> On Nov 27, 2016, at 9:53 AM, Jeff Zeitlin <xxxxxx@gmail.com> wrote:
>
> On Sat, 26 Nov 2016 22:26:35 -0500, Rob Davenport
> <xxxxxx@gmail.com> wrote:
>
>> So a J-6 ship could "double back" cheaply?  Jump out 1pc (40 hours, 12
>> fuel) and jump back (another 40 hours 12 fuel) - 80 hours total, much
>> faster than normal (300 hours).   Could be useful to get out of a jam
>> and come back on scene after 80 hours of repairs, rest, healing, to
>> "try again".
>
> Yes - but remember that when you built that ship, you paid for the
> full jump-6 capability, which means that the drive is large. You also
> have to pay for the extra fuel capacity.
>
> As an example, let's take a Marava hull (hull rate 200) and refit it
> for a J6 drive but max distance J2 (it will be able to do out-and-back
> J1 without refueling):

There would probably start to be levels of service between certain systems - IE “we can get your data/mail/cargo/people there in 40 hours rather then 150, so we will charge X more."

I’d think it would be like the fed ex overnight vs fed ex ground - you are paying for time.

For example (just a WAG)
First Class (40 hours per Parsec) 2.5x cost
Second Class (80 hours per parsec) 2x cost
Third Class (120 hours per parsec) 1.5x cost
Normal Rate (150 hours per parsec) 1x cost

I’d see a lot of first class, second class and normal rate traffic.

So if you have a package that needs to get there really fast, you can pony up and buy space on the faster ship. I see a lot of businesses doing this - for stuff and for people. If you have employees traveling for meetings, spending 150 hours in jump is a bigger money sink then spending 40 hours in jump, and time is money - salary and lost opportunities. If you have a work team idling waiting on parts or materials, getting there 120 hours quicker could be a huge win.

Honestly if you have two high pop worlds a jump or two apart, I could see a the majority of traffic using the faster jump.

>
> Using the CE SRD for reference (because I have it handy), in a Marava
> hull (hull rate 200), you'd have a 35-dton drive (Drive Code F for J6)
> instead of a 15-dton drive (Drive Code B for J2). Right there, you're
> losing 20 tons of cargo capacity, per jump.
>
> Remember that the fuel usage is percent of hull rate, not dtons of
> fuel. For a Marava hull with a standard J2 drive, you need to allocate
> 20% to fuel, or 40 dtons. To do the J2 with the J6 drive, you need to
> allocate 24% to fuel, or 48 dtons. That represents an additional loss
> of 8 tons of cargo capacity, per jump.
>
> So, your modded Marava has only 54 dtons of cargo capacity, vs the 82
> of a 'stock' Marava. That's going to play hell with the commercial
> viability, whether you use Ken Pick's Commercial Efficiency Rating to
> calculate it, or work up the financial profile the way I did.
>
> For military ships, the loss of mission space may be considered
> worthwhile, especially if your enemy doesn't know you have this drive.
> I don't think you'll see this among independent traders, and even
> large-corporation rosters are unlikely to have a large proportion of
> ships with uprated drives.
>
>
>> On Sat, Nov 26, 2016 at 6:58 PM, Jeff Zeitlin <xxxxxx@freelancetraveller.com> wrote:
>
>>> Depending on the reaction here, I may work this up into a full
>>> alternate-tech article for Freelance Traveller, much like I did with
>>> the Lyman Drive
>>> (http://www.freelancetraveller.com/features/rules/tech/lymanjd.html,
>>> reprinted from 2002 in the April 2013 issue).
>>>
>>> The core of the idea: A Jump-n drive can (usually) do Jump-m (m<n) in
>>> less time than it takes to do a Jump-n. However, it takes more fuel to
>>> do so than it would take a Jump-m drive, and the time required to do
>>> multiple jumps, even if there is zero delay between emergence from one
>>> jump and entry into the next, is greater than the single jump would
>>> be.
>>>
>>> A first cut at numbers:
>>>
>>> Assume that N is the rated jump capability of the drive, and that it
>>> uses fuel according to the standard rules (e.g., for CT, 10% of hull
>>> rate * N). Then, for a Jump M where M is strictly less than N,...
>>>
>>>  Fuel usage = M/(N-1) times the standard fuel usage.
>>>
>>> Time: 168 hours is annoying to work with - it just happens to match up
>>> nicely with "a week". Let's tweak that: A basic jump isn't "a week",
>>> though it's generally treated as such on the calendar; it's 150 hours.
>>> Given that Jump N takes 150 hours, for a Jump M, where M is strictly
>>> less than N,...
>>>
>>>  Time required for jump = M/(N-1) times 200 hours.
>>>
>>> In tabular form:
>>>
>>> Fuel (% of hull rate)
>>>
>>> Drive     Jump 6   Jump 5   Jump 4   Jump 3   Jump 2   Jump 1
>>> J6 Drive  60       60       48       36       24       12
>>> J5 Drive  --       50       50       38       25       13
>>> J4 Drive  --       --       40       40       27       13
>>> J3 Drive  --       --       --       30       30       15
>>> J2 Drive  --       --       --       --       20       20
>>> J1 Drive  --       --       --       --       --       10
>>>
>>>
>>> Time (hours)
>>>
>>> Drive     Jump 6   Jump 5   Jump 4   Jump 3   Jump 2   Jump 1
>>> J6 Drive  150      200      160      120       80       40
>>> J5 Drive  ---      150      200      150      100       50
>>> J4 Drive  ---      ---      150      200      133       67
>>> J3 Drive  ---      ---      ---      150      200      100
>>> J2 Drive  ---      ---      ---      ---      150      200
>>> J1 Drive  ---      ---      ---      ---      ---      150
>>>
>>> Note that using a Jump N drive for Jump N-1 is really not something
>>> you want to do unless it's unavoidable; it takes *longer* without
>>> saving you any fuel. Also, the drive that uses the _least_ fuel for
>>> jump N is the Jump N drive - but at the cost of being the
>>> second-slowest.
>>>
>>> Comments/Discussion?
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