New Canadian Shipbuilding Strategy

[Colin Parkinson]

The big issue with rail guns at the moment is the excessive wear. As for lasers, they have already equipped aircraft with them and had a succesful shoot down test as I recall. So the Tech is there now for them. I suspect people laughed hard when the monitor came out of the bay as well.

 

[AlexanderM]

I find it funny that someone is laughing while the Germans have a moblie system that's vaporizing mortar shells out of the sky.  lol

 

[AlexanderM]

They would need to be working and relatively debugged by the time the detailed design work is started.

Well, they are working right now, see the link.  The Germans expect to have a system 10x more powerful in 3-5 years.  It would just replace a goalkeeper unit on a ship.  All we would have to do is be able to plug it in.

Laser technology is set to progress in leaps and bounds right now.

 

[AlexanderM]

I'll pass on the thanks for the great laughing fit your ascertation that lazers and rail guns will be available for us to use in the near future gave our P1 WEng guy.  He roared with laughter and nearly shat himself with glee. 

I guess he doesn't share your optimism on the future prospects for us.

Not saying rail guns will be ready, my posts were actually calling attention to the power problems.  It's the laser that are already working.

 

[jollyjacktar]

To be fair, I did mention lazers specifically.  They may be ready now, for others, his reaction was at the thought that we might get them in the near or reasonable near future.  He said we've just caught up to the 80's, or maybe the 90's.

Maybe we will get all Buck Rodgers someday, but I expect it won't be for a long long time and I doubt that I'll be air side to see it happen.

 

[drunknsubmrnr]

The German laser system is interesting, but not really usable shipboard yet. They may get it there in time to be included in a CSC design, they may not. They've had at least one major failure with integrating land systems on a ship lately, and that was with mature technology.

 

[Kirkhill]

The German laser system is interesting, but not really usable shipboard yet. They may get it there in time to be included in a CSC design, they may not. They've had at least one major failure with integrating land systems on a ship lately, and that was with mature technology.

To be fair lasers don't have quite the recoil of a 70 cal 155.  The structural issues will be different in kind to that of the MONARC system.  Instead of managing recoil Alex needs to support a massive battery pack, an extraordinary capacitor bank,  a hazmat procedure for a few tonnes of caustic chemicals and/or a power generation system that uses sea water as part of the equation.

Lasers don't eat bullets.  They eat Joules.  The same stuff the ship eats.  They just eat them faster than the ship.

 

[AlexanderM]

To be fair lasers don't have quite the recoil of a 70 cal 155.  The structural issues will be different in kind to that of the MONARC system.  Instead of managing recoil Alex needs to support a massive battery pack, an extraordinary capacitor bank,  a hazmat procedure for a few tonnes of caustic chemicals and/or a power generation system that uses sea water as part of the equation.

Lasers don't eat bullets.  They eat Joules.  The same stuff the ship eats.  They just eat them faster than the ship.

Yes, 100% agree.  To me, the difference is that the rail guns require so much power that they aren't practical, that's why I was trying to come up with an alternate power source, and was dead wrong to think of fuel cells. 

However, I suspect that the lasers won't require anywhere near the power of the rail guns.  And, if the Germans can power that laser system on a mobile unit smaller than a tank, then the power requirements can't be that bad. 

So, I'm thinking we need a number of gas turbine generators, and two or three banks of supercapacitors per laser, so that while one bank is firing the other banks can be charging.  I expect these would charge much faster than the ones required for the rail guns.  This equipment wouldn't necessarily be physically huge, but it would likely require one good sized power room, to power lasers fore and aft.

 

[AlexanderM]

Might be more information available here if someone chooses to download and read.  I expect it would contain some information on power requirements.

http://spieeurope.com/x648.html?product_id=977780

 

[Kirkhill]

.... to power lasers fore and aft.

Sorry Alex.  I know you are dead serious and all,  and you're not far off the development curve,  but that one phrase hits me with the same impact as "photon torpedoes" and "Dropships".

How did I get so old so fast? 

 

[AlexanderM]

You're probably not that much older than I am, but I don't want to admit my age anymore than I suspect you do.  lol

I too think it's pretty crazy that we are talking about lasers on a Canadian warship and that it could possibly happen before too long.  I also think that the next arms race is going to be scary as crap, as we are going to see some very scary weapons emerge over the next 20 years or so.  We're going to see lasers on ships and battlefields.  Anti-ship missles that travel at ridiculous speeds, more development of supercavitation torpedoes and perhaps submarines as well, and warplanes that are remote controlled and can maneuver at ridiculous g forces. 

Hopefully we don't see someone come up with a superweapon and order eveyone else to surrender.  I do think that it could get pretty crazy.

 

[Colin Parkinson]

and yet you will still need a ship to deal with RPG and AK armed pirates and land forces to deal with the same sort landbased and T-55's for at least another generation. 

