bridge

Nope, It’s A Bridge

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Many of you, gentle readers, are also devotees of the Atomic Rockets web site. (As well you should be, if you are interested in matters rockety.) And, of course, you may have noted the Atomic Rockets Seal of Approval off in the right-hand column.

But today I’m going to talk about a place where I find myself, and the ‘verse, disagreeing with it. Specifically, with “It is a CIC Not a Bridge“. For convenience, I’m going to quote from it here:

That round room in the Starship Enterprise? The one they call the “Bridge?” Wrong term, that thing is a Combat Information Center (CIC). On a real wet-navy vessel, the bridge is a tiny two-station place used to control the the movement of the ship. It only had stations for the navigation and helm.

In other words, the “bridge” on the Starship Enterprise is that little console that Sulu and Chekov sit at.

The CIC is where all the data from the sensors, scoutships, intelligence agencies, central command, and other ships is gathered and evaluated. The important information is passed to the captain along with tactical suggestions. Exactly the way Uhura, Scotty, and Mr. Spock pass information and tactical suggestions to Captain Kirk.

http://www.projectrho.com/public_html/rocket/misconceptions.php#id–It_is_a_CIC_not_a_Bridge

So, here’s the thing. It’s actually slightly more complicated than that. There are three places on a wet navy vessel all of which do things that people think of as functions of “the bridge”.

There is the CIC, as described above. It’s the information-gathering and decision-making center.

Then there is the wheelhouse, which is where the ship’s movement is controlled from. This, on ships that had a bridge, was usually buried down inside the hull or beneath the superstructure – for one simple reason. You don’t want it shot off. If you lose the wheelhouse, you can’t command the ship any more, so you don’t want it somewhere vulnerable.

And then there is the bridge, which is the place you conn the ship from. It’s up high at the front of the superstructure with generous wings, etc., because its requirement is that you be able to see what the ship’s doing in order to command it.

(On a merchant ship, you probably don’t need a protected CIC, and since you don’t expect anyone to shoot your bridge off, you may have the engine-room telegraphs and wheel up there in one place. On navy vessels, on the other hand, instead of passing engine orders and steering directly, you have a bridge talker yelling “Port 40! Half ahead both!” down voice tubes to the wheelhouse.

On the other hand, the bridge is also exposed to heavy weather, so merchies that expect to encounter the rough stuff may still have a separate wheelhouse. This was actually where they first came from.)

In a historical digression, incidentally, the original bridge is an evolution of what was originally the quarter deck, the raised deck at the stern, on sailing ships. When it became more important to avoid your own smoke than see what your sails were doing, which is to say, as we moved from sail to steam, the raised area moved for’ard and became the bridge as we know it today.

As for the wheelhouse, that came from sailing ship designs in which the poop deck (the highest deck at the stern, typically forming the roof of the stern cabin) was extended forward to cover the quarter deck and the ship’s wheel, on the entirely reasonable grounds that in a storm, it’s easier to steer without being out in the full blast of wind and wave, and in battle, it’s much easier to steer if you have some protection from being shot.

So let’s bring this back around to starships.

You don’t need a bridge in the above sense. As it says further up that page, Rockets Don’t Got Windows – given space ranges and instrumentation, you are never going to be trying to conn the ship with your Mark I Eyeball, which is essentially what a bridge up high is for. Your best view is going to come from sensors, but they can be read just as easily from the CIC, buried deep in the center of the hull for maximum protection.

(Why did the Enterprise designers perch the bridge right up at the top of the saucer, with about three feet between the back of the fancy digital sensor-feed-showing viewscreen and hard vacuum, right where any Tom, Dick, or Kang could shoot at it conveniently? Were they all Romulan spies?)

Do you need a separate wheelhouse? Well, given that starships are certainly going to have fancy electronic controls rather than the hydraulic/pneumatic/etc., systems that imposed constraints on the position of wet navy wheelhouses vis-a-vis the CIC – usually buried down in the bottom of the ship where the armor is thick – I’m going to say probably not. The CIC’s already in the safest place, per above.

(You may have a maneuvering room, as they call the place on submarines, where the engineers translate your requests into detailed instructions to the engines, and given that a starship ACS is probably also rocket engines of some sort, that may also be handled from there – but that’s a different function.)

You are going to have a CIC, because you still need somewhere to coordinate information, make decisions. In my opinion, it will probably also be the wheelhouse (after all, as in the Enterprise example above, it’s just one console, and since the maneuvering orders are going to come from the officer on watch in the CIC anyway, why make him shout any further than he has to?).

The only question is whether it will be called the CIC. The above (combined CIC/wheelhouse) is essentially the arrangement they use on submarines today (where it is called the control room; the bridge is the place you can stand at the top of the conning tower when the boat’s on the surface).

That may be likely nomenclature for starships, too. (Nothing especially that civilian starships are unlikely to have a Combat Information Center.)

