Auto-Astrogators... not that bad?

[rinku]

Or peg it at .01 or even .001. Something miniscule. It's supposed to not be able to move the ship/station any great distance, so really small numbers would be better.

The thing is... if it's capable of station keeping at all, it's capable of moving the ship great distances. It just takes time.

I'm totally fine with those fractions, by the way. 0.001 is 1cm a second per second, so you get the station up to 36m/s in an hour.

And then there's auxiliary thrusters. In order to quickly point a ship in any direction they have to have a certain level of thrust, and it's also logical that they can be used as emergency propulsion. But that is getting into YTU territory, since different people have different takes on how much of that can be done by M-Drives and gyros and how much needs little rockets positioned around the ship.

 

[Terry Mixon]

Right. Despite the precedent of Thrust-0 solar sails and M-0 detachable bridges, that clearly DO travel. I take that rule to apply to stations and other massive vessels, but we can disagree on that.

But in the case of reaction drives at least (which are not made up pseudoscience tech) it makes sense that you could design one for a specific fractional thrust. Step aside from Thrust-0 and go straight to Thrust-0.1.

While the section under ships mentions maneuver 0, it is in relation to power costs. Still, that implies it would be vaiable for a ship.

Manoeuvre Drive: In order to use the manoeuvre drive, the ship requires an amount of Power equal to 10% of the hull’s total tonnage multiplied by the maximum Thrust the drive is capable of (multiply by 0.25 if the ship is capable only of Thrust 0). Note that reaction drives do not require Power.

 

[Terry Mixon]

The thing is... if it's capable of station keeping at all, it's capable of moving the ship great distances. It just takes time.

I'm totally fine with those fractions, by the way. 0.001 is 1cm a second per second, so you get the station up to 36m/s in an hour.

As referee you can do whatever you like. The book says no great distance, so no great distance it is. Us quantifying numbers seems to be a way to try and get around the rule. You can Rule 0 it if you like, but that's not RAW.

 

[MasterGwydion]

As referee you can do whatever you like. The book says no great distance, so no great distance it is. Us quantifying numbers seems to be a way to try and get around the rule. You can Rule 0 it if you like, but that's not RAW.

No, because RAW is entirely unreasonable with any understanding of physics. It doesn't matter how slow your acceleration is, with enough time, you can go interstellar distances at sub-light. Even with a 0.0000000000001-G drive, you can still reach 90+% of lightspeed if given enough time.

So, that rule needs to get thrown out because it doesn't make sense, even in the Traveller Universe.

Edit - By "thrown out" I mean gotten rid of in the next printing of the book.

 

[Terry Mixon]

No, because RAW is entirely unreasonable with any understanding of physics. It doesn't matter how slow your acceleration is, with enough time, you can go interstellar distances at sub-light. Even with a 0.0000000000001-G drive, you can still reach 90+% of lightspeed if given enough time.

So, that rule needs to get thrown out because it doesn't make sense, even in the Traveller Universe.

Edit - By "thrown out" I mean gotten rid of in the next printing of the book.

So, Rule 0 it. As written, the maneuver drives tank at 1000 diameters anyway. Just one more unreasonable rule to chuck.

 

[tytalan]

It was mentioned in the original Traders and Gunboats:

Variants: No known variants of the xboat are actually in regular service. Two variant models have been built for experimental purposes. One model incorporated maneuver drives sufficient to produce 1-G; the loss of jump potential (reduced to jump 3) was deemed unacceptable, however, and it was not produced. The second variant included a four-ton light sail (replacing the second stateroom). This model was intended to provide emergency acceleration away from a star in the event of breakout at too close a distance. The apparent benefits from this modification were
also deemed too small for mass production. However, there are reports that some examples were produced and may be in service in the Spinward Marches.

Terry, have you considered M-Drive 0? Despite the listing talking about it only being to keep space stations in their orbit, it doesn't take much actual thrust to move a ship around usefully. Otherwise, a small reaction drive could work as an emergency measure, or to aid with recovery when the jump exit is a bit off course.

Apparently mongoose again fail when using their owe rules for designing the variant X-boats since there’s no reason to decrease the jump to three to get M1

 

[Terry Mixon]

Apparently mongoose again fail when using their owe rules for designing the variant X-boats since there’s no reason to decrease the jump to three to get M1

As I proved already. If only the greedy megacorps weren’t keeping MixCorp’s innovative design out of the mix!

 

[rinku]

Aright. Let's put that aside and start to look at some numbers.

Here's a standard 1G reaction drive for a 100 ton ship:
2tons, Cr400,000, uses 0.025 tons of fuel per hour. Two and a half tons unequivocally gives you a backup drive that runs at 1G for 20 hours.

So, what would a 0.5G version look like? Well, that's pretty easy. You build a 1G reaction drive for a 50 ton hull (which I would point out is perfectly legal) and install it on a 100 ton ship (this is where we may get arguments, but the physics checks out).

