What if the submarine cruiser Surcouf hadn't been lost in 1942 ?

F.L.

F.L.

ACCESS: Top Secret
Joined
21 September 2022
Messages
1,337
Reaction score
1,831
Website
twitter.com
As a big fan of the French submarine Surcouf, I wonder what would have happened if he had fought in WWII and survived the war.

My two questions are:
What impact would this have had on the Pacific War ?
And what would have been his post-war service? How can we modernize it so that it can serve as long as possible ?

When he set off on the journey that would prove fatal, the Besson MB-411 seaplane remained in England. If it had reached the Pacific, which aircraft could have replaced it ?
And after the war ? In the 45/55 (propeller plane) period and beyond (jet or helicopter) ?
Free French Navy Surcouf (17P) in Canada (1941).jpg
Surcouf with MB-411 on deck.png
 
Last edited:
Alas, it was old and a bit cranky and clunky. BUT in FTL (France Fights On, POD June 1940: Pétain blows an aneurysm, Reynaud - De Gaulle faction prevails, France Fights On from Algiers) we did all kind of interesting things with Surcouf. Such as shelling Tokyo in parallel with the Doolittle raid. Commando raids in the Pacific.

Now it has been translated in english (at least partially). Check that !
 
Yes, but it was a one-shot ship, kinda prototype or even demonstrator with lots of unsolved issues. That only got worse after 1940 - OTL, not FTL.
 
Ah, sorry: uchronia gobbledygook.

O T L : Our Time Line. The one we are living in.

P O D : Point Of Divergence. When writting an uchronia: the moment when an event happens differently.

Which creates F T L / F F O : the divergent timeline. Where in June 1940 a set of events have the Reynaud / De Gaulle faction, willing to carry on the fight from London or Algiers: prevailing over Pétain. No armstice, there will be a Vichy France (not in vichy) of collaborators - but much diminished.

Long story short: Paul Reynaud on June 16, 1940 threw the towel to Pétain because two defeatists were manipulating him and keeping the De Gaulle faction at arm length. We took care of these two people in a car crash early June (June 6, exactly). They were: Reynaud close (defeatist and armistice groupie) advisor Paul de Villelume and... his mistress, Countess Hélène de Portes. She literally had Reynaud by the testicles, and she wanted armistice uber alles. Vive la France. We Princess-Diana-ed her on a car wreck, not too far away from the Alma tunnel, incidentally...

From mid-June 1940 instead of the shame of the armstice and collaboration, France Fights On. Part of the remaining army will slow down the germans until August 8, 1940 - near the Spanish border.

Meanwhile everything but the kitchen sink will be moved across the mediterranean: to AFN (French North Africa). The government, the industry the weapons the gendarmerie, the SNCF, Air France, La Poste ... whatever can be put on a boat or a plane, will get moved.
What cannot be moved will get dynamited or burned.

The Wermacht can no longer be stopped and they will found collaborators - but nothing else.

The whole thing has been wargamed and yes - it was doable.
 
Last edited:
I asked a similar question on another forum once. I'd have to assume that Surcouf's slow time to dive would make it very vulnerable if caught on the surface by enemy aircraft, and I'd have to assume she is rather sluggish underwater due to the large size. On the other hand the IJN were lacking in ASW capabilities and they rarely had enough escort craft or destroyers devoted to the task of protecting shipping.
If somehow she survived to the late war where some USN submarines were being fit with two 5"/25 deck guns for the sole purpose of engaging transports those 8" guns could ruin the day of even the largest merchant vessel.
 
I have a feeling that, if its service had continued into the Cold War, that perhaps the turret would have been replaced by a couple of nuclear missiles and a control room? Idk, this is an interesting counterfactual though
 
I think the aircraft hangar could have been extended in the style of the I-400s.
Perhaps a catapult could also have been installed.

But are there any WW2 seaplanes that can be adapted to enter the hangar ?
 
F.L. said:
As a big fan of the French submarine Surcouf, I wonder what would have happened if he had fought in WWII and survived the war.

My two big questions are:
What impact would this have had on the Pacific War ?
Click to expand...
Well, Japan was really hurting for ASW (despite the US losing 1 out of 6 submarines during WW2!)

