SLN, and MAlign playing catch up with Manticoran superiority

markusschaber wrote:

Theemile wrote:Very true, I was think about long endurance piracy pounce missions. Where you sit for weeks on end under emcon, waiting for someone to do something stupid. LACs have an endurance measured in days, so you'd want ships with several weeks+ endurance to in space as the hyper locus shifts past them, move, rinse, repeat.

The new fission-powered LACs have an endurance measured in years before they need to refuel.
At each of the common arrival places where the freighters hyper out, you could have like 6 of them patroling, and one or two groups patroling areas where pirates might try to hide, like asteroid belts. Then you add in 12 in orbit, for the crews to relax and refill food, and maintainance - and you can rotate them in and out of duty. A single LAC carriers worth of LACs should be enough to secure any normal solar system against pirates and other occasional ambushes.

Power, yes, but crewed endurance on a modern Manty LAC is just 18 days - they arn't designed to have vast areas for crew rest and relaxation - a couple hot bunks and a small galley and a fridge yes, but not much more. (David originally said 18 years, then walked it back to days.) Could you stretch than in a pinch? - sure, take a couple extra MRE cases and a few extra o2 bottles. Remember, most maintenance on a LAC is now done externally, so they need periodic dockings to repair and do routine maintenance, and only the most basic maintenance can be done by the crew. So for long endurance, you really should use the right tool - you really need a DD/CL.

markusschaber wrote:

Theemile wrote:Very true, I was think about long endurance piracy pounce missions. Where you sit for weeks on end under emcon, waiting for someone to do something stupid. LACs have an endurance measured in days, so you'd want ships with several weeks+ endurance to in space as the hyper locus shifts past them, move, rinse, repeat.

The new fission-powered LACs have an endurance measured in years before they need to refuel.
At each of the common arrival places where the freighters hyper out, you could have like 6 of them patroling, and one or two groups patroling areas where pirates might try to hide, like asteroid belts. Then you add in 12 in orbit, for the crews to relax and refill food, and maintainance - and you can rotate them in and out of duty. A single LAC carriers worth of LACs should be enough to secure any normal solar system against pirates and other occasional ambushes.

Their POWER PLANTS last for years, it's life support that would be a limitation. More than days certainly. Not too sure how long the life support endurance might be, but I would guess weeks at most.

Mycall4me wrote:

markusschaber wrote:
The new fission-powered LACs have an endurance measured in years before they need to refuel.
At each of the common arrival places where the freighters hyper out, you could have like 6 of them patroling, and one or two groups patroling areas where pirates might try to hide, like asteroid belts. Then you add in 12 in orbit, for the crews to relax and refill food, and maintainance - and you can rotate them in and out of duty. A single LAC carriers worth of LACs should be enough to secure any normal solar system against pirates and other occasional ambushes.

Their POWER PLANTS last for years, it's life support that would be a limitation. More than days certainly. Not too sure how long the life support endurance might be, but I would guess weeks at most.

On the one hand yes - how long the reactor can go between refueling doesn't tell you much, if anything, about how long a mission the platform can operate. A Virginia-class SSN has a 33-year reactor. But likely has a patrol endurance of less than 4 months.
And carriers are proportionately worse - a Nimitz-class carrier has a reactor refueling interval of around 25 years; but just a few weeks of aircraft fuel at normal ops tempo. (Though they can get underway replenishment of jet fuel from the fleet train oilers; so they don't have to come very far off station to gas up)

On the other hand markusschaber did specify using them with a carrier and cycling the LACs back. I don't think there was an implication that just because a LAC had power for 12 years that it could patrol for months or years -- any more than a SSN or CVN is expected to remain on patrol for years.

But the fact that the carrier doesn't need to consume fuel keeping the LACs out on patrol means it should have been designed with more room for spare, food and consumables, etc. (Kind of the inverse of the situation with the Nimitz-class, where the fact that they don't need to carry gas for their engines is part of that allows them to carry even more jet fuel for their planes than even the final US conventionally powered carriers did)

A CLAC, should be able to keep up an ops tempo of one wing at a time out on patrol for months. (Maybe longer if it can source food, hydrogen fuel for its own reactors, and basic supplies from the local planet/system). OTOH a full up DN or SD sized CLAC is probably way to valuable to a) be left out there on it's own -- it'd have escorts; and b) to tie up long term in anti-piracy work. (And you could have done the same anti-piracy work by just sending those escorts and keeping the CLAC home with the main fleet)


If we see LACs assigned doing distant anti-piracy work of any significant duration I expect they'll either be based on a station, or the Manties will build/convert some cheaper escort-CLACs which aren't full military grade capital ships. Something that carriers fewer LACs and ties up fewer personnel.

