Noose of steel: great entente submarine offensive

[Monk78]

What if the British French and Italian navies sent in their submarine fleet which outnumbered the Austrians and Germans considerably considerably to hunt and destroy all major warships in 1914 ?
With the grand fleet another fleets maintaining distance blockade The submarines can go in for the kill infiltrate Harbors bases and contest control of even the home waters of central powers
What ASW tactics in pre depth charge era the Germans and AH can employ ? And how effective are they likely to be ? Assuming depth charge tech is a good year away

 

[Count of Crisco]

What if the British French and Italian navies sent in their submarine fleet which outnumbered the Austrians and Germans considerably considerably to hunt and destroy all major warships in 1914 ?
With the grand fleet another fleets maintaining distance blockade The submarines can go in for the kill infiltrate Harbors bases and contest control of even the home waters of central powers
What ASW tactics in pre depth charge era the Germans and AH can employ ? And how effective are they likely to be ? Assuming depth charge tech is a good year away

While ASW was definitely in its infancy so was submarine warfare. Everything from getting into position, to making a torpedo attack, was still largely theoretical. Most navies were looking at using submarines to defend their coasts and harbors, not sail into enemy waters. What you would probably see is alot of dead submariners and many wrecked subs.

 

[Monk78]

While ASW was definitely in its infancy so was submarine warfare. Everything from getting into position, to making a torpedo attack, was still largely theoretical. Most navies were looking at using submarines to defend their coasts and harbors, not sail into enemy waters. What you would probably see is alot of dead submariners and many wrecked subs.

What do you think are the ways Germany and AH can conduct ASW in that period?

 

[Count of Crisco]

What do you think are the ways Germany and AH can conduct ASW in that period?

Well how well charted are the waters for both those nations? And how shallow? Its possible their best means of ASW is to just send patrols to find the wrecks of subs that hit rocks a dozen meters under the surface, or ran aground. As to what they could do themselves actively, well look at the early British attempts. You would probably see the usual two blokes with a hammer in a rowboat at first before more practical and effective means are developed.

 

[Monk78]

. You would probably see the usual two blokes with a hammer in a rowboat at first before more practical and effective means are developed.

Was there anything between sledgehammers and depth charges ?

 

[CV(N)-6]

Italian navies

Not until 1915.

The OP is pretty much what the Entente was doing with subs, trying to get shots at CP ships, plus as Count mentioned in a defensive role. The subs of 1914 were unreliable at best with undeveloped tactics. All the major fleet bases also have extensive minefields and patrols protecting them. If you could just magically have 50 subs off an enemy port and sink their fleet somebody would've done that by now but it just doesn't work that way.

 

[Monk78]

Not until 1915.

The OP is pretty much what the Entente was doing with subs, trying to get shots at CP ships, plus as Count mentioned in a defensive role. The subs of 1914 were unreliable at best with undeveloped tactics. All the major fleet bases also have extensive minefields and patrols protecting them. If you could just magically have 50 subs off an enemy port and sink their fleet somebody would've done that by now but it just doesn't work that way.

What did these anti submarine patrols accomplish if they had no depth charges ? If they found a submarine on the surface than that’s fine ramming and gun fire but if they found a snorkel and suspected a submerged Submarine then what can these patrols actually do?

 

[CV(N)-6]

What did these anti submarine patrols accomplish if they had no depth charges ? If they found a submarine on the surface than that’s fine ramming and gun fire but if they found a snorkel and suspected a submerged Submarine then what can these patrols actually do?

WWI subs generally speaking didn't have snorkels fitted because with the exceptions of a few prototypes they weren't developed until the interwar. But the key to protecting targets from subs isn't sinking them though that's certainly desirable, it's forcing them down so they can't fire to torpedoes, which a DD charging at your tiny fragile pre-WWI sub at high speed while shooting at it will do. Also note that the loitering time of subs in WWI isn't great, especially considering that they have to surface to recharge their batteries which leaves them vulnerable to the very regular patrols up and down the coasts of all the major powers.

 

[Monk78]

WWI subs generally speaking didn't have snorkels fitted because with the exceptions of a few prototypes they weren't developed until the interwar. But the key to protecting targets from subs isn't sinking them though that's certainly desirable, it's forcing them down so they can't fire to torpedoes, which a DD charging at your tiny fragile pre-WWI sub at high speed while shooting at it will do. Also note that the loitering time of subs in WWI isn't great, especially considering that they have to surface to recharge their batteries which leaves them vulnerable to the very regular patrols up and down the coasts of all the major powers.

did most early ww1 subs have to surface to fire their torpedoes ?

