OTU Only: Fleet Organization

[tjoneslo]

I'm trying to determine the structure of the Imperial Navy based upon existing canon source in order to calculate the size and distribution of the Fleets.

The Rebellion Sourcebook (p 27-31) describes a sector fleet of about 1000 combat vessels, plus an unknown number of smaller support ships. These are divided into (on average) 16 numbered fleets, 16 reserve fleets, and one named fleet. RbS implies the named (sector) fleet is an organizational layer, and the ships are assigned to either one of the numbered or reserve fleets.

Grand Fleet (p 58-59) also describes a sector fleet of about 1000 combat vessels. But only about half ("nearly 500 of its 1000 ships are assigned to the Subsector Fleets.") of the ships. These are one Cruiser squad, plus several 6-8 Fleet Destroyers, 6-8 Escort destroyers, and a larger number of smaller Escorts. The other half of the combat ships are assigned directly to the named (sector) fleet. These are the major war fighting elements, including the all the BatRons and most of the cruisers.

There are two differences between these descriptions: The first is the obvious : in the Milieu 990, the sector fleet has direct control of the majority of the Combat vessels. Whereas in the Rebellion era, the sector fleet has (depending upon the point of view) the sector fleet has control of none of the combat vessels (they're under the subsector fleet control), or all of them (the sector fleet is overview control of the subsector fleets).

The second is the nature of the fleets seems to have changed. Grand Fleet describes the fleets with more smaller (escort and patrol size) vessels, where RbS has more capital ships.

 

[mike wightman]

Fleet deployment doctrine changed in stages from 4FW to 5FW to pre-rebellion.

You have to decide on the era and build your model from that .

Other sources include the 5FW boardgame and Ct S:9

 

[rancke]

The Rebellion Sourcebook (p 27-31) describes a sector fleet of about 1000 combat vessels, plus an unknown number of smaller support ships. These are divided into (on average) 16 numbered fleets, 16 reserve fleets, and one named fleet. RbS implies the named (sector) fleet is an organizational layer, and the ships are assigned to either one of the numbered or reserve fleets.

Not on average. The number of numbered fleets is one per subsector (plus a few extras in Corridor and at Capital), so it would be a maximum of 16. A couple of sectors only have two subsectors and thus only two numbered fleets. Other sectors have somewhere between (e.g. Deneb has 13).

What is not spelled out is whether each sector really has 1000 combat vessels (for a total of 28,000 (not counting the reserve fleets) or whether it's each 16-subsector sector (for a total of 20,000) with correspondingly fewer combat vessels in sectors with fewer fleets. I've always assumed the latter.

It's quite explicit that the sector (named) fleets are composed of the subsector (numbered) fleets in the sector. The writer of Grand Fleet overlooked/ignored that.

I've always assumed that the reserve fleets were not included in the 1000 ship number, but I admit that I can't recall just where (or if) that's spelled out. I could be wrong.

The average numbered fleet has 8-10 squadrons. Since 8-ship squadrons seems to be the norm (see various writeups in S9), that fits quite well with the average fleet size of 62½ combat vessels per fleet (Average of 9 squadrons averaging 7 ships = 63).


Hans

 

[tjoneslo]

What is not spelled out is whether each sector really has 1000 combat vessels (for a total of 28,000 (not counting the reserve fleets) or whether it's each 16-subsector sector (for a total of 20,000) with correspondingly fewer combat vessels in sectors with fewer fleets. I've always assumed the latter.

If you accept the sector fleet only composed of the subsector fleets, the latter seems to be the obvious choice.

It's quite explicit that the sector (named) fleets are composed of the subsector (numbered) fleets in the sector. The writer of Grand Fleet overlooked/ignored that.

Given the author of Grand Fleet, I think it was deliberately changed. Martin Dougherty is a student of military history.

