City of Erastor Question (Minor HFQ Spoiler)

There’s not much point in their building anything smaller than one of these cruisers. They need the cruising radius, the firepower would come in handy for dealing with shore threats (if they should happen to arise), and they would be far more seaworthy (especially in terms of durability) than destroyers, while it gets very difficult to build more than 4-5,000 miles endurance into something destroyer-sized with a worth while armament.

jmseeley wrote:Has RFC posted the specification for the City of Erastor-class ironclads?

I’ve seen the posts for the KH VII and the notional cruiser configurations, but I haven’t found any specifications for the City. I’m asking because it looks to me like the Cities are going to become the workhorses of the ICN for the next few years. The missions already suggested in the HFQ snippets are convoy escort, anti-piracy patrol, support of fleet actions, and there are probably others.

In his discussion of Cruisers a couple years ago RFC said:

There’s not much point in their building anything smaller than one of these cruisers. They need the cruising radius, the firepower would come in handy for dealing with shore threats (if they should happen to arise), and they would be far more seaworthy (especially in terms of durability) than destroyers, while it gets very difficult to build more than 4-5,000 miles endurance into something destroyer-sized with a worth while armament.

Evidently he changed his mind at least a bit. I think it started out as a deep-water version of the Delthak, but the KH VII started out as a version of the HMS Warrior and has (to put it mildly) evolved a bit. When I think of the City of Erastor I see something like a scaled-down KH VII - roughly the size of a Rotweiler with twin 8in guns fore and aft and a half-dozen or so 6in mounts on each side.

I know I’m wrong, I just want to know how wrong.

jms

Randomiser wrote:ICN currently has 3 classes of steam powered warship under construction. 'Rivers' class aka Delthak 2 referred to as a riverine class, 'Cities' class, lead ship Eraystor, referred to as a coastal (littoral?) class, and the King Harald VII class of deep water 'cruisers' RFC is deliberately, i.e. with malice aforethought, keeping the specs of the first 2 classes as a surprise.

Okay, so I’ve been playing with the cruiser design for the last couple of days, and Sharon and I are flying to Des Moines this morning (leaving Greenville at six a.m.), so since I was getting up and packing early, I spent the last couple of hours playing with the River-class ironclads gunboats. It was interesting to see how close they came, in a lot of ways, in my original design to what the software produced. In fact, the actual tonnages and displacements are very, very close, but I had significantly overestimated the coal consumption, assuming that the software gets it right. It worked out pretty well, anyway, because I’d obviously underestimated weights somewhere else. They came out a little slower than my maximum speed estimate (I could’ve gotten them up to my original numbers, but while they probably would have survived standard brown water conditions in that configuration, they probably wouldn’t have survived the voyage from Charis to Siddarmark, so I went with the lower-speed) but with a lot more endurance.

Anyway, here they are:

River-class ironclad gunboat
Imperial Charisian Navy
River barge conversion
Delthak Dockyard, 895


Displacement:
Light: 1,058 tons
Standard: 1,323 tons
Normal: 1,386 tons
Full load: 1,436 tons

Dimensions:
Length (overall / waterline): 140’
Beam: 40’
Draft (normal): 10’
Draft (deep) 10/4”

Armament:
24 x 30-pdr ML smoothbores, 3 x 11 x 3 (solid shot = 32 pounds; HE shell = 18 pounds; 250 rounds/gun)
Weight of broadside (shot): 352 pounds
Weight of broadside (shell): 198 pounds
Ahead/Astern (shot): 96 pounds
Ahead/Astern (shell): 54 pounds

Armor:
Casemate: thickness = 3”; length= 126’; height = 12’; inclined 16˚
Hull (fwd/aft of casemate): thickness = 3”; length = 14’; height = 6’; no slope
Casemate roof & decks: 1”
Conning Tower: 6”; no slope

Machinery:
Coal fired boilers, double-expansion engines, direct drive, 2 shafts, 65.21 sdp (1,663 shp) = 15 knots (13 Old Earth knots)
Range: 1,800 nm @ 9.5 knots (8.25 Old Earth knots)
3,500 nm @ 7 knots (6 Old Earth knots)
Bunker: (normal): 62 tons
Bunker (maximum): 112 tons

Complement: 197

Cost: CM 126,000

Distribution of weights at normal displacement:
Armament: 140 tons, 10.1 %
Armour: 334 tons, 24.1 %
Machinery: 241 tons, 17.4 %
Hull, fittings & equipment: 343 tons, 24.7 %
Fuel, ammunition & stores: 328 tons, 23.7 %
Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
Survivability (penetrating hits to sink ship): 17 x 30-pounder shells
Stability (Unstable if below 1.00): 1.66
Metacentric height 2.9 ft / 0.9 m
Roll period: 9.8 seconds
Seaboat quality (Average = 1.00): 0.85

