Ship Profiles: Feedback and Discussion

fury interceptors being bigger than thunderhawks is not adding up. because thunderhawks are slower and more resilient than furies suggests that thunderhawks have more mass. also capital ships can't carry as many thunderhawk squadrons as they can other attack craft, which also suggests they are bigger

[quote]

A ship with a Chaos Space Marine crew may be
equipped with Thunderhawk Gunships but if so
it may only carry Thunderhawks and may not
launch Swiftdeaths, Doomfires and
Dreadclaws. Furthermore the launch capacity
of the ship’s bays’ is halved (round down). This
is because the launch bays have to be
substantially rebuilt to deal with the larger
Thunderhawks pp47 in armada rulebook

it can be said that imperial attack craft and chaos attack craft are not the same size, but it is true that imperials, like chaos, can launch more attack craft than space marines

last edited by shadowsfm

Chaos attack craft are smaller but swarmier I think.

Plus Thunderhawks are higher quality warcraft and I would think they require more maintenance, parts and all that too, plus that SM launch bays also house boarding torpedoes and such, and that SM can launch less because Thunderhawks are rarer and have SM crews.

Sm stuff, like Thunderhawks, tends to be very heavily armoured. What does not add up is a Leman Russ having more armour than a Predator.

@shadowsfm You would think, but apparently nah. Blame GeeDubz/Black Library for inconsistent writing.

last edited by CALiGeR_Reborn

@imperator said in Ship Profiles: Feedback and Discussion:

@kadaeux

It does make perfect sense though, and I would think that since it has never been obviously stated to be no longer true, it is true since it fits with Imperial Engine systems.

We do know that some ships can land on planets.

Thunderhawks have plasma mode for engines in space and non plasma mode for air travel. Either to reduce stress on the reactor or to not fry the ground troops.

We also know that Imperial plasma technology operates at a hundred million Kelvins, which is very hot. You definately not want it in your starport.

Even modern day space rockets have devastating exhausts that would fry you if you stood very near them.

So for any "spaceport" to scientifially be feasible in sci fi, the ships either need to use "mass effect" like in 40k or , well, ME, or antigrav tech like in SW or ST.

It's 40k, the words scientifically feasible quite literally isn't on the cards :p also plasma drives produce less exhaust (relatively) than a chemical exhaust, look up Ion Drives. Additionally, 'mass reduction' also doesn't fit with the physics of it, it violates physics far harder and we know the Imperium has anti-gravity technology.

Planetstrike even refers to some Imperial Transports using Halo-esque gravity elevators to mass-drop troops.

Imperium's antigrav tech is always a mess.

Nobody is clear on it. Sometimes its Starwars level aircars, sometimes its LAND SPEEDER ONLY! and everything in between.

I think the gravity elevators also appeared in other places, but I'm not sure.

@imperator My two pence is that it both is and isn't rare technology.
The Imperium is a vast and non-uniform place in terms of tech and level of civilisation, so in some areas you would get Corasant-esque just-about-bearable hive cities, in other areas tribes bashing sticks together, and everything in between.

It seems perfectly logical that this translates into warships and war gear, each planet building ships and equipment that their technology and resource level can support production of. Which also neatly explains wildly varying power calculations and sizes in 40K, it can all be explained in-universe.

Uh, damn, just realised Ive been writing these ship profiles for two years now...
My first one, on the Lunar Class Cruiser, was written on the old forum back on the 4th Feb 2016...
What am I doing with my life?

why is movement speed counted in g's when you cant feel g's with the onboard grav engines
how fast is a g on a spaceship?

This post is deleted!

@ashardalon said in Ship Profiles: Feedback and Discussion:

why is movement speed counted in g's when you cant feel g's with the onboard grav engines
how fast is a g on a spaceship?

Technically g's are a measurement of acceleration on a starship as a measure of how many gravities of acceleration. A g isn't a unit of speed but of acceleration. (One G is specifically, 9.80665 metres per second squared of acceleration)

In this case, the numbers used are those basically defined by the Rogue Trader RPG and are inconsistent with the majority of material. (Said numbers were made for gameplay reasons, the same reason the ship masses are in fact exceptionally low for their size and volume.)

