Passage, Maoria Escort Cruiser laid down 1913 (Engine 1912)
Displacement:
6,628 t light; 6,849 t standard; 8,329 t normal; 9,512 t full load
Dimensions: Length overall / water x beam x draught
389.96 ft / 380.58 ft x 32.81 ft (Bulges 52.49 ft) x 24.61 ft (normal load)
118.86 m / 116.00 m x 10.00 m (Bulges 16.00 m) x 7.50 m
Armament:
5 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1913 Model
Quick firing guns in deck mounts with hoists
on centreline, evenly spread, 3 raised mounts
8 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1913 Model
Quick firing guns in casemate mounts
on side ends, evenly spread
Weight of broadside 618 lbs / 280 kg
Shells per gun, main battery: 150
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 7.87" / 200 mm 266.40 ft / 81.20 m 13.12 ft / 4.00 m
Ends: 3.94" / 100 mm 114.14 ft / 34.79 m 13.12 ft / 4.00 m
Upper: 1.97" / 50 mm 380.58 ft / 116.00 m 6.56 ft / 2.00 m
Main Belt covers 108 % of normal length
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.98" / 25 mm 0.12" / 3 mm 0.12" / 3 mm
2nd: 0.39" / 10 mm - -
- Armour deck: 1.57" / 40 mm, Conning tower: 7.87" / 200 mm
Machinery:
Oil fired boilers, steam turbines,
Electric motors, 2 shafts, 43,163 shp / 32,200 Kw = 26.00 kts
Range 10,000nm at 14.00 kts
Bunker at max displacement = 2,663 tons
Complement:
435 - 566
Cost:
£0.587 million / $2.347 million
Distribution of weights at normal displacement:
Armament: 77 tons, 0.9 %
Armour: 1,872 tons, 22.5 %
- Belts: 1,524 tons, 18.3 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 14 tons, 0.2 %
- Armour Deck: 264 tons, 3.2 %
- Conning Tower: 70 tons, 0.8 %
Machinery: 1,721 tons, 20.7 %
Hull, fittings & equipment: 2,208 tons, 26.5 %
Fuel, ammunition & stores: 1,700 tons, 20.4 %
Miscellaneous weights: 750 tons, 9.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
8,456 lbs / 3,836 Kg = 82.1 x 5.9 " / 150 mm shells or 1.5 torpedoes
Stability (Unstable if below 1.00): 1.14
Metacentric height 1.2 ft / 0.4 m
Roll period: 20.2 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.28
Seaboat quality (Average = 1.00): 1.73
Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.593
Length to Beam Ratio: 7.25 : 1
'Natural speed' for length: 19.51 kts
Power going to wave formation at top speed: 65 %
Trim (Max stability = 0, Max steadiness = 100): 41
Bow angle (Positive = bow angles forward): 7.00 degrees
Stern overhang: 6.56 ft / 2.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 22.97 ft / 7.00 m
- Forecastle (15 %): 19.69 ft / 6.00 m
- Mid (50 %): 19.69 ft / 6.00 m
- Quarterdeck (15 %): 19.69 ft / 6.00 m
- Stern: 19.69 ft / 6.00 m
- Average freeboard: 19.88 ft / 6.06 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 84.7 %
- Above water (accommodation/working, high = better): 78.2 %
Waterplane Area: 9,073 Square feet or 843 Square metres
Displacement factor (Displacement / loading): 125 %
Structure weight / hull surface area: 77 lbs/sq ft or 375 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.84
- Longitudinal: 5.22
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is cramped
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather
25 tons boat lifts
25 tons long-range wireless
100 tons spare parts and torpedo storage
6x 100 ton Torpedo Boats
Ships of the class are to have names like Quick Passage, Fortunate Passage, Dutiful Passage, etc.
As their designation implies, this class is mostly meant to swat - and be immune to - destroyers and torpedo boats. Details on those of the latter class carried will have to wait, but my mental sketch notes - the issued requirement, so to speak - for this type's spawn is to carry two torpedoes to at least 30 knots in up to sea state five. The 'tumblehome' hull plan is actually a reflection of the way the boats are carried - they're three to a side, with their keels about lined up with the ship's waterline.
