Starship Upgrade

by Robert Klaus
Comments on this article may be made to the author.


  1. Modeling the Original Romulan Bird of Prey
  2. Design History
  3. The Filming Model
  4. The AMT Kit
  5. Scale
  6. Building the Bird of Prey
  7. Notes


Modeling the Original Romulan Bird of Prey

The Romulan Bird of Prey is one of the most striking ships to be used in the whole of the Star Trek Saga. It only appeared in two original series episodes, but left a lasting impression and went a long way toward creating the Romulan mystique. It was the first real enemy ship to appear, and the dramatic appearance of the ship, along with an exceptional script and fine performances made "Balance of Terror" one of the best episodes.

Mark Leonard, as the Romulan Commander, made such an impression that he was later brought back as Spock’s father in the original series, the movies, and The Next Generation, and as a Klingon Commander in the first movie. If anything he made too good an impression. The Romulans come across as honorable enemies: ruthless and dedicated, even fanatical, but brave, loyal and intelligent. When really nasty enemies were needed for later scripts it was necessary to create the Klingons, the Romulans were just too decent. In another reality we might have called them friends.

This upgrade is included more for historical interest than anything else, as the basic kit is no longer produced. It does however illustrate some useful techniques, which apply to other ships.

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Design History

The basic design of the Romulan Bird of Prey (RBP) was driven by the original script for "Balance of Terror". The script was based on the book and film "The Enemy Below". The story (highly recommended by the way) concerns an American Destroyer pursuing a German U-boat which has just completed a raid on a convoy, and is now heading back home. In order to reproduce the relationship between the destroyer and the submarine with space ships it was necessary to devise a threat ship that would have tactical qualities similar to a sub. The cloaking device is equivalent to submerging. The ship is rendered invisible, but can be detected approximately by instrument (sonar/sensors). While invisible its speed is greatly reduced (running on batteries for the sub, high-energy usage for the RBP). The ship is armed with a powerful weapon, which could destroy its enemy with a single hit (torpedoes/plasma weapon), but must become visible to fire it (periscope depth/decloaking). Most of the characters have direct analogs as well.

The design of the hull of the Bird of Prey somewhat resembles the main hull of the Enterprise. This is neither coincidence, nor laziness on the part of the ship's designer. In the early drafts of the script the resemblance was even greater. The Romulan was originally to have been obviously based on Federation technology. Apparently the ship was to have looked like a cruiser main hull with warp nacelles attached by short pylons directly to the hull. This was to suggest that there were traitors in Starfleet, creating the paranoid atmosphere, which would later be reinforced by the first glimpse of the Romulan crew. This idea was later discarded (only to reappear in the novelization), and the Bird of Prey evolved away from that concept, although much of the cruiser appearance remained to the main hulls basic shape. The extension at the aft edge of the hull may have been intended to accommodate small craft, and engineering functions which, in the Enterprise, were placed in the secondary hull.

Interestingly, the design concept and hull warp dynamic shape would reappear as the USS Reliant, also an 'enemy' ship with stolen Federation technology, which first damaged, and was then defeated by, the Enterprise. In both cases the story opens with the Enterprise responding to a Federation station attacked by a mysterious vessel and in both Capt Kirk used the sensor obscuring properties of natural phenomena (the comet tail and the nebula), to trap the enemy. Both enemy ships had serious, but survivable, damage and were self-destructed when their commanders detonated devices. The first story introduced the man who became Spock's father; the second introduced Kirk's son. The first had Kirk conducting a wedding that almost happened, the second had a woman that Kirk almost married. (I believe, in fact, that she was the ‘little blond lab technician’ Kirk almost married while an instructor at the Academy. "Where No Man Has Gone Before".)

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The Filming Model

The Bird of Prey filming model was a beautifully built and finished item. It was apparently about four feet across the wings, and had a multi-position armature mounting arrangement.

Some sources have stated that it was quick and dirty model, made of wood and plaster, and not intended for close shots, or long term use. Examination of the photos seems to belie this assertion.

There was extensive surface detail in the form of windows, and paint. The windows were actual clear parts, rather than being painted on as in the original Enterprise model. The basic hull was painted in at least two colors, had metallic details, and the truly remarkable "Bird of Prey" emblem on the lower hull and bottom wing surface. It had a working lighting installation, with the nacelle domes lit white. It is possible the clear windows were lit as well.

It was, overall, a better, more detailed model than the original three-foot Enterprise used in the first pilot.

After filming of "Balance of Terror" was complete the model disappeared. One source suggests that the model may have been loaned by Gene Roddenberry to a friend, and then not recovered after his death. Another says that it is in the hands of a private collector, who, on being contacted by the Smithsonian, refused to lend it for the 30th anniversary show. He may have been concerned about Paramount recovering the model. Stock footage of the ship was used in "The Deadly Years". Klingon Battle Cruisers were used by the Romulans during their next appearance in "The Enterprise Incident".

Paramount has said the model was stolen, and they would like to have it back.