So if Surcouf was still available in 1944 and 45, the big guns would have been good for chewing up any merchant ships found.


F.L. said:
And what would have been his post-war service? How can we modernize it so that it can serve as long as possible ?

When he set off on the journey that would prove fatal, the Besson MB-411 seaplane remained in England. If it had reached the Pacific, which aircraft could have replaced it ?
And after the war ? In the 45/55 (propeller plane) period and beyond (jet or helicopter) ?
Click to expand...
I'm not sure that any 1930s designed submarine would have been kept in service post-war.

I'd guess that one of the US floatplanes would have been made to fit into the hangar, even if it mean making a larger hangar to stuff an OS2U Kingfisher or SC Seahawk into.

After the war, definitely a helicopter.


F.L. said:
How could the dive time be improved ?
Click to expand...
With bigger ballast tank vents and a much larger negative trim tank. Pretty heavy modifications.

Negative Trim is to make the ship heavier than normal to pull it off the surface in a crash dive. Once underwater, the negative trim tank gets blown overboard until it's at a pre-specified level, to get the sub close to neutrally buoyant.


F.L. said:
I think the aircraft hangar could have been extended in the style of the I-400s.
Perhaps a catapult could also have been installed.

But are there any WW2 seaplanes that can be adapted to enter the hangar ?
Click to expand...
I think it'd take a significant rebuild of the hangar, into something that an OS2U could fit inside.
 
Desertfox said:
Loon or even Regulus perhaps?
Click to expand...
Depends on what you want to do with that boat.

If you get rid of the gun turret, then yes I'd load it with Loons or Regulus.

If you keep the gun turret, then you want a helicopter or maybe just an autogyro or kite.
 
These seaplanes would be interesting to embark on the Surcouf for observations missions :
Supermarine Walrus has folding wings, and maybe disassembled, it will fit in the hangar.
Supermarine_Walrus_Argentine_Navy_(4446497743).jpg

The Curtiss SOC Seagull floatplane also looks good in terms of dimensions.
Curtiss_Seagull_SOC-1.jpg

Peharps also Sikorsky R-4, after 1943.
proxy-image.jpg


I don't think the Kingfisher has folding wings, so it would be difficult to fit it into the Surcouf hangar.
 
Last edited:
Most likely she would be used mainly as supply submarine, and - maybe - underwater monitor to shell Japanese island bases at night. Post-war, it would most likely be used as training and experimental submarine. Quite probable that the 8-inch guns would be removed, and launch system for V-1 flying bombs would be installed.
F.L. said:
I think the aircraft hangar could have been extended in the style of the I-400s.
Perhaps a catapult could also have been installed.

But are there any WW2 seaplanes that can be adapted to enter the hangar ?
Click to expand...
French Navy already wanted to replace Sucrouf scout plane with helicopter (version of Dorand G.20) pre-war.
 
Last edited:
As a one-off and unusual sub I think it would be used in one-off and unusual missions. I think the Raid on Makin Island that used 6" gunned subs amd Marine raiders is a good example of what Sorcouf would be used for.
 
Scott Kenny said:
How do they fit into the hangars below decks, then?
Click to expand...
From what I've read so far, all OS2Us carried by US cruisers and battleships were stored on their catapults, or between catapults, above decks.
The Northampton-class heavy cruisers had hangars for up to 4 floatplanes, but those had to have folding wings - like the Curtiss SOC Seagull, the type that was replaced by the OS2U Kingfisher.
Cruisers of the US Navy by Stefan Terzibaschitsch, Arms and Armour Press 1988, has an image of USS Chester, with a caption that says 'Note the Kingfisher scouts on both the catapults; only aircraft with folding wings could be accomodated in the two hangars'.
 
Arjen said:
From what I've read so far, all OS2Us carried by US cruisers and battleships were stored on their catapults, or between catapults, above decks.
The Northampton-class heavy cruisers had hangars for up to 4 floatplanes, but those had to have folding wings - like the Curtiss SOC Seagull, the type that was replaced by the OS2U Kingfisher.
Cruisers of the US Navy by Stefan Terzibaschitsch, Arms and Armour Press 1988, has an image of USS Chester, with a caption that says 'Note the Kingfisher scouts on both the catapults; only aircraft with folding wings could be accomodated in the two hangars'.
Click to expand...