On the other hand, the Imperial Navy, and their merchant tradition, call it the bridge. Why? Well, unlike our submarines, there isn’t another bridge somewhere to clash with it – and you get your best view of what’s around from it – and in the meantime, it’s a name that’s got centuries, indeed millennia, of tradition behind it as The Place From Which Ships Are Commanded. It’s a word, in a nutshell, that’s got weight.

And since you’re combining all the functions back together, as they were in the beginning, that counts plenty.

The quarter deck, on the other hand, that’s somewhere else.

Building Bridges

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“Listen up, girder monkeys! Your job for today is to put the bridge in the Starwing-class courier floatin’ behind us. My job for today is to make sure you do it right.”

“Now, you are asking yourselves why the admins here at Islien have decided in their wisdom to put a bunch of rookies in charge of such an important part of the starship we’re building. That’s because it’s also the dumbest part of the starship. There’s no technical reason you need one at all: All the system primary controls are attached to their systems, and everything’s fly-by-wire. If the system bus and computers are up and running, you can run everything from your ‘lace or your pocketwatch from anywhere inside her, or within a few hundred meters of her hull if it’s a good signal day – and if they’re not working, you’re going to have to get out of your chair and beat brass with the techs’n’mechs anyway. It’s just there so the command conference has a table big enough to sit ’round and won’t all go space-crazy stuck in their cabins.”

“That is also why the plans you are holding are, for those of you who have read ahead, a one-page variant of ‘Conference Room, Microgravity, Type K-Eleven’. Everything in there – the walls, the virtuality couches, the displays, the data pillar, the armatures – is off-the-shelf stock. That’s your job – set ’em up, hook ’em in three-by-three, run the self-tests. The only exceptions are the sailing master’s hand controls. Those, and double-checking your work, are my job.”

“You, check the main lock and axial passage are clear. You go with him, post our warning v-tags. You, get back to the low power room, lock down bridge-compartment power in the off position and bring me the keys. The rest of you – parts inventory. Find what we’re missing before we miss it.”

“Now, snap it up! Rookies you may be, but I still expect you to get this done in one shift.”

– Airin Serannis, girder-monkey-herder, Islien Yards

In Lieu of In Lieu

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Well, I was going to post the second part of The Shipping Trade today, except that writing it didn’t happen because of day job, and so forth. Then, I thought I might post a sketch of the ship involved, just to give y’all an idea of what you’ll be looking at, but then that would require me to go out and hire a scanner. That, and I made said sketch, and then looked at it, and then concluded that I couldn’t possibly inflict such a terrible picture on my readers…

So permit me, please, instead to sketch a verbal picture for you of the

CMS Greed and Mass-Energy

To start with, Greed and Mass-Energy is atypically large for a free trader; in those leagues, which principally deal in small, high-value-to-mass/volume cargoes, lugging around 40,000 tons displacement of cargo is huge. (It’s still not in the major freight line league, though; those guys can use freighters that are million ton-displacement behemoths.) Thus, the shipcorp that owns her (it’s essentially a syndicate of officers, crew, and former crew, with executive power vested in the captain-owner) is pretty prosperous to be able to cover her running costs. Dealing in brokered cargo actually isn’t her main business – she specializes in contracts like the RCS-assembly charter from Kerbol to Kythera she just left, but an empty hold is a hole that drinks money, so you take the cargo when you can get it.

Also, obviously, at a size like that, she’s not streamlined, or built to land planetside (gravity wells being acutely expensive); and is even rather more massy than anything that most stations like to have dock directly to them. Her cargo’s generally ferried to station, or upwell and downwell, by local lighters at each end of the trip. Rather, she’s built very much in the classic mode; a long, relatively thin, open-frame truss structure. Attached to that, going from fore to aft, we find these different sections of the ship:

Right at the bow, sitting on the end of the main truss, is the command capsule, an ellipsoid slightly stretched along the ship’s main axis, relatively tiny compared to the rest of the ship, and containing, for starters, the bridge and associated avionics systems. (The bridge is actually buried in the center of the capsule, for its protection; it’s displaced off to the front end of the ship, however, because the command capsule is also where the primary sensors are housed to keep them out of the way of cargo, fuel, and drive radiation, and this positioning cuts down on sensor lag. It’s still pretty safe; it’s not like anyone’s going to be shooting at them.) The first of the other two notable features it houses is docks and locks, right for’ard on the axis where it’s easiest to match thrust and spin, which usually houses a couple of cutters used for taking the crew ashore and for occasional maintenance, and a skimmer for in-field refueling. (The fuel itself doesn’t pass through here – the skimmer docks aft to offload what it scoops. No fuel for’ard of the support plate, that’s the general rule.) The second, aft by the truss, is the robot hotel for all the little space-rated utility spiders you may see now and them crawling about the structure doing maintenance, thus saving the engineering department any need to get suited up and go outside for routine work, although they still may need to do so from time to time.

