CT Only: How big an infantry unit can fit into a 3,000dton hull?

[samuelvss]

Is the helicopter crew part of the squad it carries?

Hans

In no army I have ever heard of. A more interesting question is whether the APC is part of the squad. Yes in the Army, sometimes no in the Corps, with their Amtracks (sp?).

Different way of doing it, but one way of organizing IFV infantry was a squad of IFV's, and two squads of dismounts. In APC's each squad had its own.

 

[Golan2072]

What I had in mind was more of a hybrid between an IFV and an attack/transport helicopter (think BMP and Mil Mi-24 in one). The G-Carrier dismounts its squad of troopers then takes off to provide very close air support with its Plasma-A gun and VRF Gauss Gun.

 

[aramis]

In no army I have ever heard of. A more interesting question is whether the APC is part of the squad. Yes in the Army, sometimes no in the Corps, with their Amtracks (sp?).

Different way of doing it, but one way of organizing IFV infantry was a squad of IFV's, and two squads of dismounts. In APC's each squad had its own.

It also depends upon era and unit type.

If the AFV's/IFV's are a pooled asset - EG, company A has 12 G-Carriers, but which G-Carrier is assigned to which squad is the Captain's choice for the mission, nope. If, however, each squad has one permanently assigned and they have to help maintain it, probably. Points in between, definitely "maybe".

Also important is whether the vehicles are essential to the squad's job. The ambulance and the medical squad are more likely than leg infantry to get the machines in-squad organizationally.

In practice, I've seen records including TOE's which show both modes within the same year at Ft. Rich.

 

[samuelvss]

For rations, I break it down into wet (MRE's) which do not require rehydration, dry (dehydrated), and canned (low-tech MRE's, like C-rats).

Usage rates vary greatly by what sort of combat you're in, what your weapons systems are, and the support weapons are going to be the ammo hogs for "light" troops. At least for Striker, on the offense the amount of LHyd is going to be significant. Starships can refine it, but it has to be pushed forward to the potentially-expanding front.

 

[Hyphen]

How big a unit could fit into a 3,000dton ship? Into a 1,000dton ship?

Ah, you're all missing the point. It's like the ol' accountant story.

"How big an infantry unit can fit into a 3,000dton hull?"

Naval architect looks left, looks right, closes the stateroom door, sidles up to you and says, "How many do you WANT to fit?"

;-) ;-)

 

[Major B]

Ah, you're all missing the point. It's like the ol' accountant story.

"How big an infantry unit can fit into a 3,000dton hull?"

Naval architect looks left, looks right, closes the stateroom door, sidles up to you and says, "How many do you WANT to fit?"

Can I try to do that one better?

When I was assigned to an Arctic Infantry Brigade in Alaska we were sent to a Command Post Exercise with the 4th Infantry Division (Mechanized). In planning, on of their staff asked me how many Soldiers we could fit into a SUSV (our light tracked vehicles designed to drive over deep snow).

I replied, depends on how cold it is. He didn't get the joke but everyone with me who had seen whole platoons stuffed into Squad-carrying SUSVs did.

By way of apologizing for wandering off subject, perhaps you could consider this idea: Do not assume that your ships are purpose-built for exactly the right number of troops. Consider the possibility that ships designed for a light company are pressed into carrying reinforced companies due to how the campaign unfolds and shipping losses. Or the other way, company carriers now have reinforced platoons on board due to troop unit losses or commitments elsewhere drawing off available troop strength. Ships designed and built a couple of decades ago cannot forsee the new MTOE implemented just last year.

Another possible route that could have some unpredictable effects would be to design the units to fit the transports available rather than the other way around. There are a few historical examples of this working and others of it not working out so well. U.S. Rangers in WWII were organized along the lines of UK Commandos who I believe were organized around the capacity of a Higgins Boat. On the other hand, I am not a big fan of US Mech Infantry organization determined by the capacity of a M2 BFV.

