Ship Design Philosophy

Discuss the Traveller RPG and its many settings
Condottiere
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Re: Ship Design Philosophy

Postby Condottiere » Thu Oct 31, 2013 7:36 am

Can't find any mention of ordinary launch facilities, though Classic mentions one per ten thousand tons, outside of launch tubes. GURPS mentions airlock/spacedock.
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Re: Ship Design Philosophy

Postby SSWarlock » Thu Oct 31, 2013 10:58 am

Condottiere wrote:Can't find any mention of ordinary launch facilities, though Classic mentions one per ten thousand tons, outside of launch tubes. GURPS mentions airlock/spacedock.
Not quite. Mongoose's High Guard supplement, page 45, bottom of right-hand column also describes launch tubes in detail as well as hangars.

Edit: Re-reading my own post made me realize it may have sounded a bit snippy, which wasn't my intention. A more meaningful post would have been to ask, "what do you consider to be 'ordinary launch facilities'?"
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phavoc
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Re: Ship Design Philosophy

Postby phavoc » Thu Oct 31, 2013 4:28 pm

Here's what MGT HG says:

Launch tubes: Launching and recovering small craft from a larger vessel is usually an activity taking 30 minutes to launch or recovery one craft. Launch tubes allow small craft to be launched and recovered rapidly from a ship. The size of a launch tube is twenty–five times the tonnage of the largest craft that will be deployed in this manner, and they cost MCr 0.5/ton. With a launch tube, up to ten small craft can be launched per round. Multiple launch tubes can be installed.

Classic High Guard launch tubes are similar to what is listed in MGT's (description and 10-man crew). It also states that launch tubes are counted against the total number of bays you can install.

GURPS goes into more detail on a launch tube. For GURPS purposes, a launch tube is actually a magnetic catapult to accelerate a fighter to full speed upon at launch. And it's designed to rapidly launch the craft.

I would think that a launch tube would act more like a catapult ala GURPS style than just being a tube you fly out of. In that case you'd be better off with a dispersed ship mounting multiple attachment points where the fighters all launched in the same round, and a few hangars to do maintenance on them when necessary.

I'm not sure how the launch tubes are supposed to allow for rapid recovery though.

Thirty minutes to fly out of a hangar bay, specifically sized to allow you to move around a smaller craft, does seem excessive.
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Re: Ship Design Philosophy

Postby phavoc » Thu Oct 31, 2013 4:46 pm

One other thing - I was reviewing TCS rules,and it says "Ordinary launch facilities allow one craft to be launched per turn. Launch tubes allow 40 craft to be launched per turn. Recovery is at the same rates."

I'm still fuzzy on how launch tubes help for rapid recovery... but the launch rates are far more reasonable, since a turn is 6 minutes long. That would make it 5 times faster than MGT launch/recovery rates.
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Re: Ship Design Philosophy

Postby Condottiere » Thu Oct 31, 2013 5:21 pm

Recovery via launchtube; unless the tube was built for at least double that tonnage, it would like threading through the eye of a needle if you have the rest of the squadron right behind you.

I don't think it's ever really been thought out. BSG seems the most logical, with a recovery dock in the rear.

There may be any number of reasons naval architects aren't fond of dispersed structures. As such, launch and recovery could be:

1. Launch tube; spacey dock for recovery.

2. Separate space dock/airlock for launch recovery.

3. Separate space dock for launch; general hangar; separate space dock for recovery.

4. Craft grappled/umbilicalled to hull (VTOL). Separate lift/airlock and crane to stow craft below deck or maintenance.

5. Crane and lift to recover craft and stow below.
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Re: Ship Design Philosophy

Postby phavoc » Thu Oct 31, 2013 6:47 pm

Condottiere wrote:Recovery via launchtube; unless the tube was built for at least double that tonnage, it would like threading through the eye of a needle if you have the rest of the squadron right behind you.

I don't think it's ever really been thought out. BSG seems the most logical, with a recovery dock in the rear.
Agreed. Assuming you have fighters staged to be rapidly shunted into the launch tube for either accelerated launches, or full-power launches under their own power, you still have a problem with rapid recovery. It's easy to stage them, since you generally have time. But recovery at the same rate would make for some interesting issues... let alone any ship that was damaged. The recovery aspects of BSG did make a lot of sense. If I recall correctly, the original series had the Vipers launching from the forward part of the ship, wile the remake had them launching from underneath the landing bays?
Condottiere wrote:There may be any number of reasons naval architects aren't fond of dispersed structures. As such, launch and recovery could be:

1. Launch tube; spacey dock for recovery.

2. Separate space dock/airlock for launch recovery.

3. Separate space dock for launch; general hangar; separate space dock for recovery.

4. Craft grappled/umbilicalled to hull (VTOL). Separate lift/airlock and crane to stow craft below deck or maintenance.

5. Crane and lift to recover craft and stow below.
The Cylon base ships of the remake of BSG had distributed launch platforms and hangar bays. So long as the ship does not need battle damage repaired, there's no reason why an integral dock/refueling/reaming mechanism couldn't be built. Of course for human-piloted ships it would have to have some sort of airlock to let the pilot get in/out. After-battle repairs could take a while since hangar space would be limited.