Just aft of that, accommodations and secondary systems are housed in a toroidal gravity wheel. This is actually a very unusual design feature in an Imperial ship-class; just about everyone and especially the spacer-clades are genetically adapted to microgravity, and the spacer-clades prefer it, as a rule; but the Cheneos-class architects originally designed her class for near-frontier work, and included this for occasional passenger service. Greed and Mass-Energy only rarely carries passengers, so they keep it geared all the way down, producing only a tenth of a standard gravity, which doesn’t offend the spacer-clades all that much. There’s a second, smaller wheel rotating inside it to null out the gyroscopic effects; it’s used to house some other equipment that likes a little gravity, but for the most part, this one’s just a countermass.

(The wheel does, however, provide enough gravity to let the CELSS Manager run a pretty decent microbrewery in the spare volume, and perhaps more importantly, provides a place where you can drink it off-shift without suffering from a nasty case of the zero-g bloat. [Remember, folks, bubbles don’t rise in microgravity!] And apart from crew morale, having decent beer makes for good PR when traders meet.)

These areas, incidentally, are one of the few places on board where the really high-tech ontotechnological stuff makes an appearance, in the form of inertial damping. The people who built her liked microgravity, and weren’t all that keen on losing that while under thrust, especially since she was built to fly brachistochrones or near-brachistochrones (bulk tankers and ore freighters, etc., are usually built to fly economic minimum-delta/Hohmann transfers; no-one else wants to wait that long for their cargo) and so would be spending most of her time under thrust. The job of the inertial dampers is to apply the thrust of the drives evenly across the entire area’s structure and everything in it, thus ensuring that no-one actually feels any acceleration, and the lovely microgravity environment is preserved. (It also avoids having to come up with some wretchedly complicated gimbal arrangement for the already wretchedly complicated seals-and-bearings for the gravity wheel, no longer having to do which is something that made architects particularly grateful for this innovation.)

Behind this, the cargo. ‘Way back along the truss there is a very large, solid plate, the support plate. The cargo containers are simply stacked “atop” – by which we mean for’ard – of it, in six big blocks arranged around the axis with sixfold symmetry (this arrangement being a reasonable compromise between use-of-volume and convenient straight lines), and are designed to lock to the plate, the truss, and each other to form a solid interlocked structure. There’s no hold or other walls around the cargo; the containers are themselves spacetight when they need to be, and so lighters can just drop them into place and pick them up freely while in port.

The breakbulk cargo, on the other hand, is messy. It has to be podded up individually when not spacetight, and then individually lashed down and made secure atop the cargo container stacks. This annoys the cargomaster, which is why breakbulk is unpopular these days despite the fact that breakbulk shippers usually pay a premium in exchange for you having to do this (the “lash comp”). Actually, what really annoys the cargomaster is that she can punch a button and have the ship automatically query the v-tags on the container cargo for its mass stats, and so forth, whereas for breakbulk she’s got to recall her Academy training, dig out the spreadsheets, and work out the corrections to the center-of-mass-and-moment-of-inertia chart by hand. Well, still by computer, but you know what I mean.

Aft of the support plate, still in sixfold symmetry, you have the bunkerage – fuel tanks, stacked three deep in multiple rows, all filled with slush deuterium, running right to the stern, where they surround the cylindrical shroud of the mostly-unpressurized engineering hull (you can take a crawlway right back along the truss to the small, pressurized maneuvering room back this far, should you need to examine the drives close-up in flight, but the actual machinery space isn’t), which contains the interlinked systems of the main power reactors and the fusion torches themselves, strapped to the aftmost extent of the main truss.

And there are lots of fuel tanks. Even though said fusion torches are miracles of a mature nuclear technology, capable of achieving near-theoretical efficiencies and outputs and delta-v per unit fuel that routinely makes naval architects from less advanced civilizations throw down their slide rules in despair and weep into their terrible coffee-equivalents, the one unchangeable rule of space travel is that your mass ratio is always much, much less favorable than you might want it to be.

Good thing deuterium’s so cheap, isn’t it?

(Edited to add: And I must have been half-asleep this morning, because I forgot…)

…and most prominently of all from a distance – dominating the entire view of the ship from a distance, by area as well as by temperature – sweeping out from among the fuel tanks (although comfortably retracted to sit alongside them, leaving approximately a sixth of their radiative area useful, while idling in dock – the vast panels and pipework of the heat radiators. Because the other one unchangeable rule of space travel is that you always have waste heat, too damn much waste heat, and you’ve got to get rid of it somehow. Especially once you fire up those fusion torches. (The radiators, however, unlike the rest of the ship, have only fourfold symmetry – so that they can be perpendicular to each other when unfolded, because there’s very little point in radiating heat right back at your own radiators.)

 

Trope-a-Day: The Bridge

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The Bridge: Unusually for fiction, buried right in the middle of the ship where some smartass can’t shoot it off.  Also, very distinctly not the Combat Information Center, the Flight Deck/Conning Tower, any kind of conference or communications room, Damage Control Central, Flight Operations, Astrogation, or any one of the other assorted rooms scattered throughout the ship’s volume where some department or other runs its stuff.

In some designs, may even be entirely virtual.