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Krakatoa
Post subject: Re: Weymouth-Class cruisersPosted: January 23rd, 2017, 10:11 pm
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Joined: July 1st, 2014, 12:20 am
Location: New Zealand
Contact: Website
It would help enormously if the Imperial War Museum could somehow release there holding of pictures/photos/plans to be scanned and digitised for use. I suppose it would have to be done 'in house' and would require some very dedicated people.

The other point of course is if the photos/negatives are not held in perfect conditions they can degrade to uselessness which would be a tremendous loss.

It all comes down to money I suppose. The cost of transferring the originals to digital.


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RegiaMarina1939
Post subject: Re: Weymouth-Class cruisersPosted: January 24th, 2017, 2:22 am
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Joined: January 12th, 2016, 8:57 pm
Location: Wilmington, North Carolina
As someone who just acquired one of these on World of Warships, I commend your efforts!

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RegiaMarina1939


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smurf
Post subject: Re: Weymouth-Class cruisersPosted: January 24th, 2017, 9:36 am
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Joined: October 25th, 2014, 7:46 pm
Hood on Friedman I agree. But reading Covers from this time period is a bit of a nightmare and even those sources are not always consistent.
The big problems are memos describing some change, which then doesn't happen. The best sources to resolve such problems are the NMM collection of as-fitted plans. Digitising those has begun, but staff is very limited and I understand they have begun with the oldest (those in most conservation danger). Visiting days are now down to two a week.


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eswube
Post subject: Re: Weymouth-Class cruisersPosted: January 26th, 2017, 8:41 pm
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Joined: June 15th, 2011, 8:31 am
An excellent series!
(and an interesting discussion highlighting how doing the research can be tricky)


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RegiaMarina1939
Post subject: Re: Weymouth-Class cruisersPosted: January 27th, 2017, 6:19 pm
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Joined: January 12th, 2016, 8:57 pm
Location: Wilmington, North Carolina
Absolutely beautiful ships! I springsharp'd them here for everyone. I just got the program so I'm going a little nuts with it!

Weymouth, Great Britain Light Cruiser laid down 1909

Displacement:
5,120 t light; 5,300 t standard; 5,330 t normal; 5,354 t full load

Dimensions: Length overall / water x beam x draught
453.00 ft / 453.00 ft x 48.00 ft x 15.00 ft (normal load)
138.07 m / 138.07 m x 14.63 m x 4.57 m

Armament:
8 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1906 Model
Breech loading guns in deck mounts
on side, evenly spread, all raised mounts
4 - 1.85" / 47.0 mm guns in single mounts, 3.17lbs / 1.44kg shells, 1902 Model
Breech loading guns in deck mounts
on side, evenly spread
Weight of broadside 877 lbs / 398 kg
Shells per gun, main battery: 150
2 - 21.0" / 533.4 mm submerged torpedo tubes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 3.00" / 76 mm 294.45 ft / 89.75 m 8.31 ft / 2.53 m
Ends: Unarmoured
Main Belt covers 100 % of normal length

- Armour deck: 1.00" / 25 mm

Machinery:
Oil fired boilers, steam turbines,
Direct drive, 4 shafts, 24,659 shp / 18,395 Kw = 25.00 kts
Range 5nm at 25.00 kts
Bunker at max displacement = 53 tons

Complement:
311 - 405

Cost:
£0.428 million / $1.713 million

Distribution of weights at normal displacement:
Armament: 110 tons, 2.1 %
Armour: 595 tons, 11.2 %
- Belts: 308 tons, 5.8 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 0 tons, 0.0 %
- Armour Deck: 287 tons, 5.4 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 1,121 tons, 21.0 %
Hull, fittings & equipment: 3,295 tons, 61.8 %
Fuel, ammunition & stores: 210 tons, 3.9 %
Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
7,433 lbs / 3,371 Kg = 68.8 x 6.0 " / 152 mm shells or 1.3 torpedoes
Stability (Unstable if below 1.00): 1.21
Metacentric height 2.3 ft / 0.7 m
Roll period: 13.2 seconds
Steadiness - As gun platform (Average = 50 %): 62 %
- Recoil effect (Restricted arc if above 1.00): 0.25
Seaboat quality (Average = 1.00): 1.23

