Spanish Submarines too heavy

[August]

http://www.stripes.com/news/navy/conn-company-gets-contract-to-help-lighten-spanish-sub-1.224531

By Jennifer McDermott

Published: June 5, 2013

GROTON, Conn. — The first of the Spanish Navy’s four new submarines is too heavy and Electric Boat has been asked to help.
The U.S. Navy hired Electric Boat as the contractor for a foreign military sales agreement with the Spanish Ministry of Defence, in support of the Spanish Navy, according to a statement the U.S. Naval Sea Systems Command issued Monday.
The agreement is worth up to $14 million, an official at the Embassy of Spain who is familiar with the contract said. EB will provide technical assistance and review the S-80 Submarine project for almost three years, the official added.
The S-80 Submarine is Spain’s first submarine design. According to Spanish press reports, the S-81 Isaac Peral, the first member of the class, is at least 75 tons overweight. The diesel-electric submarine weighs 2,400 tons submerged and the excess weight could prevent it from surfacing after it dives.

[Subnuts]

Would be more surprised if a brand-new piece of military hardware came out of the factory under weight.

[Mr Quatro]

America should purchase the S-81 to protect the Great Lakes
due to no salt water it would be lighter.

Didn't WWII boats have a problem submerging in the Great Lakes, I think so

[AndyJWest]

We already have a thread on this: http://www.subsim.com/radioroom/showthread.php?t=204621

[August]

Didn't make much of a splash over there. Probably won't here either.

[TorpX]

America should purchase the S-81 to protect the Great Lakes
due to no salt water it would be lighter.

Didn't WWII boats have a problem submerging in the Great Lakes, I think so
In fresh water it would be less buoyant.



However, 75 tons is only 3%; that doesn't seem like a fatal margin to me.

... the excess weight could prevent it from surfacing after it dives.
This seems exaggerated. Unless the problem is worse than they admit.

[Stealhead]

Mr Quatro is thinking of the Manitowoc Shipyard on Lake Michigan they built some of the Gato and Baolos there.The Navy would run their acceptance trials on Lake Michigan.These subs where never inteded to patrol the great lakes they just where built there.

According to "The Fleet Submarine in the US Navy" in order to compensate for the lower density of fresh water they where ballasted.In other words they added weight that of course would later be removed.That was done because they where trying to simulate the higher deisty of sea water without having to change the performance of all the pumps.If a sub where designed for fresh water it would need faster pumps.

Manitowoc boats where the best finished boats of any yard that made subs during WWII.That was due to worker pride and craftsmanship or really craftswomanship because most Manitowoc workers where women.

[Catfish]

Maybe they subconsciously built them that way, so the new spanish fleet can have a good look at the old spanish armada ?
:O:

[August]

Maybe they subconsciously built them that way, so the new spanish fleet can have a good look at the old spanish armada ?
:O:


Reminds me of the screen doors on Italian submarines (or so I've heard).

[Mr Quatro]

Reminds me of the screen doors on Italian submarines (or so I've heard).

I thought it was the Turkish navy that had dived with the hatches open on an old framII boat we gave them, but instead I came up with three German U-boats scuttled in 1944.

http://www.divernet.com/home_diving_news/156013/black_sea_uboats_found.html

Six submarines of the 30th Flotilla were transported some 2000 miles by river and, partially dismantled, by road from Kiel to the Romanian Black Sea port of Constanta, to prey on Russian shipping.

From 1942, the U-boats wreaked havoc, sinking many ships but losing half of their own number to Russian defences. U19, U20 and U23 were the Flotilla's three remaining subs when, in August 1944, Romania changed its allegiance and joined the Allies, declaring war on Germany.

The subs could not get out through the Dardanelles or the Bosphorus, due to Turkey's neutrality. Their crews had no choice but to scuttle their vessels, before attempting to make their way back to Germany overland. They were all captured and interned by the Turkish military.

Undamaged due to the nature of their sinking, the U-boats promise to be well-preserved examples of their genre. With no loss of life, there will be no moral question over any decision to enter the wrecks.

I knew that Steelhead ... I was at work and didn't have time to explain ... whoops! there's the boss lady ... gotta go

[Spiced_Rum]

Surely once the Spanish crew are on board all the methane gas they produce from eating hot spicey food will create some positive buoyancy.:06:

[August]

Surely once the Spanish crew are on board all the methane gas they produce from eating hot spicey food will create some positive buoyancy.:06:

That's sorta how the German U-boats were able to go below crush depth so often and survive. Clouds of sauerkraut farts increased the interior air pressure so much that it made the hull stiffer. :yep:

[sidslotm]

I can't help but think that this type of metal engineering in Europe is by and large is on the decline, well in the UK it certainly is. 75 tonnes over weight is not an error, this should have been picked up at the design stage on the Cadam long before building ever started, something fishy going on. I know when I worked on the shop floor, drawings where changed in mid production to hide drawing room errors, it was not unknown for this to happen at night when metal workers had gone home only to return in the morning only to find a dimension had changed and the build was wrong.

It's now seems to be accepted that the errors is Astutes design where down to Admiralty changes during the building process. One of my favorite quotes by guitar builder Jim Burns sums it up well for me, "we will carry on building mass produced one offs" seems to sum engineering in the UK quite well, lol. When a Nation starts loosing it's engineering skills, they take years to replace.

[Betonov]

Don't get me started on mid production and late production design changes :/\\!!

And they always arrive on fridays and they always have to be done by monday :/\\!!

[Spiced_Rum]

I love it when engineers do not factor in all the extra weight necessary for all the cables required by the systems. I think that Embraer had a similar problem a few years back when one of their aircraft was found to be too heavy to fly after it had been fitted to match the US specifications. They had not calculated wiring weight, and so lost the multi-million dollar contract.