Not to drag things off topic, but the OS (observation-scout) types, like the Kingfisher had fixed wings, and were intended for the battleships, or types without hangars. The SO (scout-observation) types, like the SOC Seagull, came with folding wings and were intended for cruisers equipped with hangars. The failure of the Curtiss SO3C Seamew and its Ranger engine threw US shipboard aircraft into chaos. OS2U Kingfishers wound up serving on cruisers, as you point out, and the SOC Seagulls were in use well past their 'best by' date. Curtiss fortunately redeemed themselves with the excellent SC Seahawk capable of both roles and requiring a crew of only the pilot.

I highly recommend Battleship and Cruiser Aircraft of the US Navy, 1910 - 1949 by William Larkin:


It's an excellent work on the topic, with an incredible number of interesting photographs.

Regards,
 
Last edited:
The Supermarine Seagull would have been very interesting for after war, but it's far too big.
And that means redesigning the hangar. What's more, the Seagull was never put into production, but perhaps a French version could have been developed.
Although a helicopter remains the most probable.
5-2.jpg
 
Last edited:
1Big Rich said:
Not to drag things off topic, but the OS (observation-scout) types, like the Kingfisher had fixed wings, and were intended for the battleships, or types without hangars. The SO (scout-observation) types, like the SOC Seagull, came with folding wings and were intended for cruisers equipped with hangars. The failure of the Curtiss SO3C Seamew and its Ranger engine threw US shipboard aircraft into chaos. OS2U Kingfishers wound up serving on cruisers, as you point out, and the SOC Seagulls were in use well past their 'best by' date. Curtiss fortunately redeemed themselves with the excellent SC Seahawk capable of both roles and requiring a crew of only the pilot.

I highly recommend Battleship and Cruiser Aircraft of the US Navy, 1910 - 1949 by William Larkin:


It's an excellent work on the topic, with an incredible number of interesting photographs.

Regards,
Click to expand...
Thanks!

Okay, so an SC Seahawk for the late WW2 and pre helicopter observer, not a Kingfisher.
 
I can't imagine that she would not be decommissioned right after WWII. She would be all too vulnerable to the the ASW capabilities developed during the course of the war and still being improved after. The French Navy didn't have the manpower and money they would like to have had so she'd be high up on the retirement list.
Maybe she could do some work showing the flag and colonial policing but a surface ship would do that job better.
 
Colonial-Marine said:
I can't imagine that she would not be decommissioned right after WWII
Click to expand...
Maybe not outright decomissioned, but turned into training and research vessel. Her great size, large internal space and weight reserves (by removing main guns) made her quite good as testbed for new weapons and equipment. France got very interested in missiles after WW2, and Surcouf would be excellent platform for, say, V-1 launch experiments.
 
The Curtiss SO3C Seamew seems a good candidate to replace the MB.411 in 1942, if the Surcouf had arrived in the Pacific.
If the central float can be disassembled, I think it could fit in the hangar.
SO3C.JPG
 
It was a dog to fly - one reason the OS2U Kingfisher got the nod.
 
Curtiss really turned to absolute shit those days. Hopefully Boeing will never get THAT low. Only Brewster did worse.
 
F.L. said:
The Curtiss SO3C Seamew seems a good candidate to replace the MB.411 in 1942, if the Surcouf had arrived in the Pacific.
If the central float can be disassembled, I think it could fit in the hangar.
Click to expand...

I think the Edo XOSE-1 would be a better candidate, but it didn't come along until late in the war, and didn't fly until after the war was over. Nice piece on the plane with some great photos here:

plane-encyclopedia.com

Edo XOSE-1

The XOSE-1 was an observation float plane built by the Edo float company during World War II and was intended to be a possible replacement for the OS2U Kingfisher. Before being built, the type seem…
plane-encyclopedia.com plane-encyclopedia.com

Regards,
 
Dilandu said:
Maybe not outright decomissioned, but turned into training and research vessel. Her great size, large internal space and weight reserves (by removing main guns) made her quite good as testbed for new weapons and equipment. France got very interested in missiles after WW2, and Surcouf would be excellent platform for, say, V-1 launch experiments.
Click to expand...
Okay, I can see her sticking around for that.
 

Similar threads

Back
Top Bottom