Hull form characteristics:
Hull has low forecastle, low quarterdeck , a vertical bow and a round stern
Block coefficient (normal/deep): 0.866 / 0.868
Length to Beam Ratio: 3.50 : 1
'Natural speed' for length: 11.83 kts
Power going to wave formation at top speed: 66 %
Freeboard:
Foredeck: 4’ (length = 7’)
Casemate: 10’ (length = 126’)
Average: 8.8’
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 104.8 %
- Above water (accommodation/working, high = better): 88.3 %
Waterplane Area: 5,238 Square feet or 487 Square metres
Displacement factor (Displacement / loading): 108 %
Structure weight / hull surface area: 64 lbs/sq ft or 310 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.78
- Longitudinal: 4.63
- Overall: 0.93
Caution: Hull subject to strain in open-sea
Adequate machinery, storage, compartmentation space
Cramped accommodation and workspace room
Ship has slow, easy roll, a good, steady gun platform
Poor seaboat, wet and uncomfortable, reduced performance in heavy weather.

**********************************************

River-class ironclad gunboat (refit)
Imperial Charisian Navy
River barge conversion
Delthak Dockyard, 895

Displacement:
Light: 1,172 tons
Standard: 1,430 tons
Normal: 1,493 tons
Full load: 1,543 tons

Dimensions:
Length (overall / waterline): 140’
Beam: 40’
Draft (normal): 10’0.5”
Draft (deep) 10’4.5”

Armament:
20* x 6”/45 M895 BL guns (3 x 9 x 3) (AP shell = 115 pounds; 250 rounds/gun)
Weight of broadside: 1,035 pounds
Ahead/Astern: 345 pounds
Broadsides reduced by 2 guns each beause of weight differential between weapons.

Armor:
Casemate: thickness = 3”; length= 126’; height = 12’; inclined 16˚
Hull (fwd/aft of casemate): thickness = 3”; length = 14’; height = 6’; no slope
Casemate roof & decks: 1”
Conning Tower: 6”; no slope

Machinery:
Coal fired boilers, double-expansion engines, direct drive, 2 shafts, 65.21 sdp (1,663 shp) = 15 knots (13 Old Earth knots)
Range: 1,800 nm @ 9.5 knots (8.25 Old Earth knots)
3,500 nm @ 7 knots (6 Old Earth knots)
Bunker: (normal): 62 tons
Bunker (maximum): 112 tons

Complement: 157

Cost: CM 162,000


Distribution of weights at normal displacement:
Armament: 247 tons, 17.8 %
Armour: 334 tons, 24.1 %
Machinery: 241 tons, 17.4 %
Hull, fittings & equipment: 343 tons, 24.7 %
Fuel, ammunition & stores: 328 tons, 23.7 %
Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
Survivability (penetrating hits to sink ship): 10 x 6” AP
Stability (Unstable if below 1.00): 1.66
Metacentric height 2.9 ft / 0.9 m
Roll period: 9.8 seconds
Seaboat quality (Average = 1.00): 0.85

Hull form characteristics:
Hull has low forecastle, low quarterdeck , a vertical bow and a round stern
Block coefficient (normal/deep): 0.866 / 0.868
Length to Beam Ratio: 3.50 : 1
'Natural speed' for length: 11.83 kts
Power going to wave formation at top speed: 66 %
Freeboard:
Foredeck: 4’ (length = 7’)
Casemate: 10’ (length = 126’)
Average: 8.8’
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 104.8 %
- Above water (accommodation/working, high = better): 88.3 %
Waterplane Area: 5,238 Square feet or 487 Square metres
Displacement factor (Displacement / loading): 108 %
Structure weight / hull surface area: 64 lbs/sq ft or 310 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.78
- Longitudinal: 4.63
- Overall: 0.93
Caution: Hull subject to strain in open-sea
Adequate machinery, storage, compartmentation space
Cramped accommodation and workspace room
Ship has slow, easy roll, a good, steady gun platform
Poor seaboat, wet and uncomfortable, reduced performance in heavy weather

*************************************************

Delthak II – class broadside ironclad gunboat
Imperial Charisian Navy
Tellesberg, King’s Harbor, & Delthak DYs
All laid down 895 YoG
All launched & Commissioned: 896 YoG

Displacement:
Light: 1,181 tons
Standard: 1,465 tons
Normal: 1,529 tons
Full Load: 1,580 tons

Dimensions:
Length (waterline): 160’
Length (overall): 160’
Beam: 40’
Draft (normal): 10’
Draft (full): 10’3”

Armament:
22 x 6”/45 M895 BL guns 3 x 11 x 3 (115-pound AP shell; 200/gun)
Weight of broadside (13 guns): 1,495 pounds
Weight fore or aft (3 guns): 345 pounds

