How to do a naval invasion against heavily defended ports

[Simon_9732495]

Some players think they are safe against naval invasions, if they just guard the ports heavily.
In the following I will show that that is not always enough, even if there are A LOT of units guarding a port and that leaving the tiles next to a port unguarded is dangerous.


Disclaimer:
What I do here is very risky and might result in losing precious tanks. It's better to land at a port first and choose one that is not well guared. I loaded a savegame and chose a heavily guarded port to show that it is possible. In the real game I chose another port.


It's March 1942, I'm Germany and my Scout-U-Boat has found that Portsmouth is heavily guarded, but the tile next to it is not:

Spoiler: Heavily defended port

For the naval invasion I select 2 40width tanks to attack the port and 4 14/4 Infantry to spread out. (I'm person that dont like waiting. That's why I do 6 naval invasion orders, 1 for every divison to have the planning completed in 7 days.)

Ok, lets get naval superiority, and start the invasion.

Spoiler: Invasion landed

Uh, oh. The port is really heavily defended. 24 Infantry Divisions and 1 Tank.
Let's attack and spread out. (Spreading out is to make sure that my tanks are not attacked from behind and get the "in multiple battles" and "encirclement" debuff)

Spoiler: Attack and spread out

As you can see the defenders have not much change to hold against my tanks. The seasoned tank does 2000 soft attack without planning bonus. Having my cipher decrypted short before is helping them too little.

In a bit more than 1 day the defenses are broken (the 4 defending divisions deorged so fast, that the other division couldn't reinforce.)
But we have still to move into the city and have no supply.
Let's activate "Extra supplies" (my field marshal is logistics wizard)

Spoiler: Extra Supplies

3 days later the port is taken and reinforcements are brought in (another 22 Tanks to make it an Army of 24)
Supply situation is great now.
It's still a dangerous situation, because there are many enemy troops around. One 14/4 Infantry division is lost at that point. (Deorged without supply. Maybe could have saved them with last stand, but didnt notice)

Spoiler: Port Taken

1 week later:

Spoiler: 1 week later

They have no chance against the tanks.

Another 6 days later:

Spoiler: Another 6 days later

I took about 3 weeks from the start of the naval invasion to the capitulation of the UK. Another Blitzkrieg.


Maybe to say it again at the end:
Landing with Tanks at a non port tile is very risky. You take a lot less risk if you attack a port directly with Marines and CAS, circling attacks. But at a port with 25 Divisions on it this is certainly not possible.
With this thread I wanted to show that even such a port is not invincible. And that it's dangerous to leave tiles next to ports empty.

 

[Orlunu]

A further refinement is important, which is to combine this tactic with paratroopers and/or other naval invasions to surround the port. As it is, this strategy is very heavily reliant on getting so much local superiority that you can capture the port before any reinforcements can enter the equation.

 

[Simon_9732495]

A further refinement is important, which is to combine this tactic with paratroopers and/or other naval invasions to surround the port

I decided against attacking from more than one tile and against encirling the port.
My reasoning behind:

• If I encircle the port I have to kill all units on it. I cannot push them out. I thought it might take longer to kill all, even if they are encircled.
• If I attack from more than one tile I widen the combat width. The defender has enough units to fill any width and I'm afraid that he can maybe reinforce if the battle is more complicated. When I attack with 2 40w tanks typically 4 20w divisions defend and deorg all at about the same time.

I could and should have landed Infantry on other empty coast tile to distract the enemy. But I chose not to, to fully concentrate on this 1 fight. If I get Portsmouth I'm good. If not, all division of the invasion are lost.

 

[Norglics]

hmm i think if you are the attacker and you want the port , you need overwhelming numbers vs a digged in enemy in a city area
so you need as much combat width as possible -> encircle the port ,but i have little experience with this game

do those tanks really good at taking the port, i thought my infs should be able to hold the city vs tank attacks

 

[Simon_9732495]

hmm i think if you are the attacker and you want the port , you need overwhelming numbers vs a digged in enemy in a city area
so you need as much combat width as possible -> encircle the port ,but i have little experience with this game

If you want to push a stronger enemy from only one tile, you want to keep the combat width small. By attacking also from the other side I would get more defenders in the battle and win nothing.

Also, to get only one tile it's better to push then to encircle. Because, as you see in the images, I can push the many defending divsions easily. But wiping them out would take some time.

do those tanks really good at taking the port, i thought my infs should be able to hold the city vs tank attacks

Tanks are best attackers due to Armor, Hardness and Breakthrough. The also can stack high soft attack. For naval attacks they are really really really bad. That's why I land on the empty tile (no naval attack needed) and than attack the port in a "normal" land battle.
What makes it risky is, that I have no supply and no fuel. Everthing must be done in 2-5 days, or the tanks are lost.

 

[kettyo]

4000 breakthrough

As i see you have complete air supremacy over Southern England. Shame on the RAF!

 

[Harin]

@Simon_9732495, that is a gutsy play. I am not sure I could make myself do it playing ironman. Still, your rep for knowledge in HOI4 tempts me to try it out.

*Edit If I ever find myself needing a very well defended port, it is nice knowing I have a new option now.

 

[kettyo]

What makes it risky is, that I have no supply and no fuel. Everthing must be done in 2-5 days, or the tanks are lost.

Don't you get the fuel debuff for some time after invasion? It is good to know.

Also can you please show the template used for the tanks?

 

[Simon_9732495]

4000 breakthrough

As i see you have complete air supremacy over Southern England. Shame on the RAF!

