Refit Constitution Class Starship Hull Thickness

[Mike DiCenso]

I had noticed while writing up my review for Brian Young's Minbari vs Federation video that we actually have a good way to measure how thick the hull of a refit Constitution-class starship is. In this particular case, the Enterprise NCC-1701.

During the scene in Star Trek: The Motion Picture where Scotty and Kirk fly around the Enterprise in a travel pod and then dock at the stardrive hull's port midships hatch, we see this:

http://movies.trekcore.com/gallery/albu ... hd0381.jpg


You can see fairly well that the docking mechanism on the travel pod is actually rather substantial and also that the docking port itself is rather deep, plus there are doors just beyond all that as seen in this angle shot here:

http://movies.trekcore.com/gallery/albu ... hd0377.jpg

So the hull is fairly thick because not only do have have to account for the depth that allows that docking mechanism to be firmly seated all the way into the port, but the doors and everything beyond that, which in this scene here shows the doors are not exposed like those sliding doors on a track you'd see at your local supermarket, but have some structure beyond to accommodate them. Also note to the left of characters the rather thick beam there. The Enterprise is pretty sturdily built.

So can we scale the size of the travel pod and the docking mechanism? Yes, we can! This view heregives us a good complete side profile to gauge how much of the docking mechanism represents to the pod's overall length. The mechanism is approximately .96 inches deep. Travel pod is 9.74" overall. Or approximately 10 to 1 ratio. The backstage numbers give the travel pod a length just shy of 5 meters, which is consistent with the visuals. So 4.99 meters divided by 10 = .499 meters. So half a meter deep for the Enterprise's hull in that section, and we're not even taking into account for the extra depth required to accomadate the hatch doors on the Enterprise's side!

For a comparison, the armor belt on many battleships seldom exceeded 13" in thickness. The greatest battleships of all time, the Musashi and Yamato had 16" armor.

Now it is possible that the Enterprise's hull is actually a double hull, with hollow space in between that half meter plus, but even still the thick construction of the supporting beam seen next to Kirk, Scotty, and the young ensign greeting them at the cargo hold docking port argues for thick plating and little hollow space between them.

In conclusion, I think the next time firepower calculated from Wrath of Khan or other similar incidents, we have to take this into account, along with the added toughness provided by the defense fields and SIF.
-Mike

[Jedi Master Spock]

That would be about 40,000 cubic meters of outer hull material.

We've always had a bit of an issue related to the "million tons" figure thrown around for the Enterprise; it provides a substantial contrast to the 700,000 ton figure used for Voyager.

However, the thickness of the E-D's hull has seemed to be on the order of 0.1-0.3 meters. If Voyager's hull is 0.1 meters thick on average, and the Constitution class has an 0.5 meter thick hull, then the Constitution class requires three times as much hull material as the Intrepid class.

If the density of the hull material is, say, 20 g/cc, and Voyager's hull is 0.1 meters thick - which might be pushing it on both sides - then we'd have the following breakdown of the masses:

• Intrepid: 210,000 tons outer hull, 490,000 internal.
• Constitution: 560,000 tons outer hull, 440,000 internal.

Suddenly, the density difference doesn't look that strange any more. And if we assume that the hull material used for the Constitution class is a little denser than the one used on the Intrepid class as well as thicker, you push things a little further in the direction we want to see.

The model of Star Trek I've been arguing in favor of has assumed the Constitution class should have a fairly thick hull, thanks to its high mass, and confirming that supports it.

[Mike DiCenso]

I hadn't thought of it quite that way, JMS. I aways assumed that the hulls were more or less the same in thickness and density, but the primary difference was in the size of the warp nacelles, and the big, thick heavy coils inside them. Even though the Intrepids are more advanced, and presumably far faster, their warp nacelles are positively puny by comparison to those on the Constitutions.

To get an idea of what I mean there is this readout display schematic of the U.S.S. Defiant from "In a Mirror, Darkly, Part I":

http://ent.trekcore.com/gallery/albums/ ... ly_617.jpg

You can see the warp coils quite nicely, and they are huge, and just remember the Intrepid class nacelles are about one-third the size of the Constitutions'.
-Mike

[Mr. Oragahn]

Why do you use the thickness of the docking module embedded into the hull as a gauge, when we have plenty of windows on either sides which show us a considerably thinner hull thickness?
It's like measuring the thickness of the walls of your house based on the depth of the vestibule.

