Defnses of the Seine River

[JKernwerk]

Ahh Carl, that lightens things up.
So it was not the beaches they were able to shoot at.
That is more logical.
JK

[Carl Schwamberger]

For most batteries. There is still one VLR cannon suggested on that map.

Getting back to attacking the ships. The white bands at sea are the control lanes for the Allied ships 6th June & for some time after. Traffic was dense & could not go zig zagging at speed to dodge attacks. strict disciple in heading & speed was necessary to prevent collisions & get the correct ship to the correct point at the correct time. This left them a bit more vulnerable to cannon fire.

[charwo]

Charwo,
Do not think they forgot in the original planning.
I my oppinion some of the con's were;
Le Havre is surrounded by high cliffs and canals, only landing in the harbour it self and landing at a river mouth is hard to do because of watercurrents.
The same goes for most of the Seinevalley and the parts that are flat it is wet polders, really bad tankcountry.
When you land on the south side of the Seine at the same time you can not meet in te middle because of the river (so not one front), also the coast is mostly hard to cover for tanks (a bit like Omaha beach but mostly worse).
And if you land in two corners it is harder for you to deploy and keep moving in the initial stages.
The canal Riva-Bella-Caen worked pretty well as a natural border to keep the 21st Panzer at bay that could also hepled the Allies when landing South of the Seine.
255mm batteries were not present (did not exist in the German Army), but Le Havre was heavily armed with Flak and all sorts of coastal and divisional batteries up to 38cm (battery was not ready but i assume one gun could fire), on the South there were more coastalbatteries then in the actual landingplaces.
I also do think that te broad river was likely to waste more para's then the innondations did at Utah also when they had to land a bit more south (lets say between Pont l'Eveque and villerville) there were much more forests than at Utah and the British landinggrounds so harder to land if we assume a wide spread landing in the night and more losses due to the trees.
JK

Actually, I was never talking about taking Le Harve directly. THe notion of needing two divisions to take Le Haarve actually played out that way. It's Rouen that gets taken, Le Harve is bypassed and suppressed via naval and ari power, and two divisions of heavy hitters, in this case heavy artillery and flame and Petard AVRE Churchills, two or three regiments come up the road from Rouen and burn out the bunker networks from the land side. The issue is getting into the tidal pool that might not be seelable but while I don't think you could crater the LeHarve defenses into oblivion with air and Naval power, I do think they could be suppressed enough for troop transports to sail into tidal pool IF the ariborne ops were concentrated there and supported to the hilt by airpower.

The problem with the Normandy landings, which the British solved by tanking the tnaks is that there were so many ways to advance to Caen from so many directions, perfect interdiction was impossible. BUT if you land where the armor isn't and you know there are exactly three roads they can come across, you can interdict them nearly perfectly, given the gas shorates don't really give the Germans much room for operation manuver

[Manuferey]

Emmannuel,
How is it possible they concluded that a battery of K18's at Le Havre could fire at Sword beach.
The max. range was 28km that would be about Cabourg, to give fire at Sword beach they would need another 10km or more (Riva Bella was about 37km away).
Did they expect newer ammo that could fire further?
JK

JK,

The US Navy reports doesn't say that the battery in Le Havre could reach the beach, only that unloading had to stop. It could mean that the guns could reach ship lanes off the coast of Sword Beach.
The other large gun in Le Havre was the 38 cm from MKB Le Havre (Bléville La Corvée) but the gun was never ready to fire.

Emmanuel

[JKernwerk]

The shipping lanes to Sword could not be reached from Le Havre with the K18.

What I have read is you want to capture Rouen and then Paris by boat...
The shoulders of the Seine are very steep so your tanks can not deploy the way they were intended.
Rouen is about 80-90km upstream and your ships can only get to Rouen because the water is to shallow.
Furtermore the few airplanes the Germans have can make it uneasy for you to flee any bombardment.

Seems like a good match for Monty's plan for Market Garden.....
JK

[Carl Schwamberger]

While Rouen does and did have some deep water port capacity, for blue water cargo ships, the river is a difficult and slow route. One damaged ship & the channel would be blocked or even more difficult. I'm recalling a description from the 1980s of a US destroyer moving upstream and the experienced harbor pilot at the con losing control. Emergency action prevented grounding and property damage, but that involved a unplanned dropping of the anchor and blocking the channel until a tug boat could arrive & reposition the ship.