Yes. After the Soviet Union capitulated I switched my production to Fighter and Naval Bomber and put up 10.000 fighters over southern England. This makes the Allies pull all fighters from channel and my naval bombers can do their job.
For the Invasion I added 800 CAS.

 

[Gort11]

Last time I invaded the UK as Trotsky's USSR I just built four 20-width amphibious armour divisions and assaulted Dover. Much less risky, and with comprehensive air support their fourteen defending infantry divisions were still overcome fairly quickly. Then I shipped over a tank army to finish the job.

But yeah, this is a way you can do it if you're in a hurry and don't have the time or resources to build amphibious divisions.

 

[Simon_9732495]

@Simon_9732495, that is a gutsy play. I am not sure I could make myself do it playing ironman. Still, your rep for knowledge in HOI4 tempts me to try it out.

*Edit If I ever find myself needing a very well defended port, it is nice knowing I have a new option now.

Agree. I wouldn't do it in a normal game. Especially not with a seasoned Medium Tank. It's quite hard to get them to that level and the buff is insanely strong.

 

[kettyo]

I switched my production to Fighter and Naval Bomber and put up 10.000 fighters over southern England. This makes the Allies pull all fighters from channel and my naval bombers can do their job.

I guess this is an AI air logic issue as fighters over there pose no threat, they should not overreact like this and leave the RN unsupported. I'd refrain from using this tactic as it's not realistic.

After all i think you could have massacred them over the channel too and when they start losing seriously you can send in the bombers.

 

[Simon_9732495]

Don't you get the fuel debuff for some time after invasion? It is good to know.

I think the Tanks have only the fuel they take with them.
They have a capacity on 2900.
Defending takes 600, attacking 1200.
They can attack for about 2 and a half days, then the fuel is gone. The "Extra supplies" ability removes only the out of supply debuff, but not the out of fuel debuff.

Also can you please show the template used for the tanks?

 

[Simon_9732495]

Last time I invaded the UK as Trotsky's USSR I just built four 20-width amphibious armour divisions and assaulted Dover. Much less risky, and with comprehensive air support their fourteen defending infantry divisions were still overcome fairly quickly. Then I shipped over a tank army to finish the job.

But yeah, this is a way you can do it if you're in a hurry and don't have the time or resources to build amphibious divisions.

Agree.
As I say twice in my posting, this is very risky and was a showcase. If you look at the pictures you see that Dover was a lot less crowded. I look which port has the most divisons and attacked there. I chose the most difficult port.

 

[Simon_9732495]

I guess this is an AI air logic issue as fighters over there pose no threat, they should not overreact like this and leave the RN unsupported. I'd refrain from using this tactic as it's not realistic.

After all i think you could have massacred them over the channel too and when they start losing seriously you can send in the bombers.

I think they have highest priority not getting bombed in southern england. That makes them try to keep air superiority there with all they have.

I played a bit around with the air war and noticed getting a better trade in the air when I switch airzones. The AI ramps up their planes slowly and in that time they lose a lot due to beeing numerical totally inferior.
So I put 5000 fighter over the channel, and 5000 I switched between southern and northern england.
Then I noticed that there were never fighters over the channel. So I moved the other 5000 also to England and watched closely if they switch and shred my naval bombers.
They didn't.

 

[kettyo]

I think the Tanks have only the fuel they take with them.
They have a capacity on 2900.
Defending takes 600, attacking 1200.
They can attack for about 2 and a half days, then the fuel is gone. The "Extra supplies" ability removes only the out of supply debuff, but not the out of fuel debuff.

Thanks a lot!

Are so much breakthrough necessary? I'd say half of that is enough but i haven't got much experience with the game.

 

[kettyo]

I think they have highest priority not getting bombed in southern england. That makes them try to keep air superiority there with all they have.

But this should be of any concern if you actually level their industry, ports, and airfields. Otherwise keeping the RN intact should have a much higher priority. And fighters themselves are no threat to said assets.

 

[HugsAndSnuggles]

• f I encircle the port I have to kill all units on it. I cannot push them out. I thought it might take longer to kill all, even if they are encircled.

Why would it take longer? AFAIK, in both cases you only need to deorg divisions actively fighting. When encircled, divisions will get a penalty, making the task easier.

• If I attack from more than one tile I widen the combat width. The defender has enough units to fill any width and I'm afraid that he can maybe reinforce if the battle is more complicated. When I attack with 2 40w tanks typically 4 20w divisions defend and deorg all at about the same time.

You don't have to attack from all those tiles, though, just make the encirclement.

 

[Harin]

Last time I invaded the UK as Trotsky's USSR I just built four 20-width amphibious armour divisions and assaulted Dover. Much less risky, and with comprehensive air support their fourteen defending infantry divisions were still overcome fairly quickly. Then I shipped over a tank army to finish the job.

But yeah, this is a way you can do it if you're in a hurry and don't have the time or resources to build amphibious divisions.

Do you remember the template you used?

 

[Fulmen]

Spoiler: Heavily defended port

View attachment 580633

Except it isn't. That's a weakly defended port, and if you defend ports like that in multiplayer you're going to be in for a rude awakening.

A properly defended port covers the port and all coastal tiles adjacent to it, with reserves to reinforce the tiles being attacked. A heavily defended port is that, with at least 2-3 20-40 width divisions on each tile. A proper coastal area defence also consists of covering airfields, supply hubs and bottlenecks against "sniping" by paratroopers.