20,000 ton cruiser sub proposal from 1920 ...

[Captain Canada]

It's intended to fully submerge this beast ? I thought it was just a low rider...makes sense tho, it you're going to have the multiple pressure hulls.

[sandiego89]

Any conventional sub, whether it be diesel or boiler(steam), needs through hull fittings for a variety of purposes: air induction, exhaust, raw water intake, cooling water discharge, sewage, torpedos, etc.  Most of these must be secured for submerged operations, and be robust enough to withstand the pressue at operating depth. Even Nuclear submarines need through hull fittings.

The real critcal valve, at least for diesel boats was the main induction valve, a mushroom shaped valve that allowed the diesels to run.  Now our beastie here would require a huge number of valves, tanks and openings.  Likely many more air trunks, valves etc.  The "Christmas tree" showing when the boat was properly rigged for drive would be immense. A plumbing nightmare.

The turrets and guns further complicate watertight integrity.   

My thoughts on Weavers musings:

1.  She would take some time to rig for dive.  You can have quick acting valves, but this beast would have numerous valves. The level of autotamtion in the period was limited.  Many may require manual activation.  The amout of air you need to vent/water you need to take on to submerge is large.  You don't want to make the vents too large as you want good control over the ballast exchange rate.  Don't want to sink like a rock.  Hardly a "crash dive".

2. Handling would be poor.  Large subs had a repuatation as poor manuevering boats.  Constant fussing over balance, trim etc.  Poor directional control in all three axis.  Very slow to respond to directional, trim and speed adjustments.  Limited power over a large mass.  Small control surfaces.  I can not tell from the drawing what type of diving planes she was envisioned to have, only the rudder which is very small.   

3. A steam plant could be secured, like a diesel plant, but as per #1 the scale and number of valves on this one would present huge challenges.  US boats like the Gato class had only one main induction valve and a smallish number of hatches and main ballast tanks, compared to our "cruiser" here. 

I'd call her a white elephant.       

   

[Weaver]

As a fully qualified pedant (graduate of the Fat Hamster school of pedentry) I feel it my duty to point out that nuclear submarines use steam to turn their turbines.

Show me one with funnels though...

[zenrat]

A mere detail...

[ptdockyard]

The only steam subs to see service were the British K class which were notoriously problematic

On the contrary the French operated a number in WW1. The Germans had a huge U-cruiser with steam propulsion, the Projekt 50, under construction in 1918. The Italians had a steam design that had 2-twin 6" turrets in 1929.


The US had a number of contemporary designs along  with this one, carrying everything from 8-8" guns to half a dozen planes.

Dave G
The PT Dockyard

[ptdockyard]

I make a 1/1200 model of this one too

[NARSES2]

One of the club stands at Southern had a nice selection of these cruiser subs on display 

[ysi_maniac]

http://bernews.com/2013/05/new-theory-on-sub-lost-after-leaving-bermuda/
What is this ship?

[zenrat]

https://en.wikipedia.org/wiki/French_submarine_Surcouf

[ysi_maniac]

But turret and bow's shape are different.

[proditor]

Yup, the top picture is the Lorelei from a Japanese live action movie. It looks a lot like the Surcouf, but isn't.

The movie is gloriously over the top btw.

http://www.amazon.com/Lorelei-Witch-Pacific-English-version/dp/B00IFYMFKQ

You can even see the different turret shape in on the cover of the DVD.

[PR19_Kit]

The top picture in the Bernews has a raked bow, whereas the Surcouf has a straight one, the top pic is MILES shorter than the Surcouf, which was immensely long.

Not only are the gun turrets different but the directors are too. And to cap it all the one in the top pic doesn't have a hanger aft of the conning tower either.

Apart from that they're the same of course.............