The Scenario: Airships are awesome, but in the real world airship design is greatly constrained by the problem of lift. It seems like this, above all else, is what makes the elegant and compact ships of steampunk and fantasy unviable. Balloons need to be enormous to carry adequate mass. Steam engines, armor, and other fun things are prohibitively heavy.
Often, all of this is politely ignored. But I'd like to try and design a world in which the problem of lift is partially circumvented by the addition of a single unreal element, with defined parameters and otherwise realistic consequences: in this case, a machine that can produce limited antigravity.
My knowledge of physics is cursory, but so far as I know, such a device isn't possible within known laws. But setting aside, for this question, how it could be created, here is a possible rules set for it after the fact:
It projects a spherical field within which gravitational pull is reduced.
The effect is a gradient, with conditions near .1g around the device, and near 1g on the outer edges of the field.
The maximum size of a field is about 30 meters or 100 feet.
The field size/strength can be adjusted up and down.
It requires fuel.
I can see a number of potential problems with handling overlapping fields -- so I'm leaving whether they are cumulative, cancel out, etc. open for now.
These rules are intended as a reference to help evaluate the consequences of the core idea; if they prove inadequate I'm happy to modify them. The end goal, of using limited antigravity to create a wider field for designing interesting and useful airships, is what's important.
The Question: Limited antigravity would be a good aesthetic fit for this world, but I'm aware that messing with a physical law in even a small way can invite all kinds of unforeseen consequences. So, given the above premise, will a limited antigravity field have such wacky effects on physics (on the ship, crew, lift gas, surrounding air, the relation of the ship to the spin of the earth, or anything else) so as to be prohibitive? And if so, can the above rules or the typical airship design be tweaked to compensate?