How big is a 100 t torpedo-boat?
I think I'd like to see a sketch of the concept, please.
About 30m long by 5m beam by 1.5m draft; I figured it was better to guess 'large' than run out of room.
And I'm working on it now. ^_^
I'll look forward to it.
(http://i31.photobucket.com/albums/c386/valles_uf/PassageProgress.png)
An in-progress sketch. The 'working deck' is about halfway up the hull from the waterline.
Are you sure that the place for the 100t torpedo boats is the best ?
Imagine the cruiser in a heavy sea or a storm ...
Your 100t torpedo boats are going to be damage or ...lost. :(
Better place is probably in the stern... Remember the design of the aviso Saranda class
Just a remark... you made what you want...
Jef ;)
Maybe we could assign some weight for cranes and/or strenghtening of ship to carry such unusual cargo?
Borys
QuoteBetter place is probably in the stern... Remember the design of the aviso Saranda class
I do, and I agree, but I figured that I'd save myself the shrieking fit when the purists saw a well deck or quasi-transom this early.
QuoteMaybe we could assign some weight for cranes and/or strenghtening of ship to carry such unusual cargo?
I'm more concerned with upping the performance of the boats than shaving weight off of their motherships. About how much would you consider reasonable?
Ahoj!
I'll pluck a figure from thin air :)
How about a 4:1 ratio - i.e. every 10 tonnes of carried attack boats generates 2,5 tonnes of structure reinforcement/ unusaul add-ons.
This is pure speculation, mind you.
Borys
Quote from: Valles on May 22, 2008, 04:26:56 PM
QuoteBetter place is probably in the stern... Remember the design of the aviso Saranda class
I do, and I agree, but I figured that I'd save myself the shrieking fit when the purists saw a well deck or quasi-transom this early.
Actually, Orange has a 'TB carrier' with an almost well deck - a 'slip' in the stern that allows boats to be lowered in the water, TBs that are pretty similar to what you have.
SS2 assumes that you have internal armor with the bulges. Simming with full 16m beam (without bulges) would be more accurate, if the armor is external.
http://www.navalism.org/index.php?topic=337.0
I'd be thinking at least a 1:1 ratio between crane and boat. Suspending that much weight from above is going require a very sturdy structure.
I'd also want to see accommodations set aside for the boat crews.
I agree with Jef on the problems of wave action with the suspended craft - the bow wave may also be a problem for the foremost units.
I'd be curious to know how you'd operate the vessel(s): do you intend for the TBs to launch and recover underway, or at rest?
On the whole, I don't see what this can do that a 4,000 t cruiser and three mid-sized destroyers can't.
These TBs would be deliberately and utterly expendable - I figure, five to eight crewmen, total. Coxswain, commander, an engineer or two, and a crew for a small gun or something. No damage control, no long-term accommodations. Any pretense of long-range ability they might make would be an artifact of a cultural heritage of crossing oceans in glorified canoes, like a sail and a steppable aluminum mast.
I think that a cruiser-sized vessel can manage to spare thirty men or so.
The original design spec would call for underway, certainly. At rest might have to be settled for.
In terms of actual abilities, there's no real advantage, at least assuming that I can't yet build forty to fifty knot planing boats. But building thirty-knot destroyers with the handling characteristics I consider prerequisite for the seas to Maoria's south is, at the least and pardon my language, a stone cold bitch. Not worth the headaches on my part and not worth the man-hours and development time that the Maori would have to put into designing and building them.
Also, in a situation where they end up getting expended - which, for an unarmored fighting vessel, is inevitable - I'm down thirty crewmen and six hundred tons of material rather than three hundred and three thousand.
Regardless, now that I know there won't be screaming tantrums over a fantail design, I'm going to go back to the drawing board and go with that. Stay tuned!
100t TBs require more than 8 crew members. 8-9 in enough for a MTB (MAS) but not a steam turbine powered boat.
WWII:A 60t S-boot needed a crew of 12. A 100t one needed ~25 - that's with diesel engines.
The 1885 TB (similar size) 16-20.
