"King Haarahld VI"-class, paint art

pokermind wrote:Progress on Delthak II Class:



Poker

Its usual in warships to have the coal bunkers along the sides of the ship to provide a little extra cushion between the sea and the critical engineering parts of the ship. (It's easier to close a water tight door to a bunker than have to plug a hole dumping water
The boilers are also usually aligned,centered in the ship (usually ahead of the engines (so as not to foul the shafts) and mounted as low as possible as they are a significant block of mass and need to avoid being sloshed (to avoid tube ruptures). The boilers often weigh as much as the engine. The boilers also need to be kept as close as possible to the stacks for best natural draft consistent with a steep slope from the offset boilers. Aligning the boilers makes tending them easier too, as all the boiler sight glasses are visible from one location permitting reduced engine room crewing.Mounting the boilers close together also helps conserve heat. The engines are usually isolated from the rest of the ship for heat and fire management reasons, and the engine room from the boilers in coal fired ships for dust control (it makes it hard to keep the engine polished if soot keeps falling on it, and coal dust & fly ash is very abrasive so you want to keep it out of the engine room if you can). A ruptured condenser can sink a steam ship really fast unless water tight doors are provided.
We don't have any information on whether the boilers have forced or induced draft blowers, or a regenerative superheater between the cylinder stages which all complicate the plumbing to the engines, but significantly increase both efficiency and power to weight for the boilers (i.e. power density).

In short, two stacks equals either two rows of water tube boilers, tightly packed or single row of Yorkshire boilers back to back.

Guardiandashi wrote:Pokermind I realize I am not a naval architect but on your king Haarahld I was wondering if it would help to shift the rear main gun a bit further back, then put the main engine room aka the steam engines just behind, or a little bit behind the rear stack, with the steam plants under and in front of the stacks. likely with a "firewall bulkhead" separating those engineering spaces.

this would in my mind have the advantages of:
putting the engines closer to the rear of the ship thus reducing the length of the propeller shafts.
keeping the steam plants and the engines compartmentalized without making the steam lines any longer than necessary
putting at least some of the propulsion systems mass in the center (mostly) of the ship

I believe they would also likely have the coal bunkers separated, and likely with asbestos liners between the bunker and boiler rooms to try to keep the coal bunkers temperature stabilized.

I also seem to remember several navies used the coal bunkers as additional "armor spaces" to protect the vitals such as the steam, engines, and powder magazines because those were typically a lot more lethal if they had a shell detonate in them.

You usually want to place the heaviest parts of a ship as close to amidships and low down in the hull as you can because of weight distribution and stability. This avoids unnecessary longitudinal stress on the hull, especially in heavy seas. Of course, the placement is usually a compromise between the ships function and engineering realties, but the length of the shafts is usually not a problem.

Imagine if you will a ship traveling in heavy seas and when it crests a big wave both the stern and the bow may be out of the water at the same time which means the whole weight of the ship is carried by the amidships hull which places huge stresses on it which WILL flex/bend the ship. This flexing/bending may well led to metal-fatigue which will cause the hull or the internal frame to form cracks which in turn makes the ships integrity fail in the end with very wet and possible fatal consequences for all aboard.

About using coal bunkers as a spaced armor, at this point there is nothing out there that will be able to penetrate the hull of the King Haraldh I, especially below the water line but we all know that will change in time so designing the ship to use the bunkers as spaced armor is only prudent.

Regarding coal bunker fires, there is some debate on what temperature bunker fires is likely to occur. Some studies suggest that if the temperature is holding steady at 49C/120F and there is coal oxidizing in the bunker theres a high probability that a spontaneous fire will happen within a couple of days, other studies suggests that a bunker having a stable temperature of 71C/160F is not in danger of catching fire as long as the temperature is stable. Usually, bunker fires started on average 60 days after the ship left port. One wonders if it shouldn't be smart to install fire suppression into the bunkers directly. There exists a book which covers fire and how it starts called the "Ignition Handbook" by Vyto Babrauskas and there is a chapter in it about coal fires, the book can be purchased on his site (see former link) for USD 200-230 depending on which version you choose.

