Amazing new technology? I suspect it'd be easier to build a propulsive nuclear turbine at this point then building any of our modern turbofan engines which are just insanely complex and hard to build (thus why China still can't do it). It'd operate cooler overall (because the nuke heat just isn't that hot), it'd lack the corrosive problems created by jet fuel and it would not be required to start cold because you could constantly keep it warm with a preheater running off the nuclear reactor's decay heat, even with said reactor is shutdown.
Also with two coolant loops you could keep all radiation out of the turbine. The aircraft designs normally only had one loop to save weight, so the turbine had to eat some rads. Though some late ~1970s era nuclear plane concepts did have two loops. No radiation makes the materials choices much easier.
The danger of the reactor falling out of the sky though, yeah, that's kinda a not solveable problem. You could have crush protection to make it unlikely the reactor would physically split open on impact (NASA designed something like this for nuclear hovercraft to survive ~100 knot direct impacts), but no way can you ensure against meltdown with a reactor having high power density. Pebble Beds are rather bulky. If the ship crashed hardyou'd have to think in terms of burying it in place in a mound of clay or something until it cooled down.
Cities could be avoided easily enough, but you'd also have to avoid things like the headwaters of rivers which supply drinking water to cities and key farmland, which would be a big problem.
Moving the ship with gas turbines is certainly not out of the question though. It will just burn fuel like crazy, so you'd probably want to build a 100,000 ton flying tanker to go with it, which would refuel from sea going tankers.
Starglider wrote:Does it need to be built as a solid brick?
It does if you want to have hanger and bulkheads strong enough not to be torn apart open by heavy explosions at a reasonable weight.
As long as high speeds are not required, you could build it as numerous hulls/pods attached to a structural megaframe.
So all the pods are now non structural for the overall ship, but still have to meet all our other strength and protective requirements, which means the total mass of the ship will skyrocket. Meanwhile that frame is now a bunch of narrow girders vulnerable to being completely severed by single weapon hits. How much more mass do you expect to tac on to have redundant strength to avoid that risk?
Remember anti ship missiles capable of hitting a specific predesignated point on the target, with an accuracy in single digit feet, are already a service reality in the world today, such as the Norwegian NSM. The enemy would certainly program his missiles to aim for the girders and breakup the ship. We'd be loosing one of the few advantages we could get out of this flying ship, which is not needing a keeling via distributing the anti grav system throughout the ship.
You want strength in a warship as distributed and protected as possible, not concentrated into vulnerable strakes. All the extra mass a girder and pod configuration would require would be better spent on more armor. You can't armor enough to stop penetration, but thickening all the internal bulkheads would help localize damage while also making structural strength more redundant, less at risk from heat induced structural failure ect....
That way fire & damage are somewhat compartmentalised. Worst case you might be able to blow the supports to say a burning munitions storage pod with explosive bolts, and jettison it from the ship.
Ah, explosive bolts that make parts of the ship fall off. What happens when those are in the compartment that caught on fire first?
Also bolts as a concept are bad for the structure of a warship. They weigh more then welding for the same strength and they fail from shock damage easier then good welding. This is why people stopped riveting hulls not long after WW2, though it began phasing out around WW1 when welding hulls first became possible.
Overall your concept might make a lot of sense for say, a ammunition or vehicle transport ship not intended for frontline combat and not manned heavily enough for damage control anyway, yet filled with flammables, but its just a terrible idea on a warship crewed by humans.
"This cult of special forces is as sensible as to form a Royal Corps of Tree Climbers and say that no soldier who does not wear its green hat with a bunch of oak leaves stuck in it should be expected to climb a tree"
— Field Marshal William Slim 1956