Quote from: Valles on May 22, 2008, 09:55:54 PM
These TBs would be deliberately and utterly expendable - I figure, five to eight crewmen, total. Coxswain, commander, an engineer or two, and a crew for a small gun or something. No damage control, no long-term accommodations. Any pretense of long-range ability they might make would be an artifact of a cultural heritage of crossing oceans in glorified canoes, like a sail and a steppable aluminum mast.
Make that a wooden mast- like the MK barges have. Aluminium is still hidiously expensive compared to any other useable material, and the lack of good alloys, nor corrosion protection. But that's only "story line info".
Quote from: The Rock DoctorI'd be thinking at least a 1:1 ratio between crane and boat. Suspending that much weight from above is going require a very sturdy structure.
And then you're very generous Rocky.
The German 150 tonne boats for Flanders had crews of 28. With VTE though.
Borys
Quote from: The Rock Doctor on May 22, 2008, 07:54:59 PM
I'd be thinking at least a 1:1 ratio between crane and boat. Suspending that much weight from above is going require a very sturdy structure.
And also sturdy boats, if you plan lifting them at two points. But you don't need 100t weight cranes to lift a boat.
I was under the impression that a crane must be heavier than its load - folks with a better knowledge of physics can correct me.
Quoteleast assuming that I can't yet build forty to fifty knot planing boats
I think we're decades away from that yet.
QuoteRegardless, now that I know there won't be screaming tantrums over a fantail design, I'm going to go back to the drawing board and go with that. Stay tuned!
Er...hang on. What does the tumblehome have to do with suspending light craft over the sides of the ship? Why's the draft so deep? A cross-sectional sketch might help supplement the top view.
End on layout? Something like this:
__
_[ ]_
[ ]
\ /
\__/ ...but like I said that wasn't the plan I'd considered most favorable, just the most likely to be accepted by the mods. Now that a better one is known to be workable, I'm going with...
Enter ship name, Enter country Enter ship type laid down 1913 (Engine 1912)
Displacement:
6,940 t light; 7,174 t standard; 8,687 t normal; 9,897 t full load
Dimensions: Length overall / water x beam x draught
392.83 ft / 387.14 ft x 52.49 ft x 26.25 ft (normal load)
119.74 m / 118.00 m x 16.00 m x 8.00 m
Armament:
3 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1913 Model
Quick firing guns in deck mounts with hoists
on centreline, all forward, 2 raised mounts - superfiring
2 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1913 Model
Quick firing guns in deck mounts with hoists
on centreline, all amidships
4 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1913 Model
Quick firing guns in casemate mounts
on side, evenly spread
6 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1913 Model
Quick firing guns in casemate mounts
on side, evenly spread
6 guns in hull casemates - Limited use in heavy seas
Weight of broadside 644 lbs / 292 kg
Shells per gun, main battery: 150
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 7.87" / 200 mm 232.28 ft / 70.80 m 13.12 ft / 4.00 m
Ends: 1.97" / 50 mm 154.82 ft / 47.19 m 13.12 ft / 4.00 m
Upper: 1.97" / 50 mm 232.28 ft / 70.80 m 13.12 ft / 4.00 m
Main Belt covers 92 % of normal length
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 2.36" / 60 mm 1.57" / 40 mm 1.57" / 40 mm
2nd: 2.36" / 60 mm 1.57" / 40 mm 1.57" / 40 mm
3rd: 1.97" / 50 mm - -
4th: 3.94" / 100 mm - -
- Armour deck: 1.97" / 50 mm, Conning tower: 7.87" / 200 mm
Machinery:
Oil fired boilers, steam turbines,
Electric motors, 2 shafts, 43,359 shp / 32,346 Kw = 26.00 kts
Range 10,000nm at 14.00 kts
Bunker at max displacement = 2,723 tons
Complement:
449 - 584
Cost:
£0.603 million / $2.411 million
Distribution of weights at normal displacement:
Armament: 80 tons, 0.9 %
Armour: 2,156 tons, 24.8 %
- Belts: 1,460 tons, 16.8 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 98 tons, 1.1 %
- Armour Deck: 526 tons, 6.1 %