But there are good political reasons to scatter the capital elements under different commands during peace time (cf. Olav hault-Plankwell). But during the Solomani Rim war, having the main combat forces under a single unified command make much more sense.

I've always assumed that the reserve fleets were not included in the 1000 ship number, but I admit that I can't recall just where (or if) that's spelled out. I could be wrong.

My reading of both Rebellion Sourcebook and Grand Fleet are also ambiguous.

The average numbered fleet has 8-10 squadrons. Since 8-ship squadrons seems to be the norm (see various writeups in S9), that fits quite well with the average fleet size of 62½ combat vessels per fleet (Average of 9 squadrons averaging 7 ships = 63).

The squadron descriptions in Grand Fleet are also 7 to 10 ships each. But the distribution of these squadrons between the 17 fleets is different.

 

[Garnfellow]

I think Mongoose Traveller: Sector Fleet is the latest canonical work on Imperial fleet structures in 1105, and if I recall aright it's pretty similar to Grand Fleet.

 

[rancke]

I think Mongoose Traveller: Sector Fleet is the latest canonical work on Imperial fleet structures in 1105, and if I recall aright it's pretty similar to Grand Fleet.

From what I gather, the total size of the Imperial Navy is considerably smaller according to Grand/Sector Fleet than according to Rebellion Sourcebook. Since I consider the size implied by RbS to be strangely small for the IN's budget, I'm inclined not to believe in what Sector Fleet claims.


Hans

 

[whulorigan]

I think Mongoose Traveller: Sector Fleet is the latest canonical work on Imperial fleet structures in 1105, and if I recall aright it's pretty similar to Grand Fleet.

That's because Grand Fleet and MgT: Sector Fleet were both authored by MJD.

 

[tjoneslo]

From what I gather, the total size of the Imperial Navy is considerably smaller according to Grand/Sector Fleet than according to Rebellion Sourcebook. Since I consider the size implied by RbS to be strangely small for the IN's budget, I'm inclined not to believe in what Sector Fleet claims.
Hans

The difference is largely around what is considered "combat vessels" and counted in the 1000 ship per fleet. RsB, and you, assume nothing smaller than a cruiser counts. Whereas Grand Fleet includes Destroyers and Escorts. I can see why RsB would exclude the smaller ships from their counting, But if the ratios of ship sizes described by Grand Fleet are true, there are a significant number of these smaller ships in the fleet(s). Even if they are not counted as "combat vessels".

 

[rancke]

The difference is largely around what is considered "combat vessels" and counted in the 1000 ship per fleet. RsB, and you, assume nothing smaller than a cruiser counts. Whereas Grand Fleet includes Destroyers and Escorts. I can see why RsB would exclude the smaller ships from their counting, But if the ratios of ship sizes described by Grand Fleet are true, there are a significant number of these smaller ships in the fleet(s). Even if they are not counted as "combat vessels".

Oh, I'm not discounting the existence of a lot of auxiliaries. I don't know the ratios SF uses (I'm going to use 'SF' for 'Sector Fleet' to avoid confusion with GT: Ground Forces), but since we don't have any information about the number of auxiliaries in previously published information, whatever SF propounds could be just as good as anything else. Depending on just what it says, of course. What are those ratios, BTW.?

No, the problem is exactly the main difference that you point out, the reduction of the number of combat vessels. There's a big difference in cost between 1000 ships, half of them combat vessels, and 1000 combat vessels plus 1000 (or even 2000) auxiliaries. The average auxiliary costs about one twentieth of the average combat vessel. And I've always included one 5,000T escort per combat vessel in my calculations and then added 10% for the other auxiliaries. So SF is doubling or tripling an already inflated maintenance cost. And, as I said before, I'm already having a hard time believing in the maintenance figure implied by the TbS figures.


Hans

 

[tjoneslo]

While Rebellion Sourcebook does not have any breakdown of the squadrons, Fighting Ships of the Shattered Imperium (p 9) has a detailed breakdown of the different squadron types.

