Mystery US Navy "Semi-submersible torpedo craft" circa 1943

[ArmchairSamurai]

Howdy everybody, got a mystery for someone to solve. I found the following images on the history.navy.mil site by chance when doing research for my earlier Shinyo post, made elsewhere. I ended up with a bunch of photos of a mystery US naval craft, that according to the website, is only called "USN boat no. C-25465". The other description for the photos is "semi-submersible torpedo craft". It says the photos are dated to March 1943, and were taken in the Robert Jacob Shipyard, City Island, New York. Thoughts? I have never heard of this craft. It doesn't look like anything I am familiar with. A one off prototype?

https://www.history.navy.mil/our-co...c-series/nh-series/19-N-43000/19-N-43824.html

 

[EurekaBoat]

If I recall correctly, this boat had been on display at the Battleship Cove Museum in Fall River, MA. It had been used in the South Pacific during WWII in support of OSS operations.

 

[ArmchairSamurai]

If I recall correctly, this boat had been on display at the Battleship Cove Museum in Fall River, MA. It had been used in the South Pacific during WWII in support of OSS operations.

That would be fascinating if true

UPDATE: I checked into EurekaBoat's lead, and the boat mentioned at Battleship Cove is a Gimik, which does not resemble the vessel in question.

 

[EurekaBoat]

That would be fascinating if true

UPDATE: I checked into EurekaBoat's lead, and the boat mentioned at Battleship Cove is a Gimik, which does not resemble the vessel in question.

This may have been the earlier variant for OSS/ raider use only. Nevertheless, both are cool parts of history.

 

[ArmchairSamurai]

This may have been the earlier variant for OSS/ raider use only. Nevertheless, both are cool parts of history.

That's a possibility for sure. I'm hoping somebody on here may know what it is, because I am would be curious if they are related.

 

[thanos.massias]

In the off chance this is related:



https://s3.amazonaws.com/NARAprodstorage/lz/dc-metro/rg-080/29716924/M1067-031/M1067-031.pdf (PDF page #1473)
From https://catalog.archives.gov/id/149022215

 

[ArmchairSamurai]

In the off chance this is related:

View attachment 780711

https://s3.amazonaws.com/NARAprodstorage/lz/dc-metro/rg-080/29716924/M1067-031/M1067-031.pdf (PDF page #1473)
From https://catalog.archives.gov/id/149022215

That's interesting. I wonder, if this is the connection, then why not follow through with the design? The concept seems sound to me. They clearly built a whole vessel too, just to cancel?

 

[Grey Havoc]

That's interesting. I wonder, if this is the connection, then why not follow through with the design? The concept seems sound to me. They clearly built a whole vessel too, just to cancel?

Bureaucratic infighting and political maneuvering have killed many a good project.

 

[ArmchairSamurai]

Bureaucratic infighting and political maneuvering have killed many a good project.

I was thinking about the post thanos.massias made earlier, and if that small snippet is connected, then perhaps the cancellation has something to do with the SS Normandie burning in Feb. 1942. Changing priorities made it less viable? Would make sense if the vessel was completed between then and when the photographs were taken. Otherwise my only other theory is it was a lend-lease project that fell through.

 

[DWG]

The

Bureaucratic infighting and political maneuvering have killed many a good project.

And also allowed many a dodgy project to get far further than they deserved (cf Goodall complaining in his diary about having to waste yet more time on Winston's enthusiasm for Habbakuk and Seadromes).

 

[ptdockyard]

This is pictured and mentioned briefly in Friedman's "U.S. Small Combatants: A Design History." It has origins back to the Shearer Submersible MTB of 1918. There is a drawing of the craft in this post on this page:

https://www.naval-history.net/PhotoZHinds.htm
I have photos of the 1918 design which looks nothing like this drawing so there may be more than one in WW1.

My guess is the subject of this post is the 1942 Shearer prototype.

 

[DWG]

why not follow through with the design? The concept seems sound to me. They clearly built a whole vessel too, just to cancel?

You probably wouldn't be able to tell just how bad your situational awareness would be until you built it. Even a periscope would be higher above the water than the operator's eye level, especially when running closed-up. And if it's got any kind of high-speed planing ability the bow is going to completely block the operator's eye-line as soon as it starts to lift.