Just some thoughts. Hope they are of some use. I hope you plan to post the results when completed.

 

[flykiller]

not 3000 dtons, but my navy has standard j4 19000 dton transports carrying standard cargo modules of 4900 dtons, one design of which carries one reinforced combined arms battalion. 3 companies infantry, 1 company armor, 1 ew section, 1 medical section with hospital, 1 recovery/repair company, 1 flight section, all mounted (see my gigs link below). notably it has no submarines or screens.

a 3000 dton ship likely can't carry more than a single unsupported infantry company.

 

[flykiller]

A more interesting question is whether the APC is part of the squad.

imtu yes. the apc provides transport, fire support, and above all a secure environment. remember, these squads may be deployed at a moment's notice across hundreds of miles into into inherently hostile environments - the men may need a place to go.

 

[whartung]

A Liberty ship in WWII, which has been equivalenced to about 2400 dT, carried about 500 troops across the Atlantic. Mind, this is raw troop transport, and as I am to understand it, the crossings did not rate well on Yelp. But the crossing did take 11+ days, so there's that.

At D-Day, they squeezed 480 troops and 120 vehicles on them for the Channel crossing. Obviously a shorter trip, but even then, they were likely on board for several days. I'm sure a grand time was had by all with all the shuffleboard, tasty buffets, and sunning in deck chairs.

If troops are deployed forward, a single jump is basically a week plus transit to orbit. This sounds more like the Atlantic crossing scenario than a Channel crossing scenario. But in a crunch, you could overload the ships as long as the air scrubbers can keep up.

But the key point, none of these troops were "crew", and the didn't have "long term" accommodations. Simply, they did not live on the ship, rather they were cargo.

So, these kinds of things can be taken in to consideration when talking troop movements. For example, I'm sure ship marines have much better accommodations than the troops in the cargo hold with the cots, port-a-potties, extra deodorant rations, and a single shower ration.

All that said, i would not be putting troops in staterooms. I'd planet hop them from bivouac to bivouac, and cram them in like sardines at the last minute.

 

[aramis]

The problem being that Life Support in CT (and T20 & MGT) is explicitly tied to staterooms - there's only enough air-handling (and probably water handling) for 2 people per stateroom.

Now, one could reduce the size by using small craft staterooms (2td) or even bunks (1td) for troops, and that skews the numbers.

In MT, TNE, T4, and GT: life support capacity can be purchased in excess of stateroom/bunk capacity.

 

[rancke]

In MT, TNE, T4, and GT: life support capacity can be purchased in excess of stateroom/bunk capacity.

Wouldn't it be simple to use the MT, TNE or T4 rules for extra life support for CT designs? There's hardly a case for claiming that extra life support is physically impossible under CT -- it's merely not covered by the rules.


Hans

 

[mike wightman]

The problem being that Life Support in CT (and T20 & MGT) is explicitly tied to staterooms - there's only enough air-handling (and probably water handling) for 2 people per stateroom.
.

An explicit rule that is broken by the events in the first adventure in the Alien Realms CT supplement.

 

[Golan2072]

I also subsume some ship facilities into the stateroom tonnage, such as life-support gear, galley and medlab.

 

[samuelvss]

imtu yes. the apc provides transport, fire support, and above all a secure environment. remember, these squads may be deployed at a moment's notice across hundreds of miles into into inherently hostile environments - the men may need a place to go.

Ideally, yes. It's all a matter of what you want to pay for, though, more transport or more transported. The scheme I talked about with the Corps was that they had a lot more of the latter than the former. Go drop one load, go back for another.

The real issue is not how you match them up when you have enough, which is rather academic as aramis pointed out and I attempted to, but whether the MTOE will have enough. Like the CAB's in modern US divisions, every squad wants their own helicopter, but there are always fewer helicopters, so the division commander sends them to who needs the ride for that phase of the operation. A division with a helicopter in every squad would be a logistical nightmare, and likely have a lot fewer squads.

