Jump Grid vs Plates vs Bubbles

[copperhamster]

This is related more to design philosophy, not technical concerns
I think that for ships that meet the proper hull layout and are unlikely to fight (merchants, freighters, etc), especially small ones, jump grids would be much more common even with the added expense due to the added safety. a moment of inattention and some 5 ton rock wanders into your bubble as you tumble your Fat Trader out into jumpspace it can ruin your whole day. I think jump bubbles would be more common on:
Ships where the configuration requires it of course
Warships which are likely to have their grids damaged in combat.
Prototypes and experimental ships
Really large ships where the cost becomes a significant factor.
Ships designed to operate in well controlled space; I can see a Fat Trader built in the Spinward Marches with Hull Grid or maybe Plates, and a Fat Trader built in the Core area given a Jump Bubble because of greater control of space flight corridors and such.

 

[HG_B]

Does T5 delve into this area?

 

[copperhamster]

Yes. There are several factors (Jump safety, minimum safe jump distance, cost) associated with having Jump Bubbles, Plates (which make small bubbles but conform closely to the hull) and grids (which are an actual part of the hull). Essentially, grids are more expensive, bubbles less safe (as any large object within the bubble can cause a jump mishap, and a large enough object can cause an outright failure by making the 'jumped' material more massive than the jump drive can handle) and require greater minimum safe distances but are built into the cost of the drive. On the other hand ships made from hollowed out rocks, or with a framework to which bunches of modules are attached are very difficult to justify operationally with grids or plates. (I could see plates on the rock).

 

[mike wightman]

Yes, in some depth.

 

[Lycanorukke]

Grids/Plates on private commercial vessels I doubt very much. Even on a basic Beowulf a grid costs 2Mcr, and it gains little benefit for a ordinary merchant when compated to it's price tag.
Note: By 'ordinary' I mean an actual _merchant_, not adventurers who do a bit of trade as an afterthought while shooting martians and smuggling (ie: PCs).

The field strength is worse than plates or a grid, but that just means you have to jump at ~100-120 diameters to achieve the same effect you achieve from grids/plates at ~80D. While jumping as fast as possible may be important to PC's, to NPC's evey millicredit counts on the loan, and why waste money on an extravgance like jump plates/grids when spending a few hours of time (well within normal jump variance) achieves the same effect ?

Military ships however have to make the choice - jump faster, or stay a target longer. Recon/scouting vessels would probably chose faster plates/grids while frontline units would go for the more resiliant but 'slower' bubble.

 

[robject]

Yes, I think that mission would affect the choice. Recon ships would definitely want a hullgrid; and ships which skim gas giants in hostile territory would want that, too: the ability to safely jump a bit closer to a planet or star than other ships is an advantage in these cases.

 

[copperhamster]

Traveller doesn't dwell on this issue, but I could see a reasonable counter-cost. Interest rates are based on risk. Loans on houses are low rate, because most houses go up in value. Loans on used cars are low to midrange because used cars hold their value better than new cars. New cars are higher rate because they lose a significant percentage of value the moment the papers are signed. Unsecured loans (Credit cards, lines, etc) are even higher because there is no direct collateral. Loan rates also go up based on risk factors of the borrower's, such as variable employment, failures to pay.

If there was statistical, measurable risk to having a jump bubble, a small uptick in interest rate would wipe out any savings in base cost. However we don't have the ability to quantify that risk.