French Orage-class Aviso

French Orage-class Aviso

Original Date of Design: March 10, 2277

First Example Laid Down: October 9, 2278

First Example Completed: December 2, 2279

Fleets of Service: France (2, Cyclone and Bourrasque), Mexico (ex-Ouragen), and Inca Republic (ex-Orage). One (Pluie) “lost in action”.[i]

In the early 2200s warship design was relatively primitive. The modern X-ray laser was just being invented, and warships relied primarily on arrays of particle beams. These were of much more limited range than later X-ray weapons.  In 2205 Argentina and Brazil were at war. The Argentine Space Force was far larger and more capable than the Brazilians, and at Argentine forces defending their colony of Santa Maria on Tirane quickly blockaded the planet. The blockading force consisted of the obsolescent particle beam armed 25 de Mayo, and two more modern X-ray laser armed vessels, the Almirante Brown and Generale Belgrano. The X-ray armed ships completely outranged the Brazilians, and in order to break the blockade the Brazilians turned to a new weapons system – the missile.

This missile did not have the characteristics of modern missiles. Instead it was essentially an “unmanned remote control fighter”, with the fuel cell running a standard x1-2 particle beam weapon[ii] similar to those equipping the old 25 de Mayo. By placing it on a warping chassis it was hoped that they could cross through the Argentine X-ray laser barrage and attack. In practice this did not happen. The Argentine ships shot down the missiles for little damage because they could hold the range open where they could shoot, but the missiles couldn’t. However, the missile was obviously useful, but it just had to be done right.

In the mid-23^rd century French naval architecture favoured heavy batteries of X-ray lasers, and nuclear tipped stutterwarp missiles, such as the ESA Silke. With the introduction of fusion it was questioned whether the missile would remain effective given the power of the battery that ships could now deploy. However, it was unquestioned that light units, such as escorts and skirmishers, would continue to rely on nuclear devices as they lacked the raw power to do otherwise.

The Orage class came about from a staff requirement for an inexpensive and “disposable” trade warfare vessel built to naval standards. Although capable, it was not a huge success. It was superseded in production by the Aconit after only two years production, which had the virtue of being buildable “on the ground” in France proper and launchable to orbit. This had the virtue of speeding up production massively and also not being vulnerable to Manchurian ASAT weapons.

As a convoy escort, it’s designed role, it was a reasonably effective vessel. The threats to convoys are typically small and lightly armed U-ships, such as the Tunghu[iii] or Stahlhammer[iv]. Both of those vessels were based around the same concept; a vessel that has to drop out of stutterwarp and divert all power to the targeting array to deliver a missile attack. Tactically these vessels were best employed at discharge points. Standing some way off the discharge point the U-ship spots the convoy entering the “dead zone” to discharge their drives, and then fires a spread of missiles. As the missiles close the distance the U-ship lights up its active array to illuminate the target and deliver the attack. It then powers up the stutterwarp and flees the scene before the convoys defenders can climb out of the zone and begin a pursuit. The convoy escorts primary role is thus shooting down incoming missiles, and the relative lack of firepower was a problem. Interception rates against U-ship missiles sat at around 20%. However, when nations build small nuclear power escorts, like the Sachsen, the navies often want to put them with their battlefleets as a useful addition of firepower.[v]

Post WoGR the French divested themselves of the lead pair of their four surviving Orages. Orage herself was sold to the Incans and Ouragen was sold to Mexico. The remaining pair, Cyclone and Bourrasque, were placed in reduced Commission as training vessels. In all cases, the missile launchers were removed. In Mexican service the ships troops have been replaced with a missile deck handling team. They can push one missile out of the cargo airlock per turn.

One French Orage-class, the Pluie, was reportedly damaged in a sortie in the Augereau system during the War of German Reunification. It was never recovered after the sortie and is presumed to still exist somewhere in the system.

The aviso herself is a sturdy design encompassing a masked, advanced synthetic armour hull roughly 25 meters in length. A protrusion in the bow of the ship houses much of the fuel while a disk in the underbelly is dedicated mainly to the crew accommodations. The older designs of the active and passive sensor arrays extend from above the bridge, and her solar array from below the disk. The ship is not streamlined and has no thrusters for non-stutterwarp travel.