Now, the logistical support for the G-carrier may be a lot simpler than that for a helicopter. Indeed, if the CAB could make its own fuel locally, there might be a lot more helicopters.....

 

[samuelvss]

imtu yes. the apc provides transport, fire support, and above all a secure environment. remember, these squads may be deployed at a moment's notice across hundreds of miles into into inherently hostile environments - the men may need a place to go.

Ideally, yes. It's all a matter of what you want to pay for, though, more transport or more transported. The scheme I talked about with the Corps was that they had a lot more of the latter than the former. Go drop one load, go back for another.

The real issue is not how you match them up when you have enough, which is rather academic as aramis pointed out and I attempted to, but whether the MTOE will have enough. Like the CAB's in modern US divisions, every squad wants their own helicopter, but there are always fewer helicopters, so the division commander sends them to who needs the ride for that phase of the operation. A division with a helicopter in every squad would be a logistical nightmare, and likely have a lot fewer squads.

Now, the logistical support for the G-carrier may be a lot simpler than that for a helicopter. Indeed, if the CAB could make its own fuel locally, there might be a lot more helicopters..... (I'm thinking Striker/MT fuel, rather than CT handwavium batteries).

 

[samuelvss]

To explicate why I chose the numbers I did...

Leg Infantry - that 1Td per 10 men is (roughly) 1 cubic meter per man, plus 1 cubic meter of squad assets. That's, I figure, rations and ammo. If not needing life support, just food, then 1 cubic meter is 250-1000 person-meals (C-Rats+1L bottled water vs MRE relying upon local water). For a 12 man squad, 20 meals is (roughly) a week of combat or two of garrison. A basic load of ammo in clips is about 1L per clip, probably ship with 10 clips, and then 3L is 500-1000 rounds in a can. A light field tent is about 2L rolled, a more substantial one about 100L; you can use 1 cubic meter for a squad tent in canvas including a heating unit. ...

Great breakdown. I had done it a little differently, and I think gauss rifles give some flexibility here, and 1 liter per magazine is probably excessive, especially in bulk. (.4 kg / gauss mag; they don't float so .4 l is likely generous; most will not be recovered, but only a few need to be to reload/recharge with needles).

Here's the spreadsheet I did, which does mass and cost as well: http://www.travellerrpg.com/CotI/Discuss/showthread.php?p=508944#post508944

Essentially, 2 dtons does a 150 man light infantry company for about a month of medium intensity combat. That is with medium AT missiles for the only support weapons (NOT realistic!), but it is good for back-of-the-envelope figuring.

 

[flykiller]

All that said, i would not be putting troops in staterooms.

there is a distinction here between troops and marines. imtu marines live with the fleet and each one is alloted 3.5 dtons - 0.5 dton locker, 0.5 dton lowberth, and 2.5 dtons personal space, in addition to training, assembly, etc. troops - draftees with a few months of training being shipped to a specific target landing zone - might indeed be crammed in. but they would be crammed into lowberths, not staterooms.

It's all a matter of what you want to pay for ... Like the CAB's in modern US divisions, every squad wants their own helicopter, but there are always fewer helicopters

fully understood and appreciated. but you are minimizing two considerations.

one, a modern u.s. division operates in a global environment with vast national support, and will not send in any unit "piecemeal" unless it is certain it can get away with it and only when it is good and ready. a traveller naval/marine operation is fundamentally isolated from the rest of the imperium by jump distance and must operate with what it has, without knowing what else is available elsewhere or what the opponent has incoming. in that environment piece-meal operations will result in piece-meal losses thus operations will be all-in or all-out all the time.

two, the imperium has vastly more money and thus equipment than available applied manpower, thus for them men are the limiting factor in operations, not equipment. one sees this dynamic even in our limited real-world situation. in wwii the germans would recon an area using a squad while americans might do it using artillery - for the germans men were cheaper while for the americans artillery shells were cheaper. in modern times third world airforces aircraft are far more valuable than any individual pilot, while in first world airforces pilots are far more valuable than any individual aircraft. the same dynamic will be present in imperial operations.

