type 23 Corvette

[Xerxeskingofking]

The humble type 23 corvette was created as a cheaper alternative to the classic type T patrol corvette, intended to fulfill many or the roles of the type T at a lower cost per craft. Coming in at under 3/4ths the cost of a type T, the type 23 (named for its mobility profile: Jump 2, 3G maneuver) is a classic “small ship for small tasks”, such as presence patrols or convoy escort. In these roles, the higher performance of the type T is often unneeded, as the ship is often tied to protection of merchants with 1g or 2g drives and J2 at best.

By using smaller engines, significant savings in cost are achieved (62 Mcr vs 78 Mcr), and the missile barbette gives it almost the same offensive firepower on a smaller hull, which is also better armoured than the type T. The type 23 also boasts a better sensor and EW system than the type T. The type 23 retains the small craft and boarding team concept form the type T, allowing boarding and inspections while maintaining stand-off distance with the main craft, although both are smaller, and the G-carrier deleted, to keep the tonnage and cost down.

In service with subsector navies throughout the imperium, the type 23 is a familiar sight in backwater systems and in quieter frontier zones, and a welcome sight for the free traders that ply their trade in those areas. The inability of the type 23 to keep up with the main fleet has the beneficial side effect that it is rarely seconded for fleet duties, which keeps it free for anti-piracy and presence patrols, or escorting convoys (they are a mainstay of the Fist-Tyokh convoys in the Trojan Reach). For many minor systems, the type 23 is often the only Imperial Navy vessel that is seen more than once a year, and is considered the "face" of the Third Imperium.


stats (MgT 2nd Ed)

Spoiler

300 ton hull (15mcr)
Streamlined: 3Mcr
Armour : crystaliron, 8 pts (30 tons, 7.2 Mcr)

Drives:
M Drive: 3G (9 tons, 18Mcr)
J Drive: J2 (20 tons, 30Mcr)
P plant: 210PP, TL 12 Fusion (14 tons, 14 Mcr)

Fuel: 64 tons: (1x J2, 4 weeks P-plant plus 2 tons small craft fuel)

Fuel processors: 1 ton (20 tons/day, 0.05 Mcr)

Power:
Basic systems: 60 pp
M Drive: 90 pp
J Drive: 60 pp
Weapons: 18pp
Sensors: 4 pp

Bridge: standard, (20 tons, 1.5 Mcr)
Computer/15: 2 Mcr
Programs:
manoever/0
jump/2
Fire control/1
evade/1
Total cost: 4.2 Mcr
Sensors: Improved (3 tons 4.3 Mcr)

Crew:
Captain: 1
Astrogator: 1
Engineers: 2
Medic: 1
Gunners: 3
Small craft crew: 2
Ships troops: 5
Total: 15
Total staterooms: 10 (40 tons, 5Mcr)
Common areas: 10 tons 1Mcr







Weapons:
Missile Barbette: 5 tons, 4 Mcr
Triple turret: Pulse laser/Pulse laser/ sandcaster (1 ton, 9pp, 3.25 Mcr)
Triple turret: Pulse laser/Pulse laser/ sandcaster(1 ton, 9pp, 3.25 Mcr)
Ammo:
25 missiles in barbette, 84 in magazine (7 tons) (2.25Mcr)
24 sandcaster barrels in turrets (12/each), 100 in magazine (5 tons) (0.17Mcr)

Extras:
Armoury: 2 tons 0.5Mcr
Medbay: 4 tons 2 Mcr
Gig (6.732 Mcr),
20 ton Full hanger (40 tons, 8Mcr)
UNREP system: 20tons/hour ( 1 pp, 1 ton, 0.5 Mcr)
Cargo: 23 tons

Total 300 tons.
Cost “empty” = 124.75 Mcr
Cost with small craft and ammo : 133.902Mcr
monthly mortage cost: 519,791 Cr/month

life support: 10,000 Cr/month stateroom costs
15,000 CR month crew costs
maintance costs: 10,395 Cr/month
monthly upkeep costs : 35, 395 CR/Month

first ship ive designed for ages, so I probably made quite a few errors in its design. any comments, critiques and such are welcome.

As mentioned, the ship is intended to be a slower, cheaper type T. it's somewhat inspired by the numerous destroyer escort/corvette/frigate type designs of the second world war, medium capability designs that were cheap enough to produce en masse, and capable enough for the job they were needed for.

I have also heard that they was a disinclination for using full sized fleet destroyers like the Fletcher class for convoy escorts, because they were overkill for it, and not really any better at it than the smaller, cheaper ships.

