Er is that not basically irrelevant to the quoted speed as all ship to some extent slow down with sea way, fowling and load in worse case situations? KVGs where in no way 24-25Kn ships unless you want to reduce all other ships down as well.........
Alt. Battleships discussion_possible increases in battleship performance
- Thread starter Gudestein
- Start date
I'd say 30-31 would be closer, Hood needed an extra 5k to be pulled down to 28-29 knots (Her speed in 40, around 26.5 probably wasn't helped by fouling but was mainly due to a dire machinery situation)
IIRC PoW was pulling off 29 when green running with Hood on the intercept? The seaway was no pacific flat calm either
I don't see G3 making 33, but 28 is a huge drag down.
Sure, overtime speed gets pulled down with fouling (and it applies to PoW, but i digress) depends how often your ship gets into drydock to have the shit scraped off.
Last edited:
Until the invention of anti-fouling paint, every ship lost 3-4 knots when fouled compared to clean. That said, both KGV and POW made 27 and 28 knots many times in confrontations with both Bismarck and Tirpitz.
With the exception of the QE class (the problems with which we have discussed before) the DNC tended to slightly exceed their design speeds in this era. And AIUI they tended to get more conservative with their estimates after the QE’s. I would not be surprised to see the G3’s have made 32 knots.
A good discussion they had there, thanks for the link. So, we’ll have assume a small drag at low speeds, although it surprises me as they are used widely today on slower ships. Maybe it’s the crudeness if the early designs? They are basically a cut cruiser stern where the sides are converging on a point a little aft of the transom (before the stern is cut off), whereas many OTL stern maybe don’t go as deep but converge on a point much further back.
Certainly the depth raises the speed where they become beneficial.
Anyone with some specialized knowledge on ship design?
McPherson
Banned
Not my specialty, but note modern transom stern freighters and tankers have the square-cut above the V notch meet at the stern post rudder pivot? Also these commercial examples are less than 20 knots and are not so concerned with rudder kick out as they do not perform a high speed dodge maneuver like a modern warship, where skid out and the kick and the lean are important tail control issues in a tight formation.
I guess the part about otl transoms is the same. They don’t go as deep as the cut cruiser stern.
I would strongly suspect so, beamier stern with engines, a forward battery and a pointed bow that nevertheless gets buoyancy forward with the bulbous bow.
How do you squeeze 8 11" guns onto a Hipper size hull? The turrets would have to be wider than the 8" turrets and your hull width is 2 feet wider than the OTL hull. ANd I don't see how you would get the extra weight of the turret into the hull.
And if I am reading correctly you said you set the engine size to half of what it takes to get to 32 knots. This would probably give you 24-35 knots max. I'm basing that on reports I have seen that the Iowa class can cruise on half its engineering plant and only needs the other half to increase the speed from 25-33 knots. I have seen similar power curves for other warships of the era.
It’s not a hipper size hull, it just have hipper size length, beam and draught, but it’s much heavier.
Regarding each turret barbette the beam is very close to graf spee, so not impossible.
weightwise, the program does seriously penalize heavier guns and really, it’s undergunned compared to the Deutschland class when you consider how much bigger it is.
You may be right about the speed, but what I list here is half the engine weight that gives 32 knots in the program (with the engine slider at 100).
Maybe the speed difference should be bigger.
Last edited:
thaddeus
Donor
my speculation was for 3x2 11" turrets on something smaller than the historical Scharnhorst-class, although 3x3 11" guns would likely be the desired array
Probably worth mentioning
HMS Adventure (M23) - Wikipedia
She also served as a test case for transom sterns for the G3s. But who are we kidding? Ultimately the need to squeeze a G/N3 in docks would lead to the transom stern. Not speed. Just like the all forward armament. As we have been saying all along. Compromises.
All forward is dead in the water in the 30s for those paying attention. Magnetic fuses mean it is just a matter of time till ships are taking big hits under water. On one hand, with hindsight we know those hits are going to become spine destroying, but in the intermediate there is a hope dispersal of armament and engineering will preserve some fighting capability.
Hi, sorry I let the discussion die out.
On the subject of fouling I found this historical review. It seems that at the time the paints could last for 9 months while techniques were in place to extend this to 18 months, but cumbersome to use. Are these timeframes detrimental in this period?
Best regards
I like the Adventure example. It pertains to the discussion above as she was made to improve cruising efficiency which is stated at 17 knots.Probably worth mentioning
HMS Adventure (M23) - Wikipedia
en.wikipedia.org
She also served as a test case for transom sterns for the G3s. But who are we kidding? Ultimately the need to squeeze a G/N3 in docks would lead to the transom stern. Not speed. Just like the all forward armament. As we have been saying all along. Compromises.
All forward is dead in the water in the 30s for those paying attention. Magnetic fuses mean it is just a matter of time till ships are taking big hits under water. On one hand, with hindsight we know those hits are going to become spine destroying, but in the intermediate there is a hope dispersal of armament and engineering will preserve some fighting capability.
Also good point about the all forward, but how does that relate to the French designs. They were contemporary with magnetic mines?
McPherson
Banned
The evidences suggests that the French did not.
Mines of France - NavWeaps
OTOH, i did not know they had duplicated German research into radiation detector activated mines. For those not familiar with this crazy idea, the theory was that cosmic rays from outer space would be blocked partially by a ship passing over a mine. The particle counter would notice the eclipse and a signal census circuit very similar to what one finds in a magnetic field detector would notice the signal drop and an electrical circuit designed to function off this signal drop detection would fire a solenoid and BOOM.
I think this might have actually worked.
The concept is fine, but I suspect that the instrumentation needed to reliably pull it off in a military mine were a little iffy in the 40's.
Somwhow ... I've problems following you.
The second picture (post #15) of a todays or "modern" - comapared to the Yamato - cargo ship is ... a cargo ship whichs "sweet spot" of speed and economics ist at ... slow(er) and cruising speed (somewhere in the 10 to 15 knots zone despite it rather 'unspeedy' bur cargo-capacity friendly overall form) to be economic and profitable as well [fast enough] I would assume).
However, the so-called "transom stern" of the Yamato looks more like a kinda handmade wanna be construction trying to combine ever wished for abilitiy :
- increased top speed (with lower fuel consumption)
- good steerability at esp also low paces
- please the possibly rather 'old-fashioned' old-type old decider admirals
About those 'tests' for N3 and G3 ... these were tests of ... how many forms ? ... under how many conditions ? under what proer anticipations about hydrodynamics ?
Also ... every modern warship of today actually has a transom stern and due to known thights on budget (also for running a ship) they have to be most economic on the speed they most of the time travel on ... cruising speed
Unfortunatly and obviously noone of us (or at Shipbucket for that) ist actually trained and competenly teached enough in ship-design to truly argue in the above way.
Modern practise rather teach the way of Gudesteins thoughts.
Yeah, even today I would be pretty skeptical of using it in a military system of that sort. The instrumentation to detect the modulation of cosmic ray flux from a battleship passing overhead (at least for a not too deeply placed mine...) certainly exists, but it is mostly research-grade stuff. Hardening it to withstand shock (you do NOT want to be using PMTs in your fancy mine!), rough handling, big temperature swings, sitting in storage for years and years before getting deployed, sitting underwater for months or years AFTER getting deployed...that's a big challenge. Definitely not trivial, even if possible!