03 June 2011

A little Zeppelin for the fans

Just not Robert, John, John Paul, and Jimmy.

I read an interesting piece on the US Navy's fleet of zeppelins, which were used in the 1920s and 1930s.















There were four dirigible airships in the fleet: USS Shenandoah, USS Los Angeles, USS Akron, and USS Macon.

As a review: a dirigible generally has an internal structure that the skin is attached to, where a blimp doesn't have much of a structure, more like a balloon.

Germany and Britain flirted with airships as recon platforms and bombers during World War I, with what I would consider mixed results. Dirigibles didn't seem to have a long lifespan. Although they could outclimb the fighters of the day, they were slower, much larger, and filled with very flammable hydrogen for a lift gas. After the war, Britain pursued other avenues of aviation, while Germany concentrated on passenger airships. We all know how that ended-the Hindenburg explosion at NAS Lakehurst in 1937.

It would appear from reading the article in Naval History and the editor's note that the chief of Naval Aviation, Admiral Moffett, used the airships as much as a way to collect scarce postwar and Depression-era defense dollars for the Navy than in any belief in the airship as the weapon platform of the future. The Navy zeppelins crisscrossed the country, hovering over fairs and parades and visiting cities and towns of all sizes, showing the capabilities of the service and no doubt enticing more than a few souls to sign up for a chance at adventure in the skies.

And adventure is what airship crews had, because the vessels were not easy to handle on the ground or in the air. Tie a balloon to a pole and put it out on a windy day. Watch it flop around. Airships handle much the same way, as shown below:






















There were several instances of sailors being hurt or killed when securing airships as they pitched up in a wind gust, and also of damage to the airship when a downdraft slammed a moored ship to the ground. The United States used nonflammable helium as the lift gas for its airship fleet, so at least there were no colossal explosions or fires aboard any of the vessels.

The US Navy generally used zeppelins in a military role as long-range scout platforms during the various Fleet Problems of the 1930s. They were moderately successful at this-airships can loiter for long periods at slow speeds and were capable of shadowing the battlefleet, at least as long as the opposing fleet didn't have access to aircraft of their own.

It wasn't long before someone thought of giving the airships the ability to launch and recover small planes to act as auxiliary scouts and for protection. Germany first performed this task, launching a plane from the Hindenburg on two occasions (not counting the work of a certain archaeologist-adventurer and his father).

USS Akron and sister USS Macon both had facilities to carry 4 F9 Sparrowhawk fighters, using a trapeze and conveyor mechanism for launch and retrieval. The fighters were equipped with a large hook on top of the wing to latch onto the trapeze. The whole process must have looked similar to modern-day aircraft doing in-flight refueling, which is a fair feat of airmanship for all concerned.






























Impressive work. But the airships were in the end too accident-prone and vulnerable to other aircraft and even the vagaries of weather, in addition to being very expensive to build and maintain, to survive as military platforms. Three of the four Navy airships met tragic ends. Shenandoah first flew in 1923 but was caught in a squall over Ohio and torn apart in 1925. Akron was launched in 1931, only to crash off the New Jersey coast in 1933, killing 73 of the 76 aboard, including Admiral Moffett, the airships' main proponent. Macon was launched in 1933 and crashed in 1935, losing a fin in wind shear and crshing in Monterey Bay, California. Only Los Angeles had a long career, being commissioned in 1924 and decommissioned, struck, and dismantled in 1939.

That was the end of the Navy's zeppelin fleet. However, the Navy also was developing several non-rigid airship (blimp) classes, and the blimps would go on to perform yeoman service in World War II as anti-submarine patrol and search and rescue craft, where their low speed and long loiter time would prove to be advantageous-and they were kept away from significant air opposition. Blimps served the Navy as radar pickets well into the 1950s, so it seems the lighter-than-air program wasn't a complete waste of time and resources-just that the more simply-constructed blimps proved to be more capable platforms for their given missions than the expensive zeppelins.

So ends the story of the Navy's lighter-than-air ships-an interesting era in aviation.

What?

You want to hear some Zeppelin? But I want to hear some country music. Looks like a compromise is in order here.

yankeedog out.

2 comments:

  1. Here is a story about the Navy's blimp base in Miami you will never forget: http://gcrm.org/naspage.aspx#pagetop

    Signed, Jon

    ReplyDelete