 

[McPerth]

Iguess it's designed on MgT2e rules. Right?

 

[Xerxeskingofking]

sorry, yes, its 2nd ed rules. if you want to try something in 1st ed, or CT or some other system, please, go ahead. I'd edit that into the first post

 

[AnotherDilbert]

first ship ive designed for ages, so I probably made quite a few errors in its design. any comments, critiques and such are welcome.

Looks good!

Armour cost should be based on total hull cost (including configuration cost), so MCr 18 × 8 × 5% = MCr 7.2. (See Scout, HG p110)

Jump drive should be Hull × J-number × 2,5% + 5 Dt = 300 × 2 × 2.5% + 5 = 15 + 5 = 20 Dton, cost 20 Dton × 1.5 = MCr 30. (HG, p15)


You could save some space and a little money with a Docking Space for the Launch (instead of the Full Hangar).

A Launch is cheap, but has limited performance. A Gig is quite fast and capable of simple boarding actions.

You could improve the sensor performance with Improved Signal Processing (HG p42) and perhaps an Extension Net (HG p41) that allows you to identify sensor blips at longer range. A bit costly, but in line with the craft mission.

Perhaps add a Sensor Operator to get the most out of the sensors?

 

[Xerxeskingofking]

Looks good!

Armour cost should be based on total hull cost (including configuration cost), so MCr 18 × 8 × 5% = MCr 7.2. (See Scout, HG p110)

Jump drive should be Hull × J-number × 2,5% + 5 Dt = 300 × 2 × 2.5% + 5 = 15 + 5 = 20 Dton, cost 20 Dton × 1.5 = MCr 30. (HG, p15)


You could save some space and a little money with a Docking Space for the Launch (instead of the Full Hangar).

A Launch is cheap, but has limited performance. A Gig is quite fast and capable of simple boarding actions.

You could improve the sensor performance with Improved Signal Processing (HG p42) and perhaps an Extension Net (HG p41) that allows you to identify sensor blips at longer range. A bit costly, but in line with the craft mission.

Perhaps add a Sensor Operator to get the most out of the sensors?

ah, that armour mistake was because I decided to add the streamlining in very late in the design process, and I forgot to adjust the armour costs when I did that. I missed that 5Dton extra for the jump drive (thats a change form the 1e rules and its not as obvious as the p plant changes), i'll have to edit that into it.

on reflection, your right, the gig is a better small craft for the ship than the launch. I can cut the hanger size in half and keep the full hanger for it (given the ships intended mission profile of being out in the boonies, having room to work on the gig onboard is going to be quite beneficial. the extra space could be given to something else. I was toying with the TL12 PD (HG 2e, pg 33) system, which would replace a caster/laser/laser turret and give it 2d6 missle intercepts a turn, but I didn't go with it in the end (if I'd kept it at 400 tons I would likely have used it)

the extra sensor options are nice, but im deliberately trying to keep the costs down. improved sensors are like 0.1Mcr more expensive, but adding either of those options you mention would nearly double the cost of the sensor systems.

good call on the sensor op/EW guy, though. I think I might add him in, and maybe a 4 ton medbay form the tonnage freed form the gig.

 

[AnotherDilbert]

I missed that 5Dton extra for the jump drive (thats a change form the 1e rules and its not as obvious as the p plant changes), i'll have to edit that into it.

Yes, that is rather non-intuitive, but I guess necessary for compatibility with the drive tables in LBB2 and T5.

on reflection, your right, the gig is a better small craft for the ship than the launch. I can cut the hanger size in half and keep the full hanger for it (given the ships intended mission profile of being out in the boonies, having room to work on the gig onboard is going to be quite beneficial.

The Launch and the Gig are both 20 Dt, the Gig is just faster and more expensive.

The 7 G Gig allows you to chase down ships for inspection that you might have missed with a Launch.

I was toying with the TL12 PD (HG 2e, pg 33) system, which would replace a caster/laser/laser turret and give it 2d6 missle intercepts a turn, but I didn't go with it in the end (if I'd kept it at 400 tons I would likely have used it)

Laser turrets are very versatile, the PD Battery is a one-trick pony and quite large.

Laser turrets are somewhat effective against any threat-vector, there may be better weapons against some specific threats but none so versatile.

Laser turrets are almost as good at killing missiles as a PD Battery with a really good (augmented) gunner, not that I expect to see that on a local patrol ship.

... and maybe a 4 ton medbay ...

Yes, that sounds like a good idea for independent patrols.

