Scratchbuilding the “Princess Cecile” – Part 2

July 1, 2009

(The continuation of  the thought process behind re-creating – or in this case, creating – the design of the Princess Cecile, a starship from David Drake’s RCN/Daniel Leary novels.)

Early Design Decisions

How low-tech should the Princess Cecile look? Should she really be just a cylinder, with appropriate hatches, communications antennas, fittings and rigging? Should she be more streamlined, even though she almost never moves at high speed along its long axis? How “submarine-like” should she be? Should her design have more of a “steampunk” feel?

What scale is appropriate? Scale determines the level of detail that can reasonably be added to the model. Assuming all the sails are set, the Princess Cecile measures 230 feet in length by 90 + 90 + 55 = 235 feet in diameter; 70 + 70 + 55 = 195 feet if the lower mast length value is used. At 1:200 this makes the model a little over a foot long (13.8 inches), and over a foot in every other dimension. The sails make the ship harder to display unless they are folded and the masts telescoped and laid against the hull. The ship is much more visually interesting with the sails set, however.

At 1:200 the diameter of the hull is 3.3 inches – if the hull is a true cylinder this would have to be scratchbuilt. At 1:220 (model railroad Z scale) the ship is 12.5 inches long and 3 inches in diameter. Perhaps this is a better scale despite the calculations required because railroad figures could be modified to represent riggers, and Captain Leary navigating the ship through the Matrix standing on a spar…

How rounded should the ends be? If they are hemispheres they may be commercially available, but if they are more parabolic they would need to be scratchbuilt. Not much information in the book descriptions to go on, here; at one point Drake says the ship is shaped “like a cigar,” but that doesn’t help much. Here’s my theory:

Any vehicle designed to operate in the vacuum of space is a pressure vessel. No matter what atmospheric pressure is used inside the ship, the hull must be able to withstand that pressure. Nothing in the books causes us to believe the ship is kept at anything other than “standard” atmospheric pressure, whatever that must be for Cinnabar. There is little mention in the books about inhabited worlds the Princess Cecile visits having different air mixtures or pressures. It’s space opera, true, so the level of hard-science scrutiny is lower than with a book by, for example, Larry Niven and Jerry Pournelle, but it makes a significant difference in the design of the ship if it is kept at one Earth (Cinnabar) atmosphere or at a significantly lower pressure.

Lower pressure and a higher partial pressure of oxygen means the hull doesn’t have to be as strong. Higher pressure has many advantages for the crew. Not the least of these is less likelihood of fire. The main reason for the Apollo 1 fire was the use of a pure oxygen atmosphere, at much lower pressure than sea level on Earth. In pure oxygen even steel fittings can burn! There is no indication that there is much pressure change when the Princess Cecile lands and hatches are opened to bring fresh air into the ship after a long voyage. Therefore, I assume the ship uses Earth-standard air pressure and mix.

A hull that was shaped like a cylinder with domed ends would distribute stress much more evenly. The ship may have a double hull to prevent loss of atmosphere when damaged – the space between hulls is mentioned in the books. Still, a cylinder is most logical for a pressure vessel, as are domes on the ends – look at all kinds of gas storage tanks for examples. It’s not as cool-looking as, say, post-Next Generation Star Trek designs of starships, which were increasingly aerodynamic for no reason but looked like they should travel fast, but it has the advantage of being more easily repaired on lower-tech worlds. As noted above, the hull is steel, not more exotic materials. Rectangular patches could be welded onto the hull with far less effort than if they had to conform to more curves.

There are tens to hundreds of thousands of ships traveling from star to star in Drake’s universe. Most of those are commercial ships, but many high-tech worlds have their own space navies as well, and the Alliance and the Republic of Cinnabar have extensive naval forces. The construction of a starship of the size of the Princess Cecile appears to be no more complicated than constructing a similarly-sized US Naval vessel today. Plasma drive and High Drive engines are modular and are swapped in and out, even when manufacturers and ages vary, just as with modern aircraft. (As described earlier, in one book 50-year-old engines from a crashed ship are salvaged for the repair of a captured Alliance vessel.) Leary mentions several times the relative merits of modular-constructed ships and those that are built as one piece, admitting that both have advantages and disadvantages.

