Non OTU: The Gazelle Class Escort Study

Rigel Stardin · Apr 13, 2022

WARNING, I REPEAT, THIS IS A WARNING:

I've put too much hard work and effort into this post to have it closed because someone starts arguing over the fine points of the Gazelle and start name calling one another over Da Math or something else.

I Admit the following factors in this thread:

1. This is my artist interpretation of a Design someone else made.
2. The Designs are not to Traveller Construction Rules.
3. The Math is not to the Construction Rules either.
4. This is my 'real world interpretation' of this ship, if it was built using real world elements.

So please, discuss the issues with the Gazelle with respect for one another. Enjoy, the artwork to come and please use them if you like.

Gazelle Close Escort

Here is how I see it:

There are four design elements which throw the design out the window. The first one is the Internal Fuel Tank. No matter how much you reduce the size of a stateroom, reactor or any other element found on a deckplan, you have to put 100 Tons of Fuel somewhere in the depiction. The second reason, the Nacelles are added weight that cannot be handwavium away. Four Drives, a Fuel Processing unit and a 2 manned turret all add up. Finally, the Drop Tanks. 2, 50 Tons external fuel tanks is an awful large area to depict on a deckplan. You also have to depict the mounting equipment for the Drop Tank as well.

In the previous Section, I showed what happens when you start depicting internal values and fuel intakes. The average reduction in fuel for the, Hare, Rabbit and Dahu was 20 tons. You also have to depict the Access Tunnel between Decks (Range of equipment and Access Tunnels ran between 21 to 19 Tons). Nor did I subtract, the Mounting Pylons, Barbettes, and Manned Dual Laser Turrets from the overall design. I wasn't about to go that hardcore on the math since I rounded down the Tonnage to 400 Tons (300 Tons for the Main Body and 63 Tons times 2 for Nacelles), the ships came out at weighing 426 Tons and that was without the weight of the Gig.

So I Technically solved the 300 Ton myth. The Gazelle is actually 400 Tons from the start. Case Closed, Right? No, I didn't, because of the added weight of the Drop Tanks. You are looking at a ship that actually weighs 500 Tons when the Tanks are added. That throws the Gazelle's stats straight out the window.

This is where I find myself, trying to reduce the Tonnage even further. While, trying to maintain the general Stats of the Original Ship. Of course there came a point, when I just starting designing the ship to what I thought was more real world military than fantasy. So, you are going to see 5+ Deckplans in this second section.

General Note: I'm going to present these from what I believe is the oldest to the newest. The History of the Gazelle is far longer in my MTU is far older than in Traveller. It will be the last thing I write up in this thread but for now, this is all you need to know.

This is the Basic Gazelle.

The Classification was inspired by Traveller Wiki. In their write up they stated the ship was designed as an escort and courier. That's why it gets the EC designation and not the one I use for Close Escort (CE). Which is purely a combat vessel.

The Deckplans are a modified version of the Seeker Deckplans, I bought years ago. The layout of the staterooms and the location of the frozen watch are the same. I believe even the access points to each deck follows the same pattern. The First Aid Station and Kitchen layout comes from that design as well. I, of course, changed where the computer room is located because of the experimentation with the Rabbit Class. I added Life Support Systems and a reactor based on a real world design.

I never looked at the Traveller Wiki until, I started this project. Traveller in general never really guided me, it was those Deckplans, I bought decades ago that inspired me. This is just the newest version of this ship on my Hard Drive.

This was the first ship I ever tried designing using this drawing program. I had always endeavored to fit it within the designs and layout provided to me by the Seeker Deckplans. The Escorts it spawned over the years (You saw how it spawn 5 of them in this thread alone.), have been waiting to be posted and trust me after this, I will be doing that.

I guess one other thing, I should get to? The crew size I settle on was 10 because it made sense to me.

