Maximum Velocity

First off let me just say that's it been a while since I last read the HH books so if I ask a rather obvious question I’m sorry.

Is there a limit to the maximum velocity of a ship if it accelerates under tolerable levels?

axsman2 wrote:First off let me just say that's it been a while since I last read the HH books so if I ask a rather obvious question I’m sorry.

Is there a limit to the maximum velocity of a ship if it accelerates under tolerable levels?

Yes, though it doesn't affect the plot much so it's not too surprising you don't recall it.

A ship's maximum speed is determined by it's rad shielding. In normal space ships with military grade shielding can reach 0.8c, and in hyper those same ships can reach 0.6c (higher particle density in hyper translates to lower maximum safe speed)

In normal space ships with commercial grade shielding can reach, ??? (huh, I don't actually remember and can't quickly find the number; the SVW appendix simply says "lower maximum velocity"), and in hyper those same ships can reach 0.5c.



It comes up more in hyper travel because you've got time to reach it. There isn't room within the hyper limit for even a modern RMN LAC to reach its 0.8c top speed, so maximum velocity is almost never a tactical consideration since combat happens almost exclusively within the hyper limit of a system.

Thank you for the quick and thorough respons.

Jonathon didn't quite fully answer the question, there's a passage early on in the books (short victorious war I think), that mentions how the maximum speed of the impeller drive is actually theoretically lightspeed.

So, as long as you had the rad screens to keep stray particles from blowing your ship up, and compensators to handle it, you could push a ship all the way upto 0.999c.


What truly limits ship velocity is the combination of the screens to keep away dust, and compensators so crews don't turn into goo on the bulkheads.

It's possible that current missiles could go even faster than they already do (for snapshots). But missiles usually operate at a "maximum" that's really the highest balance between speed and endurance and a "half max" which is half the speed but triple endurance. Neither of which specifically rules out even higher speeds but burning out almost instantly, however that's more something that would be discussed in another thread if necessary.

Somtaaw wrote:Jonathon didn't quite fully answer the question, there's a passage early on in the books (short victorious war I think), that mentions how the maximum speed of the impeller drive is actually theoretically lightspeed.

So, as long as you had the rad screens to keep stray particles from blowing your ship up, and compensators to handle it, you could push a ship all the way upto 0.999c.


What truly limits ship velocity is the combination of the screens to keep away dust, and compensators so crews don't turn into goo on the bulkheads.

It's possible that current missiles could go even faster than they already do (for snapshots). But missiles usually operate at a "maximum" that's really the highest balance between speed and endurance and a "half max" which is half the speed but triple endurance. Neither of which specifically rules out even higher speeds but burning out almost instantly, however that's more something that would be discussed in another thread if necessary.

compensators have nothing to do with velocity, but acceleration. An important distinction which is often missed by sci-fi authors.

I love the series and appreciate the attention to detail in the unique physics in the Honorverse. Relativistic matters are addressed a little with it being pointed out that those who regularly travel at higher fractions of C do lose some time. What does not seem to ever be considered is how at very high fractions of C the actual mass of the ship/missile increases. It could make a difference in some situations as it is a means of storing massive amounts of energy that would be released on impact with a big enough object like a planet or moon.

Velocity is limited by rad shielding.
Acceleration is limited by compensation.

As a ship's V → C, M → ∞. The energy required to accelerate the ship → ∞. Which is why one can never theoretically attain exactly C. Except faster than C. (Which is a sci-fi copout) Wormholes won't allow you to travel faster, just shorter distances. A short cut.)

I'm not quite sure whether particle density in hyper would be naturally higher. Certainly perceived and encountered densities would be higher. I'm just not certain whether that would be a function of speed and or velocity. As in sitting in a hail storm your windshield is battered. While driving in that same hail storm your windshield is battered more, as a function of your speed and/or velocity.

vovchara wrote:

Somtaaw wrote:Jonathon didn't quite fully answer the question, there's a passage early on in the books (short victorious war I think), that mentions how the maximum speed of the impeller drive is actually theoretically lightspeed.

So, as long as you had the rad screens to keep stray particles from blowing your ship up, and compensators to handle it, you could push a ship all the way upto 0.999c.


What truly limits ship velocity is the combination of the screens to keep away dust, and compensators so crews don't turn into goo on the bulkheads.

It's possible that current missiles could go even faster than they already do (for snapshots). But missiles usually operate at a "maximum" that's really the highest balance between speed and endurance and a "half max" which is half the speed but triple endurance. Neither of which specifically rules out even higher speeds but burning out almost instantly, however that's more something that would be discussed in another thread if necessary.

compensators have nothing to do with velocity, but acceleration. An important distinction which is often missed by sci-fi authors.

I'll accept the nitpick, and you're right, acceleration isn't technically a factor in velocity. But you're also wrong, without acceptable acceleration rates, being capable of super high velocities means nothing.

Even the most modern podnought still has trouble getting to its maximum sustained velocity without travelling an entire solar system's width [length? diameter? whatever it should be labelled] and that's at an acceleration of around 600-700 gravities for a podnought.

So the true limiting factor in wedge velocities is actually acceleration, and not the rad shielding. And for missiles, it's a node endurance, since they burn out in around a minute.

Somtaaw wrote:I'll accept the nitpick, and you're right, acceleration isn't technically a factor in velocity. But you're also wrong, without acceptable acceleration rates, being capable of super high velocities means nothing.

Even the most modern podnought still has trouble getting to its maximum sustained velocity without travelling an entire solar system's width [length? diameter? whatever it should be labelled] and that's at an acceleration of around 600-700 gravities for a podnought.

It's worse that than, which is why I pointed out that maximum velocity is almost never a tactical concern - it really only comes up in hyper where they spend enough time to reach it (plus it's lower there, so you hit it sooner. Much sooner if you're in a grav wave which grants ~10x acceleration)

But a ship capable of 700 gees needs way more than the diameter of the hyper limit to reach 0.8c. Most stars you'd got to have a hyper limit of no more than 25 lightminute - so a 50 LM diameter (ignoring the problem that that would take you right through the sun)

But to reach 0.8c at 700 gees would take you about 9 1/2 hours during which you'd cover 3.8 lighthours. 4.5 times the diameter of the hyper limit. If you started from the Earth you'd be out past the orbit of Neptune before you hit max velocity - but our hyperlimit would like between Mars and Jupiter.



You might come close to max speed on a full power run to a wormhole terminus, Manticore's is IIRC 7 or 7.5 light hours out from the primary. But otherwise it only happens if a ship deliberately gets a long running start to deliver a frac-c ballistic bombardment (and you don't need to go that fast anymore to do that thanks to MDMs)

Something else that has to be taken into consideration is what does one want to do, when heading for a wormhole or a system destination ships have to decelerate so a lot of the velocity acquired subsequently has to be shed, and except where time to range is critical but stopping at zero relative is not, the amount of energy expended has to be offset against attaining the higher velocity, when heading away from a system with the intent to jump into hyper, the maximum velocity cannot exceed .3C anyway.