The more 'accurate' figures these days are relativistic velocities. For example, in Sabbat Martyr a Frigate accelerates from High Anchor (Geosynchronous orbit) to a position 9 AU (Astronomical Unit, 9 AU is about 1.2 Light Hours) in 90 minutes, giving it a top speed of approximately 80% the speed of light.

That is, travelling 9 AU in 90 minutes from a geostationary orbit....

@kadaeux I’ve seen .75c quoted as the most common cruising/Attack speed in a lot of places, novels, IA, etc.

@nemesor-xanxas said in Ship Profiles: Feedback and Discussion:

@kadaeux I’ve seen .75c quoted as the most common cruising/Attack speed in a lot of places, novels, IA, etc.

That was the direct quote used in Sabbat Martyr to describe the arrival of the Chaos Fleet. (Mind you, the Frigate, as I said, had to have pulled about .82c, and to go from Geostationary Orbit aka, High Anchor to that velocity puts them in the tens of thousands of gravities acceleration.

The Campanile accelerates.

It lights its main realspace drives, delivering main extending >thrust in a position where it should be almost coasting at >correction burst only. It raises its void shielding to make itself >as unstoppable as possible. It fires itself like a bullet at the >planet Calth.

The screams of its crew can still be heard, but no one is listening.
Main extending thrust is a drive condition used for principal acceleration, the maximum output that takes a starship to the brink of realspace velocity as it makes the translation to the empyrean. It is a condition that is used as a starship moves away from a planet towards the nearest viable Mandeville Point, a distance that is roughly half the radius of an average star system.
There is no such long run-up here. The Campanile is already inside the orbit of Calth’s satellite. There is not enough range for it to reach anything like maximum output or velocity. Even so, it is travelling at something close to the order of forty per cent of the realspace limit as it reaches the edge of the atmosphere. It is travelling too fast for anything physical, such as an eye or a pict-corder or a visual monitor, to see it. It is only visible to scanning systems and sensors, to detectors and auspex. They shriek at its sudden, savage, shockwave approach.
Their shrieks are as futile as the unheard screams of its lost crew.
It does not hit Calth.
There is something in the way.

Pg.158 Know No Fear (E-book)

“Even if the ports had remained open, there was nothing to see. You were brawling with – and being fired upon by – an object that might be thousands of kilometres away in the interstellar blackness, and moving at a considerable percentage of the speed of light.”

Salvation's Reach, p.162

“For the second time in less than an hour, space tore open. The reality fissure leapt and crackled like a luminous cephalopod, lashing tendrils of warp energy into real space that twisted out, fizzled and faded. Non-baryonic light flared brilliantly through the tear, backlighting the arriving ships. Monumental silhouettes, they were shot forward into real space. Four ships, one of them very large. And they were moving. Point seven five light at least, cutting straight towards Herodor. They did not slow down. They were moving at cruise speed. Attack Speed.”

The Saint: A Gaunt's Ghosts Omnibus, p.893 & 894

“Several light minutes inside the orbit of Eri, the Phalanx exploded from a warp gate with violent concussion, sending sheets of exotic lightning radiating out and away into the void. Delicate sensory devices dotting the surface of the tenth planet registered the new arrival and immediately communicated reports to relay stations on Pluto and Uranus, where in turn they would be sent onward by astropath to Terra and her dominions. The return of the Imperial Fists to humanitys cradle was long overdue. By rights there should have been celebrations and great ceremony on many of the outer colonies of the solar system to mark it. Instead, the Phalanx came in with speed and ruthless purpose, not in a stately cruise around the solar systems outlying worlds.

The mammoth craft did not fly the pennants and banners associated with the triumphant arrival of a heroic vessel. Instead, the colour on her masts and the laser lamps about the Phanalxs circumfrence were lit for urgency. Patrol ships made way, no captain daring to challenge the Master of the Imperial Fists for his haste. Drives flaring like captured stars, the fortress-vessel passed in through the ragged edge of the Oort Cloud at three-quarters the speed of light, down into the place of the ecliptic, crossing the orbit of Neptune in a flicker of dazzling radiation.”