BatRon -> 4 Battleships, 2 transports, 3 scouts, 2 Auxiliaries, 1 tanker
BatRon -> 1 Battle tender, 4 battleships, 1 transport, 2 scouts, 4 escorts
CruRon -> 5 Cruisers, 1 auxiliary, 2 scouts, 4 escorts
CarrierRon -> 1 Carrier, 1 tanker, 1 transport, 4 scouts, 10 fighter groups
AssaultRon -> 1 Cruiser, 1 tanker, 3 transports, 2 scouts, 1 auxiliaries, 4 escorts
TankRon-> 1 Cruiser, 2 auxiliaries, 4 tankers, 4 scouts, 2 transports, 4 escorts.

Beyond the description of the squadrons, there is no description of distribution. Based upon a minimal amount of common sense, but nothing else I would assign squadrons in this priority order.

1. CruRon
2. AssRon
3. BatRon
4. CruRon
5. TankRon
6. BatRon
7. CarrierRon
8. CruRon
9. BatRon
10. CruRon

For a full 10 squadron fleet, we have 3 BatRon, 4 CruRon, 1 CarrierRon, 1 AssaultRon, 1 TankRon.

For a ship total of :
12 battleships,
22 cruisers,
1 carrier,
20 escorts
6 transports
27 scouts
17 auxiliaries
9 tankers
6 transports

So you end up with 35 combat ships or 55 combat ships depending if you count the escorts. For a full sector fleet (16 numbered fleets) this is 560 ships or 880 ships. If you include the reserve fleets, but assume they have fewer ships you have the 1000 ship sector fleet.

 

[mike wightman]

This is contradicted by S:9...

 

[rancke]

BatRon -> 4 Battleships, 2 transports, 3 scouts, 2 Auxiliaries, 1 tanker
BatRon -> 1 Battle tender, 4 battleships, 1 transport, 2 scouts, 4 escorts
CruRon -> 5 Cruisers, 1 auxiliary, 2 scouts, 4 escorts
CarrierRon -> 1 Carrier, 1 tanker, 1 transport, 4 scouts, 10 fighter groups
AssaultRon -> 1 Cruiser, 1 tanker, 3 transports, 2 scouts, 1 auxiliaries, 4 escorts
TankRon-> 1 Cruiser, 2 auxiliaries, 4 tankers, 4 scouts, 2 transports, 4 escorts.

You're assuming this represents the peacetime complement of ships. To reconcile these numbers with FS, I would assume that they represent typical squadrons after years of war and the consequent combat losses.

Beyond the description of the squadrons, there is no description of distribution.

FFW countermix suggests one BatRon per two CruRons and fairly few AssRons and TankRons. For a full 10 squadron fleet I would suggest 3 BatRons, 6 CruRons and one specialist squadron.

So you end up with 35 combat ships or 55 combat ships depending if you count the escorts. For a full sector fleet (16 numbered fleets) this is 560 ships or 880 ships. If you include the reserve fleets, but assume they have fewer ships you have the 1000 ship sector fleet.

But you don't have a 1000 combat vesel sector fleet, wehich is what RbS mentions.

Also, your sector fleet would not cost enough to soak up the IN budget in a plausible manner. As I've mentioned before, the 1000 combat vessels are already strangely low cost for the canonical budget and requires that half the budget is spent on bases and logistics.


Hans

 

[rancke]

Fighting Ships of the Shattered Imperium (p 9) has a detailed breakdown of the different squadron types.

BatRon -> 4 Battleships, 2 transports, 3 scouts, 2 Auxiliaries, 1 tanker
BatRon -> 1 Battle tender, 4 battleships, 1 transport, 2 scouts, 4 escorts
CruRon -> 5 Cruisers, 1 auxiliary, 2 scouts, 4 escorts
CarrierRon -> 1 Carrier, 1 tanker, 1 transport, 4 scouts, 10 fighter groups
AssaultRon -> 1 Cruiser, 1 tanker, 3 transports, 2 scouts, 1 auxiliaries, 4 escorts
TankRon-> 1 Cruiser, 2 auxiliaries, 4 tankers, 4 scouts, 2 transports, 4 escorts.

