It is not the length but the girth in torpedoes

[Platapus]

The Germans, Americans, British, and Japanese submarines all used torpedoes that were the same size in diameter.

533 mm or 21 Inches.

This is a strange number. Not 525 mm or 550 mm but 533 mm. In imperial measurements it is still strange. Not 20 inches or 24 inches but 21 inches.

The Germans had the G7 Series
The British has the MK VIII and MK X
The Americans had the MK X, MK XIV, and MK XVIII
The Japanese had the Type 92 and the Type 95

Now all the counties’ torpedoes were different lengths but all has the same odd diameter.

Any idea why four different countries (there were actually more that used the 533 mm torpedo) who were developing individual submarine models that really did not have much in common, would all use the same odd diameter torpedo?

I don’t think there were any common components shared by these countries so that eliminates that as a reason.

Where there any shared industrial gigs or dies used by all four countries that would account for all the common submarine torpedoes to be not only the same diameter but to have the diameter to be a “strange” number 533 mm/21 Inch?

Are torpedoes 533 mm in diameter because that was the limitation of the capability to build a torpedo tube?

Or are torpedoes tubes 533 mm in diameter because that was the most efficient size for a torpedo?

Is there an optimum diameter for torpedoes?

Inquiring minds want to know

[Rockin Robbins]

that there's not an optimum diameter for torpedoes because air dropped and ship launched American torpedoes had different diameters. That still leaves a mystery. Did the Germans plan on capturing superior American submarines and using them against the coutry of their origin?

Were the British going to ally with the Germans and have compatible torpedoes? Were they all taught to make torpedoes by the same advanced extraterrestrial life form? And what about Mary Lou?

Edit: hey man, those space aliens do get around. I found a list of the world's torpedoes and although there are many torpedoes that are not 21" or 533mm, the US, UK, Holland, USSR, China, Germany, Japan, and Sweden all use or have used that diameter torpedo! I am sure there are probably others and we could plot the course of the flying saucer around the world. This is truly bizarre!

[Slateford-5]

I'm no expert on this by any means, but is it not likely that the marine physics people of the belligirents did a water resistance vs speed vs payload calculation and came up with roughly the same answer?

[Platapus]

Originally Posted by Slateford-5

I'm no expert on this by any means, but is it not likely that the marine physics people of the belligirents did a water resistance vs speed vs payload calculation and came up with roughly the same answer?

Good question.

Is a 533 mm torpedo efficient with respect to water resistance? Is water resistance solely defined by diameter? I think parasitic drag is also effected by length.

Does anyone have any references that cite any such marine physics testing?

Considering all the bonehead mistakes all four countries made (although each country eventually changed their torpedo designs with the Americans bringing up the rear), I kinda doubt that this much thought went in to the design of the torpedoes with respect to the diameter.

Was this a treaty issue? Washington Naval Treaty does not make torpedo size restrictions but was there another treaty that did designate a diameter restriction?

This is starting to drive me nuts

[AVGWarhawk]

Originally Posted by Slateford-5

I'm no expert on this by any means, but is it not likely that the marine physics people of the belligirents did a water resistance vs speed vs payload calculation and came up with roughly the same answer?

I think Slateford has a darn good theory here. It is odd that all countries have the same diameter. The fleet boats was probably standardized for all tubes in the boats and probably the other countries as well. But, for all to the same diameter?:hmm:

Here is something that will make your head spin:

http://www.sciencedirect.com/science...fa5688d888fe71

[Mush Martin]

I think if we dig into it it will turn out to be that 21" and 18"
(which just to confuse things more was 17.7") were probably
started as British torpedo's that enjoyed some distribution
and as torpedo manufacture came along to be marketable
then the new torp would be more cost effective if it fit
into an existing tube.

(This was only speculation)
M

[Keelbuster]

Really interesting observation. And mysterious. On a sillier note, i was always wondering why they didn't build a _really big_ torpedo - like a BB buster - one big bastard - a tactical nuke

[Amiral Crapaud]

Originally Posted by Keelbuster

Really interesting observation. And mysterious. On a sillier note, i was always wondering why they didn't build a _really big_ torpedo - like a BB buster - one big bastard - a tactical nuke

Because you need the tube to fire it, and this tube would be unable to fire anything else ^^

But don't worry, after the war, as soon as they found a way to miniaturize nuclear warheads, they did put them into torpedoes (and everything else, including artillery shells, depth charges and air to air missiles...). The Soviets were especially fond of that kind of torpedoes - remember that the original Shkval, to compensate for its inaccuracy, was supposed to be nuke-fitted, so that the attacker firing the first torpedo wouldn't have a chance to avoid the backfiring blast...

[Subnuts]

Originally Posted by Keelbuster

Really interesting observation. And mysterious. On a sillier note, i was always wondering why they didn't build a _really big_ torpedo - like a BB buster - one big bastard - a tactical nuke

The original design for the Russian November-class SSN would have carried a single giant nuclear torpedo, 1550 mm in diameter and 77 feet long.

[Keelbuster]

Originally Posted by Subnuts

The original design for the Russian November-class SSN would have carried a single giant nuclear torpedo, 1550 mm in diameter and 77 feet long.

- now that's what i'm talking about! But perhaps squeeze in a tube or two for regular service torpedoes. I just wish sometimes in SH3, that I could lauch a sure-fire BB buster - one that _will_ crack her armour...

[Sailor Steve]

Here's another monkey wrench in the works, World War I torpedoes came in three sizes:

British: 18", 21", and 24" (which was the size Nelson and Rodney carried)

German: 45cm (17.7"), 50cm (19.7"), and 60cm (23.6")

Go figure.

[bookworm_020]

I believe the reason for the difference in torpedoe sizes came down ti the fact that aircraft couldn't carry the larger torpedo due to weight restritions, still hapens today in that the ASW torpedo is smaller than the Mk 48 or similar.

The reson for the early varation in sizes is due to limitations in propulion and space reqirements in early subs (smaller torpedo means smaller tube and less space to carry them in) As they became more advanced they grew (as did the submarine) and gained a bigger warhead to cope with bigger , more heavly armored targets.

The Russians do have a 650mm tube in their newer subs

http://en.wikipedia.org/wiki/Type_65_torpedo