 

[Xerxeskingofking]

ok, i've corrected the J drive size, switched the launch to a gig and installed the med bay. its eaten into the cargo space a bit more than i'd like (I normally aim off for about 10% tonnage as cargo room for spares and supplies), but it'll do.

 

[AnotherDilbert]

Looks good!

 

[Matt123]

A CT HG design

Not quite the same specs but hopefully close. Inspired by your description of patrolling alone "[FONT=arial,helvetica]For many minor systems, the type 23 is often the only Imperial Navy vessel that is seen more than once a year", was able to retain the G-carrier, include a Lab/medical facilities plus 4 specialists and space for 4 military passengers (or prisoners).
[/FONT]
Type 23, Provincial Escort
300 ton, TL 11 Military Design, 217.28 MCr
12 crew plus 10 Marines (Command: 1+1, Engineers: 1+1, Flight: 0+1, Gunners: 1+1, Marines: 1+9, Specialists: 0+4, Medic: 0+1)
4 Military passengers

__Ton._____MCr.____EP.____
| ___.__ | _24.00 | _.__ | Flattened Sphere, streamlined, fuel scoops
| _45.00 | _31.50 | _.__ | hull armour #4
| __7.00 | __0.03 | _.__ | purification plant
| _20.00 | __1.50 | _.__ | bridge
| __3.00 | _18.00 | 1.00 | computer model 3
| __9.00 | _36.00 | _.__ | drive jump #2
| _24.00 | _12.00 | _.__ | drive maneouver #3
| _27.00 | _81.00 | _.__ | power plant #3
| ___.__ | ___.__ | 6.00 | agility #2
| __9.00 | ___.__ | _.__ | fuel, PP endurance 4 weeks (12 weeks powered down)
| _60.00 | ___.__ | _.__ | fuel, jump range 2 parsecs
| __1.00 | __0.75 | _.__ | sand caster (turret) #4 x1
| __2.00 | __4.50 | _.__ | HE/Nuc missile (turret) #3 x1
| _16.00 | __2.00 | _.__ | staterooms x4
| _44.00 | __5.50 | _.__ | cabins x22
| __1.00 | ___.__ | _.__ | 1 ton cargo capacity
| __4.00 | __0.50 | _.__ | laboratory
| __8.00 | ___.__ | _.__ | g-carrier, berth
| _20.00 | ___.__ | _.__ | hanger space for 20 ton Launch
‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒
| 300.00 | 217.28 | 7.00 EP used, PP generates 9.00 EPs

219.46 MCr (first ship, includes architect fees) built in 56 weeks
173.83 MCr (20% discount in volume, TCS) built in 45 weeks
CT Ship Designer by Matt. Visit https://tca-2014-12.herokuapp.com

 

[Xerxeskingofking]

nice, only critique I have is the lack of cargo space for supplies. for a independent patrol ship, I'd prefer more room to carry spare parts in. I normally aim off for about 10% displacement for cargo room for this reason, and I didn't quite manage that with this design.

but hey, I don't have the CT rules to build it in CT, nor would I understand the meta to make a decent one if I did.

 

[BRJN]

nice, only critique I have is the lack of cargo space for supplies. for a independent patrol ship, I'd prefer more room to carry spare parts in. I normally aim off for about 10% displacement for cargo room for this reason

As a convoy escort, part of organizing the convoys will be restocking the escorts. You don't have to carry months and months of stuff yourself.
I really should use _Interstellar Wars_ to figure out how many man-days of rations you can stuff in a dTon. But if you have "about" as much cargo space as other patrol ships that size, you can call it Good Enough. (Maybe up-engine the ship to get your 2-3 performance at 400 tons and call the extra space a long-range cargo pod?)

 

[Matt123]

Maybe up-engine the ship to get your 2-3 performance at 400 tons and call the extra space a long-range cargo pod?

I quite like that as an idea, and you wouldn't need 100tn, say a 30tn cargo module for a modular cutter. It would meet Xerxes specs and provide a heck of a lot of modular versatility which is easily swapped out at any A B or C starport. Fancy a 10tn fighter module? Perhaps a mixed cargo and low berth module for secure prisoner transfer.

Knocking up the variant, I liked the idea enough to incorporate a Cutter and two modules within the 300tn, sacrificing other features but retaining core specs.

