Provides simulated gravity, and Casey has grav-plates

On such topics, Project Rho is often a major source of information.

http://www.projectrho.com/public_html/rocket/artificialgrav.php

atticusedwards wrote:This was over in Baen's Bar, and the most helpful on the explanations was wlarrison, who seem to have an excellent grasp on the problem of rotational force and vertigo and the possibility of barfing if one stood up or turned too quickly in such an environment.

Which sets the minimum size of such a section, so the rotational effects are minimised: the bigger the radius, the lower the angular velocity needs to be.

There's also a question of just how much gravity we need to live and still be healthy: is it half a g? A third of a g? Or do we need nearly a full one? How long can a cruise be without returning to full gravity?

As for why two counter-rotating sections, that's easy: it keeps the ship's full angular momentum zero.

Enclosing in a non-rotating cylinder requires more mass, so the question is whether you can pay it. In the HV, there doesn't seem to be much of a radiation problem, either inside the wedge during transit, or without one while in orbit, so they don't seem to need to have passive anti-radiation armour around living areas

ThinksMarkedly wrote:Enclosing in a non-rotating cylinder requires more mass, so the question is whether you can pay it. In the HV, there doesn't seem to be much of a radiation problem, either inside the wedge during transit, or without one while in orbit, so they don't seem to need to have passive anti-radiation armour around living areas

HV-ships have particle shielding, see https://infodump.thefifthimperium.com/e ... stems.htm/

As far as the effectiveness of a "down-the-throat" attack on a major combatant, the particle shielding definitely would present difficulties. I'd have to run the numbers, but the particle shielding is basically designed to handle collisions with solid objects massing up to about two metric tons at velocities of up to 60% of light-speed.

Those numbers... O_o

Joat42 wrote:

ThinksMarkedly wrote:Enclosing in a non-rotating cylinder requires more mass, so the question is whether you can pay it. In the HV, there doesn't seem to be much of a radiation problem, either inside the wedge during transit, or without one while in orbit, so they don't seem to need to have passive anti-radiation armour around living areas

HV-ships have particle shielding, see https://infodump.thefifthimperium.com/e ... stems.htm/

As far as the effectiveness of a "down-the-throat" attack on a major combatant, the particle shielding definitely would present difficulties. I'd have to run the numbers, but the particle shielding is basically designed to handle collisions with solid objects massing up to about two metric tons at velocities of up to 60% of light-speed.

Those numbers... O_o

Though I don't know whether the particle shielding were anywhere near as capable back 370-ish years prior to the start of the main series. Remember we're talking back in Travis Long's time, when (some) ships still used rotational gravity. Those old ships might (or might not) have needed more physical shielding than Honor's ships did.

Jonathan_S wrote:Though I don't know whether the particle shielding were anywhere near as capable back 370-ish years prior to the start of the main series. Remember we're talking back in Travis Long's time, when (some) ships still used rotational gravity. Those old ships might (or might not) have needed more physical shielding than Honor's ships did.

Entirely true. Sadly, there isn't much information available.

Jonathan_S wrote:Though I don't know whether the particle shielding were anywhere near as capable back 370-ish years prior to the start of the main series. Remember we're talking back in Travis Long's time, when (some) ships still used rotational gravity. Those old ships might (or might not) have needed more physical shielding than Honor's ships did.

That's why I also mentioned orbits. It's quite clear that the ships strike their wedges as a routine measure once achieving orbit at that time, though it may be an effect of not being at war. But depending on just were in orbit above a planet you are, you may be outside of the protection of the planet's magnetic field. Or worse: you may be travelling exactly where said magnetic field funnels radiation to or just has a weak spot on (see the South Atlantic Anomaly article on Wikipedia for an example). Moreover, we've seen in the multiple incursions into Manticore space that the RMN at the time did not keep their ships with wedge up, unless they were out in patrol.

However they protect their crews with the wedge down, it must be enough that they didn't need a cylinder armour around the rotational crew spaces.

ThinksMarkedly wrote:

Jonathan_S wrote:Though I don't know whether the particle shielding were anywhere near as capable back 370-ish years prior to the start of the main series. Remember we're talking back in Travis Long's time, when (some) ships still used rotational gravity. Those old ships might (or might not) have needed more physical shielding than Honor's ships did.

That's why I also mentioned orbits. It's quite clear that the ships strike their wedges as a routine measure once achieving orbit at that time, though it may be an effect of not being at war. But depending on just were in orbit above a planet you are, you may be outside of the protection of the planet's magnetic field. Or worse: you may be travelling exactly where said magnetic field funnels radiation to or just has a weak spot on (see the South Atlantic Anomaly article on Wikipedia for an example). Moreover, we've seen in the multiple incursions into Manticore space that the RMN at the time did not keep their ships with wedge up, unless they were out in patrol.

However they protect their crews with the wedge down, it must be enough that they didn't need a cylinder armour around the rotational crew spaces.

