We have been lucky enough to be able to contact Lieutenant José Luis Bernal Sánchez, a Spanish Navy submariner, who has had the opportunity to sail aboard the Italian submarine S-526 Todaro.

Within the excellent relations that the Spanish Navy maintains with the Italian Marina Militare (as an example, we can mention the Joint Spanish-Italian Amphibious Force SIAF) it is common to exchange officers to improve understanding, knowledge, community and interoperability between both allies.

Lt José Luis Bernal at the Italian Tarento naval base with the submarine S-526 Todaro (Picture: José Luis Bernal Sánchez)

In this case, with his posting the aboard the submarine Todaro, Lieutenant José Luis Bernal Sánchez has had the opportunity to live with and share experiences and procedures with fellow Italian submariners, while experiencing first-hand a fifth generation submarine like the U-212A and thus be able to compare it with our own S-80 + (Plus), under the command of our friend Lieutenant Commander Manuel Corral Iranzo.

After contacting with Lt Bernal, we have obtained his permission to reproduce in our blog the present article, written for the excellent Revista General de Marina (the Spanish Navy official magazine), about his experience aboard the S-526 Todaro and how it compares with our own Isaac Peral class. Given how interesting this article is for those of us who follow these topics, we believe that it’s worthy of being shared in our blog.

We in Foro Naval can only thank Lieutenant José Luis Bernal Sánchez for allowing us to reproduce his article on our blog and wish him the greatest successes in his career as a submariner in the Spanish Navy.

The article’s author with his fellow Italian submariners pictures at the officer’s wardroom of the submarine S-526 Todaro (Picture: José Luis Bernal Sánchez)


By Lt. José Luis Bernal Sánchez

Translated by Gorka L. Martínez Mezo

I have to admit that comparisons between different models are more typical of car magazines, but being these two submarines I think it is correct to do it here, in the Revista General de Marina.

Perhaps the reader may think that it’s too early to write this type of article and that it would be more prudent to wait until the S-81 Isaac Peral has sailed her first miles and has submerged her first meters.  However, at the time I write these lines, it is not even 24 hours since I have disembarked from the S-526 Todaro.  It has been 28 days on board and it is now when I have my recollections fresh.  Furthermore, the best is the enemy of the good.

The posting aboard the Todaro has been a magnificent experience, both professional and vital, and it has given me the opportunity to meet the Italian submariners, who have stood out for their kindness, welcoming me as one of the crew.

Comparison between submarines U-212A and S-80 + (Picture: Foro Naval)

Sailing aboard has allowed me to compare three different platforms, the S-70, the U-212A and the S-80, although it is true that the latter only theoretically. Having been able to see the insides of the Type 212 and knowing first-hand those of the S-80 is what has encouraged me to write this article.

Both submarines have similar sonar technology, both are equipped with cylindrical, flank, towed, passive rangefinder and interceptor sonar among others.  Both are fitted with AIP technology, although it is true that the S-80 not at first, but let’s things get their course.  Both have a modern platform control system and a state-of-the-art combat system that includes the latest technology to practice of TMA (Target Motion Analysis) based underwater tactics.

However, there are small but at the same time notable differences that, in my opinion, place the S-80 above the U-212A. The missile launch capability may be the most obvious, but not the only one, although it is true that the U-212As could acquire this capability in future modernizations.

Italian submarine S-526 Todaro at periscope depth as seem from a German P-3C Orion during the Dynamic Manta 2021 NATO ASW exercise, note the green paint used on Italian submarines optimized to operate in the Mediterranean Sea (Picture: José Luis Bernal Sánchez)

No, I am talking about details, some more notable than others, that during my month of navigation have captured my attention and have made me compare both platforms over and over again.  After all, the devil is in the details.

Without further ado, I list them here.


I consider this to be the Achilles heel of the U-212A;  Having only one diesel generator has two very significant drawbacks: the first is that snorkeling takes forever, spending too much time at periscope depth performing noisy operations.  The second drawback is that by having only one diesel they do not have a real back up system;  Indeed, they can use the AIP to propel the ship, but this too is limited.

The U-212A’s AIP technology is based on a chemical reaction based on hydrogen and oxygen.  This provides the submarine with sufficient electrical current to propel the submarine, enough but not in excess.  That is, if for any reason we must increase the speed, the AIP simply cannot by itself and the submarine must consume electricity from mixed sources (AIP and batteries).

This means that, in practice, the U-212A has no real redundancy when charging the batteries. It only has one diesel and if it fails, everything is at the expense of an AIP system that is not capable of generating the same amount of current as the diesel generator. It is still too early to establish the amount of current that the S-80 AIP system will be able to generate, but one thing is clear, the S-80, with three diesel generators, solves with guarantee the two deficiencies raised, both redundancy and current generation capacity, the latter resulting in significantly shorter snorkelling time.

