Converting a Freighter for combat use

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Condottiere
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Re: Converting a Freighter for combat use

Postby Condottiere » Mon May 20, 2019 5:38 am

I think it may have been legacied from the original Classical, too unconcerned to look it up.

Tee Five differentiates how armour is applied, so I, personally, think you can add or subtract armour and protection upto the technological level of the shipyard, under specific circumstances and depending on the hull configuration.

You already have possible variances with breakaways.

As regards to arming and tasking commercial vessels for frontline combat roles, that usually doesn't end well.

Historically, destroyer escorts were purpose built convoy escorts, replacing commercial specced "frigates" and releasing actual destroyers for aforementioned frontline combat roles.
DickTurpin
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Re: Converting a Freighter for combat use

Postby DickTurpin » Mon May 20, 2019 5:53 am

There are a lot of good ideas for converting a freighter into a fair warship, but they will require months or years in a shipyard and eliminate any cargo capacity. What if those options are unacceptable? Say you are the Captain of a heavy freighter and need to keep hauling cargo to make the mortgage, but a war breaks out, or there is a huge increase in pirate activity in the area. What are your options to increase survivability while staying (mostly) on schedule and still making a profit?

  • Improve the sensors to at least Military grade, consider Improved Signal Processing if it is available; seeing your enemies is critical.
  • Add turrets, lasers are best for both offence and defense, sandcasters for laser protection. Missile racks are good weapons but expensive to operate; a few might be a good deterrent but don't over do it.
  • Without staterooms for gunners you will want to upgrade your computer and add Virtual Gunner or Virtual Crew software.
  • Increase power capacity to power the weapons, batteries or a small additional powerplant dedicated to the guns.
  • Speed: Not much you can do. Maybe strap on some High Burn Thrusters but the fuel gobbles up cargo space quickly.
These upgrades do not need to be new, if there is a space ship junk yard around you might be able to scavenge most of the needed supplies. A scrapped Seeker could supply Military sensors, a 4 ton power plant and a double turret. Outdated ships may provide reaction drives that can be used as HBTs. Your own crew might even be able to install the gear, mount the external components before jumping out and install the power plant and run the power lines during jump. It won't be pretty, it won't be the toughest ship in space, but it might be enough to get you out of a bad situation once in awhile.
Moppy
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Re: Converting a Freighter for combat use

Postby Moppy » Mon May 20, 2019 11:05 am

DickTurpin wrote:
Mon May 20, 2019 5:53 am
Staterooms shouldn't be a problem on a freighter. They can sleep in the smallcraft if you get really short on space (triple occupancy is fine for short term) and can't put up a porta-cabin in the cargo bay. (Smcraft can obviously have interior systems powered while docked, or embarking and undocking would be hard).

Yopu probably want to hire an escort.

In a war zone (why are you there without a military convoy?) you need to decide how you're going to not look like spies. Putting military sensors on your freighter is maybe not a point in your favor.
phavoc
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Re: Converting a Freighter for combat use

Postby phavoc » Mon May 20, 2019 7:09 pm

The idea of a refit supplement complementing High Guard seems like a potential add-on for MGT...
Condottiere
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Re: Converting a Freighter for combat use

Postby Condottiere » Tue May 21, 2019 5:39 am

Not really necessary to restrict it to purely paramilitary pursuits, since default designs could be customized to suit their current owners' tastes or souped up for increased performance.

It tends to be cheaper and faster to have the ships designed from the start to be militarizable, though experience tends to bring unexpected results.

Fast passenger liners were to be tasked to take on commerce raiders, due to their inherent continuous high speed performance but it turns out their most optimized used was for fast troop transports.

Half the Chinese trawler fleet probably is being used as surveillance and rapid response vessels by the Politburo, the other half designed to be militarized quickly.

Her Majesty's Ship Ocean was built to commercial standards.