Armor:
Casemate: thickness= 3”; length = 146’; height = 14’; inclined 16˚
Freeboard fore & aft: thickness=3”; length = 14’; height = 4’
Casemate roof/decks: 1”
Conning tower: 6” (no slope)

Machinery:
Coal fired boilers, double-expansion engines, direct drive, 2 shafts, 45 sdp (1,147 shp) = 14 knots (12.2 Old Earth knots)
Range 1,800nm at 9.5 knots (8.25 Old Earth knots)
Range 3,500 nm at 5.7 knots (5 Old Earth knots)
Bunker (normal): 59 tons
Bunker (max displacement): 115 tons

Complement: 158

Cost: CM 168,000

Distribution of weights at normal displacement:
Guns: 281 tons, 18.4 %
Armor: 286 tons, 18.7 %
Machinery: 166 tons, 10.9 %
Hull, fittings & equipment: 448 tons, 29.3 %
Fuel, ammunition & stores: 348 tons, 22.7 %

Overall survivability and seakeeping ability:
Survivability (penetrating hits to sink ship): 17 x 6”/45
Stability (Unstable if below 1.00): 1.81
Metacentric height 3.3 ft / 1.0 m
Roll period: 9.2 seconds
Steadiness as gun platform (Average = 50 %): 68 %
Seaboat quality (Average = 1.00): 1.35

Hull form characteristics:
Hull has low forecastle, low quarterdeck , a normal bow and a round stern
Block coefficient (normal/deep): 0.836 / 0.838
Length to Beam Ratio: 4.00 : 1
'Natural speed' for length: 14.6 knots (12.65 Old Earth knots)s
Power going to wave formation at top speed: 57 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 0.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = length of deck as a percentage of waterline length):
- Forecastle: 10.00 %, 4.00 ft
- Forward deck: 30.00 %, 10.00 ft
- Aft deck: 50.00 %, 10.00 ft
- Quarter deck: 10.00 %, 4.00 ft
- Average: 8.80 ft
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 105.1 %
- Above water (accommodation/working, high = better): 91.7 %
Waterplane Area: 5,823 Square feet
Displacement factor (Displacement / loading): 100 %
Structure weight / hull surface area: 82 lbs/sq ft
Hull strength (Relative):
- Cross-sectional: 1.02
- Longitudinal: 4.66
- Overall: 1.19
Adequate machinery, storage, compartmentation space
Adequate accommodation and workspace room
Good seaboat, rides out heavy weather easily

********************************************

I think the biggest surprise I got was when the Delthak IIs, the purpose-built ironclads, ended up rated as a “good seaboat, rides out heavy weather easily.” I expected to improve their seakeeping ability when I made them 20 feet longer (which will make them less useful than the Rivers on the older canals) and settled for lower-power engines (if you remember, folks were reflecting that the Rivers were over-powered), but I didn’t expect as much improvement as I got. Mind you, I doubt anyone is going to enjoy getting through a storm at sea in one of these, but they probably won’t panic at the mere thought of facing one.

I’m also fiddling around with a Shan-wei-class superdreadnought mounting 10 x 16”/45 firing the USN’s superheavy shell. It’s looking like coming out around 70-75,000 tons standard displacement with oil-fired boilers and geared turbines. Of course, that’s providing Montana-style underwater protection on the theory that while it probably won’t have to deal with torpedoes, it might have to deal with a fairly serious mine threat by the time they were laid down . . . assuming, of course, that any such monstrosity might ever be built . . .

Randomiser wrote:Except that, on October 8 2014 on page 6 of the Thirsk and Ahlvarez topic RFC wrote

"And, no, I haven’t given you the details on either the Delthak II or Eraystor designs."

So I guess things have changed since 2013.

n7axw wrote:Also, read snippet nine for Staynairs rumination about use of the Cities.

Don

Claw Island would be a critical part of their end game strategy for the Gulf of Dohlar once the King Harahld VI I-class ships commissioned, but they’d hoped it might also serve as a support base for a squadron of the new City-class coastal ironclads. The Cities were too big to operate along the mainland canals the way the River and River II-class ships were intended to, and they were over four knots slower, but that extra displacement gave them marginally thicker armor and almost twice the endurance. More to the point — and despite Halcom Bahrns’ near miraculous feat of seamanship in the Tarot Channel — they were far better seaboats.

Randomiser wrote:ICN currently has 3 classes of steam powered warship under construction. 'Rivers' class aka Delthak 2 referred to as a riverine class, 'Cities' class, lead ship Eraystor, referred to as a coastal (littoral?) class, and the King Harald VII class of deep water 'cruisers'

RFC is deliberately, i.e. with malice aforethought, keeping the specs of the first 2 classes as a surprise.

n7axw wrote:Also, read snippet nine for Staynairs rumination about use of the Cities.

Don