Okay, so Arsenal page 102 gives correlations for vehicle sizes up to body 4. For bigger vehicles, though, there seems to be no indication as to how big they're supposed to be.

For instance, take the Harland and Wolff Classique III. With Body 24....Is it 30 meters long? 50? 60?

Important, for example, if you're trying to determine if a ship can go through the Nicaragua Canal, or does it need to take the loooong way around Cape Horn.

In short, what I'm asking is: Is there -any- size correlation for these bigger vehicles?

I'd say somewhere between .4 and .6, but you need to keep in mind that "size" is comprised of several unrelated measures. Size correlates with weight, but the zeppelin (IIRC) has the highest Body published and it's lighter than air, so clearly that's not the only thing. Similarly, width, height, volume and density will all vary.

What's the IRL size limit for the Nicaragua Canal?

EDIT: .4 and .6 are statistical measures for a correlation indicating that it's moderately strong, but there's still a lot of unexplained variance... It was basically an attempt at a joke. Be not confused.

The Nicaragua Canal is the SR replacement for the Panama Canal...All written before the Panama Canal was expanded IRL.

The max stats prior to the expansion for "Panamax" ships are:

Length: 965 ft (294.13 m)
Beam (width): 106 ft (32.31 m)
Draft: 39.5 ft (12.04 m) in tropical fresh water (the salinity and temperature of water affect its density, and hence how deep a ship will float in the water)
Air draft: 190 ft (57.91 m) measured from the waterline to the vessel's highest point

...Okay, so most yachts will have no problem with those stats.

But it's still helpful (for figuring out where the things can dock, whether they can fit various things, etc) to know how big the damn boats are supposed to be.

It's all GM handwavium.

Body is a measure of how much damage a vehicle can take, it just so happens that bigger vehicles can take more damage.

Good point. I figure it is totally possible to have a really small vehicle with a large body because it is built tough, while also having a large vehicle with a small body because it is flimsy.

Take the hindenburg for example. That thing was massive but seemed to have a body of about 0. I mean think about something like a... sailboat, compared to a similarly sized ground vehicle. I'm sure the ground vehicle would have more body because it is built alot tougher than the sailboat.

Note that the armor stat does cover how resistant to damage the vehicle is to a point, body usually has something to do with mass, but yes even a fairly large vehicle that is fragile(small damage track) would have a low body, and some smaller vehicles are built like tanks.

I've run up against this in planning for stuff that's not in the rule book.

I've found body to be a better proxy for mass than size. I use the number itself as a simple comparison. Something body 18 is 'about the same size as a big semi tractor.' Something body 3 is 'about the same size as a dude.' Something body 4 is 'about the same size a big dude.' I also use the 'body should be bigger than anything it can carry.'

So, something like an M1 abrams would be about body 30 - bigger than a yacht (H&W Classique), smaller than a zeppelin (Luftschiffbau), about the same size as a medium-sized cargo plane (Skytrain). This represents some interpretation, but seems about right.

I agree with TheOOB re: body and armor - separate the calculation. I think heavily armored vehicles (like an M1) will also have huge body attributes, if only because you have to have a very heavily constructed vehicle to take all that armor.

Biggest place it runs into problems is with drones, and REALLY BIG vehicles. If you use this comparison, all the drones in the book are pathetically small and there are no drones for big tasks that should be quite automated. A drone forklift big enough to pick up a fully-loaded air force palette would be about body 16. One of those big dump trucks that they use at quarries should be about body 24. And those strike me as the kind of things that SHOULD be drones, much less stuff like the Vulcan, Beaver, and Schildrote, which seem pathetically small for what I'd design a drone for in those situations.

Likewise, the patrol corvette and the boston class sub are about right for a large boat/very small ship (think slightly bigger than the coast guard intercept boats in the movies). Something like an aircraft carrier or superfreighter would be about body 60+, and a semisubmersible drilling rig would be damn near body 100.

But, I figure, if ti comes up in game, well, that's what GMs are for.

re:Penta's comment about the zeppelins - zeppelins can get as big as you want. The Luftschiffbau seems about the right size for a cargo zeppelin, which could easily carry two or three tanks.

One other thing - this comparison also breaks down for comparing vehicles and people on anything aside from base averages. C'est la vie.

102 Arsenal gives correlations for DRONE sizes, not vehicles. A drone with Body 4 can be anywhere from a motorcycle to a small car, but actual motorcycles can be as high as 8. There's no correlation there. Body is more a measure of how tough you are and how much of a beating you can take. While it's often comparative, it's not necessarily so.

Vehicles aren't really given any absolute sizes. That's really up to the GM.

I really suggest you just pick an RL comparable vehicle to whatever you want to compare and use those stats. For an H&W Classique III, just find yourself stats for a yacht and use those sizes.

It's also used as a measure of the amount of extra equipment - modification - the vehicle can take, so presumably it also correlates somewhat with size, but even a casual inspection of the vehicle tables shows this correlation is not strong. In Shadowrun 3, "capacity" and "ability to resist damage" were two different attributes; the price we pay for simplification in SR4 is abstraction at the cost of accuracy.

The main problem with that is yachts range in size from under 50' to over 300'. You'd have a similar problem with zeppelins since they also come in just about any size you could want them in.