A lot depends on how long you expect that ship to remain in service, as to how much you want to spend on it; converting commercial ships to perform military roles, usually second line, is a short term solution for the short and medium term, since unless the ship was prepped, like the British considering storing guns and ammunition onboard so that conversion can take place almost anywhere and at any time, said conversion usually takes a lot more time.
Moppy
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Re: Converting a Freighter for combat use

Postby Moppy » Tue May 21, 2019 9:26 am

Condottiere wrote:
Tue May 21, 2019 5:39 am
Fast passenger liners were to be tasked to take on commerce raiders, due to their inherent continuous high speed performance but it turns out their most optimized used was for fast troop transports.

Her Majesty's Ship Ocean was built to commercial standards.

A lot depends on how long you expect that ship to remain in service, as to how much you want to spend on it; converting commercial ships to perform military roles, usually second line, is a short term solution for the short and medium term, since unless the ship was prepped, like the British considering storing guns and ammunition onboard so that conversion can take place almost anywhere and at any time, said conversion usually takes a lot more time.
The "fast liner commerce raider defense" was a product of the early 20th century because ships (especially submarines) were slow, sensors were poor, and many ships couldn't make or exceed their hull speed. It certainly won't work today. It probably isn't going to work in Traveller. The liner isn't going to be outrunning a missile or fighter, Traveller warships aren't constrained by hull speed, and I don't see (under the ruleset) how you can fail to detect a jump.

As you noted with HMS Ocean, she was a purpose-built design for budgetary reasons to civilian standrds, and not a civilian conversion which is kind of what we were discussing. But I agree that it's relevant. And as you note, they paid real cheap and it started to fall apart early prompting a sale. Luckily the thing never got itself hit, would probably have burned or sunk worse than HMS Sheffield or USS Stark.

edit: Thanks to baithammer for catching a rule I missed. And I think you can match acceleration with a fighter, but who seriously builds a 9G liner for civilian use?
Last edited by Moppy on Tue May 21, 2019 10:50 am, edited 4 times in total.
baithammer
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Re: Converting a Freighter for combat use

Postby baithammer » Tue May 21, 2019 9:53 am

Jumps need to be in sensor range to be detected.
Normally, a ship that emerges into real space
will be automatically detected if it emerges within the
‘minimal’ detail range of the sensor.
Reynard
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Re: Converting a Freighter for combat use

Postby Reynard » Tue May 21, 2019 11:27 am

I'd read that as a jump flash is detected when the flash reaches a sensor's detection range. Ship's exiting or entering jump around a gas giant will flash and this signal will travel at light speed so ships and ground/orbital facilities in various locations in the system will eventually detect it at time depending on distance from the source at their particular sensor grade's range.

I though I read a long while back when researching Q ships for Traveller that freighter conversions were mostly desperation when civilian vessels for combat duties were slapped together but not for frontline roles and never meant to have a great survival records and Q ships had lousy survival records once they were outed. They were a trap hoping to lure enemies close enough to hopefully shell them enough before they could counter attack. I don't see navies putting the best weapons on these ships as it makes then cost effective targets.

I always assumed the armor design rules in High Guard was placed after hull design to show it's integral, armor is part of the overall hull construction rather than filling a dismantled suite of staterooms or a cargo hold with metal and saying the entire ship is protected. Only reason you could do that with Armored Bulkheads is by taking tonnage directly from the section being armored, the engineering area will be tougher but smaller.

Purpose build Q ships or any ship meant to look like a freighter is a whole different story. I actually designed Q ships that were warships that have the exterior look of Free and Far Traders that power down to look like a Trader's energy signal. Same could be done with larger freighters. Most of this though is still meant to deal with enemy commerce raiders or as commerce raider themselves.
baithammer
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Re: Converting a Freighter for combat use

Postby baithammer » Tue May 21, 2019 11:54 am

Regular sensors need to be in range to detect a jump, gravitational analysis suite on the other hand can detect a jump at any range given enough time for the flash to reach the sensor.