Assuming these are war-reduced squadrons, we can make some guesses as to peacetime composition:

BatRon -> 8 Battleships, 4 transports, 8 scout/couriers, 2 tankers¹, 4 other auxiliaries (what?)

¹ Big enough to allow the whole squadron one one-parsec jump?​

BatRon -> 2 Battle tenders, 8 battleships, 2 transports, 4 scout/couriers, 8 escorts. (Battleship-sized riders?!? 4 of them would require a minimum payload of 800,000T With the maximum ship size 1,000,000T, I don't think you can design a tender that can carry more than half that.)

CruRon -> 8 Cruisers, 8 escorts, 4 Scout/couriers, 2 other auxiliaries (what?)

CarrierRon -> 2 Carriers, 2 tankers, 2 transports, 8 scout/couriers, 20 fighter groups

AssaultRon -> 8 troop transports, 2 Cruisers, 2 tankers, 4 scout/couriers, 8 escorts, 2 other auxiliaries (what?)

TankRon-> 8 tankers, 2 Cruisers, 8 scout/couriers, 4 transports, 8 escorts, 4 other auxiliaries (what?).

To get the average of 7 combat vessels per squadron, roughly half the squadrons would be a division understrength (6 rather than 8 ships). Squadrons with an odd number of main vessels would be rare.

General musings:

1) I'd be inclined to assign one full squadron (8) of scouts/couriers to each squadron.

2) OTOH, all ships assigned to a squadron ought logically to be able to keep up with the squadron, so the classic J2 Scout/Courier is out anyway. Perhaps they should just all be retconned to be Fleet Couriers.

3) Personally, I'd assign all couriers to the fleet rather than individual squadrons and let the fleet admiral parcel them out to any squadrons he detatched from his immidiate command. Squadrons accompanying the fleet would not need their own scouts or couriers.

4) Squadrons with missile-armed combat vessels would need transports to carry extra missiles.

5) Resupplying bases and other logistics would require a lot of transports, probably assigned directly to the fleets or to the bases.


Hans

 

[aramis]

In Re Battle Riders - ISTR that a tender carrying 6x100KTd riders was considered a battleship equivalent... That's the largest I can recall seeing.

 

[rancke]

In Re Battle Riders - ISTR that a tender carrying 6x100KTd riders was considered a battleship equivalent... That's the largest I can recall seeing.

Yeah, the whole question is a bit of a mess. Assuming one tender's worth of (average) cruiser-sized battleriders are a match for one or perhaps two battleships, each individual tender would be the equivalent of a battleship and a squadron full of tenders would be a BatRon.

What I don't believe should be the case, whatever any combat system implies, is that one tender's cargo of cruisers-sized battleriders should be a match for a full squadron of battleships, the 157th BatRon to the contrary notwithstanding. Because if it was, the choice between buying one battleship BatRon or eight battlerider squadrons would be a no-brainer rather than a subject of debate.

It would also increase the perennial problem of using up the canonical Imperial naval budget.


Hans

 

[tjoneslo]

Yeah, the whole question is a bit of a mess. Assuming one tender's worth of (average) cruiser-sized battleriders are a match for one or perhaps two battleships, each individual tender would be the equivalent of a battleship and a squadron full of tenders would be a BatRon.

What I don't believe should be the case, whatever any combat system implies, is that one tender's cargo of cruisers-sized battleriders should be a match for a full squadron of battleships, the 157th BatRon to the contrary notwithstanding. Because if it was, the choice between buying one battleship BatRon or eight battlerider squadrons would be a no-brainer rather than a subject of debate.