Well, not a KH or Dethalk, but still impressive, i think:


http://fc08.deviantart.net/fs70/f/2014/ ... 839b46.png

Joat42 wrote:

Guardiandashi wrote:Pokermind I realize I am not a naval architect but on your king Haarahld I was wondering if it would help to shift the rear main gun a bit further back, then put the main engine room aka the steam engines just behind, or a little bit behind the rear stack, with the steam plants under and in front of the stacks. likely with a "firewall bulkhead" separating those engineering spaces.

this would in my mind have the advantages of:
putting the engines closer to the rear of the ship thus reducing the length of the propeller shafts.
keeping the steam plants and the engines compartmentalized without making the steam lines any longer than necessary
putting at least some of the propulsion systems mass in the center (mostly) of the ship

I believe they would also likely have the coal bunkers separated, and likely with asbestos liners between the bunker and boiler rooms to try to keep the coal bunkers temperature stabilized.

I also seem to remember several navies used the coal bunkers as additional "armor spaces" to protect the vitals such as the steam, engines, and powder magazines because those were typically a lot more lethal if they had a shell detonate in them.

You usually want to place the heaviest parts of a ship as close to amidships and low down in the hull as you can because of weight distribution and stability. This avoids unnecessary longitudinal stress on the hull, especially in heavy seas. Of course, the placement is usually a compromise between the ships function and engineering realties, but the length of the shafts is usually not a problem.

Imagine if you will a ship traveling in heavy seas and when it crests a big wave both the stern and the bow may be out of the water at the same time which means the whole weight of the ship is carried by the amidships hull which places huge stresses on it which WILL flex/bend the ship. This flexing/bending may well led to metal-fatigue which will cause the hull or the internal frame to form cracks which in turn makes the ships integrity fail in the end with very wet and possible fatal consequences for all aboard.

About using coal bunkers as a spaced armor, at this point there is nothing out there that will be able to penetrate the hull of the King Haraldh I, especially below the water line but we all know that will change in time so designing the ship to use the bunkers as spaced armor is only prudent.

Regarding coal bunker fires, there is some debate on what temperature bunker fires is likely to occur. Some studies suggest that if the temperature is holding steady at 49C/120F and there is coal oxidizing in the bunker theres a high probability that a spontaneous fire will happen within a couple of days, other studies suggests that a bunker having a stable temperature of 71C/160F is not in danger of catching fire as long as the temperature is stable. Usually, bunker fires started on average 60 days after the ship left port. One wonders if it shouldn't be smart to install fire suppression into the bunkers directly. There exists a book which covers fire and how it starts called the "Ignition Handbook" by Vyto Babrauskas and there is a chapter in it about coal fires, the book can be purchased on his site (see former link) for USD 200-230 depending on which version you choose.

Or you ventilate the bunkers with flue gas from the boilers - 4% Oxygen doesn't support much of a fire.

Joat42 wrote:You usually want to place the heaviest parts of a ship as close to amidships and low down in the hull as you can because of weight distribution and stability. This avoids unnecessary longitudinal stress on the hull, especially in heavy seas. Of course, the placement is usually a compromise between the ships function and engineering realties, but the length of the shafts is usually not a problem.

I think you are confusing Poker. I think he has the engines a little far forward. What you are overlooking is that it is the entire mass of engines and boilers that will straddle the keel amidships with as little as practical between them and the bottom of the hull. There are two reasons for putting a set of coal bunkers between the boilers and the outer hull, added "armor" and convenience of access for the stokers.

To get the shafts a few percent shorter the engines are at the rear of power set, which will put the front of the forward boiler well ahead of amidships. Shorter shafts are better than longer shafts, but on a ship there are other more important considerations.

Hi Castenea
On the ships I served on while in the Navy the firerooms and enginerooms were seperated by bulkheads. The forward fireroom was bow first then forward engineroom, aft fireroom then aft engineroom. After taking battle damage such as a torpedo in one or two of the engieering spaces the equipment could be cross connected and the ship could continue to fight and then make it back to port.