2 Officers (Pilot and Co-pilot)
2 Engineers
4 Gunners
1 Medic
1 Steward

I don't like Frozen Watches. They seem a waste of energy and resources on such a small ship. The reactor depiction seems small for the ship's overall size so it might have power issues.

I know these ships are really nothing more than Fleet Piñata that soak up damage while the Big Boys get into position but, they have that mystic of American PT Boats or German S-Boats from WW II. They have the firepower to do serious damage to larger ships but, they are made of plywood.

This version is a pure combat vessel and Close Escort denotes this. This title is given to small combat vessels who have proven themselves in combat and who's battle history proves their combat effectiveness over time.

I flipped the Airlock and Stateroom on the Bow Starboard side (The Importance of this will come later). I have removed the cargo bay and moved 2 of the staterooms towards the aft on the upper deck so the Gunners are closer to their respective weapon systems. I have added a First Aid Station right next to the Port side Access Ladder. The placement of the Station here was because of the Cryo Chamber Bay. I felt logically, if there was a problem with someone on the Frozen Watch, you would not want to lug him through the ship to reach the First Aid Station as depicted in the Imp-532-EC Deckplans. Aft Access Ladders run through the Pylons to reach the upper and lower deck as well as the Center Nacelle Deck. The Reactor has also been made larger.

Drop Tanks:

The 800 pound gorilla in the room.

Yes, I've seen the threads which talked about how the Gazelle is a broken design. I've kinda disproved that myth by looking at it from a real world perspective. But I never got into the math which makes it a bad design. My opinion is far more basic and rooted in the real world.

Sex appeal, without the Drop Tanks the ship is a thing of beauty in my eyes. Most artist renditions show, the ship with two Big Honking Boxes strapped on the side of the vessel. It is suppose to be a fighting ship, not a box van with guns. Show me a 22.5 Ton Modern Fighter Aircraft with 2, 7.4 tons Drop Tanks strapped to its wings and I'll shut up and walk away. Yes, there are some big drop tanks out there but, nothing like 7.4 Tons. 2 of those giants would just turn a fighter into bus.

I admit, I'm ex-Army and my research is from Google and Wikipedia, so I have no real world experience with Fighter Jets. Then you have this ideology within the game designer community that a Starship is part aircraft, part sea going vessel and things get messy real quick.

Now you know where I stand on the subject. Lets dive into the design aspects of a drop tank as it is concerns the Gazelle.

Vignette 1: is just your run of the mill Standard Production Model any military can buy in my MTU.

Vignette 2: This is the only space that concerns me during the design process. The area between the Airlock Door to the front of the Nacelle minus 3 Meters. 1.5 M from the Door and edge of the Nacelle is all the clearance I need to depicted the locking claps opening. That leave .5 M between the clap and the Tank's outer wall. Of course, it must store 50 Tons of fuel.

I know there is many different ways to mount these Drop Tanks. So, I'm going to rely on the most common artist interpretation I have seen on the Internet. Off Center and to the lower part of the hull. It makes sense to me because it not only can house all the clamps, hydraulics and other equipment to lock the tank to the Gazelle but it can also house the mooring clamps for the Gig. Vignette 3 shows this arrangement.

Vignette 3: The Green Color shows the housing for the equipment to clamp the tank to the side. Pink shows the open area left after making allowances for the equipment. The Bow On view has had the nose removed for clarity.

Vignette 4: This drawing show the tanks attached to the ship and how ridiculous they look and from a real world perspective just how ungainly the ship would be. This is why in MTU the Gazelle does not have drop tanks of this size.

Another thing I see wrong with the design at this point, is the Maneuvering Speed of the ship. The Wiki lists the Maneuvering as 4/5. The ship is carrying 1/3 more weight, therefore I believe the Maneuvering should be 3/5 just on simple math alone. My logical brain also tells me with such a load on either side of the ship, the stresses on the clamps and hydraulics systems would need to be lowered or you would tear the Drop Tanks off under higher speed. Another thing my logical brain is telling me is, the range should be lower on the first jump than on the second due to the added weight

Rigel Stardin · Apr 13, 2022

This is in my eyes are what a Gazelle looks like with drop tanks. As you can see it is ugly as sin (My opinion). It does not have the streamlined appearance as the first, two drawings. It also increases the weight of the original of 400 tons to 600 Tons (200 Tons) The average Tons for the central Hulls has been running around 350 Tons when I do the math. So adding 50 tons for the Tanks clamps and hydraulics isn't a stretch of the imagination.