Flight of the Eisenstein, p.278

“Close-range lascannons on the hull of the drive module blew apart the paper-thin sheath of metals hiding the aft section of the ship, and the Ultio's drive section blasted free of the station wreck in a pulse of detonation. Fusion motors unleashed the tiny suns at their cores and pushed the craft away, climbing the acceleration curve in a glitter of void shields and displaced energy. In moments, the vessel was rising to one-quarter lightspeed.”

Nemesis, p.482

"‘Contact echo, sir,’ the tracking officer replied. ‘An object just appeared on the scopes, inbound to 42 Hydra Tertius.’
‘Appeared?’ Van Aunger repeated.
‘I don’t understand it, sir,’ the tracking officer replied, adjusting his control panels with fast, expert hands. ‘There are no energetic or magnetic profiles that would suggest a real space translation. The object just appeared. I speculate that it was previously cloaked.’ ‘Track it and project, full assessment,’ Van Aunger ordered.
‘Yes, sir,’ replied the officer.
‘General quarters!’ Van Aunger called out. ‘Shields and batteries to stand by!’
A klaxon started to sound. The bridge staff, over a hundred officers, bustled to their stations, their voices overlapping as they exchanged data and instructions.
‘Trajectory projection!’ the tracking officer announced.
‘Main display,’ Van Aunger replied.
The primary hololithic display lit up with a complex graphic diagram of the planet, the position of the fleet components, and the sweeping vector of the object.
‘That will take it directly to the venue zone,’ Van Aunger murmured. ‘Have you identified vessel type or designation?’
‘Negative, sir,’ the tracking officer replied. ‘It doesn’t even read like a vessel. It’s inert on all scans. It’s… oh Terra…’
‘What?’
‘I’m marking it in excess of point eight superluminal, and it’s big, sir. It’s at least as big as we are.’"

Pg.522 Legion

Warp technology permitted travel at tremendous – albeit relativistic – inherently incalculable speeds, but intra-system transit remained as arduous as it must have been in the pre-expansionist epoch. At their current relative positions, Thennos was five light hours from Medusa. From the vibrations in the decking, Stronos could tell that the Clan Vurgaan system frigate, the Onslaught, was still accelerating towards its maximum velocity, about ninety-five per cent of light speed. One day there, a few hours to convince the Iron Council of the logic of rescinding their interdiction orders, and then one day back. Stronos would be back with his clave before the order to push out passed through the interlink manifold.

Eye of Medusa

last edited by Kadaeux

A correction on the Caestus Assault Ram lore: It has been in service in substantial numbers since the Great Crusade, not since M39.

@hjalfnar_hgv Ah crap, my fault!
Was late and read M31 as M39 and thought 'hmm, must be fairly modern then'. Double reading I realise that was a total brain fart.

@kadaeux There is a difference between max/accelerating speed and the speed you actually fight at (ie: cruising/attack speed). Actually, you quoted one of those .75s. Do you know if there is a higher showing than eye of medusa's .95c, or is that the fastest sublight the imperium has a showing for?

@nemesor-xanxas said in Ship Profiles: Feedback and Discussion:

@kadaeux There is a difference between max/accelerating speed and the speed you actually fight at (ie: cruising/attack speed). Actually, you quoted one of those .75s. Do you know if there is a higher showing than eye of medusa's .95c, or is that the fastest sublight the imperium has a showing for?

There is certainly a difference between max acceleration and the speed you fight at. As I said, the same source for the .75c as Attack Speed flat out demonstrates thousands of gees of acceleration when a ship goes from Geosynchronous orbit and crosses 9AU in 90 minutes.

Over 9 AU in 90 minutes from a geostationary postion the ship had to undergo a maximum of 18'845.8 gees of acceleration (this assumes flipping halfway to decelerate back to a relative stationary velocity.) (With a maximum velocity of .857c)

However, as far as I know .95c is the highest known stated velocity we've seen from the Imperium.