Design Notes

This started as an attempt to backengineer the Orage. There were several issues. Firstly, the hull was far too large. The internal volume of a 10m diameter, 76 m long cylinder is ca 5,700 m3, and that is a minority of the vessels volume. All the internals listed required a lot less than this. Hence I rescaled the hull to approximately the needed volume. In the process I dropped the fuel tankage from 1,500 tons to 500 tons. This is still 5 weeks full power cruising, and 10 weeks at 0.5 MW. When escorting a convoy it is unlikely to be doing more than warp = 1.0, and probably less than warp = 0.75.

The array below the disk was made a solar panel. The mass of a solar panel is listed in the 2^nd edition DG (pg 65), but there was no price. I imputed one.

The hull is a weird design, and I modelled it as a 25 m long 6 m cylinder for the spine, and a pair of disks, one the spin hab (18 m diameter and 4 m wide) and another the lower hull (15 m diameter and 6 m wide). The MV was 47, but there is overlap where the lower extension and cylinder meet. Without doing calculations I simply declared the value implied from the SSS (40) was right.

A major issue is that to armour said hull is really expensive and can’t be reconciled with the listed cost of the vessel, but the mass is about correct with the armour. An armour value of 4 would push the Orage upto ca. MLv50. Each level of armour costs MLv9, since the designer chose the most expensive armour material. Given the choice I dropped the armour down to 1, which put the price in roughly the right range, but lowered the ships mass to give higher speed.

The reflected profiles came out correct, as they are dominated by surface fixtures. The profiles vs shot were slightly off.

On the topic of accommodations; there was confusion in the formulae. The rules are written that each individual accommodation is 10+(volume/10), and thus a standard 25 m3 stateroom is 12.5 tons of mass. The Kennedy example was done differently, and thus there is an argument. Here both interpretations are presented.

Crew: Bridge: 12, Tactical Action Centre: 6, Engineering: 6, Ship's Troops: 10, Medical: 1. Upto 5 passengers.

PERFORMANCE CHARACTERISTICS

Warp Efficiency: 1.36-1.54 (1,627 tons) or 1.50-1.78 (1,237 tons)

Power Plant: 5 MW MHD Turbine and 1 MW solar array (in life zone)

Fuel: 500 tons, sufficient for 5 weeks of high speed cruising

Range: 7.7

Mass: 1,237 tons or 1,627 tons, fully fuelled but with empty cargo bay. The two values are from the two different accommodation formulae

Cargo Capacity: 260 m3

Comfort: 0, Total Life Support: 40. 40 standard staterooms in spin hab. Oxygen for 180 days, and enough cargo space for food and water.

Ordnance Carried: originally 2 Ritage-1 missiles in individual tubes but now none standard, but ordnance common in cargo hold,

Price: MLv22.348

SHIP STATUS SHEET

Move: 3

Screens: nil

Radiated Signature: 1(4) at full power, -2(1) whilst cruising

Radial Reflected: 4

Lateral Reflected: 4

Target Computers: 0

Radial Profile: -1

Lateral Profile: 0

Armour: 1

Hull Hits: 14/3

Power Plant Hits: 14/3

Active: 7

Passive: 3

Weapons

2 x1dbl masked/UTES (1238 and 1278)

(2 Ritage-1 missiles in original configuration, now removed)

Crew Hits

Bridge: Captain, Navigator, Helm, Communications, 2x Computer

TAC: Active Operator, Passive Operator, 2x Fire Control and 2x Remote Pilots

Damage Control: 3+6+10 =19 (in Mexican and Incan ships the troops are reassigned to hauling missiles out of the airlock instead and so 9 DC pax)

Notes on WW2 Escorts and What Type is Desirable in 2300AD

There is not really an equivalent to the submarine in 2300AD. The nearest would be a stealthy, missile armed, MHD and solar powered vessel. There is however the possibility of effective raiding. Put a gun mount on the side of a light merchant and it will shred undefended ships.

In WW2 there were really four kinds of convoy escorts, listed largest to smallest:

Frigates (Destroyer Escorts in US service): These were conceived as an enlarged corvette with good range, seakeeping and a sufficient armament and sensor suite to hunt subs. They kept the diesel machinery etc. of merchant vessels rather than turbines and so were slower than turbine vessels, but cheap and long ranged.