I should have explained this better somewhere along the line but, I guess this the best place for it. IMP-625-CE is as much a file name as it tells you the displacement of the ship. This is that naval aspect of starships. So, when I figure out the weight for these ships, I do the Hulls and Nacelles first. In this case, the Hulls=349 Tons + Nacelles=71.5 add these together and you get: 420.5 Tons. Round down and you get 400 Tons. All the odds and ends, I normally don't count, like that 30 tons of equipment and mounting bracket for the Fuel Tanks. Then I add the Fuel, Cargo and Additional Craft to that number; 200 Tons fuel + 25 Tons and that gives me 625 Tons. Which brings me to how I do my Range.

To Recap, (Fuel x 83) 625= days of operation or 1 Light Year per Day (15.8 Light years). To convert this back into Jump values, just divide it by 3.25 Light years equal to 1 Parsec. in this case, the Jump Value for this ship is, 4.8 or Jump 5. I am explaining all this to make a point about the Traveller designed Gazelle.

This comes from a real world observation. Drop Tanks, to my understanding work like this. The fuel from the tanks are used first so, if they go into combat, they are not wasting fuel. When you see 13.3 Light Years with Drop Tanks in the Data Plate, that is the Gazelle burning off the fuel in the Drop Tanks first. The weight of the ship is greater at this point, thus reducing the Range. This gives the ship Jump 4 at the beginning of its mission. Then it 'drops' tanks and goes another Jump 5 (It has to be in Normal space to drop the tanks in my MTU). This gives the ship an operational range of 9 Jumps or 9 parsecs. Which to me sounds fair but, I know it is a bone of contention with the Traveller Fanbase. I do not have a dog in this show, so I will leave it there.

One last thing about Gazelles with Drop Tanks. The vast amount of military knowledge my neural network maintains astonishes me at time. This is a case in point.

The A-6 Intruder was, I believe, the last carrier based bomber. It also had another role as a Tanker for the carrier air wing. Apply that principle to the Gazelle and just think how many fighters and small craft 100 Tons of fuel could refuel? The only Change I would make, would be to remove the Gig from the ship and add a purpose built refueling station. I would also give it the designation IMP-625-KE (Tanker/Escort).

Fuel Tanks become an option after this because of their ugliness.

While browsing a used book store, I came across the cover for GDW's Vigilante. It was just the cover but it gave me the Subsidized Liner deckplans and a depiction of this Gazelle with a High Visibility Bridge. It was the best $2 I spent.

With this one, the problem I have had with this one is the depiction of the Bridge. Clearly the artist wanted to make you feel as if you were in the cockpit of a two seat fighter. I've always seen it as B-47 cockpit layout but never able to construct a proper deckplan, what you see is the closest, I can get. I'm hinder by the line of fire of the Particle Cannon Barrette over the Bridge. (PS: after making sure I had the right nomenclature for the B-47, my search engine popped up with a several pictures of the cockpit of the bomber, something that never happen before, so another try might be in the works...)

The ship now has a Collapsible Airlock and a full size First Aid Station. I have also given it a Hulled Down Turret with an Old School Vibe.

My logical brain strikes again. The only small problem I have with his design is the High Visibility Bridge. It looks cool and all, but it puts the Pilot and Copilot in the center of a very large bull's-eye. There is just no way, you can up armor the glassiloy canopy to stop missile and gunfire. One hit on this design of Bridge, and you would lose all command and control over the ship

My logical brain caused this redesign and it is years old redesign. The biggest change you may have noticed is there is no longer an access ladder leading to the turret in the Nacelle. Nor is there a hulled down weapon station or the turret is a manned one. It is now control by a remote operator in the lower hull. The thought behind this came from prototype auto cannon of the late 80's/early 90's. Putting the crew down in the hull of the vehicle seemed to make much more sense because the armor could be made thicker.