Q ships are more of a patrol force tool where they use it to lure in pirates / raiders then either civilian or military organizations. ( Merchant gunships are more of a thing for civilians.)

The design rules break hulls and armour in separate categories and a breakaway hull isn't required to have the same armour across sections.

However, slapping on armour for a ship would require more than repair facilities and knowledge as it would require architectural planning to balance the design out.
Moppy
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Re: Converting a Freighter for combat use

Postby Moppy » Tue May 21, 2019 1:38 pm

Thickening the hull on the inside seems like a rebuild, but one should be able to use external bolt-on armor and tune the drives up for the additional mass if needed. It's not a thing in Traveller, which is fine, but it should be possible - though harder if streamlined or jump capable, and maybe it doesn't get applied to the wingy bits. I assume megafreighers probably don't land and instead offload to an orbital terminal.
phavoc
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Re: Converting a Freighter for combat use

Postby phavoc » Tue May 21, 2019 4:09 pm

One of the new kickstarted expansions has a new gravitational sensor that can detect ships lightyears away (at the speed of light). So that kind of breaks all pre-existing sensor rules and concepts. Personally I think it's way out of line, thus I just discard that capability. For stellar objects, fine. For ships jumping I see a big fat nope in it's future.

Q-ships come in two flavors - purpose built ones that resemble regular freighters and liners, and ones that use an existing hull and upgrade it from there. Purpose-built ships have a lot more potential advantages as they can incorporate additional bulkheads, armor, etc as part of the initial design (thought within reason, it still has to look like a regular ship from the outside and sometimes from the inside as well). Traveller rules aren't clear on how a lot of this works, so it's very hand-wavium for the GM and players.

Q-ships built out of existing hulls can have upgraded engines, power plants, weapons, electronics and weapons. They will be more limited on armor and such since their superstructure is not designed with this in mind. Adding external armor would be a giveaway. Still, coming up on a subsidized merchant that is armed with particle accelerators, military-grade sensors and ECM and maybe even a few nuclear missiles is going to ruin the average pirates day. Remember that pirates are generally cowards and won't stick around for a fair fight - there's too much risk to them and it's not like the average pirate has an industrial base to freely support their activities.
Sigtrygg
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Re: Converting a Freighter for combat use

Postby Sigtrygg » Tue May 21, 2019 4:59 pm

There may be a way to rationalise the use of gravitational sensors over interstellar distances - other than the afore mentioned detection of big stuff (planets and stars) the gravitational ripples of regular jump drive use within a system may leave a tell tale signature. Note I would require lots of regular traffic for this to be noticeable.

While scouting a new area your sensors would be able to confirm jump traffic in a distant system, with the caveat that the information is years out of date so something may have happened in the intervening years...

as for Q ships I once had a group of PCs in The Traveller Adventure transporting AFVs as cargo - they were bounced by pirates and had to surrender. They checked the AFVs and found a couple of them to be battlefield meson sleds...
Sigtrygg
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Re: Converting a Freighter for combat use

Postby Sigtrygg » Tue May 21, 2019 5:08 pm

Moppy wrote:
Tue May 21, 2019 1:38 pm
Thickening the hull on the inside seems like a rebuild, but one should be able to use external bolt-on armor and tune the drives up for the additional mass if needed. It's not a thing in Traveller, which is fine, but it should be possible - though harder if streamlined or jump capable, and maybe it doesn't get applied to the wingy bits. I assume megafreighers probably don't land and instead offload to an orbital terminal.
If you bolt anything onto the outside of your ship you increase the volume of the hull - your drive performance degrades as a result. You can not 'tune up the drives' as you put it.
Bolt 10t of armour onto the outside of a 400t subbie and you now have a 410t ship so you will need new drives to achieve the same performance - possibly a reduced size higher TL drive could fit in the space available...
Moppy
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Re: Converting a Freighter for combat use

Postby Moppy » Tue May 21, 2019 11:55 pm

Sigtrygg wrote:
Tue May 21, 2019 5:08 pm
If you bolt anything onto the outside of your ship you increase the volume of the hull - your drive performance degrades as a result. You can not 'tune up the drives' as you put it.
I am sure they can, but like adding external armor, there are no game rules for doing it long-term.