If the PNS Farnese is anything to go by then even ships in orbit with their wedge down still have "standard, station-keeping particle screens" [EoH] however "those were intended mainly to keep dust from accumulating on her hull. They had never been intended to deal with something like [one BC fusion reactor blowing at less than 600 km]"



That said, despite those shields which seem far weaker than those used to fend off relativistic particles while underway there was no mention of any of Farnese's crew taking lethal radiation doses from the fusion blast. Given that the combo of even station keeping screen and the hull + armor seem like they'd be able to easily ward off danger from orbital radiation. And it's implied that Honorverse modern medicine can do more to treat radiation damage that we can today

(OTOH the "much closer" CA Hachiman's crew was far less lucky -- 2/3rd died almost instantly from the destruction of the ship's structure and explosive decompression; and half the remainder took lethal radiation doses "not even modern medicine could do a thing about" (despite presumably also having station keeping particle screens up)

Jonathan_S wrote:If the PNS Farnese is anything to go by then even ships in orbit with their wedge down still have "standard, station-keeping particle screens" [EoH] however "those were intended mainly to keep dust from accumulating on her hull. They had never been intended to deal with something like [one BC fusion reactor blowing at less than 600 km]"

Just why do they care about dust accumulating on the hull? And how does dust accumulate in space anyway, unless the hull is charged?

I guess it's not about the dust itself accumulating, but the effect of that dust abrading the hull and the eventually larger particle (micro-meteoroid) pitting it.

ThinksMarkedly wrote:

Jonathan_S wrote:If the PNS Farnese is anything to go by then even ships in orbit with their wedge down still have "standard, station-keeping particle screens" [EoH] however "those were intended mainly to keep dust from accumulating on her hull. They had never been intended to deal with something like [one BC fusion reactor blowing at less than 600 km]"

Just why do they care about dust accumulating on the hull? And how does dust accumulate in space anyway, unless the hull is charged?

I guess it's not about the dust itself accumulating, but the effect of that dust abrading the hull and the eventually larger particle (micro-meteoroid) pitting it.

Without a particle shield the hull will get charged due to the charged particles being emitted by the local star.

Dust can be a problem if it is allowed to accumulate since it will tend get into every little crack and crevice which can make maintenance more difficult. It will also get into the ship if people use the airlocks for maintenance tasks. If you have the technology and if it is cheap enough to run, why not use it.

Joat42 wrote:Dust can be a problem if it is allowed to accumulate since it will tend get into every little crack and crevice which can make maintenance more difficult. It will also get into the ship if people use the airlocks for maintenance tasks. If you have the technology and if it is cheap enough to run, why not use it.

It's not that anti-dust particle screens are 'cheap to run', it's that running them is unquestionably cheaper than the cost of the additional maintenance required if you don't use it.

Civilian freighter crews are tiny, despite being somewhere between a heavy cruiser to superdreadnought in size, which means if you didn't have the screens present, then the "workload" of some poor sucker(s) would have very frequent EVA's to ensure everything important such as your Warshawski Nodes remain fully functional and clear of dust. Assuming they still follow a standard 40-hour work week, if you need to EVA more often you could easily push into extra pay situations:

1. overtime which is pay and a half from 40 to 60(?) hours/week
2. double-time pay when you go past the above overtime hours per weeks
3. possibly also danger pay which is another time-and-a-half

That all adds up pretty quickly. Or to avoid a danger pay on double-time scenario, you'd have to hire additional EVA-specific crew... who you now have to pay a daily (standard) wage in addition to paying for:

• more emergency gear. The civvie skinsuits that aren't customized to wearer, but not necessarily gumbies. Gumbies are only for civilians to wear in emergencies, where the only thing they need to do is survive until 'trained' rescuers can reach them, but freighter crews surely must have something between naval skinsuits and shipyard hardshells, that allows them to handle accidental 'loss of pressure' situations
• more foodstuffs aboard ship due to higher daily consumption plus needing a larger reserve in case of emergency, both of which require additional storage space specific to the operation of the ship (which means you can't/shouldn't be using it to make money with)
• possibly having the air recirculating equipment enlarged, if not entire extra units installed; if you need to hire more than a handful of extra crew
• places for said crew to sleep, so you'll need more cabins. This reduces how many passengers you can carry (crew are now occupying some of those rooms), or slightly reduces how much cargo you carry because you would have to add complete new cabins, complete with air & utilities
• any of the three above expenses mean paying not only for some engineers to design it, but paying a shipyard to do the work in adjusting the internals which requires completely opening up your ship (think CA-Nike at Hancock, opened up to expose her broken fusion plant)
• lost profits while the ship is being converted due to the shipyard time

Or you just pay to run a 'simple' particle screen permanently, which only adds a little bit of extra maintenance work, and could probably be done without any EVA at all. Hell, it'd likely remove 90% of most EVA work (for freighters at least) into being something only required at shipyard overhauls, so the standard shipyard visit to replace worn Alpha nodes which last something like 10 years or so right? And if you're docked to a shipyard for any reason anyway, any EVA checks of the ship exterior would be done by the shipyard personnel, not by the ship crew, and the cost for doing so would be part of the standard fee on the overhaul, so you're not paying anything extra.

Naval crew don't quite follow the same timetables, nor pay boosts, but running the screen (and pulling maintenance on it) would mean those crewmen could do multiple other tasks. Rather than their sole job being to EVA and go brush, or vaccuum, or use a space-version of a leaf-blower to remove dust from the various warship-only equipment that absolutely cannot afford to be down from 'dust accumulation'; like radar or lidars.