Star Wars had an interesting aspect where they stacked Tie's vertically. Maintenance couldn't be performed that way, but just storing them for launch later make sense. Then you just have a carosel to drop the fighter out the bottom of the bay. Recovery would naturally take longer, but that's the same for carriers today.
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Re: Ship Design Philosophy

Postby Condottiere » Fri Nov 01, 2013 9:22 am

Another interesting aspect is the exact dimensions of launchtubes, since even for a given tonnage, craft come in all shapes and structures.

Personally, I envisioned my range of generic smallcraft to be cylinderical, which meant they would fit snugly into the tube, and actually may allow some reduction of size. Or spherical, though that would actually increase the diameter.

There are some smallcraft hangars that are form fitting, and I think they should be allowed a 5% volume increase, though that means the bay was specific to that or a smaller tonnage smallcraft. Launch would be normal, but recovery should be harder and twice as long. I don't see much possibility for external maintenance.

Hangars may have bay clamps so that the smallcraft don't move unexpectedly, cranes, both independent and overhead to move the smallcraft into position, and possibly lifts.

I was actually wondering if a TIE fighter was possible, though I'd have to calculate how many solar panels that would take; having looked up the Imperial class Star Destroyer, they do have a mixed wing of seventy two TIEs, which does call into question what exactly the designer thought they were supposed to do. Anyway, launch facility is described as a chute, which feels like you could drop them off rather than catapult them forward, which in itself seems a viable option probably needs less energy, maintenance and space.
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Re: Ship Design Philosophy

Postby SSWarlock » Fri Nov 01, 2013 1:35 pm

phavoc wrote:One other thing - I was reviewing TCS rules,and it says "Ordinary launch facilities allow one craft to be launched per turn. Launch tubes allow 40 craft to be launched per turn. Recovery is at the same rates."

I'm still fuzzy on how launch tubes help for rapid recovery... but the launch rates are far more reasonable, since a turn is 6 minutes long. That would make it 5 times faster than MGT launch/recovery rates.
Regarding recovery via launch tube, I've always thought that the same equipment that kicks the craft out faster than normal are also used to slow them down and guide them to staging areas. All a pilot would have to do is line up on the tube entrance properly and recovery equipment takes over automatically while he/she/it enjoys the ride.
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Condottiere
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Re: Ship Design Philosophy

Postby Condottiere » Sat Nov 02, 2013 12:55 pm

You've got to ensure that you won't hit the armoured hull while making your approach, or that meatball that you're looking at will be you splattered on the forecastle.

You have two ships both on a fast collision course, with the next fighter half a minute behind. The approach will likely be on autopilot, the launch tube will be energized with repulsor fields to that your fighter doesn't hit the walls and tractor beams to guide it in. Then you have to kill the momentum and clear the tube for the next craft.
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Re: Ship Design Philosophy

Postby SSWarlock » Sat Nov 02, 2013 1:40 pm

Condottiere wrote:You've got to ensure that you won't hit the armoured hull while making your approach, or that meatball that you're looking at will be you splattered on the forecastle.

You have two ships both on a fast collision course, with the next fighter half a minute behind. The approach will likely be on autopilot, the launch tube will be energized with repulsor fields to that your fighter doesn't hit the walls and tractor beams to guide it in. Then you have to kill the momentum and clear the tube for the next craft.
Sorry, no repulsor fields or tractor beams in the Imperium. Pilots come in under power, just like today's carrier landings. Now computer controlled landings may be standard operating procedure with the software having centuries of debugging to get the kinks out.
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Condottiere
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Re: Ship Design Philosophy

Postby Condottiere » Sun Nov 03, 2013 6:57 am

Actually, I just had an idea for an article, the development of launch chutes.

The major difference between a barrier/arrestor wire carrier landing, which is described as scary to begin with and takes years of training and trying to perfectly align yourself in a rather long tube that your craft doesn't bounce off the walls for any number of reasons (space turbulence, battle damage, etcetera), is that our modern naval aviators appear to have considerable greater margin of error, and if it goes really wrong, they can always dump the aircraft over the side into the sea.