Type 23a, Provincial Escort
300 ton, TL 11 Military Design, 206.63 MCr
11 crew plus 10 Marines (Command: 1+1, Engineers: 1+1, Flight: 0+1, Gunners: 1+1, Marines: 1+9, Specialists: 0+3, Medic: 0+1)
no passengers

__Ton._____MCr.____EP.____
| ___.__ | _24.00 | _.__ | Flattened Sphere, streamlined, fuel scoops
| _36.00 | _21.60 | _.__ | hull armour #3
| __7.00 | __0.03 | _.__ | purification plant
| _20.00 | __1.50 | _.__ | bridge
| __3.00 | _18.00 | 1.00 | computer model 3
| __9.00 | _36.00 | _.__ | drive jump #2
| _24.00 | _12.00 | _.__ | drive maneouver #3
| _27.00 | _81.00 | _.__ | power plant #3
| ___.__ | ___.__ | 6.00 | agility #2
| __9.00 | ___.__ | _.__ | fuel, PP endurance 4 weeks (12 weeks powered down)
| _30.00 | ___.__ | _.__ | fuel, jump range 1 parsec
| __1.00 | __0.75 | _.__ | sand caster (turret) #4 x1
| __2.00 | __4.50 | _.__ | HE/Nuc missile (turret) #3 x1
| _16.00 | __2.00 | _.__ | staterooms x4
| _34.00 | __4.25 | _.__ | cabins x17
| __2.00 | ___.__ | _.__ | 2 tons cargo capacity
| _30.00 | __1.00 | _.__ | cutter module, fuel
| _50.00 | ___.__ | _.__ | hanger space for 50 ton Cutter
‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒
| 300.00 | 206.63 | 7.00 EP used, PP generates 9.00 EPs

208.70 MCr (first ship, includes architect fees) built in 56 weeks
165.31 MCr (20% discount in volume, TCS) built in 45 weeks

One of the cutter modules is a fuel module, modified to allow the jump drive to access it's 30tn of fuel to extend jump range to J2.

The other module may be customized according to mission requirements. It is surface mounted allowing both internal access through standard access points and safe release of payload, for example, a 10tn fighter or a G-carrier. The fuel module may be placed here and its contents may still be used as jump fuel. Note that this implies two fuel modules allows a J2 followed by a J1 without refueling.

A Type 23a may in effect represent a 300tn warship, plus a fighting Cutter and a 10tn Fighter to a would be attacker. The 10 person squad of Marines allows for boarding and inspection actions. Up to three specialists (or military passengers) are also carried, often to oversee local commerce inspections.

CT Ship Designer by Matt. Visit https://tca-2014-12.herokuapp.com

 

[Xerxeskingofking]

As a convoy escort, part of organizing the convoys will be restocking the escorts. You don't have to carry months and months of stuff yourself.
I really should use _Interstellar Wars_ to figure out how many man-days of rations you can stuff in a dTon. But if you have "about" as much cargo space as other patrol ships that size, you can call it Good Enough. (Maybe up-engine the ship to get your 2-3 performance at 400 tons and call the extra space a long-range cargo pod?)

maybe, but just to name a canon trade route that has imperial convoys on it, the Fist-Tyokh route between the imperial trojan reach and the aslan section is 6 jumps long. the imperial navy doesn't go into aslan space, so if a ship goes off on a convoy, its not going to be back in imperial space for, roughly, 4-5 months, theirs not many hi tech worlds with the industry to makes spares (only wildeman and Tech-World have the TL for it, and both are low pop, non industrial worlds).

so, if you want to be certain that you can have spare parts available, you need to take them with you. Food and fuel isn't a issue, but what about, say, parts for your ECM rig?

Also, their are times that a lone escort out in the boonies might be required to move a high-value cargo, or military supplies that cant be shipped in non-Naval cargo ships, or they need to carry the Plot Coupon so the players have to fight and get it.


not looking for a argument, just pointing out the logic for why I like a decent amount of cargo room on my warships, and more than the bare minimum.
.

 

[Jame]

nice, only critique I have is the lack of cargo space for supplies. for a independent patrol ship, I'd prefer more room to carry spare parts in. I normally aim off for about 10% displacement for cargo room for this reason, and I didn't quite manage that with this design.

but hey, I don't have the CT rules to build it in CT, nor would I understand the meta to make a decent one if I did.

If you mean the meta about the universe of the 3rd Imperium, then it's almost entirely the same for CT and MGT.
The main differences are the inclusion of cybernetics, and whatever viewpoint differences might (or not) exist between Mongoose and GDW as publishers who are separated by 40 years.
(I have both versions, so as far as I can tell it's mostly cosmetic.)

