WI: Causewaylion? The Nazis try to build a causeway to Britain after defeating the Soviet Union.

[RamscoopRaider]

I like the idea of the construction of the causeway being done as a way to force the British to attack on Germanys terms and opening up the way for it being a killing ground fortified with costal anti air, Wolfpacks ambushing ships and periodically laying costal mines. Instead of the Battle of britan by building up airfields in the area the British are forced to come to the germans either attacking the causeway directly or the german anti air defenses and air fields in France

This is effectively reversing the otl British advantage of the Battle of briten where lost British fighters could parachute down on friendly tarritory while german pilot's got captured resulting in a lose of experianed piolets while the british retained thiers. The germans never need to complete the causeway and just use it as a obvios killbox that despite knowing that the british cant avoid falling in the trap becuse it requires contesting and periodicly attacking it to hamper construction or destroy sections becuse if they chose not to play the germans game the causeway could eventually serve as a overland invasion rought

In the ideal scenario the germans approve the project as a unavoidable british killbox that requires contesting in order to force the british airforce to make attack runs past anti air and a intact luffwaffa and thier navy needing to make these same runs past axis Wolfpacks and naval mines along with german close air support with naval bombers since they are close enough for the airforce to be a factor in naval combat. For the germans this is a win win in the sense that they either get thier invasion rought if uncontested or the British bloody thier nose on a unavoidable trap.

The problem with this is that the British don't need aircraft or ships to attack it, they have long range guns that can hit France from Britain, and the causeway is just a big target, so they can use those, and since it is the sort of project likely to take a decade in peacetime, they have plenty of time to build more. It's going to be cheaper for the British to shell the causeway with railway guns than the Germans to build it, so the equation is in British favor

Well that's a problem at least, there are a lot more problems, but that's the one I'm going to answer

The whole force Britain to attack thing is better done by say V weapons, or those long range smoothbore railway guns Germany tested late in the war and attacking London directly

 

[James Ricker]

The end in France gets routinely bombed drawing the Luftwaffe into a war of attrition they can't win.
The slave labor used to construct the causeway aren't used for something else, like building weapons.
The Soviets will benefit from both

 

[David T]

Points for creativity, I'll say that much.

The one sensible plan for the invasion of Britain is mine (build a mole) and even that is weird."
--Joseph Askew, alt.history.what-if, Oct. 20, 1996

https://groups.google.com/g/alt.history.what-if/c/KPwJH_9-tCc/m/kYZ4L2uCdV4J

 

[Coulsdon Eagle]

So, the point of attack is 15 yards wide - or, if we try a second time - 30 yards.

I think even British generals will figure out where the Schwerpunkt of this particular Blitzkreig will be. Won't even need to concentrate all of the RA at this point. Just install a tollbooth, that will b*gger up the Nazi plan (hey, I watched Blazing Saddles too!).

I mean, have you ever tried getting through passport control at Dover? Marching on Moscow would be quicker..

[I knew I shouldn't have got dragged in...]

 

[Coulsdon Eagle]

The one sensible plan for the invasion of Britain is mine (build a mole) and even that is weird."
--Joseph Askew, alt.history.what-if, Oct. 20, 1996

https://groups.google.com/g/alt.history.what-if/c/KPwJH_9-tCc/m/kYZ4L2uCdV4J

Nah - giant Montgolfier balloons. We can even call them Zeppelins...

 

[The Tai-Pan]

The one sensible plan for the invasion of Britain is mine (build a mole) and even that is weird."
--Joseph Askew, alt.history.what-if, Oct. 20, 1996

https://groups.google.com/g/alt.history.what-if/c/KPwJH_9-tCc/m/kYZ4L2uCdV4J

It is weird seeing an internet thing from 1996.

 

[YYJ]

I remember in some previous unhinged Sealion thread someone (jokingly) suggested the Nazis fill in their shortage of ships with Project Habakkuk type pykrete ships, to which I responded that if they had all that refrigeration equipment, they could use it to freeze the Channel.

