Re: Landing vs hovering (was Re: [TML] What class of Port is this?) Christopher Sean Hilton (16 Aug 2017 20:26 UTC)
Re: Landing vs hovering (was Re: [TML] What class of Port is this?) Christopher Sean Hilton (17 Aug 2017 02:19 UTC)
Re: Landing vs hovering (was Re: [TML] What class of Port is this?) Jeffrey Schwartz (24 Aug 2017 13:38 UTC)
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Re: Landing vs hovering (was Re: [TML] What class of Port is this?) Jeffrey Schwartz 24 Aug 2017 13:37 UTC

And in T5, the "Z-Drive" aka "Lifters" is listed as negligible power.
On the other hand, it has a max altitude of something like 2 meters,
and a max speed of around 30kph.

It also comes free with the hull...

On Thu, Aug 17, 2017 at 1:02 AM,  <tmr0195@comcast.net> wrote:
> Evening PDT,
>
> CT LBBs for simplification does not calculate  the power needed to operate
> the grav generators while CT Striker Book 3, and TNE FF&S, do provide
> guidelines.
>
> CT Striker Book 3 p. 8 Each .02 m^3 of grav generators produces 1 ton of
> thrust and requires 0.1 megawatts of power from the power plant.
>
> TNE FF&S p. 75 Contra-Grav Lifters
> TL 9 Standard Lifters require 0.3 MW per displacement ton of hull
> TL 10 Improved Lifters require 0.2 MW per displacement ton of hull
> TL 12 High Efficiency Lifters require 0.1 MW per displacement ton of hull
>
> Looking at MT Referee's Manual, T4 Book 1 QSDS, T4 Book 2 Starships SSDS,
> and T4 FF&S the thruster plate, reactionless thruster, and contra-gravity
> drives appear to be used to hover. However, these systems all have a power
> requirement.
>
> Tom Rux
>
> ________________________________
> From: "C. Berry" <xxxxxx@gmail.com>
> To: "TML" <xxxxxx@simplelists.com>
> Sent: Wednesday, August 16, 2017 1:35:20 PM
> Subject: Re: Landing vs hovering (was Re: [TML] What class of Port is this?)
>
> There's zero energy cost for hovering. Otherwise, by your analysis, I would
> be expending a gigantic energy cost for hovering 400,000km over the surface
> of Luna. :) An object motionless in a g field has constant potential energy,
> hence no energy input is required to keep it there.
>
> On Wed, Aug 16, 2017 at 1:26 PM, Christopher Sean Hilton
> <xxxxxx@vindaloo.com> wrote:
>>
>> On Tue, Aug 15, 2017 at 06:35:24PM +1000, Tim wrote:
>>
>> > I'm certain that a ship could hover instead of setting down, in a way
>> > that addresses all the safety concerns in this thread and so on.  I
>> > just don't see yet what advantages that would offer.
>> >
>>
>> Agreed, hovering isn't hard. We've been doing it with ships and boats
>> on Earth since ~ TL3. It's a solved problem.
>>
>> And I see a potentially big disadvantage. The energy cost for a ship
>> to hover in the manner is:
>>
>>      Energy = (m) * (g) * (h)
>>
>> Where:
>>
>>      m -- Mass of the ship.
>>
>>      g -- Local acceleration due to gravity.
>>
>>      h -- Distance from the surface (?) to the CG of the ship.
>>
>> This energy gets paid for no matter how the ship "lands". If it's on
>> landing gear then the real landing gear is acting like a spring and
>> storing the energy from the compression force between the ship's CG
>> and the ground underneath it. Or, if it's hovering in this way it burns
>> fuel. How fast, I don't know [1]. But, burning fuel creates heat because
>> our power plant is entropic and that heat is gonna have to be carried
>> away by radiation and convection with the local atmosphere.
>>
>> Looks like a starship operator has a choice here not of: "wear and
>> tear" vs. "no wear and tear", but rather of what wears out, the big
>> hunks of metal that are the landing struts, or the: fusion plant, heat
>> dissipation, and contra-grav circuits.
>>
>> ----------------------------------------
>>
>> [1] I'm at work but I'll do a back of the envelope calculation when I
>> get home.
>>
>> --
>> Chris
>>
>>       __o          "All I was trying to do was get home from work."
>>     _`\<,_           -Rosa Parks
>> ___(*)/_(*)____.___o____..___..o...________ooO..._____________________
>> Christopher Sean Hilton                    [chris/at/vindaloo/dot/com]
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