The Princess Cecile was built on Kostromo and “appropriated” by Lieutenant Leary during an Alliance-backed military coup, but it was later substantially rebuilt several times on Cinnabar in Leary’s own yards (originally owned by his uncle, famed astrogator Stacey Bergen). It also was extensively repaired on several other planets. By now the Princess Cecile is something of a patchwork. I would expect some plating patches to be visible on the hull, along with burn marks and melted spots showing she has been “in the fight.”

So: the hull is a steel cylinder, with multiple hatches, holes repaired with steel patches welded in place, cylindrical ends, antennas, masts, the riggers’ semaphores, the oleo struts for the outriggers, two plasma gun emplacements, missile hatches, and various fittings to help step masts and repair rigging. No windows are present, and no mention is made of external paint markings of any kind.

Probably nothing will affect the overall appearance of the ship more than the sails. Drake alludes to three sails per mast by sprinkling some sailing terms into the descriptions, but he spends little time talking about the sails. (He spends considerably more time complaining for his riggers about the lack of reliability of masts, yards and rigging!)

Planning Construction

Once I decided on the cylindrical tube shape, I was able to select parts to begin hull construction. I navigated the Plastruct site despite the fact that it is extremely difficult to search, and selected a piece of 3 inch ABS tubing, 18 inches long (TB-300, if you are interested) and two hemispherical end caps (#95859). That set me back just over 20 dollars plus shipping. Once it arrived I began to map out locations of hatches and fittings.

Since the outriggers are of smaller diameter, and no dimensions are given in the novels, I planned to use locally-obtained tubing for those parts. My next issue is how to build the plasma nozzles. I assume they should look like jet engine “turkey feathers” since the are often described as opening and closing to vary thrust. I may actually try resin casting for the first time…

(To update the above paragraph, I decided to buy 1 inch tubing from Plastruct after all. I also bought some plastic sheet designed to simulate decking (for the tops of the outriggers) and some other pieces designed to look like steel bracing. Not sure where that will go…)

The Question of the High Drive

In several locations in the novels the plasma thruster nozzles are described as being on the underside of the vessel, where they would be out of the water when the ship had landed on its outriggers. The High Drive engines are noted as being on the outriggers, and partially submerged when the ship is floating…that is, except for here, in Lt. Leary Commanding:

The High Drive delivered its thrust from a multithroated central port rather than eight—six during most of this liftoff—widely separated plasma nozzles. It was as though the Princess Cecile were balancing her thirteen hundred tons on the point of a needle. The controls kept the corvette aligned by minute changes in the thrust vector. The direction of “down” changed many times a second.

Repeated text searches through all the novels found nothing about the number of High Drive engines on the outriggers. Other vessels have from four to forty-eight, depending on size and use. Even Alliance and Cinnabar-built missiles have two High Drive engines, so I can’t believe this paragraph was anything but an oversight. Later in the same book:

The Princess Cecile was through the squadron, dismasted and with half her High Drive nozzles unserviceable.

Perhaps Drake meant a single antimatter generator fed all the nozzles. This is logical (and described several times), although moving antimatter to the nozzles on the outriggers is no small trick!

So how is antimatter delivered to the nozzles? I would speculate that there is a fail-safe delivery system that requires the outriggers to be retracted against the hull, since the High Drive cannot be activated in an atmosphere without devastating consequences. However, in The Far Side of the Stars Adele Mundy booby-traps an Alliance craft, the Goldenfels, by cross-connecting the controls for the plasma drive to the High Drive. When the Goldenfels’ captain tried to lift off, the ship is severely damaged by the violent interaction of antimatter with the ship and the surroundings. Perhaps the Alliance isn’t smart enough to make the High Drive fail-safe; but this is mature technology and it seems that it not likely. Leary describes the Alliance spacers as being undertrained and often pressed into service and therefore unmotivated, but he rarely sneers at the quality of Alliance warcraft.