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.572
Length to Beam Ratio: 9.44 : 1
'Natural speed' for length: 21.28 kts
Power going to wave formation at top speed: 52 %
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 (% = measuring location as a percentage of overall length):
- Stem: 23.41 ft / 7.14 m
- Forecastle (20 %): 14.90 ft / 4.54 m
- Mid (50 %): 14.90 ft / 4.54 m
- Quarterdeck (15 %): 14.90 ft / 4.54 m
- Stern: 14.90 ft / 4.54 m
- Average freeboard: 15.58 ft / 4.75 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 88.1 %
- Above water (accommodation/working, high = better): 141.4 %
Waterplane Area: 15,491 Square feet or 1,439 Square metres
Displacement factor (Displacement / loading): 144 %
Structure weight / hull surface area: 138 lbs/sq ft or 672 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.89
- Longitudinal: 2.37
- Overall: 1.93
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Good seaboat, rides out heavy weather easily

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Best regards,

RegiaMarina1939


Last edited by RegiaMarina1939 on January 28th, 2017, 3:43 am, edited 1 time in total.

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reytuerto
Post subject: Re: Weymouth-Class cruisersPosted: January 28th, 2017, 3:25 am
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Joined: February 21st, 2015, 12:03 am
Hi RegiaMarina:
I think that the guns were BL. Cheers.


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RegiaMarina1939
Post subject: Re: Weymouth-Class cruisersPosted: January 28th, 2017, 3:42 am
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Joined: January 12th, 2016, 8:57 pm
Location: Wilmington, North Carolina
reytuerto wrote:
Hi RegiaMarina:
I think that the guns were BL. Cheers.
Oh dang! I didn't see that! Thanks for pointing it out!

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RegiaMarina1939


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smurf
Post subject: Re: Weymouth-Class cruisersPosted: January 28th, 2017, 11:40 am
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Joined: October 25th, 2014, 7:46 pm
RegiaMarina1939 Oh dear. Where have your figures come from?
5,120 t light; 5,300 t standard; 5,330 t normal; 5,354 t full load That cannot be.
I know you have bunker 53 tons so that your standard and full load displacements correlate, but 53 tons of fuel won't take you very far.
Weymouth's legend displacement was 5250 tons, but she turned out light at 5044tons. Trials run at 5220tons.
I haven't got a figure for Weymouth, but the Chathams had legend displacement 5400tons, full load 6000tons.
Fuel load was 1500tons, mostly coal. Towns class carried between 235 and 260tons of oil (except Chester, oil fired with 1161tons). The oil was burnt in the four boilers in the central boiler room, sprayed on the coal for maximum power.
Weymouth was not flush-decked. She had a forecastle. You can see that from your freeboard figures and the drawings. The difference affects hull strength. On later Towns the forecastle was longer, about 2/3 overall length.
If you look at the drawings you will see that the ships have a 'peak' below the waterline, so the overall length must be more than the waterline length. Beam was 48ft 6in; normal draught 15ft 6in
Range I suppose you mean 5 thousand nm (though 5 might be about right with only 53 tons of fuel!)
Armament weights for all Towns except Bristols with 4in guns were over 300tons but that would include 8 or 9 armoured shields for the 6in at 5tons each. Hull weight was about 2300tons.
"7,433 lbs / 3,371 Kg = 68.8 x 6.0 " / 152 mm shells" You don't really think that a light cruiser with 2in deck armour would withstand 70 hits from 6in 100lb shells, do you? I know Wiesbaden stayed afloat a long time at Jutland, but that was exceptional.


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Garlicdesign
Post subject: Re: Weymouth-Class cruisersPosted: January 28th, 2017, 1:04 pm
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Joined: December 26th, 2012, 9:36 am
Location: Germany
Hi everyone

@Smurf: No need to jump at Regiamarina1939 over SpringSharp's inadequacies; he has it newly installed and likes to play with it. So did I when I had it new. He'll get better. So did I (hopefully). It's all a game, nothing more.

SpringSharp is useful to check self-designed ships for feasibility, because it often sets the bar higher than real physics: Both USS Iowa and HMS Nelson come out structurally unsound if you enter their data into SpringSharp, the former rather badly; I tried. As for the 'hit points': The programme calculates an abstract 'flotation' value, which is simply divided by some equally abstract value symbolizing the destructive power of her own main guns, resulting in an abstract number of 'non-critical penetrating hits' (whatever is meant by non-critical) needed to sink it. As I said - it's a game.

Greetings
GD


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RegiaMarina1939
Post subject: Re: Weymouth-Class cruisersPosted: January 28th, 2017, 3:57 pm
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Posts: 442
Joined: January 12th, 2016, 8:57 pm
Location: Wilmington, North Carolina
I have absolutely no idea how to correctly use this program... I will figure it out eventually. I need some more time to play with it!

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RegiaMarina1939


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