Project Habakkuk - Wikipedia

en.m.wikipedia.org

Of course, this creates an actual role for the Petroleum Warfare Department, who get busy melting the Channel with Flamme traps as quickly as the Nazis can freeze it.

Petroleum Warfare Department - Wikipedia

en.m.wikipedia.org

 

[marathag]

It is weird seeing an internet thing from 1996.

Imagine how I feel.
This was the first Computer Terminal I used

in 1974, to talk with a DEC PDP-8 minicomputer. Oh, and at this time, that was around $10,000. You could buy a house with that kind of money.

At the blinding fast speed of 110 baud. Since not many businesses could afford that, you would call in(mine had acoustical cups for the phone headset, not the ultra modern touch tone keypad shown in that ad for a timeshare Server/client setup

 

[David Floyd]

Yeah, but if the Nazis tried this, the British would counter by invading through the Frisian Islands…

 

[CaptainCalvert]

The causeway will take a couple of years to build. By the time it reaches Britain, the British will have had time to build a wall across the site where it comes ashore.

All that work for nothing!

 

[CaptainCalvert]

So, the point of attack is 15 yards wide - or, if we try a second time - 30 yards.

I think even British generals will figure out where the Schwerpunkt of this particular Blitzkreig will be. Won't even need to concentrate all of the RA at this point. Just install a tollbooth, that will b*gger up the Nazi plan (hey, I watched Blazing Saddles too!).

I mean, have you ever tried getting through passport control at Dover? Marching on Moscow would be quicker..

[I knew I shouldn't have got dragged in...]

Not so much ninja'd as didn't read the posts.

 

[Alex1guy]

Yeah, but if the Nazis tried this, the British would counter by invading through the Frisian Islands…

"It's an older reference sir, but it checks out."

 

[The Gunslinger]

A Nazi Germany that can build the causeway has probably already won the war. Realistically, it just gets pounded by artillery and bombs and never makes it very into the English Channel and goes down as another Nazi boondoggle.

 

[Spamquisition]

So what's stopping the Brits from making their own causeway from Dover or somewhere else and counter invading Europe while the Nazis are building their causeway?

Really though, if I was the one in charge of the British anti-causeway defence operation I'd let the Nazis build it to a certain length then just blow up the causeway in the French end with bombers or naval bombardment. It'll be funny to see how they'll deal with evacuating the workers, architects, and engineers stranded on the Once Causeway Island. Not to mention any defence assets they'll have stuck in the middle of the causeway.

Also I've just noticed the "we must build a canal" tag on this thread lmaooo. IF the causeway is successful and IF the Nazis win, will they make a canal in the middle of the causeway to facilitate channel shipping? Or will they keep the causeway as a monument?

 

[CaptainCalvert]

So what's stopping the Brits from making their own causeway from Dover or somewhere else and counter invading Europe while the Nazis are building their causeway?

Really though, if I was the one in charge of the British anti-causeway defence operation I'd let the Nazis build it to a certain length then just blow up the causeway in the French end with bombers or naval bombardment. It'll be funny to see how they'll deal with evacuating the workers, architects, and engineers stranded on the Once Causeway Island. Not to mention any defence assets they'll have stuck in the middle of the causeway.

Also I've just noticed the "we must build a canal" tag on this thread lmaooo. IF the causeway is successful and IF the Nazis win, will they make a canal in the middle of the causeway to facilitate channel shipping? Or will they keep the causeway as a monument?

Causeway Island. Has a nice ring to it.
I can imagine the captain of a ferry or tour boat pointing it out on the way past 70 or 80 years later.

 

[David T]

It is weird seeing an internet thing from 1996.

Usenet was the Twitter of the mid-1990s, especially after AOL introduced its gateway Usenet service in March 1994. https://en.wikipedia.org/wiki/Eternal_September

 

[BlueTrousers]

Thing is the only tidal in one direction (ie, tdie come in form eth Waddenzee to the Zuiderzee/Ijsselmeer and then back out), the channel as tide flows in both directions, also didn't they have to constantly sluice water out from one side to teh other (Ijsselmeer to teh Waddenzee) not sure you can do that between the north sea and the Atlantic.