The limitation of modern LACs are their crews. Older LACs carried larger enough crews to be able to maintain a decent shift pattern, plus supplies for them to operate longer than modern LACs do, despite being lighter and almost always attached to their home system.

Nuclear submarines show that it is possible for a man-made vehicle to be filled with over a hundred people for months underwater. Some nuclear missile submarines happen to mass around the same as LACs.

I know that aircraft analogies don't usually hold up, but the crew size is more comparable to a bomber than a submarine and that's where the limitations come in. If you only have one engineer, one comms, two pilots, two gunners and so on, then everyone is pulling double shifts and frequently covering roles that aren't their primary responsibility in order to operate for days. That drains the crew heavily within those two-and-a-half weeks.

The RMN is probably aware that they've hit the minimum viable crew size for extended deployments with the Rolands and Wolfhounds. They're not going to send their modern LACs patrolling in the same manner they used to with old LACs. Fortunately, they don't have to because they're building them in far greater numbers, so a system which might have gotten one or two old LACs now instead gets one squadron of new LACs.

That, I imagine, is going to be a pretty strong disincentive for any pirates to visit.

munroburton wrote:The limitation of modern LACs are their crews. Older LACs carried larger enough crews to be able to maintain a decent shift pattern, plus supplies for them to operate longer than modern LACs do, despite being lighter and almost always attached to their home system.

Nuclear submarines show that it is possible for a man-made vehicle to be filled with over a hundred people for months underwater. Some nuclear missile submarines happen to mass around the same as LACs.

I know that aircraft analogies don't usually hold up, but the crew size is more comparable to a bomber than a submarine and that's where the limitations come in. If you only have one engineer, one comms, two pilots, two gunners and so on, then everyone is pulling double shifts and frequently covering roles that aren't their primary responsibility in order to operate for days. That drains the crew heavily within those two-and-a-half weeks.

And also like (most) airplanes modern RMN/GSN LACs also have very little maintenance that the crews can do from inside the vehicle. As mentioned earlier in the thread, they were designed for most maintenance to be done by opening panels or pulling things out through the nose; while it was nestled into the oversized docking collar of the CLAC. Given their shorter planned deployments they accepted an inability to access many systems for internal maintenance in exchange for easier maintenance once back aboard and a more compact design that could fit more into a given CLAC.

Given all that I'd expect routine maintenance needs are going to force those LACs back to base after a couple of weeks even if the tiny crew was somehow able to keep themselves going longer.


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There was that weird and wonderful period of aircraft, mostly in the interwar '20s and '30s where some were built with ways for the flight engineer to access the engines during flight -- usually from within the wing. Thus allowing some maintenance, repairs, or at least fluid top ups to happen during flight. (Especially if you were in a plane with enough engine redundancy to temporarily shut one down)

Jonathan_S wrote:
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There was that weird and wonderful period of aircraft, mostly in the interwar '20s and '30s where some were built with ways for the flight engineer to access the engines during flight -- usually from within the wing. Thus allowing some maintenance, repairs, or at least fluid top ups to happen during flight. (Especially if you were in a plane with enough engine redundancy to temporarily shut one down)

Of course, that was during a period where you NEEDED to have access to the engines to maintain them every few hours to keep them running.

It's insane to think that at the start of WWII, a plane engine had a lifespan of a couple hundred of hours between major rebuilds, and mid-war jets had an average lifespan of 30-50 hours between rebuilds. GE's first jet (copy of the British) had a lifespan of just 30 hrs - the engineers couldn't believe this and lowered the operational temps (and thrust) to get a 80-100 hour lifespan.

The British didn't pass along a metallurgical breakthrough necessary for the compressor blades, limiting the US copy's lifespan. This breakthrough (along with the whole design of the 3rd gen Neva engine) was "accidentially" passed along to the Russians and led to the engine in the Mig-15-19.

My dad flew Spitfires (among other things) in WW2.
I remember him pointing out that the Merlin was the iconic WW2 engine, admired by all. However it was still an English design, so when ferrying it on a long flight they had an oil drop tank as well as AVGas drop tanks. You pumped it out into the sump midway then dumped it. How do you know if a British motorcycle is out of oil, it stops leaking it?

Theemile wrote:

Jonathan_S wrote:
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There was that weird and wonderful period of aircraft, mostly in the interwar '20s and '30s where some were built with ways for the flight engineer to access the engines during flight -- usually from within the wing. Thus allowing some maintenance, repairs, or at least fluid top ups to happen during flight. (Especially if you were in a plane with enough engine redundancy to temporarily shut one down)

Of course, that was during a period where you NEEDED to have access to the engines to maintain them every few hours to keep them running.

