How long to apply a hull patch?

[rinku]

I'd be careful abut giving an example of a 6G constant boost to Saturn - that's not a typical run for a Traveller ship, and most ships *won't* have the armour to survive collisions at those velocities.

Not true. M-6 ships have the EXACT same default amour per the rules as other ships. See ship design rules.

Umm... I never said 6G ships have different armour. But they do achieve higher velocities over a given distance, thus being more vulnerable to collisions with micromasses.

A 6G trip that travels a long distance is going to reach a much higher peak velocity than a 1G trip that travels a short distance.

The rules don't go into it, but in reality there's going to be a "safe" cruising speed (based on ship armour, hull and structure,

Nope, the rules do cover intra system travel quite well. Reread them if you like.

I think you may have misunderstood me slightly; the intrasystem travel table assumes constant acceleration to midpoint then constant deceleration to destination. That means that *at midpoint* the ship will be travelling at a very high velocity, and an impact will be more dangerous than earlier or later on in the trip, assuming an average mass and velocity.

My thought was that for a given armour value, hull and structure rating there would effectively be a speed beyond which it was hazardous to travel. This is the angle that I was referring to that the rules do not go into. Thus, you would accelerate to the cruising speed, coast toward the target, then decelerate to stop.

 

[DFW]

My thought was that for a given armour value, hull and structure rating there would effectively be a speed beyond which it was hazardous to travel. This is the angle that I was referring to that the rules do not go into. Thus, you would accelerate to the cruising speed, coast toward the target, then decelerate to stop.

No, see the travel tables. The ships are built to take it. They are just damn tough. Of course, there are some ships with windows. I wouldn't give them a long life expectancy nor, their crews or passengers. I guess that's why the design rules don't list installing windows and screen doors.

 

[rust]

Of course, there are some ships with windows.

Looking at the various illustrations of the classical Traveller ship types
from the different versions of the game, I am unable to identify any
"player character type" starship without windows, and some of them
are almost flying greenhouses (see the front of the Far Trader) when it
comes to windows.

Either Imperial naval architects sincerely hate the owners and crews of
Far Traders, or there must be some way to protect the windows during
high speed flights - some kind of shutters, probably.

 

[DFW]

Either Imperial naval architects sincerely hate the owners and crews of Far Traders,

Naw, just clueless artists and the game designers wanting the design to look "kool".

or there must be some way to protect the windows during high speed flights - some kind of shutters, probably.

Sure, remember the shuttle craft from the original star trek? But, it would be INCREDIBLY stupid to put your bridge hanging out like that. The bridge would be well protected inside the ship as 1: There is NO need for windows as there is nothing you need to see that you wouldn't use sensors for. 2) It is critical that the bridge doesn't get damaged and the crew incapacitated. Plain logic.

 

[rust]

Reminds me of what one of the players called the "Margaret Mitchell Ma-
neuver", just get a good hold and aim at the bridge window behind your
enemy, which is quite easy to hit, and the poor guy is "Gone With The
Window".

 

[DFW]

Reminds me of what one of the players called the "Margaret Mitchell Ma-
neuver", just get a good hold and aim at the bridge window behind your
enemy, which is quite easy to hit, and the poor guy is "Gone With The
Window".

That's funny! Have to remember that. Also, just spray some glop mixed with super glue on the windscreen and the Star Destroyer can't steer. LOL

 

[rinku]

Windows can be of use during low speed operations (i.e. docking, planetary operations), if only to provide a backup in the event of sensor damage or failure (a likely consequence of battle). Also, who's implying the windows are a weak point or are made of glass? There's a lot of materials even now that are transparent or can be made transparent that are tough enough.

They are handwavium, but there's nothing inherently impossible in concept about Star Trek's "transparent aluminium" or Niven's supertough (but transparent) general hulls.

I'm more than happy with shutters as a standard fearture, even so.

DFW, I'm afraid you don't seem to be getting my point about hull vs velocity. Just leave it. You're the one who brought up the point about the danger of collisions at high velocity. If you can't see that the kinetic energy you calculated is enough to punch through ship armour, and that therefore Traveller ships are NOT inherently immune from these hazards at those speeds, I can't help you. Yes, for most purposes in the game you can ignore the issue. But if you do have a ship reaching these sort of velocities, it's something to think about.

 

[justacaveman]

Actually Transparent Aluminun is a real substance, it's called ALON commercially, and it's made of aluminum oxynitride. It's much more expensive than glass or polymers, so it's not in general use.

 

[DFW]

Windows can be of use during low speed operations (i.e. docking, planetary operations), if only to provide a backup in the event of sensor damage or failure

I guess you can use them if moving a couple of feet/sec in your berth at the star port. Not much else. If you have lost sensors/instruments to the point that you have look out a port hole; either abandon ship, do an SOS or, make out you will...

 

[far-trader]

Windows can be of use during low speed operations (i.e. docking, planetary operations), if only to provide a backup in the event of sensor damage or failure

I guess you can use them if moving a couple of feet/sec in your berth at the star port. Not much else. If you have lost sensors/instruments to the point that you have look out a port hole; either abandon ship, do an SOS or, make out you will...