Mongoose 2 has an "Overload Drive" action for engineers that can break the drive but adds 1G which means the engine can be "tuned-up" somehow. Adding 1G to a free trader seems drastic, but you only need a few % for armor. It'll probably last until the 100D limit. Probably. Ask your GM and be prepared to pay much higher maintenance costs. Still better than being pirated.

I wouldn't recommend trying it with a jump drive.
baithammer
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Re: Converting a Freighter for combat use

Postby baithammer » Wed May 22, 2019 1:17 am

Ship sensors are insufficient to spot a jump flash outside of sensor range, as it seems the flash is a gravity ripple that requires a much more sensitive sensor array to pick up.

As to the Q ship, they are by nature purpose built as it is designed to conceal its nature while having hidden weapon systems.

The other description is what is referred to as a gunship, where you take a ship and add more weapon systems.

Armour can't simply be bolted on to a ship as it requires adjusting the hull to fit the plating, ie removing a portion of the hull to fit plating in order to accommodate the space taken by up by the upgrade.
Reynard
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Re: Converting a Freighter for combat use

Postby Reynard » Wed May 22, 2019 2:20 am

You can add all the weapons you like but if the ship has a massive armor glass jaw, it's toast in the first round. Q ships try to fake it and gain surprise before the enemy can react hoping to do significant damage with weapons meant to do that against particular types of vessels. This usually means you stay away from warships. Dton for Dton, purpose built warships are more efficient ship killers compared to a conversion.

Interesting thought, freighter conversions were more often than not done to cheap older ships again often as an act of desperation. What if these hulls are actually older ships and they come with Quirks from the Older Ships section in Traveller Core Book.
Moppy
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Re: Converting a Freighter for combat use

Postby Moppy » Wed May 22, 2019 3:37 am

In reality, the cargo bay is half the ship. Laser goes in one side, maybe comes out the other, no-one notices. :-)

Need to hit something vital, or use shrapnel. Explosives won't generate a blast wave in vacuum.

Be like putting holes in the back of a panel van.

Second idea: You have a lot of cargo space for sand. Release a cloud of sand and drift along with it. Like a sand caster except it's many tons of sand. Could you do this with water ice to reflect lasers?

errata: Replace "reflect" with "absorb".
Condottiere
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Re: Converting a Freighter for combat use

Postby Condottiere » Wed May 22, 2019 11:07 pm

1. Fast passenger liners are probably vehicles of mass transit and a balance of acceleration and jump range between popular destinations.

2, Queue ships are most effective at the beginning of a war, since no one expects a cannonish exposition; once the other side cottons ons, they sink then at a distancem rather than attempting to close and board.

3. Armed fast passenger liners were expected to be able to handle destroyers and protected cruisers, and shadow armoured cruisers, if confrontation isn't necessary, in their role of trade protection.

4. Freighters converted to commerce raiders are likely to have a couple of bays, and probably somewhere between one and ten kay tonnes; anything smaller seems trawler class.

5. I'll buy the fact that transitioning down and exiting the rabbit hole spikes gravity waves; the question is how far they'll ripple.

6. Over penetration is likely for weapon systems optimized for use against large armoured warships.
Moppy
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Re: Converting a Freighter for combat use

Postby Moppy » Thu May 23, 2019 2:40 am

These days liner implies luxury. Mass transit is a ferry and we don't really have long duration ferries anymore.

They don't have steerage class anymore but it wasn't very nice. The steamships were like this for the cheaper classes. They lived in those for months, which is how long the trip took.

Image

Traveller doesn't have steerage. If they did it would probably be 6x occupancy or a civilian barracks module. Looks like it was replaced with low berths.
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Re: Converting a Freighter for combat use

Postby AnotherDilbert » 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.

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