The “usual” way to confine and manipulate antimatter is by intense magnetic field. This would require some sort of transfer tubing for the antimatter flow (and the corresponding water reaction mass as well) to the outriggers. Should it be some kind of flexible tubing, assuming room-temperature and flexible superconductors? It would be safer, I would expect, if there was some kind of nested fitting: as the outriggers retract, the fittings on the hull connect to their mates on the outriggers. This adds a safety feature the Goldenfels did not have – the High Drive motors could not possibly be engaged on the ground.

Again, just how much suspension of disbelief is required? I just don’t believe in the reliability of a “superconductor magnetic hose” that moves antimatter and remains flexible. The technology of the Leary universe only supposes a few “magical” developments: the plasma thruster, the antimatter converter, and the holographic computer displays and virtual keyboards. So far I’ve stayed on conservative side, and I will again: there will be a fitting on the hull on either side to mate with another on each outrigger.

There is another safety feature evident in this configuration. Antimatter is channeled from the converter to the two fittings, so it travels the absolute minimal distance necessary in the ship. Placing the High Drive motors on the outriggers minimizes the danger of antimatter mixing with matter near the crew. (Unfortunately, there is much more danger from the missiles, which use two High Drive motors each. They must somehow be fueled from the antimatter converter before launch. Not a job I’d volunteer for!)

Beginning Construction

On June 12, 2008 the 3 inch tube and end caps arrived. I compared the profiles of the end caps to the sketch I made a few days ago. I also made some hatches out of thin sheet styrene while I was waiting for paint to dry on another project. I did a little math to approximate how large the hatches should be if they were designed to allow two riggers, in suits, to leave the ship at once. They are about 3/8” high and 1/2” long.

If we assume five decks with double-hull construction, each deck is only about 1/2” high or less. At 1:220 the average height for a man is 72/220 inches or .327 inches – a little over 5/16”.

The first job will be to cut the tube. I may not attach the end caps right away. I can’t screw this up because I only ordered enough for one tube!

I also ordered some balsa foam from Dick Blick, the art supplies company. It’s expensive stuff but you can carve it with sanding sticks and sandpaper. I’m working on a possible High Drive motor casing shape. If I come up with something workable it may ultimately be used as a master to cast resin copies.

Here’s the cut cylinder with the end caps taped on, to give you an idea of the general proportions of the vessel:

cylinderThe little peanut in front is the test balsa-foam High Drive motor casing. The curve on the left side was cut so it could fit onto a cylindrical outrigger. I may still abandon that design. Somewhere in one of the books I read a High Drive motor described as a “lump,” so I thought of it as a more curved shape than the other main parts of the ship. They are also supposed to be movable from ship to ship, so perhaps this is a nacelle with the motor inside, just like commercial jets that could use GE, Pratt & Whitney or Rolls-Royce engines inside the same housing. Having a bit of streamlining can’t be a bad thing.

Outrigger Struts

Drake says the outriggers are attached to the hull by “oleo struts” and that the outriggers retract to the hull once the ship is in space. The High Drive motors would be engaged after the retraction is complete. As I’ve tried to visualize this similar to aircraft landing gear, I can’t see a simple, load-bearing way for the High Drive motors to remain vertical with the outriggers extended for landing. Since this particular model is to be finished in a “rigged for the Matrix” mode, with the antennas extended, the struts would be retracted and the outriggers would be tight to the hull. (Note: I am not as sure of this as I was a year ago. I may build the first one in the “landed” configuration, perhaps with a couple of antenna masts extended and crew working on them.) The outrigger tubing and hemispheres arrived from Plastruct yesterday (6/17/08) and I started to fashion a semi-working set of struts from brass and aluminum tubing to get an idea of how these should work and should look. At first I thought I would make them functional, but I decided that once I know how they should look I will build them all in the “retracted” mode.

