I forgot how to physics and require assistance.

[Brother Mythos]

Here's a photo of a very basic trebuchet:



Simply start with this very basic design, and scale it up to your particular needs.

[chaotic neutral observer]

Now don't get me wrong, I have nothing against dirigibles. But, steam punk is a whole different genre. If we're going to go that route, then someone should have told me that in the first place.

The fleet of dirigibles was just an example.  The OP clearly has some sort of problem, which he believes can be solved by flinging a nuclear plant with a catapult.  However, before we spend too much effort on this, we need to stop and determine if there is a better way to accomplish the OP's real objective, which he hasn't stated.

We also need to consider questions such as:

Is the plant being flung to somewhere, or away from somewhere?  What are the accuracy requirements?  Would it be acceptable to dismantle the plant, fling the individual components, and then reassemble it at site?  (Hurling one building at a time would help reduce the scale of equipment required).

Why a catapult in particular?  Has using rocketry and/or explosives to put the plant into a sub-orbital trajectory been considered?  I've already expressed my preference for dirigibles, but if the hurling part isn't strictly necessary, very large flat-bed trucks might also be appropriate.

Nuclear power hasn't been very popular lately.  Why not fling a solar power installation, instead?

Of course, if hurling a nuclear plant is the objective in itself, then this analysis is unnecessary, although Brother Mythos does have some good points, and it would make sense to do a comparative study of catapults vs. trebuchets prior to proceeding.

[Doktor Howl]

Now don't get me wrong, I have nothing against dirigibles. But, steam punk is a whole different genre. If we're going to go that route, then someone should have told me that in the first place.

The fleet of dirigibles was just an example.  The OP clearly has some sort of problem, which he believes can be solved by flinging a nuclear plant with a catapult.  However, before we spend too much effort on this, we need to stop and determine if there is a better way to accomplish the OP's real objective, which he hasn't stated.

We also need to consider questions such as:

Is the plant being flung to somewhere, or away from somewhere?  What are the accuracy requirements?  Would it be acceptable to dismantle the plant, fling the individual components, and then reassemble it at site?  (Hurling one building at a time would help reduce the scale of equipment required).

Why a catapult in particular?  Has using rocketry and/or explosives to put the plant into a sub-orbital trajectory been considered?  I've already expressed my preference for dirigibles, but if the hurling part isn't strictly necessary, very large flat-bed trucks might also be appropriate.

Nuclear power hasn't been very popular lately.  Why not fling a solar power installation, instead?

Of course, if hurling a nuclear plant is the objective in itself, then this analysis is unnecessary, although Brother Mythos does have some good points, and it would make sense to do a comparative study of catapults vs. trebuchets prior to proceeding.

I can't argue with this sort of superior logic.

[rong]

If the plant is on this planet (or any planet for that matter)  it is already hurtling through space at a very high rate of speed.

[chaotic neutral observer]

I can't argue with this sort of superior logic.

When you spend six months designing and building a 200-ton robot monster, only to discover that a roomba with a salad fork duct-taped to it would have worked just as well, you think about these things.

[Con-troll]

Sorry, I was off the grid for a moment, dodging flying potatoes with wires attached to them.

So the plant doesn't exactly need to stay intact during the flight phase, but if it did the result would look way more spectacular in the evening news. The main mission objective is to powerlevitate something heavy enough that the modern missile defense systems would just sigh, give up and go to a holiday somewhere warm and nice where there isn't any flying nuclear plants.

Also the trebuchet seems to be fitting my purposes better, thanks for suggestion. Anything more modern than that would kind of ruin the point I'm trying to make.