Re: Diesel aircraft engines

From:         jbarrett@indirect.com (John Meyer)
Organization: Internet Direct
Date:         03 Sep 96 01:17:00 
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Gerard Foley <gfoley@freenet.columbus.oh.us> wrote:

>   The first thought is to ask why not the hydrogen.
Using the lifting gas as fuel for the engines would have an effect on
the weight and balance of the ship, effectively making it heavier as the
flight progressed. This would have to be compensated for by dropping
ballast. The fuel used was a gas resembling propane called BLAUGAS. This
weighed roughly the same as air, so as it was consumed it had no effect
on the weight of the ship. The HINDENBURG carried roughly a million
cubic feet of this stuff. The engines were V-12 Diesels made by
Daimler-Benz specifically for airship use.

In a previous post it was stated that weight was a minor consideration
in airship design; the opposite is true! Airship designers (except for
the R101 team) were obsessed with keeping everything as light as
possible, including the engines.

> The second thought is that they might have hoped for helium sometime
> if the political situation
> cooled or they won the war.  The third thought is could Graf Zeppelin and
> and Hindenburg float with helium?
The Graf Zeppelin was designed to use hydrogen, but could probably have
flown with helium. It wouldn't have been able to carry much of a useful
load, however, as helium has less lifting capacity than hydrogen. The
Hindenburg was designed specifically for helium, hence it's much larger
size and gas capacity. Negotiations were underway to obtain helium from
the Americans, but the Navy nixed the deal for political and military
reasons. The Germans felt that hydrogen was safe if handled properly,
which they had done for decades. When it became clear they could not get
helium, the Hindenburg's designers added some extra passenger cabins
since the ship's payload was better with hydrogen.
>
>   The Germans, of course, built the only rigid dirigibles (save one,
> R101) did not suffer an inflight structural failure.  The Los
> Angeles flew ok with helium, but maybe it was designed for it.
It's hard to say what would have happened if the big German ships had
been flown directly into squalls the way the Akron and Macon were. The
Macon had suffered damage to its ventral fin in a ground handling
accident, and it was not adequately repaired before its fatal crash. The
Akron and Macon were the most advanced dirigibles ever built. The
Germans stayed with more conservative design for the Hindenburg and her
sister ship, the LZ130 Graf Zeppelin II.
>
>   If people on the thread don't remember, Nevile Shute (Norway)
> was one of the design team for R101 and in a book on it insisted
> it was done right.  It didn't have much chance to prove it.
Nevile Shute was part of the Vickers team which built the R100. He
worked under Barnes Wallis, the brilliant engineer who designed (among
other things) the Wellington bomber with its geodetic structure, and the
special bombs used by the Lancaster "Dam-Busters." The R100 was a
well-designed ship, but was grounded and scrapped after the crash of
it's badly designed competitor, the R101.
>
>   I went to Lakehurst to see the arrival of the Graf Zeppelin on its
> first transatlantic crossing.  What a traffic jam there was getting
> back to Philadelphia that evening!
What I wouldn't give to see what you have seen! I wish one of these
billionares with time on his hands would take a serious interest in
rigid airships....Richard Branson, are you listening??

John Meyer