- Conning Tower: 72 tons, 0.8 %
Machinery: 1,729 tons, 19.9 %
Hull, fittings & equipment: 2,224 tons, 25.6 %
Fuel, ammunition & stores: 1,747 tons, 20.1 %
Miscellaneous weights: 750 tons, 8.6 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
10,677 lbs / 4,843 Kg = 103.7 x 5.9 " / 150 mm shells or 1.6 torpedoes
Stability (Unstable if below 1.00): 1.08
Metacentric height 2.2 ft / 0.7 m
Roll period: 14.8 seconds
Steadiness - As gun platform (Average = 50 %): 53 %
- Recoil effect (Restricted arc if above 1.00): 0.22
Seaboat quality (Average = 1.00): 1.17
Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.570
Length to Beam Ratio: 7.38 : 1
'Natural speed' for length: 19.68 kts
Power going to wave formation at top speed: 63 %
Trim (Max stability = 0, Max steadiness = 100): 45
Bow angle (Positive = bow angles forward): 6.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 22.97 ft / 7.00 m
- Forecastle (20 %): 19.69 ft / 6.00 m
- Mid (50 %): 19.69 ft / 6.00 m
- Quarterdeck (20 %): 19.69 ft / 6.00 m
- Stern: 19.69 ft / 6.00 m
- Average freeboard: 19.95 ft / 6.08 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 81.9 %
- Above water (accommodation/working, high = better): 120.7 %
Waterplane Area: 14,451 Square feet or 1,343 Square metres
Displacement factor (Displacement / loading): 124 %
Structure weight / hull surface area: 82 lbs/sq ft or 399 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.88
- Longitudinal: 3.24
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
QuoteI think we're decades away from that yet.
I figured.
Ahoj!
The crane is one thing. Machinery to run it, another. And the strengthening of the structure yet another. AFAIK MAddox is the closest thing to an engineer this board has ...
As to tumblehome - the benefit is that the boats suspeneded along the sides are closer to the centre of gravity - they are not entirely over the sea, but partly above the hull of the mother vessel. Lesser motion/momentum.
Also, they can be made secure against the hull (maybe even be on some sort of slides?) Or secured more easily.
Borys
I am a mechanical engineer (at least have a paper telling that) >:(.
The crane must be heavier than the load to counterbalance. And that extra 100t on a ship would make the ship list a lot, hm...
After a bit calculation, Lifting a 100t boat would cause 15 degrees of list. (ShipWeight*GM*sinALPHA=LiftingArm*BoatWeight).
Due to the bulges, 15 degree list would wet 2m freeboard (Beam/2*sinAlpha). The bulges must have at least that high freeboard or the ship might roll over due to the lack of stability margin. Add natural roll to it and you are already at 4m freeboard.
Theoretical solutions to this problem are:
- Increase metacentric height (helps some but not much)
- lift/lower two boats at the same time on the sides. Would only work during trials.
- have pumps move fuel to counter it. This would make each lifting/lowering operation taking hours.
- lower the ships on a slide at the stern, close to the centerline.
All of these would limit the utility as a gun platform.
I'm reminded of Wesworld's Loki for some reason.
Quote from: P3D on May 23, 2008, 01:21:45 PM
I am a mechanical engineer (at least have a paper telling that) >:(.
Sorry for missing that part of your bio!
Quickly sacrifices black rooster to appease P3D's wrath ...Borys
Commodore Green built Loki as a freighter, lifting MTBs out of a central hold, over the side and into the water while at low or no speed (I believe). I don't recall what engineering considerations went into the design, but it'd be in the Wesworld : Denmark encyclopedia somewhere.
Quote from: P3D on May 23, 2008, 01:21:45 PM
The crane must be heavier than the load to counterbalance. And that extra 100t on a ship would make the ship list a lot, hm...
Wouldn't the ship's mass serve as counterweight?
Quote from: P3D on May 23, 2008, 01:21:45 PMAfter a bit calculation, Lifting a 100t boat would cause 15 degrees of list. (ShipWeight*GM*sinALPHA=LiftingArm*BoatWeight).
After reading this bit, Borys was last seen with steaming brains oozing out of ears ....