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Ship duration days

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magmagmag

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All of you hello,

What kind of opinion does the citizen have about a ship duration days in MT?

MegaTraveller Referee's manual shows that
"Fuel Tankage: All craft must be fitted with fuel tanks during the design and construction process. A 30-day supply is considered optimum".

1)However, the duration days are various in sample ship data below .:confused:

***** sample data ******
Rebellion Sourcebook

BC-11 30,000 1G 4J 0A 25day
CA-11 10,000 1G 2J 0A 18day
CL-15 30,000 3G 3J 0A 26day
BB-13 200,000 2G 3J 0A 22day
CA-15 75,000 2G 5J 0A 28day
CA-13 10,000 3G 3J 0A 26day

Fighting Ships
BB-11 300,000 3G 2J 0A 30day
BB-13 300,000 2G 4J 0A 24day
BB-15 700,000 2J 4J 0A 24day
BL-13 200,000 3G 4J 0A 24day
BL-15 200,000 3G 4J 0A 23day

BT-15 700,000 1G 5J 0A 22day
BR-15 30,000 6G 0J 0A 10day

CA-15 100,000 4G 4J 0A 21day
CJ-15 100,000 2G 6J 0A 30day

VS-15 100,000 1G 6J 0A 30day

ED-15 10,000 4G 4J 1A 21day

2)Mr. Clayton R. Bush shows a calculation method below in his worksheet of Lotus123.:confused:

Power: 3730/7460, Fusion= 671400 MW, Duration= 10/30
( No Wpns, Agility; M-3 = 207889 MW, Duration= 32/97
No Wpns, Agility; M-1 = 115489 MW, Duration= 58/174
LifeSupport & Controls; M-0 = 22094 MW, Duration= 304/912)

Anyway I want to contact Mr. Clayton R. Bush.
I have used his worksheet for 15 years. I translated this for me.
I want to distribute it to all Japanese if he he admits it.
Do you know his mail address?:confused:
 
Standard is 28 days, which is also 4 weeks, and exactly one Imperial Month
A year being 13 imperial months plus 1 day.

Fighting Ships is a poor reference, as the ship designs can not be replicated with the MegaTraveller rules.

Certan non-commercial designs can short-cut duration somewhat...

As to Mr. CR Bush... haven't seen nor heard from him since the 1990's that I can recall, myself.

His methodology is not considered standard; subdividing the PP was permitted in the eratta, and produces similar results.
 
The "30 day optimum" is a hold-over from Classic Traveller.

MegaTraveller made a number of assumptions that resulted in 30-day durations being a significant strain on available volume in ship design, particularly in military designs with high energy needs. The Rebellion Sourcebook came out before the idea of split plants, so the solution was to cut the overall duration down by a few days. Once split plants became an option, the basic functions of the ship returned to having a 30 day duration, while power-hungry functions that are normally not needed all the time dropped to much shorter durations.
 
Not MT, but I noticed this in the Summary Block for the Far Trader Marava in the Trader & Gunboats supplement, page 24

Range: Four weeks maneuver. One jump-2. Three months.

We're not sure what the "Three Months" is for at this point. You might find more answers on the TML archives or some such.

Tangent: the T4/Milieu-0 book offers that using Fusion+ works off deuterium
and the unit is sealed to protect vs reverse engineering. It doesn't mention whether the deuterium is in separate external tanks or not (I don't have Fire, Fusion & Steel for T4). On the GURPS boards, their system used fusion reactors and IIRC they speculated 1 or 2 century duration on them. I don't believe those used any type of external tanks, but I'm not a Gearhead.

Ooops, just grabbed the T4 mainbook and found that the HEPLAR Maneuver drive uses a fuel tank and "20 hours of fuel" requirement, which I assume can be supplemented by more tankage space.

They also offer Thrust Plates (reactionless drives) for maneuver which only require electricity from the main power plant, which I assume is what GURPS uses.

Anyway, with a good engineer and the right amount of space, you should be able to expand the duration as needed, depending on how wild your plan is.


>
 
The OTU uses a 28 day month. (4 weeks.) The OTU calendar is a CT innovation, drawn from then-current proposals to switch to a 13 months of 28 days each calendar in the US...

In MT, the 28-day month is explicit.

Note that MT Ref's, page 60, specifies in the section on fuel, "A 30 day supply is considered optimum."
 
Last edited:
Wrong forum?

Not trying to derail a good conversation, but shouldn't this be in the MT forum?
 
While this is supposedly an edition-specific question, the gist of it applies to all editions with sufficient control over fuel tankage. Starships tend to be a bit "meta-edition" in any case, which is why The Fleet is not edition specific.
 
Gadrin said:
Range: Four weeks maneuver. One jump-2. Three months.
>
Click to expand...

I've always thought the "three months" part was consumables for life support (food, water, laundry detergent, that sort of thing.

--Doyle
"The difference between a disaster and an adventure is, did you live to tell the tale?"
 
magmagmag said:
I want this detail. How can I obtain the details?
Click to expand...

I will look for an explanation printed somewhere, but the 'details' on subdeviding power plant requirements are simple:

1. select which items need to run all of the time (Maneuver, Life support, etc.) and design PP#1 to generate enough power for the 'all of the time items'. Provide enough fuel to run PP#1 for 28 days (or whatever duration you decide on).

2. select which items only run some of the time (weapons) and design PP#2 to generate enough power for the 'some of the time items'. Provide enough fuel to run PP#2 for 24 hours (or whatever duration you decide on).

3. Note on the ship design that it can operate normally for 28 days but it can only operate for about 24 hours in combat.

The power hungry and fuel hungry weapons will not require giant power plants that run all of the time. This reduces the total fuel requirements.

The only limitation is the 1 ton minimum for each power plant (to avoid the small power plant penalty). This is usually not a problem.
 
Last edited:
atpollard said:
1. select which items need to run all of the time (Maneuver, Life support, etc.) and design PP#1 to generate enough power for the 'all of the time items'. Provide enough fuel to run PP#1 for 28 days (or whatever duration you decide on).

2. select which items only run some of the time (weapons) and design PP#2 to generate enough power for the 'some of the time items'. Provide enough fuel to run PP#2 for 24 hours (or whatever duration you decide on).

3. Note on the ship design that it can operate normally for 28 days but it can only operate for about 24 hours in combat.
Click to expand...
One power-hungry ship system that only runs some of the time is the maneuver drive. In fact, it only runs for about half a day every 14 days (7 days in jump, maneuver 6 hours from arrival point to destination world, spend 6 days scrounging around for cargo and passengers, maneuver 6 hours out to jump limit). Which makes it even sillier that HG requires a ship to spend several percent of its tonnage on power plant fuel. Even if power plants really were so inefficient as the fuel consumption numbers imply (which is silly to begin with), there's absolutely no need to carry 30 days worth of fuel around (or, rather, 30 days worth of fuel would not take up that much space).

Of course, I firmly believe that a new ship is designed to spend far less than 6 days on the ground between jumps, but even after you account for that, the drive will be on less than 10% of the time.


Hans
 
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