WesWorld

So as some of my stories with Kirk have indicated, Thailand will be aquiering the ability to outfit subs with snorkels in 1942. I have been looking into refitting most of my existing subs with them in addition to the subs that will be equipped with them from the start (laydown in 1942). I was wondering what section of the refit rules that adding snorkels to an existing sub would fall under. Talking with Bruce and Shin on IRC yelded three opptions, but more are welcome.

Option 1: Major Refit under the "Changes to superstructure (i.e. lengthening or widening a deck, adding a deck house): P" clause. This option assumes that internal alterations to both the coning tower and the hull are minimal, so the changes amount to mainly external.

Option 2: Partial Reconstruction under the "Replacement of superstructure: P" clause. This option still assumes that the interior hull alterations are minimal, but that the coning tower needs to be completely reconstructed to accommodate the changes.

Option 3: Partial Reconstruction under the "Replacement of superstructure: P" and "Change to powerplant (type and output): D" clauses. The assumption here is that the current ventilation system of the hull is completely inadequate for use, and therefor needs to be completely replaced.

Acorting to Conways 1922-45, several Type VIIB and Type VIIC subs were fitted with snorkels later in the war. This leads me to the oppinion that major alterations to the hull itself were not required outside of the coning tower, so Options 1 and 2 seem the most logical to me.

Any thoughts on this?

I wouldn't rule out a Level 2/Minor Refit, myself.

The question is of great interest to me since my French and Chilean submarines were theoretically snorkel-equipped when built, but I never really stated that IC or even really decided if I was going to push that line. So if I decided they weren't delivered with snorkels, then they'll be "designed for but not fitted with", as the saying goes, and a refit ought to be simple and cheap.

Might I propose that once we've determined the correct refit level for snorkels that we add it to the list?

makes sense to me, but I see lumping it in with the superstructure portion of the rules to be an easier way to go.

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Originally posted by snip
makes sense to me, but I see lumping it in with the superstructure portion of the rules to be an easier way to go.

Regardless of what category we determine that it fits in, then we ought to set that in stone in the rules.

I agree

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Originally posted by Brockpaine

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Originally posted by snip
makes sense to me, but I see lumping it in with the superstructure portion of the rules to be an easier way to go.

Regardless of what category we determine that it fits in, then we ought to set that in stone in the rules.

On the dutch Subs it's a superstructure feature which folds down into the casement as historical. While I presume there is fitting through the pressure hull, I expect it may be the same one they use when running engines surfaces, so superstructure refit seems reasonable there.

For the Dutch they are specified in the subs Misc weight. I probably asked iif the amount of weight seemed reasonable waaaay back when I previewed the O-5 Subs for 1934, OTL @2007.

mutters about foriegn subs with schnorkels

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Originally posted by Kaiser Kirk
mutters about foriegn subs with schnorkels

Eh? What's that? Stop muttering!

I'm amnible to making it a Major Refit, IF it is realized that dive depth is limited by some number (75% of orginal?) on refits, since the addition of a new snorkal would weaken the pressure hull of the submarine.

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Originally posted by TexanCowboy
I'm amnible to making it a Major Refit, IF it is realized that dive depth is limited by some number (75% of orginal?) on refits, since the addition of a new snorkal would weaken the pressure hull of the submarine.

Please cite specific historical evidence of this.

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Originally posted by TexanCowboy
I'm amnible to making it a Major Refit, IF it is realized that dive depth is limited by some number (75% of orginal?) on refits, since the addition of a new snorkal would weaken the pressure hull of the submarine.

Is there some hard data to back up that assertion? I realize that at first glance it might seem so, but I'd be interested in the thought process behind it.

I presume that the main induction (the air intake used by a surfaced submarine) would be the point of entry for the air mast. The superstructure for the telescoping mast would, I think, sit above the main induction and be sealed by the devices that close and secure the main induction itself. It that line of thinking is correct, the pressure hull is not compromised. I could, of course, be wrong.

Well, from what I think would happen, the point of entry of the new telescoping mast would be a fairly large hole that the submarine was not designed for. As it enters the submarine, the hole created is now a "void" in the pressure hull, and despite anything that occurs, the pressure hull will not be as strong as it was formerly, because of the addition of new materials. Of course, I might be on a completely wrong track here...

I can't really cite examples, because I don't think a scenario like this happened in OTL.

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Originally posted by TexanCowboy
Well, from what I think would happen, the point of entry of the new telescoping mast would be a fairly large hole that the submarine was not designed for. As it enters the submarine, the hole created is now a "void" in the pressure hull, and despite anything that occurs, the pressure hull will not be as strong as it was formerly, because of the addition of new materials. Of course, I might be on a completely wrong track here...

I can't really cite examples, because I don't think a scenario like this happened in OTL.

The Germans refitted snorkels on a large number of their boats late in WWII. Perhaps you could start there and move on to the GUPPY refits and the British installation of "snorts" on the Amphions and the T-boats?

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Originally posted by TexanCowboy
Well, from what I think would happen, the point of entry of the new telescoping mast would be a fairly large hole that the submarine was not designed for.

The main induction on a submarine is a large existing hole in the pressure hull; no 'new hole' is required. The mast itself would be external to the pressure hull and the pressure hull sealed by the existing main induction valve.

Since numerous types of submarines - German, American, British, were retrofitted with air masts there is no significant problem with the refit itself.

so no take on any of the options for possible costs for these?

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Originally posted by snip
so no take on any of the options for possible costs for these?

The Level 3 refit's really the highest I see as plausible.

Option 1 seems the best to me.

Using the same air intakes etc wouldn't pose a problem and the addition of the actual snort tube (if its a fold-flat type) shouldn't be any more troublesome than fitting a light mast. Afterall its only a steel tube with a float valve at one end, won't weight too much. Internally I guess the fans might need upgrading and some kind of float valve added into the system as a double-sfaegaurd to stop the engines taking in water.

I won't pretend to know anything about snorkel conversions, but for simplicity sake, I'd say number 1 seems the more likely. I, with a limited search granted, can't find any indication that the entire sail was replaced on any of the subs that had snorkels added later.

So it seem that the first option is the most poplar. I propose to make that the rule regarding snorkel conversions