While there are a couple of semi-comparable designs - the Italian MT/MTMs and the British Boom Patrol Boat, they were all short-range designs designed for special operations, so even if the concept worked you also needed a delivery system. The Japanese Shinyos were different in being a defensive system where the target would come to them.
Operationally, with the majority of PT targets in the Pacific being barge traffic - Daihatsus and the like, the design only featuring torpedoes is a major limitation. The more experienced the PT fleet got, the more they emphasised guns, not torpedoes.

(See also a whole slew of WWII fighter aircraft the US built and then ditched without production orders).

 

[ArmchairSamurai]

This is pictured and mentioned briefly in Friedman's "U.S. Small Combatants: A Design History." It has origins back to the Shearer Submersible MTB of 1918. There is a drawing of the craft in this post on this page:

https://www.naval-history.net/PhotoZHinds.htm
I have photos of the 1918 design which looks nothing like this drawing so there may be more than one in WW1.

My guess is the subject of this post is the 1942 Shearer prototype.

I see what you mean. Thank you. The puzzle pieces may be coming together.

You probably wouldn't be able to tell just how bad your situational awareness would be until you built it. Even a periscope would be higher above the water than the operator's eye level, especially when running closed-up. And if it's got any kind of high-speed planing ability the bow is going to completely block the operator's eye-line as soon as it starts to lift.

While there are a couple of semi-comparable designs - the Italian MT/MTMs and the British Boom Patrol Boat, they were all short-range designs designed for special operations, so even if the concept worked you also needed a delivery system. The Japanese Shinyos were different in being a defensive system where the target would come to them.
Operationally, with the majority of PT targets in the Pacific being barge traffic - Daihatsus and the like, the design only featuring torpedoes is a major limitation. The more experienced the PT fleet got, the more they emphasised guns, not torpedoes.

(See also a whole slew of WWII fighter aircraft the US built and then ditched without production orders).

That's fair. If we go with the theory the vessel is a parasite torpedo boat, only being able to chart around whatever ship it was being carried by, it would be better than nothing, especially for the large convoys traversing the Atlantic. Remember, the Battle of the Atlantic was still contested by this point, and prior to this, was in the Axis' favor; that being said, I don't see what use it would be against a submerged wolf pack as you pointed out with it only being armed with 2 torpedoes. Maybe the German high-seas fleet of WW1 would be more fitting a opponent, but for 1943, perhaps it was too obsolete? Hard to say. It makes even more sense as a lend lease vessel for the British or even the Soviets during 1941-1942. The Arctic Convoy and the Black Sea come to mind for those roles respectively. Of course if you really think about it, we don't even know when this vessel was started in the design phase. Perhaps it was a pre-war vessel and only saw its completion by 1943 due to budget restraint or government oversight. I can see a company investing in a side project beside what the government delegated it to do. It wasn't unheard of then.

 

[DWG]

It makes even more sense as a lend lease vessel for the British or even the Soviets during 1941-1942. The Arctic Convoy and the Black Sea come to mind for those roles respectively.

I read the first sentence and was already going to say it made no sense for North Sea conditions, and then I got to to the second one, and the Arctic Ocean, and just no.

 

[covert_shores]

Gave this fascinating craft the Covert Shores treatment, http://www.hisutton.com/USN-Semi-Submerged-Torpedo-Boat.html

I think that the suggestion that its a Willian B Shearer design, or at least inspired by his earlier designs, is likely. But I have not found any additional info on this 1943 design beyond the original post here.

 

[Antonio]

Covert Shores treatment

Brilliant!

 

[ptdockyard]

Wonderful! Thanks for sharing!

Here is the other images I have on the earlier Shearer boat

 

[ptdockyard]

Shearer did a second boat that was bigger- 58' long- after WW1

 

[ArmchairSamurai]

I read the first sentence and was already going to say it made no sense for North Sea conditions, and then I got to to the second one, and the Arctic Ocean, and just no.

I didn't say it was a good idea haha. I said it just made sense in that role, as a parasite--design shortcomings or not. It may not have been up to par with US standards, and yet so many subpar weapon systems were sold as arms exports back then. As was said earlier in another post, a lot of proposals were cancelled or passed over for something else throughout the entire war, and lend lease could explain the lack of information on the vessel in question. I don't know, so its all up for debate.

 

[covert_shores]

Shearer did a second boat that was bigger- 58' long- after WW1

thanks! Those images are new to me. On the schematic, can you see what the label says in the space above the torpedo at the front?

 

[Torsionbar]

MR.W.SHEARER'S ONE MAN TORPEDO BOAT

 

[Nik]

Similar principle to RN's X-class mini-subs.
Near-unique, high-value targets, a scary-mary delivery system...