The second is I moved the galley/lounge down to the lowest deck along with the airlock. I figure, if your ship is going to be boarded you would want as many doors between you and your enemy. I mean in the original designs, the airlock was always very close to the Bridge. All the bad guys had to do was break through the airlock and they were right outside the Bridge. Blow the door, and you were in control of the ship.

Finally, across from the airlock is a small room filled with box type cargo. I am talking about cargo type objects that can be carried into the ship by a person and not fit on a shelf. It does not count as cargo hold because of the size of room and what is stored in there. An office was also added because, you know those bean counters in logistics need a place to do their counting.

From OTU to my MTU:

We are about to leave the Traveller Universe and enter my Universe. The Basics are as follows:

1. The real world as it is now, plays an important understanding in my vision (I also write as a hobby). Computers are no longer massive hunks of technology, they have grown smaller and more powerful. Networking between computer is also common place. It allow for the survivability of the computer and combine they run the ship.

2. Technological advancement plays a role in the ships design element. Things tend to get smaller and more compact. Jump drives become Hyperspace Generators (1 Light year per day limit). Laser and Particle weapons start off big and get smaller and more powerful. (For game's sake, I lock down the technology at Tech Level 12-14) Hand-held weapons were mainly firearms of today with sci-fi based ammo types. Laser weapons as seen on TV and Movies are above the civilian's pay grade. However, Megacorporations and Governments could afford them with easy. Simplified version of Scanners and Sensors from Star Trek are present. These are just a few of the things, I imported into my setting.

3. Science Fiction that makes sense.

I'm going to give you one example from my gaming days:

After I imposed the 1 Light Year Per day rule and set the standard for leaving a planet and then landing at the other end. Jump Drives were still in game but only at Jump 2 at that moment. Why you ask? It takes 7 Days for a Jump 2 to travel 6.5 Light years (I was using Traveller maps at the time.) Of course, my Hyperspace Generators could travel 7 Light years in a week, so technically it worked out. The thing I found interest, and would have brought into the game, had I been able to find a group, was what happened after Jump 2.

Things got interest when Jump 3 was used. In 7 days, you could travel almost 10 light years with a Jump drive. With a Hyperspace Generator installed, you would have travel 7 light years.

Therefore, the Imperium had the edge over the Innerempires in certain tech.

So with that said, let's move on.

This design actually came from a story I wrote and it's up in Cleon Memorial Library under the title Search Radar, if you're interested? I basically added a third seat to the Bridge. The Trainer (an experienced escort commander) teaches new recruits how to operate an escort.

From the exterior, the 575-ET looks exactly like a 525A, except for the large front viewport. The interior as well, remains the same except the office has been replaced with a stateroom for the Trainer. Here is where the major differences can clearly be seen on the Deckplan. And it is a result of microization.

All those tanks required to reduce and purify the hydrogen collect, by the fuel scoops then turn it into its liquid state, have now been reduced in size and fit on one deck. The central deck of the Nacelle can now be used for other things, like fuel, except of course for the turret mounting. This gives this version of the Gazelle 50 Tons of extra fuel (26 Tons of Fuel minus 2 Tons for the Hard Points.)

I had actually discovered this during my construction of my MTU version, but I am showing it here because drawing two more ships just to show this, really is not worth the effort besides, these designs have not really changed much since I started showing you my take on the Gazelle.

I have posted 5 previous designs each with minor changes to the Nacelle, weapon systems and interior. This is the first depiction I can actually call the Mark 2 Gazelle because of the major changes which have taken place. Larger Fuel capacity, total microization of the Turrets and the Fuel Scoops totally revamped. This is all due me looking at it from a real world perspective.