@kadaeux well, yes any ship that could travel close to light speed would have to have similar acceleration or it would take days to get to and from its speeds. I was never trying to argue that, just contribute my knowledge of speed (not sure if I communicated that properly). The old rouge trader figures mean very little now, with most of that stuff being retconned as years went by, legion sizes for example increased. Gees is kind of nebulous as similar to firepower it’s not really explicitly stated anywhere in the newer material what it is, like firepower, so you have to math it (or maybe it is and I missed it from space marine novella 305 or somesuch).

@nemesor-xanxas said in Ship Profiles: Feedback and Discussion:

@kadaeux well, yes any ship that could travel close to light speed would have to have similar acceleration or it would take days to get to and from its speeds. I was never trying to argue that, just contribute my knowledge of speed (not sure if I communicated that properly).

Ah, yeah I getcha now.

The old rouge trader figures mean very little now, with most of that stuff being retconned as years went by, legion sizes for example increased. Gees is kind of nebulous as similar to firepower it’s not really explicitly stated anywhere in the newer material what it is, like firepower, so you have to math it (or maybe it is and I missed it from space marine novella 305 or somesuch).

Officially speaking, the canon policy is that there is no such thing as retcons, the 1st ed material is as canon as the current material. But there are basically three schools of thought on 40k firepower that are reasonable.

"Low End" is high kilotons (as in hundreds) to high megatons. In my experience the people who strongly support this interpretation deliberately ignore references to higher firepower because it doesn't suit their narrative of 40k being, well, shit in space. The same people who insist that the single digit g's is the gospel.

"Mid End" is high gigatons (with 1st Ed Space Hulks citation giving a torpedo 112 five gigaton submunitions, and it was implied that it'd take 300 of them to destroy a Space Hulk sufficiently.) to low teratons (single digit) per main weapon shot. This is supported the most widely with most bombardment descriptions fitting in to that area. The people who favour low ends tend to argue that it's "just flowery language", the people who support the 'high ends' tend to cling to 'calculated' values higher interpretation.

"High End" is low teratons to petatons. These are generally based off of extremely high end interpretations, such as calcs based on the fact a Nova Cannon shell travels at .99c or how the most recent core rules stated that the Navy preferred to bomb planets into fields of rubble as their preferred form of Exterminatus. In my experience, these people tend to cling to these values mostly because it pisses off the low end interpretation folks.

There is also what I call the "Retardo End"

These exist on both ends of the scale, like those who insist that the word "tetrajoules" must mean 40k ships have 4 joule broadsides, or those who use the most ridiculous calcs to suggest Nova Cannons aren't used in orbital bombardment because they'd do a Death Star scale mass scattering of a planet.

As for explicit statements, there aren't a lot of explicitly stated yields in newer material that I know of, but there is a relatively frequent recurrence of the word "kilotonne", "megatonne" and "gigatonne" all of which are measurements of weight/mass not yield. And if a ship is dropping gigatonnes of ordnance on someone, sane logic says that the actual yield is going to be much higher overall. (But smaller individually. If I were to, for example, drop 1 gigatonne of Fat Man atomic bombs... that'd be 217391304 of them. And let's be honest, over 217 million Fat Man atomic bombs is frankly utterly horrifying. With a total yield of 4565217391 kilotons of detonations.

@kadaeux That sounds about like what I’ve heard elsewhere. So Tonne is the mass measurement and Ton is yield? I was never sure about that, thanks for the clarification. For “retardo” end as You put it I once heard some guy go on about exaton torpedoes. Want the nova cannon supposed to be a Petatonish Fleet Killer? At least that’s what I heard. There also the issue of the other fleets not really getting good showing in these novels (eldar nids etc) so who knows what their like beyond better/worse than the imperials. Anyways, do you know how fast the torpedoes go? They have to go really fast if they don’t get run down by the ships that fired them, but slow enough that it doesn’t trigger the shields. The nids mention this dilemma in the newest Baal book (too slow means getting outrun, too fast means fun in the warp time)

the nids speak?
please tell me that was a mistake, the nids dont speak, please dont let the nids speak
😖