If there's an accident inside the tube, it may destroy the carrier's ability to launch craft, let alone recover them.
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Re: Ship Design Philosophy

Postby Infojunky » Sun Nov 03, 2013 8:23 am

SSWarlock wrote: Sorry, no repulsor fields or tractor beams in the Imperium.
>Loud Annoying Buzzer!!!< Wrong Answer!!! The Imperium indeed does have Repulsors and Tractors with in the Tech range that MgT covers.... It is just Mongoose hasn't given specific rules for them yet....
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Re: Ship Design Philosophy

Postby Condottiere » Mon Nov 04, 2013 7:44 am

I always wondered if you could construct a flight deck on top of a hull, maybe magnetized, since I don't think you can create a gravity bubble, with elevators and catapults. You can then carry more fighters than the hangars normally store.
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Re: Ship Design Philosophy

Postby SSWarlock » Mon Nov 04, 2013 12:14 pm

Infojunky wrote:
SSWarlock wrote: Sorry, no repulsor fields or tractor beams in the Imperium.
>Loud Annoying Buzzer!!!< Wrong Answer!!! The Imperium indeed does have Repulsors and Tractors with in the Tech range that MgT covers.... It is just Mongoose hasn't given specific rules for them yet....
Doh! Silly me. A look at CT's High Guard shows the same. Sometimes I don't know where my head is at. (Nobody offer suggestions, please. :P )
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Re: Ship Design Philosophy

Postby SSWarlock » Mon Nov 04, 2013 12:19 pm

Condottiere wrote:I always wondered if you could construct a flight deck on top of a hull, maybe magnetized, since I don't think you can create a gravity bubble, with elevators and catapults. You can then carry more fighters than the hangars normally store.
Grav bubble, maybe not. But Jump bubble, yes. In fact, why would any carrier have its fighters stored in an enclosed space? Would it make more sense to have them attached to pylons with a movement tube/airlock built-in for faster launching and re-docking? A much smaller hangar for repairs and maintenance could be included in the carrier's decks. Or would having the fighters out on pylons expose them more to dangers in the vacuum of space?
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Re: Ship Design Philosophy

Postby Condottiere » Mon Nov 04, 2013 6:10 pm

You can, especially when docked. Damage might be ignored if the craft have sufficient armour, or there's some form of an extendable hangar, which may or may not be enclosed for an atmosphere and gravity.

It may be that this is more common for stations than carriers, since it's been indicated that dispersed structures can't stand too much acceleration. Grappling to the hull would be the preferred option.
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Re: Ship Design Philosophy

Postby phavoc » Mon Nov 04, 2013 6:14 pm

Condottiere wrote:I always wondered if you could construct a flight deck on top of a hull, maybe magnetized, since I don't think you can create a gravity bubble, with elevators and catapults. You can then carry more fighters than the hangars normally store.
Some of the earlier illustrations had flight decks on the surface of the ships, though I think that was more from a launching aspect rather than storage.

A distributed ship, with small craft on the outside, can launch its entire complement in a single turn. Though they are all exposed, plus that's a lot of extra airlocks to put in, not to mention rearming/repairing while they are stowed outside. Think of the ulcers for the CAG who has to direct all that traffic!!!
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Re: Ship Design Philosophy

Postby Condottiere » Mon Nov 04, 2013 6:37 pm

There is that aspect, and depending how large the dispersed structure is, do you centralize the air group personnel, or distribute them, and have briefings by teleconferencing.

What you could do for returning fighters is operate a form of open dock/pit stop, where the mechanics and or automated waldos change the tires, refuel and rearm, rather than return to their hangars.

Space debris and meteorites are just a fact of life, but if the ship is moving, and you set up walls, that would shield the smallcraft without actually adding to the tonnage of the ship,
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Re: Ship Design Philosophy

Postby Somebody » Tue Nov 05, 2013 7:06 pm

Actually the launch/recovery should be a lot easier than on real world flattops.

Fighters have "unlimited energry" and can "hoover". So they will likely come to "full stop" short of the recovery bay. A recovery bay that is not affected by wind/waves etc. At that point it is

Grapple and pull
Slowly moving on auxilaries
Tractor beams

and get in. Since no unexpected movements will happen that is easier than crashing a Harrier.

The main bottleneck for both start/recovery is the airlock(s) needed assuming you want the main hangar to be under pressure. IMHO a "launch tube" is a number of rapid cycle airlocks that can do the job a lot faster than the standard method that may even involve evacuating the hangar bay since there is no lock but rather a gate.
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Re: Ship Design Philosophy

Postby Condottiere » Tue Nov 05, 2013 8:57 pm

We have auxiliaries?

The easiest approach, it seems to me, is approaching from and docking in the rear.

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