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The AMT Kit

The Romulan Bird of Prey kit was produced during the original run of the series, and never re-released. Its AMT number was S957. It is possible that its mold was lost at the same time as the original production Enterprise. It is a very simple kit, consisting of just eighteen gray plastic parts including the unique three-leg stand. No clear or chrome parts were included. It did, however, have a beautiful four-section decal of the Bird of Prey emblem.

AMT also produced (and still produces) a small scale Bird of Prey in the Classic Three Ship Set, along with the Enterprise and the Klingon Battle Cruiser. The size relationship between these three ships is consistent with the larger scale models. Originally this was kit number S953, currently 6677. The small-scale ship appears to be a simplified copy of the larger model.

Several other companies have produced even smaller versions of the ship, in most cases apparently based on the AMT kit, rather than on the original.

AMT reportedly did not have access to the filming model (or, apparently, detailed plans) when they went to make their duplicate, and had only episode footage to go on. It is possible they had a three-view drawing. (The kit box has a two view with a scrap view of the cupola.) Note that the two main areas of error in the kit, the boat tail and the hull edge, would not be readily apparent in a three view. They did not do a bad job, under the circumstances, but the model does need some help.

Careful examination of surviving photos of the original filming model may convince you that it is not possible to build an accurate model from the kit, and that you’d be better off scratch building one (or giving up the whole idea and selling your unbuilt kit to a collector). Don’t get discouraged. While it may not be possible to build a 100% accurate model from this kit, it is possible to take it from about 60% to at least 90%. General outline of the main hull, wings and engine nacelles is good. The vertical cross section and some of the details are less accurate.

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Much debate has arisen about the scale of this kit, and the size of the original. At one time AMT listed this as 1/635, making it very close to the Enterprise kits’ actual 1/629.2. (The reference in question also lists the Enterprise kit as 1/635.) Most fan sources contend that the real Romulan vessel was much smaller than the Enterprise, based on its smaller crew and ‘cramped’ appearance.

The first point, the ‘smaller crew’, is one that has always perplexed me. Nowhere in the episode is there a reference to the size of the crew. Only a handful is seen, but not many more of the Enterprise crew are seen in some episodes, certainly never all 430. A close examination of photos of the original model (available from Lincoln Enterprises) shows that the ship had two rows of windows on the hull sides, implying it was two decks thick at the edge, just like the Enterprise. (Actually, at some points it seems to have two and a half lines of windows, maybe sleeper decks, like a Pullman Car or a Douglas DST.) Since the deck to deckhead height was similar to the Enterprise (in fact it was identical, as the Romulan Bridge used a redressed Enterprise set) the hull should be about the same thickness at the edge. Comparing the model kits, one finds they are of similar thickness at the edge. Looks like AMT got this one right.

Legitimate alternate explanations for the ‘cramped’ conditions could be the large amount of space taken up by the plasma weapon, the generally lower level of technology exhibited by the Romulans at that time resulting in larger internal machinery, or, the Spartan philosophy and style the early Romulans displayed. The actual size of the Bird of Prey, and the scale of the model, probably doesn’t matter if you are building a stand-alone model for display. If you wish to display it with other ships, or landed in a diorama, on the other hand, the scale is critical. I don’t insist that my conclusions are correct, I only suggest that you should come to some decision.

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Building the Bird of Prey

Three significant areas should be addressed when building the Bird of Prey: the boat tail area, the hull edge, and the nacelle domes. The first two of those problems appeared very difficult to solve, and in fact delayed my completion of the kit by some twenty-five years (mine was a birthday present in, I think, 1968. Thanks, Mom).

The Boat Tail. The boat tail area, under the aft hull, is incorrectly molded. It should be concave, rather than convex. This shows very clearly in some of the available photos. This problem turned out to be very simple to cure. I took the lower hull part, and carefully scribed lines from the apex of part to each back corner. These then served as guides to cut through the part with a razor saw. The cut edges were cleaned up, and then the removed section was flipped over and reinstalled. This produced the required concave shape. The part was aligned exactly at the aft edge, which is parallel to the waterline. Since the lower hull shape is domed rather than conic there were mismatches at the middle and front of the join lines. The front was carefully filed down to match before the part was installed. A small half round file was then used to dish out the leading edge of the part to continue the concavity.

The assembly was carried out with the parts sitting on a slab of finished marble, to assure alignment. Sheet styrene reinforcers were installed on the inside. The join was filled, and carefully sanded to maintain the sharp break seen on the original. (The mismatch at the center of each join was taken care of by filling and blending the area with putty.) The reworked hull bottom was now ready for the balance of the assembly.

The Hull Edge. The hull edge on the kit is vertical. It should have a slope, not unlike the Enterprise hull. Blueprints available show a slope of about 45 . Photographs of the original show closer to 20 or 25 off vertical. (The front view drawing on the side of the kit box shows this correctly.) Photographs of the original also show a sharp edge to the top of the hull, a narrow flat area, and then a raised center area. It turns out that solving both these problems was also fairly easy.