It's insane to think that at the start of WWII, a plane engine had a lifespan of a couple hundred of hours between major rebuilds, and mid-war jets had an average lifespan of 30-50 hours between rebuilds. GE's first jet (copy of the British) had a lifespan of just 30 hrs - the engineers couldn't believe this and lowered the operational temps (and thrust) to get a 80-100 hour lifespan.

The British didn't pass along a metallurgical breakthrough necessary for the compressor blades, limiting the US copy's lifespan. This breakthrough (along with the whole design of the 3rd gen Neva engine) was "accidentially" passed along to the Russians and led to the engine in the Mig-15-19.

Jonathan_S wrote:And also like (most) airplanes modern RMN/GSN LACs also have very little maintenance that the crews can do from inside the vehicle. As mentioned earlier in the thread, they were designed for most maintenance to be done by opening panels or pulling things out through the nose; while it was nestled into the oversized docking collar of the CLAC. Given their shorter planned deployments they accepted an inability to access many systems for internal maintenance in exchange for easier maintenance once back aboard and a more compact design that could fit more into a given CLAC.

Given all that I'd expect routine maintenance needs are going to force those LACs back to base after a couple of weeks even if the tiny crew was somehow able to keep themselves going longer.


---
There was that weird and wonderful period of aircraft, mostly in the interwar '20s and '30s where some were built with ways for the flight engineer to access the engines during flight -- usually from within the wing. Thus allowing some maintenance, repairs, or at least fluid top ups to happen during flight. (Especially if you were in a plane with enough engine redundancy to temporarily shut one down)

With skinsuits any starship's crew can conduct external maintenance. But yeah, any LAC that can't be fixed by cable ties or duct tape should go back to its hangar bay.

munroburton wrote:

Jonathan_S wrote:And also like (most) airplanes modern RMN/GSN LACs also have very little maintenance that the crews can do from inside the vehicle. As mentioned earlier in the thread, they were designed for most maintenance to be done by opening panels or pulling things out through the nose; while it was nestled into the oversized docking collar of the CLAC. Given their shorter planned deployments they accepted an inability to access many systems for internal maintenance in exchange for easier maintenance once back aboard and a more compact design that could fit more into a given CLAC.

Given all that I'd expect routine maintenance needs are going to force those LACs back to base after a couple of weeks even if the tiny crew was somehow able to keep themselves going longer.


---
There was that weird and wonderful period of aircraft, mostly in the interwar '20s and '30s where some were built with ways for the flight engineer to access the engines during flight -- usually from within the wing. Thus allowing some maintenance, repairs, or at least fluid top ups to happen during flight. (Especially if you were in a plane with enough engine redundancy to temporarily shut one down)

With skinsuits any starship's crew can conduct external maintenance. But yeah, any LAC that can't be fixed by cable ties or duct tape should go back to its hangar bay.

Eh, they might be able to go outside, open up the panels and remove things - but I suspect that since the LACs were designed to be maintained by their CLAC that the designers also omitted most of the onboard spares, workshops, etc.; as those would be better kept on the CLAC -- allowing the LAC tonnage and cubage to be devoted towards their intended role of fairly low endurance high intensity combat.

So even if they can go external to pull a failing component they probably don't have a replacement (or room to store a replacement) to the equipment to service the pulled part.

Jonathan_S wrote:

munroburton wrote:
With skinsuits any starship's crew can conduct external maintenance. But yeah, any LAC that can't be fixed by cable ties or duct tape should go back to its hangar bay.

Eh, they might be able to go outside, open up the panels and remove things - but I suspect that since the LACs were designed to be maintained by their CLAC that the designers also omitted most of the onboard spares, workshops, etc.; as those would be better kept on the CLAC -- allowing the LAC tonnage and cubage to be devoted towards their intended role of fairly low endurance high intensity combat.

So even if they can go external to pull a failing component they probably don't have a replacement (or room to store a replacement) to the equipment to service the pulled part.

Not only that, the repair specialists are spread throughout the squadron/wing. You might have an Engineer and asst. onboard each LAC, but the Engineer's #1 specialty is running the Fission reactor, drive system and plasma ring capacitors. His secondary specialty is something necessary for the Wing maintenance and operation. So while one LAC might get the Graser specialist or the Fission plant repair specialist, another will have the Crew Refuse Plumbing system specialist. And while any of them have the basic skills to repair any sub-system, When the Graser goes to Sh!t, you don't necessarily want the guy that specializes in Sh!t leading in repair. (but when you are knee deep in it, you are so glad he's there.)