Converting a Freighter for combat use

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AnotherDilbert
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Re: Converting a Freighter for combat use

Postby AnotherDilbert » Thu May 23, 2019 9:23 am

HalC wrote: If you had to convert a heavy freighter over to escort duty, as a hull that can be modified faster than it can be built at a ship-yard, would you make the effort to do so?
A reasonably economical freighter is no match for a warship.

But the canonical Corsairs, Patrol Corvettes, and Broadswords are not warships either.

Freighters have a great advantage: Size, and with it lots of Hull- and hard-points. Fill its hardpoints with fixed mounts (that does not cost any tonnage or gunners), and rely on the Hull to absorb damage. Weapons in fixed mounts will cost a fair bit, but will be reasonably combat effective and will not compromise the income-generation potential.

HalC wrote: Take for example, a 1,500 dTon hull that has three separate holds, two that are 60 dTons each, and one that is 200 dTons (labeled as Aft, Port, and Starboard holds). It already can carry two fighters plus a pinnace and a fuel skimmer - but you want to beef it up more.
Hangars and Docking Spaces are form-fitting to specific craft.

I would treat a cargo hold as a generic Docking Facility (HG, p60) if the hold has a deck height of at least 6 m [double normal height] (since few small craft has a height of less than 3 m), requiring 3 Dt for each Dt of craft.

I might make an exception to the deck height for small Light Fighters (~10 Dt).


At 1500 Dt you have something like 540 Hull points and 15 hardpoints, far more than a few fighters. Fill it with 15 triple fixed mounts and any standard Corsair would be foolish get into range...

HalC wrote: Would you expect that you could simply remove the cargo bay doors for the port and starboard cargo holds, refit it with rudimentary launch facilities for extra fighters, and have the freighter act as its own escort vessel in normal space by launching its own fighters?
Everything is possible, but I would not consider it easy or cheap to make it practical.

Any DIY solution would be extremely jury-rigged and risk things falling out or jump space intruding into the hold (likely with catastrophic effects).

I would allow craft carried externally with minimum fuss, but that would affect drive performance and streamlining.
Reynard
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Re: Converting a Freighter for combat use

Postby Reynard » Thu May 23, 2019 11:54 am

Don't forget to keep clean pillows and blankets plus MREs for the people in the stables.

"Weapons in fixed mounts will cost a fair bit, but will be reasonably combat effective and will not compromise the income-generation potential."

Wouldn't ships with turrets have advantage of range since fixed point weapons have all their ranges reduced. Stand off and eat away at those hull points.
AnotherDilbert
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Re: Converting a Freighter for combat use

Postby AnotherDilbert » Thu May 23, 2019 1:32 pm

Reynard wrote: Wouldn't ships with turrets have advantage of range since fixed point weapons have all their ranges reduced.
Weapons in fixed mounts don't have reduced range; weapons mounted on small craft have reduced range whether fixed or in turrets.
Reynard
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Re: Converting a Freighter for combat use

Postby Reynard » Thu May 23, 2019 2:13 pm

Ah, the wording was a bit fuzzy for me. I was reading those two words as interchangeable (Firmpoint on a small craft is a fixed mount).
Moppy
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Re: Converting a Freighter for combat use

Postby Moppy » Thu May 23, 2019 2:27 pm

AnotherDilbert wrote:
Thu May 23, 2019 8:23 am
Moppy wrote: Traveller doesn't have steerage.
?
Core, p149 wrote:Basic Passage: Also called steerage, this is where
a ship’s captain tries to fill all available space with low-paying passengers. It is generally considered more trouble than it is worth, but there is nearly always someone desperate enough to use basic passage. Up to four basic passengers can be crammed into one stateroom and other areas of the ship can be kitted out with simple bunks to carry more – two tons of space is required for every basic passenger not in a stateroom.
Oh, I missed that. Thank you. It's the rate (2dton/passenger) as barracks which sounds about right.
baithammer
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Re: Converting a Freighter for combat use

Postby baithammer » Fri May 24, 2019 3:11 am

I would treat a cargo hold as a generic Docking Facility (HG, p60)
A cargo hold lacks the facilities needed for docking, but you could modify part of the cargo bay to create a docking facility or other arrangements.

A cargo hold can contain a ship for shipping but wouldn't be able to deploy or support it.

Turning the 200 dt bay into a Launch Tube / Recovery deck for 10t fighters would be rather easy.
Condottiere
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Re: Converting a Freighter for combat use

Postby Condottiere » Fri May 24, 2019 8:29 am

1. I think fast ferries were converted into minelayers.

2.You just need a cargo hatch large enough to push out a spaceship; the more practical issues is whether it's diectly from the holding hold, tying down loose items, and whether you evacuate the air first. Reembarkation may be more tricky.
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Re: Converting a Freighter for combat use

Postby baithammer » Sat May 25, 2019 6:21 am

You need enough space to prep the ship for launch as well as something to maneuver the ship itself into space as trying to do that with power risks damage to both ships, further it would take longer than with either the docking space / hangar / launch facilities so not very useful in a response situation.