1 ton, Cr200,000, uses 0.0125 tons of thrust per hour. Identical cost and volume to a 0G one, but the zero thrust version doesn't have a fuel cost, so that's fine, I guess.

Taking that one step further, we can describe a 1G reaction drive for a 10 ton ship, which produces 0.1G when installed as a drive on a 100 ton ship.

0.2 tons, Cr40,000, uses 0.0025 tons of fuel per hour.

 

[rinku]

Apparently mongoose again fail when using their owe rules for designing the variant X-boats since there’s no reason to decrease the jump to three to get M1

Well, it's always a bit chancy directly comparing CT to later editions (not only Mongoose). And CT X-Boats had two full sized staterooms too.

 

[boggo2300]

Apparently mongoose again fail when using their owe rules for designing the variant X-boats since there’s no reason to decrease the jump to three to get M1

umm that's CT and predates Mongoose's existance as a company by decades, so you're being more than a little unfair. CT Supplement 7 page 10

 

[rinku]

But we CAN compare things to the solar sails...

For a 100 ton ship: 5 tons, MCr1.

I think I'd rather have the 1G reaction drive with 3 tons of fuel (120 hours endurance) for MCr0.4, myself.

 

[tytalan]

umm that's CT and predates Mongoose's existance as a company by decades, so you're being more than a little unfair. CT Supplement 7 page 10

Than which traders and gunboats are they talking about since mongoose just published their own?

 

[boggo2300]

Than which traders and gunboats are they talking about since mongoose just published their own?

the original one like he said, which is CT supplement 7 (and directly contains the variant design mentioned) Mongooses Traders & Gunboats doesn't contain X-Boats or any variants thereof.

 

[tytalan]

Maneuver 1 jump 4 x-boat. It costs only slightly more than the standard one has twice the cargo space and everything the standard one does. The slightly higher cost is more than cover by the massive decrease in the number of Tenders needed when they are replaced by stations. tenders are incredibly expensive and you need a average of 4 per system in the network, most systems only need 2 a few only need 1 but some systems need as many a 12, while you need a lot fewer stations if the X-Boat has maneuver and stations cost 1/2 to 2/3 as much to support a similar number of X-Boats.

 

[tytalan]

the original one like he said, which is CT supplement 7 (and directly contains the variant design mentioned) Mongooses Traders & Gunboats doesn't contain X-Boats or any variants thereof.

My apologies I missed that. With a 1/3 to 1/2 of all mongoose ship designs not adding up in one way or another it was a easy mistake to make

 

[Condottiere]

That can't have been a surprise.

Acceleration factor/zero is pretty much plot driven.

There is no consistency, even between spacecraft and spacestation design sequences, in the same book.

 

[tytalan]

Anyone ever notice that the tender doesn’t have extra fuel to refuel the X-boats, even if it uses its own fuel it can only refuel 5 x-boats every 2 days if you don’t count travel time to get the fuel. That of course if it’s refining and skimming the fuel itself

 

[rinku]

Tenders also service Type-S scout/couriers. Those can shuttle in fuel if needs be. Or, you know, maybe they might put a fuel cutter or three in the ship bay.

And (at least from 1981) not every X-Boat jumping in is going to need a full load of fuel. Lots of X-Boat routes are J-3; some are even J-2.

I would think that for the most part their positions would be just outside the 100D of a fuel source.

However.

The original CT one had an extra 50 tons of fuel for the boats, and the MGT2e22 High Guard one does not, but has a big 78 ton cargo bay. I disagree with that change, but I guess it may add flexibility.

Simply swap cargo space for extra fuel tankage, at zero cost, or put in temporary fuel storage in the cargo area. Some cutters with extra fuel modules would seem to be a simple way to improve things too. Two X-Boats on board, two 50 ton cutters on board and maybe 2-3 extra 30 ton modules should all fit in the 400 ton bay.

 

[tytalan]

Tenders also service Type-S scout/couriers. Those can shuttle in fuel if needs be. Or, you know, maybe they might put a fuel cutter or three in the ship bay.

And (at least from 1981) not every X-Boat jumping in is going to need a full load of fuel. Lots of X-Boat routes are J-3; some are even J-2.

I would think that for the most part their positions would be just outside the 100D of a fuel source.

Takes time to skim and refine, scout/couriers would be constantly shutting fuel from the Highport/starport if used for this purpose (2 trips to refuel one x-boat) you could put two cutters in the full hanger since the docking spaces are needed for the X-Boats but than you can’t do maintenance or repairs on X-Boats. Any logical way you look at it not having maneuver drive on the X-Boat and using stations instead of Tenders just makes more sense. Now don’t get me wrong I do see a use for tenders, temporary stops for various reasons would use tenders as well as new stops before their station is built. As for not always needing the full 40 dTons of fuel that really not a thing because just as many jumps are the full jump 4 and that’s what you have to plan for

 

[rinku]

A tender stationed at the junction of two J-3 links knows the incoming boat is going to need 30 tons