 

[HJ Tulp]

did most early ww1 subs have to surface to fire their torpedoes ?

An incredible percentage of ship sinkings by submarines in WWI was actually done by deck-gun, not by torpedo.

 

[Riain]

did most early ww1 subs have to surface to fire their torpedoes ?

They didn't have to, but often used the 'awash' position where the hull was submerged but the upper casing and sail were above the water.

WW1 subs were submersible torpedo boats and operationally are best described as moving minefields. The ones available in 1914 were feeble compared to those in 1918 and by WW2 evolutionary boats were much more rounded with things like directional hydrophones, lobg range radios and firing solution computers. However despite the apparent similarities between a 1914 sub and a 1944 sub it is a mistake to think they could do the same things.

 

[Monk78]

An incredible percentage of ship sinkings by submarines in WWI was actually done by deck-gun, not by torpedo.

Sure but not not battleships and cruisers

 

[Monk78]

They didn't have to, but often used the 'awash' position where the hull was submerged but the upper casing and sail were above the water.

WW1 subs were submersible torpedo boats and operationally are best described as moving minefields. The ones available in 1914 were feeble compared to those in 1918 and by WW2 evolutionary boats were much more rounded with things like directional hydrophones, lobg range radios and firing solution computers. However despite the apparent similarities between a 1914 sub and a 1944 sub it is a mistake to think they could do the same things.

So even without depth charges were they not some kind of explosive sweeping devices in use to combat submarines like fishing nets with explosives attached?

 

[Monk78]

If you could just magically have 50 subs off an enemy port and sink their fleet somebody would've done that by now but it just doesn't work that way.

Forgive my ignorance but why is that ? Too many submarines should be challenging to deal with for even the best navies

 

[CV(N)-6]

Forgive my ignorance but why is that ? Too many submarines should be challenging to deal with for even the best navies

Because subs require a lot of maintenance, you're lucky to have a third of them on station at one time. So you need 150 subs just to start with to shut down that enemy port and do absolutely nothing else, and a lot more to do anything else. Plus in the shallow waters off an enemy port, your rate of attrition is going to be very high between all the patrols and minefields, and once effective ASW weapons are developed in about 1916 aircraft and ASW craft will inflict a lot of casualties in shallow, constrained coastal waters.

 

[Count of Crisco]

Sure but not not battleships and cruisers

And the reasons why are quite apparent. No one was stupid enough to surface their 250-750 ton submarine next to a 25,000 ton BB with 8-12 large guns and start shelling it with their pop guns. A submarine needs to be submerged and use torpedoes if it has a chance of surviving.

But that's the problem. The sub has to be submerged. Which means crawling along a few knots for a short while. Meanwhile a BB can scream around at 20-23 knots no worries, and even 18 isn't slow comparitively speaking. A sub has to be perfectly placed, almost know where a BB will be hours in advance, to get a shot off.

And because a sub needs to be submerged to have a hope of success in such an environment it means the boat will need to head out to sea in order to surface and charge it's batteries, then creep in submerged into its operating area, and then do the same back out again a little while later.

 

[Monk78]

So to summarize submarines of 1914 are
Too short ranged
Slow
Mechanically prone to breakdown
Poor under water endurance
Lack good aiming mechanisms for their torpedoes
Rudimentary attack tactics
To be used offensively ?

So how about night attack by submarines?

were French and Italian subs of that era ( before 1915) superior to German subs ?

 

[CV(N)-6]

So how about night attack by submarines?

The fleet's in port behind minefields and harbor defenses, you'll get lucky once in a while in less defended places like Scapa but Wilhelmshaven or Split or Scapa once it's fully defended are nearly impossible to get into unless you're doing special ops.

 

[Monk78]

The fleet's in port behind minefields and harbor defenses, you'll get lucky once in a while in less defended places like Scapa but Wilhelmshaven or Split or Scapa once it's fully defended are nearly impossible to get into unless you're doing special ops.

were submarines nets already in use by 1914 ? seem like in earlier times it was mostly boom defences with floating barriers against surface ships

 

[Cryhavoc101]

The fleet's in port behind minefields and harbor defenses, you'll get lucky once in a while in less defended places like Scapa but Wilhelmshaven or Split or Scapa once it's fully defended are nearly impossible to get into unless you're doing special ops.

I would imagine places like Wilhelm "SHAVEN" would similair defences to the one at Portsmouth's 'Submarine wall' (a series of large blocks not a continuous wall) - in addition to less permanent defences like nets and mine fields.