As to Q-ships, it won't be able to compete with a warship so using pop-up turrets would be a better deal.
Sigtrygg
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Re: Converting a Freighter for combat use

Postby Sigtrygg » Sat May 25, 2019 8:28 am

Here is a link to what the Germans did with freighters as q-ships during WW2:
http://www.bismarck-class.dk/hilfskreuz ... ction.html
Moppy
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Re: Converting a Freighter for combat use

Postby Moppy » Sat May 25, 2019 8:52 am

Dispersed structures:

They need to add rules to define how a dispersed structure hull works. There is no exterior hull - just a frame to clip to, or perhaps the ship is interconnected boxes. The idea of "hull volume" is inappropriate here. Is it the volume covered by the drive's magic bubble? Adding weapons or craft to a dispersed structure is in theory easy and requires no extra special clips, or you'd be paying for clips as part of regular construction.

Hardpoints on a regular hull:

Hardpoints are a retrofit and can contain turret volume + some.They therefore already have some strong external points to attach to or can add them after construction. If you want to make an extrernal armor shell or craft bay (that increases the dtonnage of the ship) that plugs into hardpoint sockets, why can I not do that?

Although, I do not see why I need to. You should be able to bolt things to the hull because Traveller hulls are strong. In didn'tjt check but i assume docking clamps can be retrofit so there is no need to worry about internal bracing?

edit : No longer on a phone. Droptanks, Detachable Bridge (self-contained lifeboat), External Cargo Mount all appear to be retrofittable in Mongoose 2. It should therefore be possible to add (lesser effective) physical armor to a hull via these means after construction.

Why is detachable bridge retrofittable?
AnotherDilbert
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Re: Converting a Freighter for combat use

Postby AnotherDilbert » Sat May 25, 2019 11:18 am

Moppy wrote: Dispersed structures:
Dispersed configuration is well-defined. It's just cheaper than other configurations. You still need Docking Clamps to attach external hulls.

Moppy wrote: Hardpoints on a regular hull:

Hardpoints are a retrofit and can contain turret volume + some.They therefore already have some strong external points to attach to or can add them after construction.
The hardpoints are always there at no cost. Adding a turret socket is an upgrade that can always be done.

Moppy wrote: If you want to make an extrernal armor shell or craft bay (that increases the dtonnage of the ship) that plugs into hardpoint sockets, why can I not do that?
Traveller spacecraft are not 20th century wet ships; the armour in not added in patches over sensitive areas, the armour IS the hull (like a tank).

Adding an armoured shell is simply building a new hull outside the old hull, compromising drive performance. I don't see why we can't do that. Compare with the TNE ship that chopped the front off a Gazelle and welded a Scout in its place.

An external craft bay could be added as a pod or craft held in clamps, again compromising drive performance.

Internal bracing is assumed to be there at no specified cost, just like a lot of other components, e.g. a few airlocks.

Moppy wrote: Although, I do not see why I need to. You should be able to bolt things to the hull because Traveller hulls are strong. In didn'tjt check but i assume docking clamps can be retrofit so there is no need to worry about internal bracing?
I assume we can simply weld stuff to the exterior of the hull, what's to stop us? We don't generally do it since it would compromise drive performance and (I assume) streamlining.
baithammer
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Re: Converting a Freighter for combat use

Postby baithammer » Sat May 25, 2019 3:01 pm

Tanks armour isn't the hull, there are plates involved for protection and spaced armour packages.

If armour were the hull then an armour rating of 1 would be required, however traveller allows for zero armour and the hull requires 10 damage at personal scale to inflict 1 hull damage.

In order to put armour on and still have the same hull displacement requires the underlying hull to be paired back to accommodate the armour so as not to compromise the integrity of hull.

As to welding things to the hull, it would definitely lose any streamlining as per External Cargo mounts, Drop Tanks and Docking Clamps.
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Re: Converting a Freighter for combat use

Postby Moppy » Sat May 25, 2019 5:07 pm

I believe AnotherDilbert means that a tank "hull" has a base level of armor making it thicker than it needs to be for purely structural reasons, and on top of that they place the additional layers of special protection. In other words, an "unarmored" tank has an armor value greater than zero.
phavoc
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Re: Converting a Freighter for combat use

Postby phavoc » Sat May 25, 2019 6:11 pm

In reality armor, to properly function, requires a defined and purpose-built infrastructure underneath the armor or else the armor will fail when needed most. There is (or at least used to be) an entire area of expertise in naval engineering to design armor in warships. In Traveller, since there are kinetic energy weapons, the underlying structure to channel the energy from kinetic energy strikes is quite important. As naval designers learned through combat with wet navies, failing to do this meant the armor would collapse or else the energy from the strike was poorly distributed, thus causing the armor to fail or localize all of the energy in the area that it was struck.