Castenea wrote:

Joat42 wrote:You usually want to place the heaviest parts of a ship as close to amidships and low down in the hull as you can because of weight distribution and stability. This avoids unnecessary longitudinal stress on the hull, especially in heavy seas. Of course, the placement is usually a compromise between the ships function and engineering realties, but the length of the shafts is usually not a problem.

I think you are confusing Poker. No dificulty confusing the confused I think he has the engines a little far forward. What you are overlooking is that it is the entire mass of engines and boilers that will straddle the keel amidships with as little as practical between them and the bottom of the hull. There are two reasons for putting a set of coal bunkers between the boilers and the outer hull, added "armor" and convenience of access for the stokers.

To get the shafts a few percent shorter the engines are at the rear of power set, which will put the front of the forward boiler well ahead of amidships. Shorter shafts are better than longer shafts, but on a ship there are other more important considerations.

Well guys moved all boiler's forward using one stack for all six. Sorry there is a coal bunker between the boiler room and the engine room and more weight to the stern but adds more coal bunkerage



Enjoy kibitzing, Poker

pokermind wrote:Well guys moved all boiler's forward using one stack for all six. Sorry there is a coal bunker between the boiler room and the engine room and more weight to the stern but adds more coal bunkerage

Enjoy kibitzing, Poker

Poker, I think your design would be more workable with the boiler array rotated 90 degrees, then possibly using 3 stacks, or go with only two pairs of slightly larger boilers and use two stacks.

I look forward to others opinions of what I have completely wrong.

I am REALLY annoyed (Mainly with myself) that this vigorous thread has been so active while I am on holiday over 6000 miles from my reference library.
(I am in the same time zone as Novosibirsk, so this probably puts me east of Dilandu, as well as somewhat warmer, if wet)

Have any of the protagonists of this thread read the three excellent books by R.A.Burt on the evolution of the British Battleship, effectively from HMS Warrior up to the KGV class of WW2?

Incidentally, here on Planet Earth, the Royal Navy is the British Navy (although I have severe doubts about the way our politicians are treating it and I worry for its continued existence)
Then surely , on Safehold, the Charisian Navy should be the Royal , and now the Imperial, Navy, the RN not the RCN; the IN, not the ICN.
This would also be "sticking a metaphorical two-fingers up" at anything the lesser, CoGA supported, navies of Safehold do.

pokermind wrote:

Castenea wrote:I think you are confusing Poker. No dificulty confusing the confused I think he has the engines a little far forward. What you are overlooking is that it is the entire mass of engines and boilers that will straddle the keel amidships with as little as practical between them and the bottom of the hull. There are two reasons for putting a set of coal bunkers between the boilers and the outer hull, added "armor" and convenience of access for the stokers.

To get the shafts a few percent shorter the engines are at the rear of power set, which will put the front of the forward boiler well ahead of amidships. Shorter shafts are better than longer shafts, but on a ship there are other more important considerations.

Well guys moved all boiler's forward using one stack for all six. Sorry there is a coal bunker between the boiler room and the engine room and more weight to the stern but adds more coal bunkerage



Enjoy kibitzing, Poker

Closer to what I was thinking but you want the boilers aligned and balanced as close to the centerline (or more precisely the metacenter (point around which the ship moves)) as possible to avoid water sloshing in the boilers in rough seas. Common flues are fairly standard on coal fired boilers where you don't have to worry about gas leaks flowing back, and it aids draft when starting the secondary boilers (for long range travel it was common not to light all the boilers but rather fire one boiler as hard as it could go to maintain cruise speed as this is the most efficient way of firing a coal fired boiler - the other boilers were lit as required to provide additional power (this typically takes about an hour, which seems like a long time, but with 20nm sight lines and 10kt cruising speeds is more than adequate, particularly against 4kt sailing ships)).
I am a little puzzled why you don't have the boats on davits to speed launching - a single crane is a severe bottle neck when you are in a hurry - i.e. sinking or sending a boarding party away. Given that they are using modern knowledge with an old technology - why not go to freefall lifeboats - i.e suspended at 45 degrees off the stern on hoists with quick releases. http://en.wikipedia.org/wiki/Lifeboat_%28shipboard%29