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Zeppelin Design: Umberto Nobile and the Italian N-1 Airship
From: Columbia University
| By:
Kenneth LeishColumbia University Oral History Research Office |
EDITOR'S INTRODUCTION |
Airships used by the Italians during World War I were easy to shoot down because they were slow and flew only 12,000 feet off the ground, according to Umberto Nobile, an Italian aeronautical engineer. In this excerpt of a 1960 interview conducted by Kenneth Leish on behalf of Columbia University's Oral History Research Office, Nobile explains why the German airships were more successful, and how his post-World War I Italian N-1 airship imitated the best of German designs with one major difference: a streamlined tail. |
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| Umberto Nobile describes the Italian N-1 airship. | |
Question: How did you first become interested in lighter-than-air aviation, or in aviation at all? What was your first interest? |
Umberto Nobile: It was about 50 years ago, half a century ago. |
Nobile: 1910, yes--1909, 1910. Then I began. I began here in Rome. |
Nobile: I started to follow a course of lectures on aeronautical structures. |
Q: What made you take that course? |
Nobile: It was the Army Department. |
Nobile: No, I was not in the Army, but I applied and I found that the work lasted about one year. |
Q: Mostly about airships or planes, or aeronautics in general? |
Nobile: Aeronautics in general. However, I decided to take an interest in airships. I was appointed to come to Rome by the Army Department and then I worked in the establishment of the Constructione Aeronautical--that means an aeronautical military factory. At that I stayed for many, many years, till 1929. |
Q: Do you remember your first flight in an airship, the first time you went up in one? |
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| The Graf Zeppelin lands at Lakehurst, after a record 5000-mile non-stop flight from Germany. | |
Nobile: Oh yes, I remember it. It was a very nice impression. It was the airship M-1, I suppose. It was a military airship of a very old type, but I was very much interested, very pleased, yes. |
Q: How was that one so very different from the later models? |
Nobile: Oh, there is a great difference. The Airship Type N was altogether different because the Airship N had a different hull from the nose to the tail. In these old types there was the inner cell, containing the crew, and the engine was suspended by ropes to the envelope. It was a very old type; the spindle was very low, the consummation was rather high. |
Nobile: Oh, not over 65 kilometers an hour, while the Airship Type N-1 and N-2 and N-3, and the N-5, could reach 115 kilometers an hour. |
Q: You were concerned with building airships? |
Nobile: With building airships, and later on I was concerned with flying--with flying the airships I built by myself. |
Q: Can you tell me a bit about how Italy used airships in the First World War? Did they use airships in the First World War? |
Nobile: Yes, they used them for bombardment. They were used by the Army. The Navy used them for exploration for submarines, but not very much. Most of them were used for bombing, while the other type, the old M type and the P type, were the two types used during the war. Several of them were destroyed. |
Q: Would you say that the airships were successful for war use, or were they too expensive, too easy to hit? |
Nobile: Too easy targets, even then. No, I don't suggest that they were very useful for bombardment, these types of airships. In Germany they used zeppelins for bombardment, but they were flying very high and they were more successful in bombing. |
I remember during the last year of the war, one zeppelin came over Rome and proceeded to Naples, and bombarded Naples. |
Q: Did it do much damage? |
Nobile: Not so much. Only military objectives--arsenals, harbors. Yes, only military objectives. Not much damage. It was flying very high. It was about 15,000 feet. |
Q: But the Italian ships could not go that high? |
Nobile: Not so high. They could reach certainly 4,000 meters. Four thousand meters--that means 12,000 feet. |
Q: Did you do any piloting during the war? Flying? |
Nobile: No, not piloting. Flying, yes, all right, but piloting I started after the war, between the First World War and the Second World War. I started about in 1920, 1921--then I started piloting. |
Q: The airship Roma was one that you had designed, was it not? |
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| The airship Roma. | |
Nobile: Yes, we had designed it. It was my idea, but we designed it--three people. I worked with Uselli, with Crocco and with Pissone, but it was built under my supervision here in the factory in Rome, and two times I was director of this factory. |
Q: You were director and the Roma was your idea, really? |
Nobile: The first idea was mine. |
Q: Can you tell me what this new idea was? |