Cutaway of the forthcoming Type 212 Batch ll submarine by researcher H.I. Sutton. The Batch ll kepts the basic power plant (H I Sutton/Covertshores)


As with the diesel generator, they only have one A / C unit.  The way I see it, this is another serious redundancy problem.

During the DYNAMIC MANTA-21 ASW exercises, the condition of maximum silence was established, which lasted for quite some time.  This condition leads to the shutdown of the A /c and the temperature in the CIC rose considerably.  The hotness I went through did nothing but alert me to the temperature that the electronic equipment that surrounded me would be reaching.

The S-80, with thirteen independent air conditioners distributed throughout the ship and a cooling system dedicated to the combat system, also has more than enough redundancy in this regard.

Cutaway of the forthcoming lsaac Peral class submarine by researcher H.I. Sutton. The three Diesel generators will be placed behind the AIP module, to be installed from S-83 on and fitted on S-81/82 during their first major overhaul (H I Sutton/Covertshores)


This has been the first time that I have sailed in a submarine with an integrated combat system and it has meant for me a remarkable change in the way the platform operates.  It has also served to realize that, although the ship has modern tactical forms of representation, in the end a leopard doesn’t change its spots and the submariner tends to look at the sonar and, specifically, the time/bearing trace.

For this reason I think the console layout on the S-80 makes more sense than on the U-212A. In the Italo-German design, the tactical action officer is isolated from the sonar display and must get up from his console to see the time/bearing trace.  In the Spanish design, the TAO is situated between the sonar supervisor and the tactical supervisor;  in this way, you have a perfect knowledge of the surface situation, being able to correlate the tactical information with the sonar information at a glance.

The commander told me on several occasions that in 2025 the ship will undertake its half-life upgrade and this will mean a complete modernization of the combat system. However, the size and shape of the CIC cannot be changed.

German Type 212 submarine U-31 (S-181) on drydock during a maintenance period. We can see some of yhe tanks related to her AIP plant after the outer casing has been removed. The U-31 and the Todaro were both the first units of their class operational with the German and Italian navies. (Source: Internet)


The U-212A has a very limited space for the crew, during the period of my commission we were thirty-one people on board and ten had to hot bunkt. There are only twenty-six bunks and each shift has 12 men, so the submarine is designed to work with two watches (24 on guard and 26 beds available). In my opinion, this is an excessively demanding organization. At the end of the navigation, fatigue was evident on everyone’s faces. In the case of the S-80, the submarine is equipped with 46 bunks and requires 11 men to operate.

This means that going to three watches requires a minimum of 35 people to crew her (33 standing guard, with both the commander and the cook exempt). In short, the ship is designed to sail on three watches, a much less demanding situation than that aboard her Italian colleague. Sleep is a weapon.

Submarine S-81 Isaac Peral waiting to be put afloat at the Navantia covered submarine construction hall at Navantia Cartagena (Diego Quevedo Carmona)


These are the four main differences that I have found between each one and that makes me choose the Spanish design.

Both are excellent vessels: one has 19 years of experience behind it, which makes it a platform with proven capabilities, while the other still has everything to prove and, luckily, her time has come.


Copyright José Luis Bernal Sánchez.
Total or partial reproduction is prohibited without permission or mention of its authors.


  1. I would like to know if the S80 has solved the buoyancy and AIP problems. Our submarines have been sailing for more than 15 years while yours has just left the shipyard.
    Furthermore, the NFS U212 will receive new upgrades in electronics, AIP, communication systems, on-board armament and much so on! We’re a decade ahead of your submarine, at least!

  2. It is already floating, man. And it is way better than the 212 regardless how many upgrades. You can not throw a bigger sonar in an smaller hull.

  3. Bueno Ambos países Tienen Diferentes requerimientos de operatividad El U212 como para un país como Israel que está rodeado de países islámicos Que amenazan a Israel a diario y recordemos La Guerra de los 6 días dónde Rusia Dio aviso a través de su inteligencia que Israel según Hiba a atacar de allí rusia Dio apoyo logístico y Apoyo en las maniobras de ataque, Dicho esto , El submarino se adapta a las necesidades de Israel que es combatir no lejos de su tierra , En cambio España siendo parte de la OTAN Necesita más terreno que abarcar y mucho más distancia a diferentes países para prácticas y maniobras… Dicho esto pues cada país tienen requerimientos muy diferentes… A menos que Israel se un a la OTAN o decida defenderse del control y apoyo Ruso a países islámicos alrededor de Israel y así estar prevenido de su influencia e inicie otra guerra De países islámicos Invadan a Israel… Por los momentos no es necesario submarino de mayor capacidad en distancia ni Otro requerimiento…

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