The text in High Guard implies there is a tradeoff between the non-jump battle rider and the jump-capable battle ship. A battleship needs to allocate 45% of it's space to Jump drive and fuel. It makes a certain logical sense that you can pack the same fire power into a ship half the size.

But the reality, the spinal mount setup doesn't allow much differentiation, and the hull size limitation on the number of secondary weapons makes the larger ship more powerful. The other potential advantage, maneuver drive, is capped at M6, agility 6, and isn't costly enough (in terms of space on the ship) to be limited on the battleship thereby not giving an advantage to the rider.

I think it is a little different for other design systems, but the FSotSI designs are so bad its hard to do the analysis.

GT:Starships only has the Azaniti High Lighting, the Kokirrak, and the Tigress. The GURPS ship design system may provide more differentiation because the armor vs. M-Drive capability, and drive power is limited only to the space allocated to it. But not the weapons allocation.

 

[tjoneslo]

4) Squadrons with missile-armed combat vessels would need transports to carry extra missiles.

This is the primary mission for the auxiliaries. In addition the FSotSI auxiliaries carry a second set of fuel shuttles for the tanker(s), and other necessities for a few thousand people.

 

[Dagrill]

Also, your sector fleet would not cost enough to soak up the IN budget in a plausible manner. As I've mentioned before, the 1000 combat vessels are already strangely low cost for the canonical budget and requires that half the budget is spent on bases and logistics.
Hans

Hi,

The Military Budget also needs to include Bases, Training, R&D, refits, new build, equipment and munitions. Oops and intelligence (and this is just off the top of my head).

IMTU the reserve/colonial fleets are funded by the local Duchy (as they have huge budgets). I've also adjusted strike so that 60% goes to the Planetary forces and only 40% to the Planetary Navy (and it still produces huge planetary navies)

Regards

David

 

[Meteoric Assault]

While Rebellion Sourcebook does not have any breakdown of the squadrons, Fighting Ships of the Shattered Imperium (p 9) has a detailed breakdown of the different squadron types.

BatRon -> 4 Battleships, 2 transports, 3 scouts, 2 Auxiliaries, 1 tanker
BatRon -> 1 Battle tender, 4 battleships, 1 transport, 2 scouts, 4 escorts
CruRon -> 5 Cruisers, 1 auxiliary, 2 scouts, 4 escorts
CarrierRon -> 1 Carrier, 1 tanker, 1 transport, 4 scouts, 10 fighter groups
AssaultRon -> 1 Cruiser, 1 tanker, 3 transports, 2 scouts, 1 auxiliaries, 4 escorts
TankRon-> 1 Cruiser, 2 auxiliaries, 4 tankers, 4 scouts, 2 transports, 4 escorts.

Beyond the description of the squadrons, there is no description of distribution. Based upon a minimal amount of common sense, but nothing else I would assign squadrons in this priority order.

1. CruRon
2. AssRon
3. BatRon
4. CruRon
5. TankRon
6. BatRon
7. CarrierRon
8. CruRon
9. BatRon
10. CruRon

For a full 10 squadron fleet, we have 3 BatRon, 4 CruRon, 1 CarrierRon, 1 AssaultRon, 1 TankRon.

For a ship total of :
12 battleships,
22 cruisers,
1 carrier,
20 escorts
6 transports
27 scouts
17 auxiliaries
9 tankers
6 transports

So you end up with 35 combat ships or 55 combat ships depending if you count the escorts. For a full sector fleet (16 numbered fleets) this is 560 ships or 880 ships. If you include the reserve fleets, but assume they have fewer ships you have the 1000 ship sector fleet.

I am surprised by some of the organizations....... no escorts with a carrier squadron? What is the Zhodani for "chicken ready to be plucked"

 

[Condottiere]

The Army probably costs a lot more than mentioned, since you have to maintain and transport divisions, corps and armies across interstellar distances.