I’ve also been thinking how to display this thing – with all 24 antennas extended it will be a porcupine in space!

Update on July 1, 2009 – I spent the last year working mainly on a Moebius big Seaview, which is about 80% complete now. Tonight I came up with a possible strut arrangement:

strut prototype sketch

strut prototype sketch

I’m mocking up a version of this to see how it might work. I’m also working on the High Drive “peanut” to see if it’s a viable motor design. More on this later…



  1. Greetings,

    Only recently discovered the RCN and was looking for other fans and scratch modelers when I stumbled over your Blog of the Sissy build. — I think its GREAT! I can hardly wait to see more.

    Keep It FUN!
    Dan G

  2. I’m a big fan of David Drake and especially his RCN series. It’s been a while since this was posted…has there been any progress made?

    Looking forward to seeing it.

    • There are five or six other posts I did after this on the progress of the build. I think I need to put a “Search this site” function up…

      Anyway, I’ve not touched it for months, unfortunately. Last summer I got a new part-time summer gig and I spent quite a bit of time at my parents’ home in Ohio, helping them out. Since school started again (I’m a high school teacher) I’ve just not had the time. My life has been overcome by work. I hope by Spring Break, at least, I can get back to it.

      • Aha…I was able to Google up some of the later posts. What I’ve seen looks good. I know all about real life intruding into hobby time, so I won’t fault you for taking your time. Keep up the good work.

      • I put the search widget on the page. I hope it helps. I suppose I should create a page with the links to all of those articles on it. I’ll definitely do it when I’m finished! (Whenever that is…)

  3. The Plasma weapons on the Princess Cecile are in 4 turrets. The turrets contain one 4 inch plasma cannon each. They are on extending turrets, that have access from the inner hull. (Though that access has to be through airlock hatches. There are several instances where the upper turrets are extended to help with ventilation, and the ship also retains air pressure while the cannon turrets are extended.) Just wanted to provide more information, from what I read, it seemed like you thought the turrets were a two cannon on one turret affair, and that there was only one on top, and one on bottom.

    • The book states “Two twin four-inch plasma cannon provided the corvette’s defensive armament in turrets offset toward the starboard bow and sternwards to port.”
      Two turrets, twin mounts in offset positions fore and aft. Just wanted to provide more information, from what you wrote it seemed like you thought the turrets were a one gun per turret affair in four turrets mounted who knows where.
      The book, page four of my copy, clearly describes two offset turrets and the gun mounts they contain, never does the book suggest a turret mount top and bottom.

      • …and now I’ll have to look it up, since two of you guys gave conflicting info! I tend to think the Reverend is correct, since that is what I recall as well (!)…but the wonderful thing about the Sissy is that it kind of changed from book to book. Since Dave Drake never made any sketches – at least not up until my correspondence with him – I assume the ship could be a bit changeable.

        My plan is two turrets, one at either end, with two cannons in each. A four-inch plasma cannon on a 1:200 scale model will be pretty small, and if it has traditional-looking gun-type barrels, they could be very thin. My plan right now is to make them extremely thin and probably not very long, either, partly to stay in scale and partly because at that scale a lot of detail is lost.

        While the Princess Cecile definitely has a top and a bottom, it is basically a cylinder with rounded ends, or “cigar-shaped” in some books. In actual battle the ship must maneuver in three dimensions, so I think one turret will be accessed from an upper deck and one from a lower deck. so both the “top” and the “bottom” of the ship are protected.

        I’ve got to get back to work on this thing…I recently moved and reworked the hobby work area. Maybe I can get back to it in a month or too, finally…

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