I guess the Apollo missions with their portholes and navigation by visual star plots using a manual sextant are just part of the myth we never went to the moon then

 

[DFW]

I guess the Apollo missions with their portholes and navigation by visual star plots using a manual sextant are just part of the myth we never went to the moon then

No, the myth is that they navigated using that without external ground control
data as to their position. On board radar for landing and docking, and would have been lost (dead) without it. My luck, I have two close relatives who worked on the project as engineers. One of them still has all the tech manuals for the whole thing, including emergency procedures, etc.

Despite the word "primary" in its name, PGNCS (onboard telescope, sextant, inertial guidance system) data was not the main source of navigation information. Tracking data from NASA’s Deep Space Network was processed by computers at Mission Control, using least squares algorithms. The position and velocity estimates that resulted were more accurate than those produced by PGNCS. As a result, the astronauts were periodically given REFSMMAT updates to enter into the AGC, based on ground data.

 

[AndrewW]

The onboard computer in the Eagle lander getting too much information didn't help.

 

[far-trader]

My point wasn't that it was the primary, I'm aware it was a backup and for times when ground wasn't available. It was also used to verify ground as a check. The point is portholes aren't useless on spacecraft, and you aren't sol if you lose electronics out in the black travelling at speed. Presuming of course you aren't so confident in your fancy electronics that you build your ship without portholes and a backup like a stellar sextant. Kind of a "for the cost of nail" lesson imo. So yeah, you can bet my Traveller ships have portholes (though I do find the classic Far-Trader greenhouse bridge a bit extreme and disturbing) and sextants. And Navigators/Astrogators will know how to use them and all the associated hard copy charts and tables.

 

[DFW]

The onboard computer in the Eagle lander getting too much information didn't help.

No, the "overflow" sure caused a problem. Luckily the on board radar didn't go out instead... BOOM

 

[DFW]

My point wasn't that it was the primary, I'm aware it was a backup and for times when ground wasn't available. It was also used to verify ground as a check.

It wasn't used as a check on the ground based radar. It was used for the short period when behind the moon and out of radio contact. "Shooting stars" was FAR too inaccurate to do navigation for any length of time to be on course for orbit, docking, etc. For purposes of space navigation for the needed accuracy, (remember they were on a course that had been drilled for months) a porthole is as good as dead. If that ever happens to PCs they should call for help and if none available, evacuate before getting too close to a gravity well...

A major problem would be establishing extremely accurate relative velocity data with a planetary body. With those hand held mechanical instruments you could get a pretty good idea where you are but not enough to be able insert into orbit, etc. But the inertial guidance system (no external input) gives you that anyway and, more accurately than hand held.

I do agree though that the greenhouse thing IS weird. Portholes that open and close aren't a problem, you are correct in that. But, I would still have my bridge as deep within the ship as possible. Much like CIC on a present day combat ship.

 

[far-trader]

My point wasn't that it was the primary, I'm aware it was a backup and for times when ground wasn't available. It was also used to verify ground as a check.

It wasn't used as a check on the ground based radar...

So you're saying my memory and a quick google finding this site are wrong?

http://www.ion.org/museum/item_view.cfm?cid=6&scid=13&iid=293

"Astronauts periodically used a sextant... to verify the accuracy of the Earth-based tracking data."

I wouldn't be surprised to find my recollection inaccurate but I trust the site linked has it correct more than your memory of events

I guess we'll have to agree to disagree on the wisdom and utility of backups like portholes and sextants for spacecraft.

 

[rust]

While I think that an airlock would be just as useful as a window for using
simple navigation equipment like a sextant in space, I cannot imagine at
least a ship built for atmospheric operations without windows - there are
too many things that can go wrong with sensors.

 

[DFW]

So you're saying my memory and a quick google finding this site are wrong?

I have no idea what you originally were told or heard so I can't say. The site itself is misleading though. I asked my relative and he gave me a url for a write up from an AF guy he knows who was on the ground tracking end. http://www.honeysucklecreek.net/msfn_missions/MSFN/tom_sheehan.html

As you can see, ground did it... This is why I love knowing people who actually lived this part of Man's history.

 

[DFW]

While I think that an airlock would be just as useful as a window for using
simple navigation equipment like a sextant in space, I cannot imagine at
least a ship built for atmospheric operations without windows - there are
too many things that can go wrong with sensors.

IF, after a few thousand years, so much is going wrong with sensors, ship loss rate would be VERY high. Even today at our low TL, aircraft can land without looking out the window. BTW - how do you think airliners fly at night?

No, 3 (or even more) whole tech levels from today and you won't even have the almost nonexistent problems that are experienced today. Multiple TL 11 sensors that have had the bugs worked out over thousands of years.

 

[rust]

Still, if I had the choice between a craft that is only IF capable and one
that is also VF capable and has a pilot trained for VF, I would not hesi-
tate to take the latter one.