First, I traced around the edge of the kit's upper hull part (which incorporates the vertical sides), to provide an alignment plan, and to design the new upper deck part. Then I took the upper hull section and carefully cut away the vertical portion of the sides with a razor saw blade. To make this cut I first measured inside to determine where the upper hull met the sides. I then measured and marked the outside all around. I used a fine cut razor saw blade, without the handle, and very gently cut away along the line. (I have found that using a razor saw without the handle attached gives more precise control.) This left a large closed horse hoof shaped rim, and the separate hull top.

The rim was cleaned up and internal bracing, in the form of a longitudinal, and a transverse 1/4" square Plastruct beam (ST-8), was installed to help the hull retain it's shape. I installed the transverse beam first, let it dry, then fitted the longitudinal beams fore and aft of the transverse beam. The assembly was again carried out with the parts on the alignment plan, taped to the slab of marble, with the braces being flush with the upper surface of the rim. The previously modified hull bottom piece was then glued on. All seams were filled, and the bottom of the hull prepared for finishing.

Taking the hull tracing I had previously used as an alignment plan I drew an outline that would extend 1/4" around the existing part edge. The outline was then transferred to a large sheet of 20 thousandths styrene (actually I had to use two sheets at the time, the division running along the centerline, larger stock is available now so you can use a single piece). I used adhesive backed clear acetate sheet in a plain paper copier to transfer the designs, then cut the parts out with very sharp scissors. Normal drafting techniques to transfer the design would work as well.

The new upper deck was then installed on the bottom hull section, glued all around the edge, and onto the previously installed internal bracing. Be careful aligning this.

About eighty small triangular braces were then installed between the vertical sides, and the overlapping bottom of the new upper deck, leaving the area where the wings attach free. After these dried I plated over the area with 10 thousandths sheet. (If I had it to do over, Milliput would work better than sheet stock to fill the gap.)

Next I installed the wings. All gaps were filled and sanded, including blending the bottom of the wings into the bottom of the hull so the decal would sit more smoothly.

Going back to the cut-off top hull portion, I smoothed the cut edge, and glued the piece to the top of the new hull deck. This achieved the rebated edge seen on the original. Again, alignment is critical. Use reference marks, plans and alignment jigs.

The center fin had to be relieved on its inner edge to clear the new parts. At the same time the back edge of the fin was undercut to match the original. (The AMT part is vertical on its back edge.)

The nacelles should have translucent or lighted hemispheres on the front, rather than the opaque three-quarter spheres in the kit. The nacelle domes were replaced with Plastruct VHH-24 hemispheres. They were backed with silver painted disks, and lightly frosted to reproduce the original appearance. The rest of the ship was assembled per the kit instructions.

Small details I included were the plasma weapon emitter on the forward hull, and numerous windows, ports and panels made with dry transfers. The plasma emitter was carved from a block of plastic, with the detail added in finishing. If I did another one I would build this up from tubing and thin sheet to indicate the emitter array more clearly.

I used Navy Aggressor Gray for most of the ship, with Camouflage Gray for the boat hull area.

I was concerned that the large Bird of Prey decal would be a problem. Not only was it very large, but it was also twenty-five years old. I painted over the entire decal with Micro Liquid Decal, and used the same material on the hull over the whole contact area. This seemed to work, as the decal only had four small tears going on. After it dried thoroughly I applied another coat of Liquid Decal as a sealer, and a semi-gloss spray coat after that was dry.

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If you wish to build one of these classic old kits, I would recommend you do a few things I didn't. As usual, I found several good reference sources after completing the model. Overall the outline of the model is not bad, but there are three structural areas I did not address in building mine which could improve yours. First, the aft extension of the main hull may be longer on the original than on the kit. This could be extended with sheet styrene along the existing shapes. Second, the upper fin may be thinner, and the back undercut further. Fabricate a new one from sheet stock. Third, the first step of the cupola is shorter on the original. Cut off the kit part flush with the upper hull surface, sand it down and reinstall.

In paint and finishing there are several improvements which could be made. There was a wavy edge pattern on the vertical fin, and on the top aft edge of the wings and main hull. This should be painted on before applying the decal. This may be an additional feather edge pattern, or a catenary arch pattern. One source suggests this was in pink! The same source suggests that the lighter colored area behind the bird design may have been brushed aluminum.

From photos it appears the warp nacelle ‘exhaust nozzles’ were longer on the original. These could be made from plastic tubing of appropriate diameter.

The kit decal is quite transparent. If I had it to do over I would paint the whole bottom of the ship in the lighter shade, apply the decal, then carefully mask the decal and paint the area forward of it in the darker shade.

Nice variations could include:

Maybe if we all ask nice AMT will bring it back. My Bird of Prey model is currently on display in ‘The Hobbit’ hobby shop in Fayetteville North Carolina. They were the source of constant help and encouragement, and for all the supplies and tools used in the construction of this classic old ship.

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