 

[samuelvss]

For grav vehicles, IFV or APC, the ideal is a on-on-one relationship between vehicle and squad, as has been said. There is a great deal of interior space relative to the soldier's load (small arms ammo and the like). The added drain on logistics is fuel, however, especially in the offense. I worked up a relatively robust APC (or wimpy IFV?) at 60 Mw, 4,320 liters gave it 48 hours. At that rate, though, one cutter fuel module can do 92 such APC's for 48 hours. Not a huge drain on starship-scale logistics, but the distribution system needs to be there. Probably one XO/1SG vehicle per company/troop, that has more fuel storage, to do tailgate resupply would be the ideal.

 

[aramis]

Great breakdown. I had done it a little differently, and I think gauss rifles give some flexibility here, and 1 liter per magazine is probably excessive, especially in bulk. (.4 kg / gauss mag; they don't float so .4 l is likely generous; most will not be recovered, but only a few need to be to reload/recharge with needles).

Here's the spreadsheet I did, which does mass and cost as well: http://www.travellerrpg.com/CotI/Discuss/showthread.php?p=508944#post508944

Essentially, 2 dtons does a 150 man light infantry company for about a month of medium intensity combat. That is with medium AT missiles for the only support weapons (NOT realistic!), but it is good for back-of-the-envelope figuring.

Well, assuming cylinders for individual rounds, rather than half-cones, we get (4-pi)/4 of the volume used. But needles are likely 50% cone, 50% cylinder...

so (4-pi)+(4-0.333pi)/8 of the unit volume. assuming single stack (as most, about 60%, detachable magazines are), you get about 47% empty space.

Now, double stacks effectively shave the corners. About 30% of the volume is empty. And we know that most ferrous metals run SG 8.

But then you have the spring compressed volume which is 90% empty, the packing losses (around 10% to 30%) to allow for easy removal from crates (a serious issue in supply). In fact, you want to be able to get the first one out without a tool... except for the key to lock the case... in case of emergency issue.

And then the latch mechanisms and the protective deadspace inside the magazine. (which protects against minor dings causing damage to the rounds and/or jams within the mag. A buddy had a jennings 22 - the spare mag got very slightly bent, and wouldn't feed the last half of the mag. Cheap, single wall, no protective deadspace - not a useful combat magazine.)

But as for that 1L per magazine, I was thinking the 30 rd M16 - actual volume is a little under, but they don't stack neatly so the packing volume is higher. The 20 rds, however, are about 3/L, and I wasn't thinking that hard on it. Still, highballing the required volume gives a useful floor number.

 

[Hal]

The problem being that Life Support in CT (and T20 & MGT) is explicitly tied to staterooms - there's only enough air-handling (and probably water handling) for 2 people per stateroom.

Now, one could reduce the size by using small craft staterooms (2td) or even bunks (1td) for troops, and that skews the numbers.

In MT, TNE, T4, and GT: life support capacity can be purchased in excess of stateroom/bunk capacity.

For 1,100 credits per soldier, life support requirements can be cut by 1/60th in the sense that 1 stateroom will provide life support for 60 people. It is the Fast Drug and Fast antidote.

Simple "bunk bed" cargo pallets could house the soldiers while they are in a hibernation like state (1 hour = 1 minute for them). All that would remain then, would be the war materials they'd need for when they deploy.

No Saving roll versus Death as with Low Berths, and if they're sleeping, 60 hours would seem to be as if 1 hour. 168 hours under "fast" would feel like approximately 2.8 hours sleep for the soldiers.

Might be a useful method for shipping soldiers into combat using the bog standard CT rules. Me? I use GURPS TRAVELLER where they had "bunk rooms" for soldiers being carried. A 30,000 dTon Keith class transportt could carry a Brigade into combat, The 1,200 dton landers could carry a Battalion into combat zones. That however, is GURPS, not classic Traveller.