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] >> ----- >> The Traveller Mailing List >> Archives at http://archives.simplelists.com/tml >> Report problems to xxxxxx@simplelists.com >> To unsubscribe from this list please go to >> http://archives.simplelists.com > > > > > -- > "Eternity is in love with the productions of time." - William Blake > > ----- > The Traveller Mailing List > Archives at http://archives.simplelists.com/tml > Report problems to xxxxxx@simplelists.com > To unsubscribe from this list please go to > http://archives.simplelists.com > > > ----- > The Traveller Mailing List > Archives at http://archives.simplelists.com/tml > Report problems to xxxxxx@simplelists.com > To unsubscribe from this list please go to > http://www.simplelists.com/confirm.php?u=vSy3NFQJMSbZKrzPfC3XucFBsUCMtKrI