Nobile: It was to increase the speed, by installing six motors, six engines, and by having a keel, tubing--steel tube keel going all along from one end to the other end. And the pilot cabin was attached to it, to this keel, and the engines, the motors, were also attached. There was quite a difference from the previous types. |
Q: These were the first ones that didn't have the engines hanging? |
Nobile: Yes. From Type P, Type M was completely different. We made several flights near Rome, and on one of these flights participated the American ambassador, Robert Johnson Underwood. He was a poet. He wrote a beautiful poem about this flight--I have it. |
We flew over Naples, around Capri and so forth. It was a nice trip, a trial trip. We went on several trial trips. They were successful, but when the Roma was dismantled and transported to America they changed the engines there. They put on Liberty engines; I do believe that these Liberty engines increased the speed. |
You know, during the trial flights in America, just by accident, it was destroyed. It was an unlucky circumstance that the airship met this high-tension wire. Otherwise nothing would ever have destroyed it. |
Q: The US government bought the ship from you, is that right? |
Nobile: Oh, no. The government bought it here. The US Army bought this airship from the Italian government. |
Q: In other words, you were working for the Italian government. It was not private? |
Nobile: Oh, no. The construction was made by the Italian government under my direction. The project was the project of three people. I did the designing. |
Q: Could you tell me, between 1921 and before the time you started the North Pole flights, what kind of things were you doing? |
Nobile: I was director of this factory, where we built many airships, and also other aeronautical equipment. It was then, from 1919 till 1922, that we built airships for the Argentine Navy, the Spanish Navy and for the American Navy. We built some new types of airships. They were small ones. |
Q: What were the new developments--the new kind of thing--between 1920 and 1925? What were the new developments you were working on? |
Nobile: My aim was just to reach the same characteristics of the German zeppelins. I mean, just the same--almost the same speed and almost the same consummation of gasoline at a given speed. They were very expensive, the old types, and we were successful because time by time we would change it. |
First of all, I modified the tail completely. Till then, it was made with a fault. It was a kind of cellular, just like an airplane--just like a spoletta on the tail. It was the very worst point, from the structural point of view. Then I decided it should be on the order of the German Essex--fins on the envelope. |
Q: We were talking about the period following World War I, and I asked you how the N-1 differed from the M series. What was new about the N? And you were telling me that one of the things was the tail, that previously it had been like an airplane's. |
Nobile: Yes. The older types of airships, they had a stiff keel, stiffening it by some frames of tubing, not joints of superficial frame, which were suspended by the ropes. The control cabin, which included also the engines, this type was obsolete. It was used very much during the First World War, but it was obsolete in many ways. First of all, the efficiency was very low and the speed was very low, on account of all those ropes--suspension ropes--which offered resistance to the air. |
Now, the airship which I did--the series, one after another--they were improving the type little by little. I first started with a small airship of about 5,000 cubic meters, then I went to the M-1, which was about 19,000 cubic meters. Before M-1, as I told you about, the dirigible Roma was called the 18-M in our shops--it was "T-34": Thirty-four because, more or less, the useful lift of this airship was 34 tons. |
I had the idea to abolish this stiffening of the envelope, substituting triangular tubing frame--triangular. This triangular frame was connected up with the engine in the pauling, which we called the carapace. Anyhow, this was the first improvement introduced with this airship T-34 that was named Roma and that was sold to the American Navy, American Army. |
Then I made one step towards the perfecting of this airship, and this perfection concerned the tail, with the very old obsolete type of tail surfaces before, for directing the airship in the original plan as well as vertically. It was a very inconvenient form of tails. I abolished it. I wanted to change the type of tail, which was already used in the German types and zeppelin types: the cruciform, in the shape of a crucifix, a cross. |
This indeed was a very important improvement. As a result, the N-1, the first airship of this type, was called the N-1. It was excellent. They were even superior, the speed was more--it was about 150 kilometers--so it was a good shape of airship. But the N-1, as it was, was the first example of this new type. It was rather heavy, because I had to utilize the material that I already had at my disposal in the shops. I could not choose the most suitable material, so it was rather heavy. |
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