which I cant currently locate to the effect that when the compensator is constructed, the parameters for mass and volume are set for a fully loaded ship.

Thus, a freighter cant go faster when it is empty because the compensator is permanently set for a loaded ship.

Relax wrote:

Weird Harold wrote:So in the 44th century they classify ships by how much water they would displace? Why not just say Cubic meters?

That would be a question to ask RFC. FWIW, read up on the "Great Resizing" for the exact fluid used for figuring displacement of spaceships; it isn't water is all I remember.

It is water by definition as he is using the SI system. 1kg is defined by water in earth's gravity.

As to why not say Cubic meters? Simple actually, because when he first started writing the series he started with mass... in kg... without a definition of volume/density. Then along came the observation that his ships were the density of smoke and that foopah. Then along came CLAC's/SD'P's/Tractored pods and why ships do not increase acceleration. To DIG HIMESELF out of the hole, he came up with compensator field which he had ALREADY semi defined in earlier books and then tied the compensator efficiency/field TO THE VOLUME, and not true "mass". Therefore the "mass" in said field just adds/subtracts "stress" on the impeller nodes.

Ultimately, the total mass, would eventually prove to great on the impeller nodes and here I would assume they would "burn out". For instance if you had a solid gold ship, it would be ~19X the true mass of a nominal 8M ton compensator field which is set at 250kg/m^3 which is actually fairly close to shipping tonnages for containers here on earth... 1 TEU = ~40 m^3 = ~10 tons So, for those who can't do the math... 10tons/40m^3 = 250kg/m^3 or EXACTLY what RFC set his ships density to... A standard TEU shipping container here on earth...[/quote]
It is not water. From "House of Steel"
Reliant-class battlecruiser (Flights III-IV)
Mass: 934,250 tons
Dimensions: 727 × 92 × 82 m

A honorverse ship is wider than tall, but necks down, so tha actual area should be close to a cyclindar the max height of the ship, or 82M in diameter 727M long has an are of 3,839,299 cubic meters. One cubic meter of water is one ton, or about 1/4 the density of water.

Most water ships have more of their hull above water than below water, so the great resizing would put a honoverse ship as the same volume. As an example a courier boat or frigate would be the biggest ship that would fit into the panama canal.
Tonnage: 52,500 DWT
Length: 289.56 m (950 ft)
Beam: 32.31 m (106 ft)
Height: 57.91 m (190 ft)
Draft: 12.04 m (39.5 ft)

and the new panamax would corrispond to an old light cruiser, as theroland would not fit.

Length 366 m (1,200 ft)
Width 49 m (161 ft)
Draft 15.2 m (50 ft)

tonnage approximatly 150K tons

darrell wrote:One cubic meter of water is one ton, or about 1/4 the density of water.

Someone hasn't used Jr. High Science class in a while...

1kg water = 1L
1000L of water = 1 CUBIC meter
1000kg = 1 TON

250kg/m^3 is effectively the maximum density allowed in a TEU which oh so "coincidentally" just happens to be density used by RFC and Bu9 when designing the ships in the Honorverse in HoS...

Both of which are tied directly to the density of water...

Relax wrote:

darrell wrote:One cubic meter of water is one ton, or about 1/4 the density of water.

Someone hasn't used Jr. High Science class in a while...

1kg water = 1L
1000L of water = 1 CUBIC meter
1000kg = 1 TON

250kg/m^3 is effectively the maximum density allowed in a TEU which oh so "coincidentally" just happens to be density used by RFC and Bu9 when designing the ships in the Honorverse in HoS...

Both of which are tied directly to the density of water...

BuNine has already done the math:

Mission of Honor CD wrote:The Great Resizing

One of the first interactions with David that we had was trying to rationalize a ship design engine that could be used to make ships in the game. We started with the mass and acceleration curves in the appendix at the back of On Basilisk Station, and then started working out (from the lengths, and Russ Isler’s drawings) volumes.

As a general rule, if the outer shape remains the same, linear dimensions go up at the cube root of volume. In David’s books, we had superdreadnoughts running at around 65x the mass of destroyers…and were roughly 11x the linear dimensions, when they should have (assuming equal density) been about 4x the length/width/depth. (The cube root of 65 is a smidge over 4.) Clearly, something was amiss – to keep the listed dimensions and the listed mass, the superdreadnought needed to have its density drop by a factor of 20, which would make it not quite as dense as cigar smoke.

So, with great trepidation, we approached David with the fact that we’d found an error. He said that, yeah, someone had pointed that out to him in book four or thereabouts, which was part of the reason why he’d stopped putting in quite so many specifications on ships, along with the fact that Honor was focusing more on being an admiral rather than direct ship handling.

Taking the listed dimensions of a Reliant-class battlecruiser (HMS Nike), we built a spreadsheet to calculate the approximate volume That spreadsheet was later generalized to estimate the volume of an entire range of ship sizes using the basic Honorverse hull form, with parameters that could be set for different length-to-beam ratios, hammerhead sizes and even the shapes of the hammerheads. After presenting David with a range of options for hull density, he agrees that a density of 0.25 as an average for a fully loaded ship was about right for the setting.

Reliant Class image omitted due to image size restriction on davidweber.net, available at webpage link above.

From there we were able to generate a new size chart that showed the two acceptable options; either keep the dimensions the same as the books and adjust mass or keep the mass the same and adjust dimensions.

At the same time, we did a thorough search of all of the books to find all references to length or mass. While there were perhaps two dozen length references that would need to be changed over the entire series, there were over a dozen mass references per book. This, combined with the fact that David’s own shipbuilding system was mass based, led to the decision to . x mass as a constant and adjust lengths to match.

Boldface and underlined text is my emphasis.

Relax wrote:

darrell wrote:One cubic meter of water is one ton, or about 1/4 the density of water.

Someone hasn't used Jr. High Science class in a while...

1kg water = 1L
1000L of water = 1 CUBIC meter
1000kg = 1 TON

250kg/m^3 is effectively the maximum density allowed in a TEU which oh so "coincidentally" just happens to be density used by RFC and Bu9 when designing the ships in the Honorverse in HoS...

Both of which are tied directly to the density of water...

I was responding to a quote by Brigade who wrote: So in the 44th century they classify ships by how much water they would displace? Why not just say Cubic meters?

sorry sloppy posting. Instead of saying or 1/4 the density of water I should have said Honorverse ships are 1/4 the density of water.

if you look at it, as written it says that water is 1/4 the density of water, a contradiction in terms.

Relax wrote:

darrell wrote:One cubic meter of water is one ton, or about 1/4 the density of water.

Someone hasn't used Jr. High Science class in a while...

1kg water = 1L
1000L of water = 1 CUBIC meter
1000kg = 1 TON

250kg/m^3 is effectively the maximum density allowed in a TEU which oh so "coincidentally" just happens to be density used by RFC and Bu9 when designing the ships in the Honorverse in HoS...

Both of which are tied directly to the density of water...

Just nitpicking, but 1000kg= 1 tonne = 2204lbs
1 ton = 2000lbs or 2240 lbs depending on whether Imperial or American