[Mike DiCenso]

I considered that issue, as well as the possibility of a double hull construction. However, while there may be thinner hull structure around say, the officer's lounge, with it's big open windows and were armor would be pointless because of that, I went with the construction of the inside views of the walls around that area. For example, consider this image:



This is the main cargo area adjacent to where Kirk, Scotty and the Ensign are. Not the very heavy-duty construction of the overhead and side hull frames. I don't believe this is just simply something because the area around the port hatches are a vestibule, they have too much surrounding hull structure for that to be the case (again look back at the images I linked to of Kirk, Scotty and the Ensign). For a higher res look, there is this HD image here. Look immediately to the left of the cockpit of the work bee shuttle towing the cargo module train, and you can see a hatch similar to the one Kirk and Scotty exited, there is structure all up and down the hull, it is not simply a box and then thin hull. And again, look at the heavy frame structures. So at least in areas of the stardrive hull, it is double or even perhaps triple hull as we see on the lower most level a hallway that heads outwards 90 degrees to the main cargo hold and goes several meters before the view is blocked of it.

And here's another issue; when the Reliant's phasers carve up the Enterprise's port side torpedo room, they hit around of the docking hatches, which should be of similar construction as the one in the midships docking port area, and that still requires a lot of energy to punch through. As for the window hull thickness, it's difficult to gauge since we don't have good shots of them. But we do have this in one of the rec room windows and you can see multiple planes of (presumably) transparent aluminum and the depth of the window frame looks quite thick indeed. By contrast, the windows around the officer's lounge in the dorsal superstructure below the bridge has slightly thinner hull as seen here.

So I think there's definitely some hull variation for thickness, but overall I believe the case is made that the hull is much thicker in the areas that matter most, like the stardrive and main saucer section hull.
-Mike

[Mr. Oragahn]

On the second big picture I fail to see any hatch at all, only openings through the inner beams that compose the structure. Notice that such elements of a superstructure, on modern ships, appear thicker than the hull of the boats.

This picture is the only one that conclusively suggests a thicker hull. Perhaps .4 m. All other shots featuring windows show a thinner hull. Simply put, the thick hull appears as an oddity, not as the norm, either on the back of the ship or at its midsection.
It would seem that to keep the ship lighter, they put more armour in few but prime areas and let the rest go with much less material.

[Mike DiCenso]

What other ones? The only one that shows differently is the huge windows of the officers' lounge on the tail end of the dorsal superstructure. The one view with the guy looking out the little porthole to one side of the docking port doesn't tell us anything really and the transparent material (glass or transparent aluminium or whatever it is) could be as thick as the glass on a deep diving submersible like the ones seen here on Russia's Mir 2 submarine. You can't tell those windows are nearly 8 inches (20 cm) thick of acrylic.

Another suggestion of hull thickness is found in this travel pod POV shot looking at the open hanger bay and fantail section of the stardrive hull:



Looking in we can see that thick ribbing frame work, and on the outside and either side of the doors is a roughly 5 meters thick hull or double hull. Either way, anyone trying to blast open a Constitution refit's hull in those areas is going to have to work pretty hard at doing so.
-Mike

[Mr. Oragahn]

What other ones?

All pictures featuring windows, bar the one with Kirk and the doc.

The only one that shows differently is the huge windows of the officers' lounge on the tail end of the dorsal superstructure.

Yes, that one is the only one that looks remotely convincing as far as thick windows go.

The one view with the guy looking out the little porthole to one side of the docking port doesn't tell us anything really and the transparent material (glass or transparent aluminium or whatever it is) could be as thick as the glass on a deep diving submersible like the ones seen here on Russia's Mir 2 submarine. You can't tell those windows are nearly 8 inches (20 cm) thick of acrylic.

Although the picture is of bad quality, I'd suggest you look at the window on the right, not the frontal one, to get a situation similar to what we see here:
http://movies.trekcore.com/gallery/albu ... hd0381.jpg
Pick the crappy picture, boost luminosity and reduce contrast, and you'll see that we don't have any difficulty accepting the idea that the glass could be 20 cm thick.
Funnily enough, that's quite the same overall impression of thickness we get from the movie shot, with the following one giving an idea of the size of the window, thanks to the head we see through the right one:
http://movies.trekcore.com/gallery/albu ... hd0377.jpg

As for transparent steel, I suppose that ST4 could provide some degree of information.

Another suggestion of hull thickness is found in this travel pod POV shot looking at the open hanger bay and fantail section of the stardrive hull:



Looking in we can see that thick ribbing frame work, and on the outside and either side of the doors is a roughly 5 meters thick hull or double hull. Either way, anyone trying to blast open a Constitution refit's hull in those areas is going to have to work pretty hard at doing so.
-Mike

The ribs seem radially deep, but it doesn't say anything about the hull plates' thickness, unless I'm missing something here?