So you can't just slap slabs of armor on top of things and expect it to work. But Traveller does not recognize the required structure necessary to make this work - at least not like the same way things work in reality. So with handwavium it works just by increasing your armor factor and paying the added cost.
Linwood
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Re: Converting a Freighter for combat use

Postby Linwood » Sat May 25, 2019 7:49 pm

You probably could still have add-on armor packages with very well-defined limitations. For example, reactive armor add-ons could provide some protection against missiles but not other attacks and its protective value would drop after every hit.

Having said that - I doubt i’d ever implement that in my own campaign, except maybe in a very specific scenario. It’s one more level of complexity than I want to deal with. For me the current rules mostly work fine as is.
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Re: Converting a Freighter for combat use

Postby Condottiere » Sat May 25, 2019 8:10 pm

There's a somewhat different dynamic involved in ironcladding, in that naval architects had to figure out which parts of the warships needed protection, and what was the optimal amount without sacrificing significance amounts of manoeuverability and firepower, which were forms of pseudo protection in themselves.

Armoured vehicles aren't evenly coated with the same thickness of armour plating, nor configured the same way all around.


Oh yeah, speaking aerospacedynamically, Tee Five limits acceleration on differing hull configurations, so I'll go with you can attach what you want on a hull, just don't expect it to stick around once you go above a certain acceleration.
Last edited by Condottiere on Sat May 25, 2019 8:17 pm, edited 1 time in total.
AnotherDilbert
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Re: Converting a Freighter for combat use

Postby AnotherDilbert » Sat May 25, 2019 8:15 pm

Moppy wrote: I believe AnotherDilbert means that a tank "hull" has a base level of armor making it thicker than it needs to be for purely structural reasons, and on top of that they place the additional layers of special protection. In other words, an "unarmored" tank has an armor value greater than zero.
Something like that... At least the armour is the outer shell, generally all around the tank (except the outer suspension), unlike wet ships.

Not that all tanks are identical, I believe the Leclerc actually have patches of armour over sensitive areas (from some angles), in some sense like wet ships.


baithammer wrote: If armour were the hull then an armour rating of 1 would be required, however traveller allows for zero armour and the hull requires 10 damage at personal scale to inflict 1 hull damage.
Spacecraft with armour rating 0 in the spacecraft scale have always had substantial armour in the personal scale, perhaps a few cm thick, as CT and MT clarifies.

E.g. in CT Striker the design example appears to be a PzKpfW V 'Panther' with a front glacis of 8 cm sloped hard steel giving armour rating 31 vs armour rating 40 for an "unarmoured" spacecraft.
AnotherDilbert
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Re: Converting a Freighter for combat use

Postby AnotherDilbert » Sat May 25, 2019 8:23 pm

phavoc wrote: In reality armor, to properly function, requires a defined and purpose-built infrastructure underneath the armor or else the armor will fail when needed most.
Armour have generally included internal bracing, as CT HG puts it:
HG'80, p28 wrote:Armor: Hulls may be armored with strengthened exterior skins and interior bracing.
Internal bracing was specified separately in FFS, but the added complexity had very little practical effect. It was hardly worth the added work...
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Re: Converting a Freighter for combat use

Postby Moppy » Sat May 25, 2019 9:21 pm

phavoc wrote:
Sat May 25, 2019 6:11 pm
In reality armor, to properly function, requires a defined and purpose-built infrastructure underneath the armor or else the armor will fail when needed most.
It depends what you mean by "fail". They up-armor cars today, so you can attach it on vehicles lacking "purpose built infrastructure" so long as you do it properly - at least for small arms. I don't think it will stop a .50 sniper or MG, but I couldn't know for sure - and I know even some APCs don't like those.

Suspension will likely break in a few months from weight and good luck opening the doors (car doors are already heavy for me) but at least you don't get shot.
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Re: Converting a Freighter for combat use

Postby phavoc » Sun May 26, 2019 2:19 am

Armored cars are not an equivalent to naval armor, specifically cruisers and battleships. Aside from a frame there is very little structural reinforcement to an armored car - at least the ones I'm familiar with. Besides, most armored cars are meant to be either a poor man's tank or else they are meant to go up against combatants whom are assumed to not possess very lethal weaponry (ATGM and large-caliber weaponry).

Large naval shells carry a great deal of potential energy. The first layer of defense is the armor itself, but assuming the outer armor does it's job that energy needs to be transferred somewhere or else the structure underneath will receive the energy. The structure underlying the armor is designed to channel that energy away from the impact site so that it is not wholly concentrated on the impact point.

Modern warships do not armor up since the intent is to avoid being hit in the first place, so there are no modern equivalents. Tanks have something similar in their structure, though tank warfare is more about trying to do a pinpoint hole using HEAT or APFSDS rounds. Spalling in a turret is usually lethal to the crew. Ships, with their compartmentalization and far larger scale, don't have to deal with that problem on the same scale.

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