Rigel Stardin · Apr 13, 2022

This was the design I discovered that fuel could be stored in the nacelles, it was also the first Gazelle I built. I have upgraded the interiors and Barbettes because it made more sense to me. The rest is from the original drawing. I also redid the math, and found out they could hold up to 60 Tons in either side. So I'm being kind here with the Range. It allows me to draw the ship with only two decks as well.

I never liked the idea of having a full deck used as a fuel tank or fuel stashed all over the ship. I've seen too many space adventure movies where the ship blows up as soon as our heroes hit them with single blast of their laser cannons. I have also seen and read about ships be vac in order to stop explosive decompression. The problem with that is you are only reducing the atmosphere to a level where it does not happen. That still leaves oxygen molecules inside the hull. Hydrogen plus Oxygen makes for a big bang. So moving the fuel to the Nacelles seems like a good idea.

On top of that, compartmentalization was a big thing in military design circles back in the 80's-90's. Blow out compartments for ammo and fuel cells were all the rage. They are still used on some Main Battle Tanks. So building a ship able to brawl with the Big Boys, it made sense to me to incorporate these ideals into the ships I design.

You also will see, I've gotten rid of the Frozen Watch. Never liked the idea of waking up in the middle of combat after being frozen. There are mental and psychological issue there. Those Cry-Chambers are for the seriously wounded.

Wrap Up:

Four weeks of work later and I'm finally done. I've added a dozen files not and that's not counting the Deckplans I'm presenting to you in this post. Nacelles alone, I've design quite a few, made stamps for new rooms and redesigned cockpits and avionics bays. Yeah it's been a blast and hard work as well because I was limited by factors in the original design. I have learn a few things along the way and here are the basics.

The Basics:

This only counts the designs based on the original design and without Drop Tanks.

Average Length: 58 Meters
Average Diameter: 9.6 Meters

Average Tonnage of the Main Body: 349.9 Tons
Average Tonnage of the Nacelles: 69.5 Tons
Average Tonnage of the Fuel: 101.7 Tons

I think that covers it. It's been a blast and I have fun compiling all this. You have any questions about the math, I'll gladly supply it but it's spread out over 15 pages.

Hope you enjoy my work.

LTJGBeam · Apr 14, 2022

Interesting post! And, the aesthetics of these deck plans are fantastic! What software are you using to create them?

Rigel Stardin · Apr 14, 2022

Neopaint, goes by a deferent name now. PixelNEO. Image editor software-VisualNeo is the new name.

whartung · Apr 14, 2022

Rigel Stardin said:
I've put too much hard work and effort into this post to have it closed because someone starts arguing over the fine points of the Gazelle and start name calling one another over Da Math or something else.

I think folks should self-reflect a bit about this community that you felt you had to put in a disclaimer like this.

Condottiere · Apr 14, 2022

Tanker variant would only make sense for small craft with reactive rockets, not manoeuvre drives, or combined as afterburner.

Rigel Stardin · Apr 14, 2022

@whartung, I just remember the days when there were heated discussions on this forum. I know things have changed quite a bit since then, but it has been my understand the Gazelle is hot button topic, thus the warning.

@Condottiere. A standard 10 ton fighter has 1 ton of fuel. From my perspective, that's a few hours of fuel at most. Even under my system of determining running time, that is 8.3 days. And that is if you survive the battle for that long. I don't remember the fuel tonnage for scouts or 100 ton ships, but at some point they need to be refueled. Their fuel tonnage is lower enough that 100 tons stored in the Drop Tanks, might be enough to refuel them. especially on covert op missions? I did a mental comparison and saw the similarities between the Drop Tanks and the A-6 as a tanker. It was just a thought anyway.