As for cargo, back when I was very into Traveller I designed a bunch of ships and left some space over for cargo even in Warships. The crew would not want to be dependent on supply ships for everything, plus there's also a chance of mis- or blind-jumps.

 

[AnotherDilbert]

As for cargo, back when I was very into Traveller I designed a bunch of ships and left some space over for cargo even in Warships. The crew would not want to be dependent on supply ships for everything, plus there's also a chance of mis- or blind-jumps.

Hard-core high-jump real warships can't really afford any significant cargo space.

Low-end coast guard ships, like the Type T or the Type 23, can afford such luxuries, and I agree that it's a good idea, but perhaps not necessarily as much as 10%.

 

[willtron3030]

I really should use _Interstellar Wars_ to figure out how many man-days of rations you can stuff in a dTon.

Short answer: 2000 person-days occupies 1dt, masses 12tons, costs $12000.

Judging by fuel cost comparison ($350/$80 vs Cr500/Cr100), thats in the ballpark of kCr16, or Cr240/mo, 20% more than "ordinary" subsistence living, and far less than preserved rations (Cr600/mo) or dehydrated rations (Cr750/mo) listed in LBB1.

Both preserved and dehydrated rations are a LOT lighter, so there's more than just food in those supplies -- water, maybe. I'd always assumed air and water were handled in life support supplies and costs.

 

[Xerxeskingofking]

If you mean the meta about the universe of the 3rd Imperium, then it's almost entirely the same for CT and MGT.
The main differences are the inclusion of cybernetics, and whatever viewpoint differences might (or not) exist between Mongoose and GDW as publishers who are separated by 40 years.
(I have both versions, so as far as I can tell it's mostly cosmetic.)

As for cargo, back when I was very into Traveller I designed a bunch of ships and left some space over for cargo even in Warships. The crew would not want to be dependent on supply ships for everything, plus there's also a chance of mis- or blind-jumps.

i meant the meta of effective ship design, in that don't know the CT construction rules, and what design choices are effective and which are sub-optimal.

 

[flykiller]

left some space over for cargo even in Warships

two months endurance as-built, plus 2 months for each .01 of non-fuel non-armor dtonnage devoted to cargo/supplies.

Hard-core high-jump real warships can't really afford any significant cargo space

they're the ones that need it the most. it's not a luxury, it's a necessity.

 

[Grav_Moped]

If you mean the meta about the universe of the 3rd Imperium, then it's almost entirely the same for CT and MGT.
The main differences are the inclusion of cybernetics, and whatever viewpoint differences might (or not) exist between Mongoose and GDW as publishers who are separated by 40 years.
(I have both versions, so as far as I can tell it's mostly cosmetic.)

As for cargo, back when I was very into Traveller I designed a bunch of ships and left some space over for cargo even in Warships. The crew would not want to be dependent on supply ships for everything, plus there's also a chance of mis- or blind-jumps.

The big meta difference is whether you're using LBB2 or High Guard for design and/or combat.

For LBB2 combat, armor isn't a thing and maneuver drive rating is mostly for picking range and having the option to break off/pursue -- it's not a defensive DM. On the other hand, maneuver Gs don't cost much (relatively) until they're higher than the Jump rating (2nd Ed.). There is no need for a power plant rated higher than either your Jump or Maneuver Drive. Computers let you run better attack/defense programs, and these are your +/- combat DMs. Once you max out the attack/defense programs, you might not need a bigger computer.

From a design standpoint, the main difference between CT (LBB) and pretty much everything else Traveller is the TL paradigm: Bigger is better, and higher TL lets you build bigger. Everything the same size is pretty much equal, regardless of TL (a TL 15 Type T Patrol Cruiser is the same as one built at TL 10, but you can have a very upgraded computer if you want). The main TL constraint is the maximum available Drive Size (letter), and it's possible to get higher Jn for small ships than in High Guard (or other Traveller rules). The other thing is that Maneuver Drive Gs have the same TL constraints as Jump Number(!)

For HG combat, armor is very much a thing, as is maneuver drive rating. They're both costly in tonnage and MCr. Computers are a +/-DM for all combat, so it's worth getting the biggest one you can afford (or TL allows).

 

[AnotherDilbert]

two months endurance as-built, plus 2 months for each .01 of non-fuel non-armor dtonnage devoted to cargo/supplies.

House rule?

they're the ones that need it the most. it's not a luxury, it's a necessity.

If you feel you need massive cargo space, use the fleet train. It is far cheaper to add cargo space in another ship than in tightly packed warships.