[Mike DiCenso]

lthough the picture is of bad quality, I'd suggest you look at the window on the right, not the frontal one, to get a situation similar to what we see here:
http://movies.trekcore.com/gallery/albu ... hd0381.jpg

The right side? The "glass" is distorting the view into the porthole at this sharp an angle. What I do note is that there are at least 5 planes. Which gets us to....

Pick the crappy picture, boost luminosity and reduce contrast, and you'll see that we don't have any difficulty accepting the idea that the glass could be 20 cm thick.
Funnily enough, that's quite the same overall impression of thickness we get from the movie shot, with the following one giving an idea of the size of the window, thanks to the head we see through the right one:
http://movies.trekcore.com/gallery/albu ... hd0377.jpg

The porthole on the left side gives a good indication of the depth, unlike the one with the man's head, which when viewing straight on as we are, can lead to optical distortion as is the case with the Mir 2 sub pic I linked to. The other one, if you fiddle with contrast and brightness, you can see that unlike the first screencap, the depth is much further back and there are more than 5 window panes.

The ribs seem radially deep, but it doesn't say anything about the hull plates' thickness, unless I'm missing something here?

It's a general theme of heavy duty construction we're seeing here. The idea being that having heavy beam and ribbing to support heavy plating, and making the ship not only stronger, but making for more material that an enemy ship's weapons have to cut, burn, or punch through.
-Mike

[Mr. Oragahn]

lthough the picture is of bad quality, I'd suggest you look at the window on the right, not the frontal one, to get a situation similar to what we see here:
http://movies.trekcore.com/gallery/albu ... hd0381.jpg

The right side? The "glass" is distorting the view into the porthole at this sharp an angle.

In retrospect, we shouldn't even attempt at comparing both. Even a similarity in the orientation of the window we study in relation to the camera's axis isn't enough.
For one, the windows on the submarine contain only two panes as far as I can tell, and they're embedded into a conical hole. The windows on either side of the Enterprise's docking ring seem to be largely built inside a cylinder and contain four panes.

Besides, we can't know the index of refractivity of the material in Star Trek.
Hence the point of using ST4, which had Kirk and pals using transparent steel (I think) to create a pool for the whales.

What I do note is that there are at least 5 planes. Which gets us to....

It isn't even useful unless we know the thickness of each pane precisely.

Now, another point. I could be wrong on this because my school lessons are far behind me, but since there could be vacuum between each pane, each photon would go through a series of stronger and weaker refractions corresponding to the alternance between a windowpane and vacuum, until it got through the entirety of the mesh.
Which means the path of light would be progressively altered.
As with the submarine, which windows look slightly thinner than what they are, if the window panes were equally spaced, what we would see would be panes and the space between them being progressively thiner the more we'd look inwards.

I pulled the picture showing the windows left and right of the docking ring (with the head behind the window on the right), and even with all kinds of tweaks on the light and contrast, I couldn't obtain any view of the ridges marking the presence of panes, which are easily visible though on the shot of the same ring, but at a severe angle.
On the picture I fiddled with, it makes the windows look like those of the submarine : two panes, and nothing else.
Aren't there any other pictures showing better views of those windows at varying angles?

Pick the crappy picture, boost luminosity and reduce contrast, and you'll see that we don't have any difficulty accepting the idea that the glass could be 20 cm thick.
Funnily enough, that's quite the same overall impression of thickness we get from the movie shot, with the following one giving an idea of the size of the window, thanks to the head we see through the right one:
http://movies.trekcore.com/gallery/albu ... hd0377.jpg

The porthole on the left side gives a good indication of the depth, unlike the one with the man's head, which when viewing straight on as we are, can lead to optical distortion as is the case with the Mir 2 sub pic I linked to. The other one, if you fiddle with contrast and brightness, you can see that unlike the first screencap, the depth is much further back and there are more than 5 window panes.

The ribs seem radially deep, but it doesn't say anything about the hull plates' thickness, unless I'm missing something here?

It's a general theme of heavy duty construction we're seeing here. The idea being that having heavy beam and ribbing to support heavy plating, and making the ship not only stronger, but making for more material that an enemy ship's weapons have to cut, burn, or punch through.
-Mike

Not if the projectiles and shots miss the ribs, which are sufficiently spaced for that to happen often.
The ribs are there to help the superstructure remain as much whole as possible, but are not meant to be of protection much.
This is why the amount of evidence for plate thickness is terribly scant.