 

[Kirkhill]

If Blackbeard got alongside you with grenadoes and cutlasses you would still have a problem today.  Some things never go out of fashion.

 

[Occam]

Anti-ship missles that travel at ridiculous speeds

I won't get terribly worried until they reach ludicrous speed.

I have to admit it's funny seeing all this talk about warships and lasers, while I'm still trying to keep a supply of Pentium 3 computers and IDE hard drives on the shelves for replacement parts.

 

[AlexanderM]

Yes, ludicrous speed would be right over the top.  lol

 

[Good2Golf]

Yes, 100% agree.  To me, the difference is that the rail guns require so much power that they aren't practical, that's why I was trying to come up with an alternate power source, and was dead wrong to think of fuel cells. 

However, I suspect that the lasers won't require anywhere near the power of the rail guns.  And, if the Germans can power that laser system on a mobile unit smaller than a tank, then the power requirements can't be that bad. 

So, I'm thinking we need a number of gas turbine generators, and two or three banks of supercapacitors per laser, so that while one bank is firing the other banks can be charging.  I expect these would charge much faster than the ones required for the rail guns.  This equipment wouldn't necessarily be physically huge, but it would likely require one good sized power room, to power lasers fore and aft.

Have you actually run the numbers or are you taking generic quotes out of articles, and damning turbines (or other power sources) with generalities?

Let's dust off our electrical engineering textbooks and do that (address specifics) for a moment.


Current rail gun max energies: depending on the builder, 35-50 MJ (megajoules) or about one tenth the average power of a lightening strike (500 MJ).

Current power output of a GE LM2500+G4 gas turbine: 35 MW (megawatts) or about 48,000 shp.


Power is the rate at which work energy is created/expended: P = w / t (power = work / time).  In SI Units the P=w/t formula is represented as: 1 Watt = 1 Joule per second ( 1 W = 1 J/s).  Conversely, work energy equals power output times duration of the output - again in SI units, 1 Joule = 1 Watt•second)

Using rail gun energy and power source output, we will solve for time to determine how long the power source would have to work to charge up whatever storage system (capacitor/compensating alternator) the rail gun was using.

Power (of the LM2500)  35 MW = Energy required of the rail gun (let's use) 50 MJ ÷ time, t (sec)

35 x 106 W = 50 x 106 J ÷ t

t =  50 x 106 J (or W•s) ÷ 35 x 106 W

(Watts on the right side cancel out leaving just seconds)

t = 50/35 = 1.43s

So, specifics of the electrical storage medium notwithstanding, it would take just 1.43 seconds of an LM2500+G4's output to produce enough electrical energy to supply a 50 MJ rail gun.  All other parts of the system appropriately designed, that means an LM2500 could be used to power a rail gun system with a cyclic rate of fire of 42 rounds per minute (60 sec/min ÷ 1.43 sec/rd).

The article you quoted used a lot of generalizations.  Yes, power generation is a notable part of the system, but more so is its storage and other aspects of the weapon system.  The real challenge will be in developing the storage system that can then expend huge amounts of potential electromechanical power AND do so while withstanding the huge forces (megaNewtons) during firing and rails not being ablated after just a few firings.

The whole issue comes down to: operationalization of the energy production/expenditure system in a reliable form factor that is smaller/more manageable than the current chemical/physical system whilst producing enhanced operationally employable lethality.

I would make that case that physical energy production (from say an LM2500 gas turbine) into the such a system is not the long pole in the tent.


Regards
G2G

 

[AlexanderM]

I expect they would use superconductive materials throughout the system, in the super-capacitors, conduits, and rails themselves, which would greatly reduce or eliminate heat generation, as most heat comes from resistance in the system.  Then, simply suspend the projectile in a magnetic field, so there is no actual contact with the rails.  They can suspend a train on an magnetic field, a projectile should be no problem.  If the generators can provide the power, all the other technology already exists, just a matter of putting it together in one system, which of course, represents a substantail amount of design work.

 

[Good2Golf]

You do know that the projectile forms the circuit between the positive and negative rail, and thus MUST be in contact with both rails, right?

 

[AlexanderM]

Contact with the shell itself is never required.  It is always an armature that completes the circuit. One can use plasma as the armature, in which case absolutely no contact with the shell is required, and it could, in theory, be suspended, however there is still tremendous heat from the plasma.  There is a lot of testing currently being conducted looking for a system that works.  I'm still thinking that lasers are much closer.

 

[Good2Golf]

The armature sabot still contacts the rails.  The starting current required to initiate plasma generation would put orders of magnitude great strain on the current carrying components of the rail assembly.  Whether single stage rail propulsion or two-stage, the first being a light-gas (low molecular number) system to 'kick-start' the projectile/armature assembly into the rail structure, currently developing RGs are still using contact initiated current flow.  If you have examples of a pure-plasma rail gun prototype, I (and others) would be quite interested to see how the rail ablation elimination solution is going.

Regards
G2G