Condottiere · Apr 15, 2022

1. Manoeuvre drives are tied in with the power plant; so as long as they have power, the ship has locomotion.

2. Endurance depends on number of crew and life support.

3. Effectiveness partially on the weapons loadout.

4. Assuming it's pilot and weapons officer, in a cockpit, that's twenty four hours.

5. Since they're human, optimal duration is twelve hours, maximum sixteen unless they use stimulants.

6. Tankers, specifically with the Gazelle's capacity, are only useful to top up smallcraft to increase the duration of their flight.

7. Likely patrol or transition to the combat zone.

8. You're not likely to run out of fuel in twenty four hours for the powerplant driven manoeuvre drive.

9. You probably will for a constant use reactionary rocket.

Rigel Stardin · Apr 15, 2022

I was looking at it from the real world perspective. Modern fighter jets flights are between 6 to 10 hours. I'm assuming after 6 hours, the fighter has to meet with a tanker to reach 10 hours. An that 10 hour limit is govermental limitations on pilot's flight hours, combat is probably different.

Quick Gooogle search, an F-18 carries about 7.5 tons of fuel internally. That's 6 fighter a 50 Ton Drop Tank .

I suppose that the difference between MTU and Traveller, I take real world and just advance them a century or more. I don't know what else to say?

Spinward Flow · Apr 15, 2022

In LBB5.80 Traveller, 1 ton of fuel will power 1 EP of fusion power plant output for 28 days.
That's a consumption rate of ~0.0357 tons per 24 hours per 1 EP.

For a 10 ton small craft, 1 ton of fuel is a 10% of hull fuel fraction (so more akin to 1 parsec than 1 day).

The real limiting factor on small craft endurance is life support.
Acceleration Couches only have 24 hours of life support reserve for routine operations (12 hours in combat conditions).
That's a pretty short range "tether" for a small craft like a fighter, that places some pretty severe limits on their loiter time away from a parent craft.

For a longer duration in life support endurance, you need to allocate 2 tons to a small craft stateroom (single or double occupancy). Only inclusion of small craft stateroom accommodations will allow a small craft to exceed the "1 day limit" on life support endurance.

Note that 12-24 hours endurance is usually "plenty" for orbital transfers to/between moons of a planet, but rarely going to be adequate for interplanetary travel (except under highly favorable orbital ephemera positions for transfer orbits).

At closest approach, Venus is 0.3 AU from Terra and Mars is 0.6 AU from Terra.
Neither distance can be crossed in a transit of less than 12 hours, even at 6G of acceleration.
3G can transit 0.3 AU in almost 24 hours.
5G can transit 0.6 AU in almost 24 hours.

Interplanetary Travel Distance by Time and Acceleration (reference link)

So in the Sol system (for example) ... Acceleration Couches are sufficient for passenger service transport between Terra and Luna at any time (less than 12 hours transit, always), and sufficient for limited passenger service transport between Terra and Venus (depending on relative orbital positions) as well as Terra and Mars (again depending on relative orbital positions) within 24 hours with portions of the Terran orbital year putting both Venus and Mars "too far away" to reach within 24 hours, even at 6G constant acceleration.

This would mean that "cattle car commercial" interplanetary transport relying on Acceleration Couches only in small craft between Venus, Terra and Mars would be a kind of "seasonal" business, where windows of opportunity for orbital transfers open and close that are within the life support endurance limits before needing to resort to use of small craft staterooms.

LTJGBeam · Apr 15, 2022

Rigel Stardin said:
Neopaint, goes by a deferent name now. PixelNEO. Image editor software-VisualNeo is the new name.

Thanks! I'll have to look for it.

Duke Craig · Apr 20, 2022

Awesome set. Many thanks for these naval architectural designs. I'd note that TNE does a Gazelle Class TL14 at 280/400 tons, with a bit of fudging. Two laser turrets and two laser barbettes. Jump-3 and 3G maneuver with drop tanks; and Jump-5 and 5G without Drop Tanks capability. Looks like an interesting Class for further investigations with FF&S (and Paint) at various tech levels.

Non OTU: The Gazelle Class Escort Study

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