Also I may be wrong but think the channel will be deeper than that,

It's not a perfect analogy, but it does indicate that - on some level - this kind of construction is possible. As far as pumping water from one side to the other goes: the North Sea and the English Channel is connected to the Atlantic on both ends. Certainly, there would be currents, which would pose difficulties, but it's not intrinsically infeasible.

As far as depth goes: yes, the Strait of Dover is rather deeper than the mouth of the Zuiderzee. The average depth of water for the latter is in the region of 4 to 5 metres. I can't find a definite figure for the latter, but eyeballing some hydrographic charts, I'd say about half the crossing is in the region of 25 metres deep, with a maximum depth somewhere around 50 metres.

Apart from that they build the Afsluitdijk from two sides, and it took quite some time.

Six sides, in fact: they started by building two artificial islands, then working outwards from those and the land on either side.

How do you build it starting from a side against artillery fire the RAF and whatever the Royal Navy can send?. Let say the impossible happens and you have got the "Causeway Bridge" How the H*** do you support an invasion of Great Britain from a single road?, no problem "I (you) shall use ships to help". Welcome to the Royal Navy (again). By the way what is Bomber Command doing? It is my (very much) humble opinion that one thousand bombers raid against the caseway each night is going to have some effect.

With great difficulty. There's a reason I caveated the statement with 'in peacetime'. Really, there are two questions here.

First, is it possible to build a causeway across the Channel? I think yes, though not without difficulty.

Second, is it in any way a sensible invasion plan? Almost certainly not. Building it would be easily disrupted, would telegraph the point of landing years in advance, and it would be a colossal bottleneck. Especially since the shortest route lands you in Britain at the foot of a cliff!

 

[Astrodragon]

This... I... what????
The Channel is one of the nastiest bits of seaway in the world. The tides are one thing, but the currents are another thing entirely and would eat anything constructed pretty fast - and that's without bearing in mind any winter (or spring, or summer or autumn) storms, which can be just vicious.
It's not possible with the technology of the time, or the strategic situation (the British are going to bomb and shell the thing to bits in no time flat) and it would make a modern engineer peer at the person who came up with the idea and wonder aloud if they'd been concussed.
It would require breakwaters on either side of it that would be almost as big as the causeway and... my mind is boggling.
NO. Just... no.
I need a sit down and cup of coffee to restore myself, this silliness has damaged my calm.

I need two

 

[CaptainCalvert]

It's not a perfect analogy, but it does indicate that - on some level - this kind of construction is possible. As far as pumping water from one side to the other goes: the North Sea and the English Channel is connected to the Atlantic on both ends. Certainly, there would be currents, which would pose difficulties, but it's not intrinsically infeasible.

As far as depth goes: yes, the Strait of Dover is rather deeper than the mouth of the Zuiderzee. The average depth of water for the latter is in the region of 4 to 5 metres. I can't find a definite figure for the latter, but eyeballing some hydrographic charts, I'd say about half the crossing is in the region of 25 metres deep, with a maximum depth somewhere around 50 metres.

Six sides, in fact: they started by building two artificial islands, then working outwards from those and the land on either side.

With great difficulty. There's a reason I caveated the statement with 'in peacetime'. Really, there are two questions here.

First, is it possible to build a causeway across the Channel? I think yes, though not without difficulty.

Second, is it in any way a sensible invasion plan? Almost certainly not. Building it would be easily disrupted, would telegraph the point of landing years in advance, and it would be a colossal bottleneck. Especially since the shortest route lands you in Britain at the foot of a cliff!

If you have just built a cross-channel causeway, an extra flight of steps or a ladder shouldn't be too difficult.

 

[Dan]

If this were to happen, The Allies would wait until Nazi Germany collapsed under the weight of ineptitude and use the part finished dam as a landing Jetty to liberate France and the Low Countries, then invade Germany.

After the war they would thank the Germans for making the D-Day landings so much easier.

Either that or 633/617 Squadron have a new target for their Grand Slam bombs...