Sloops: These were relatively expensive, fully naval specification vessels which were built throughout peacetime as convoy escorts. However, destroyers were given preference, as the more expensive destroyers could perform fleet duties as well as convoy escort, whilst the reserve was not true.

Escort Destroyers: These vessels were designed to combat small fast surface raiders (E-boats) rather than subs. They were essentially new builds of 40 year old destroyer designs, sans the torpedoes. They primarily served in the North Sea to counter the threat of German light surface vessels.

Corvettes (Patrol Gunboats in US service): These were built based on a whaler as a coastal AS vessel. They were the cheapest, easiest to build design possible, but were sub-optimal. Once sufficient frigates became available they were withdrawn.

In 2300AD, fleet speeds have been in the 2.5-3.5 range for nuclear/ fusion powered vessels. It is really difficult to build a cheap and effective escort capable of going at fleet speed. The Cayuga barely reaches warp 2.5 carrying a really respectable armament (4 double turrets), but at a cost of ca. MLv61 (52 plus the missing targeting computers and workstation costs). She has a “neither fish nor fowl” element to her. She is very expensive for a disposable convoy escort, but too slow to keep up with a modern battlegroup composed of fusion powered vessels. The Hampton is similar, and her lack of spin habitats renders her horribly ineffective. The question of why America would build such vessels is interesting. It seems they are looking at a vessel capable of being a (rather naff) fleet combatant as well as a (rather overpowered) convoy escort.

The German Sachsen is interesting, if not very NAM. She has a 25 MW fission plant and devotes fully 80% of her power output into energy weapons. This will make her a really effective convoy escort against U-ship type attacks, capable of knocking down a significant missile strike. With a warp efficiency of ca. 1.5 she makes no pretence of being a fleet vessel. However, she’s about MLv40-50, and so not a cheap vessel.

The two French escorts, the Aconit and Orage, are pretty cheap. They are not built down to civilian specification though. The French took up merchants, and the likes of the Necessite class auxiliary cruiser (a light freighter with a single laser turret and missile launcher installed) would be equivalent to WW2 corvettes. They (Aconit and Orage) are something like the Royal Navy sloops of the 1920’s-30’s. They cost ca. MLv20-25, making them cheaper than the American or German vessels, but are less powerful combatants. However, 2 Aconits can be built for the price of a Hampton, and in terms of combat power the 2 Aconits would roughly equal a Hampton or Cayuga.

What is lacking is an equivalent to the WW2 frigate; a vessel with a (relatively) large MHD turbine and stutterwarp, but limited to OC tech for easy and cheap production.  I could probably design a very effective convoy escort for around MLv10, but it would not be suitable for the Kafer War, as they didn’t operate swarms of cheap raiders but rather detached heavy units to those tasks. There’s a challenge – the MLv10 escort.

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[i] In my campaign this is untrue. Pluie was in fact transferred to French Intelligence special activity forces, and her loss was a cover story. She is maintained for potential false flag operations against INAP.

[ii] I monkeyed a bit with the stats. There is no centralised fire control computer, but rather each mount (or TTA?) has its own TC.  By a bit of monkeying I declared the old ships to have no TC (hence 0), but the guns to be -2 or -3 PBWS.

[iii] The Tunghu has 4 communicators but only 6 missiles. It clear is optimised for the delivery of a single heavy missile attack. Since they usually operate in groups, a Tunghu wolf pack probably launches an alpha strike of 8 or 12 missiles against the convoy, aiming to gut some of the transports before running. Against unescorted, unarmed transports the Tunghu can simply pull alongside and gut the target with her X-ray lasers, which is obviously preferable. However, transports converted into auxiliary cruisers make this a hazardous proposition.

[iv] The Stahlhammer design has only a single communicator, and a much weaker active array. It is thus likely to be far less effective. However, a small nuke can be devastating. The optimal attack would be delivered just as the target is leaving the dead zone. At this point the target is not warping but the missile can warp in close enough to detonate a few meters off the target and vaporise it.

[v] As a design, a relatively small nuclear powered vessel with little speed, no armour but a large battery of guns would be useful. However, one suspects the design would quickly creep with the addition of missiles, armour etc.