shuttle LOX line vs Saturn V LOX lines

How is it that the Shuttle can pump sufficient LOX through one long line
(140 feet?), which apparently has at least a few near-90-degree bends in it,
while the S-V had to run five huge lines, maybe 50 feet long each, straight
through the RP1 tank to the engines? It must have been a tremendous PITA to
get those tank pentrations, tunnels, bellows, etc, all worked out and
manufactured. Is it just a matter of the huge difference in flow rates
between the two vehicles? Why wouldn't one giant line, the size of a
Redstone tank, say, draining into a big sump in the S-IC's thrust structure
have sufficed? Would boost pumps in the sump have been the only way to make
that work?

J

"Mr Jim" wrote in
:

How is it that the Shuttle can pump sufficient LOX through one long
line (140 feet?), which apparently has at least a few near-90-degree
bends in it, while the S-V had to run five huge lines, maybe 50 feet
long each, straight through the RP1 tank to the engines? It must have
been a tremendous PITA to get those tank pentrations, tunnels,
bellows, etc, all worked out and manufactured. Is it just a matter of
the huge difference in flow rates between the two vehicles? Why
wouldn't one giant line, the size of a Redstone tank, say, draining
into a big sump in the S-IC's thrust structure have sufficed? Would
boost pumps in the sump have been the only way to make that work?

Take a good look at how the Russian N-1 moon rocket handled it.
The lines, and there were many more of them, were all external.

--Damon

Damon Hill wrote:

Take a good look at how the Russian N-1 moon rocket handled it.
The lines, and there were many more of them, were all external.


That was a complete mess of a way to handle it, but they were limited by
having the kerosene on top in the first three stages; running plumbing
through the LOX tank meant the pipes would have chilled during fueling
to the point where the kerosene would have frozen when it passed through
them: http://www.astronautix.com/graphics/n/n1cut.gif

Pat

In article ,
Mr Jim wrote:
How is it that the Shuttle can pump sufficient LOX through one long line
(140 feet?), which apparently has at least a few near-90-degree bends in it,
while the S-V had to run five huge lines, maybe 50 feet long each, straight
through the RP1 tank to the engines?

Well, it wasn't a question of "had to" -- rarely are alternative designs
*impossible*. Mostly you get to choose which headaches you prefer. :-)
It's a mistake to infer that the designs actually put into service are
somehow optimal; in fact, sometimes it's more a case of "it seemed like a
good idea at the time...".

In this case, some of it was differences in requirements. The Saturn V
had much higher flow rates to support far higher engine thrust, and very
little room under the kerosene tank. While the shuttle had a requirement
for a joint at which the plumbing could cleanly separate... a joint that
had to be covered by mission-critical doors in a surface exposed to high
heating on reentry. So the S-IC designers had major incentive to provide
the simplest and most direct flow path to five voracious engines, while
the orbiter designers urgently wanted to minimize the width and complexity
of the connection to the ET.

...Why wouldn't one giant line, the size of a
Redstone tank, say, draining into a big sump in the S-IC's thrust structure
have sufficed? Would boost pumps in the sump have been the only way to make
that work?

Something like that might well have been necessary, given that the S-IC's
designers rejected even going around the outside of the kerosene tank as
difficult for those flow rates.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

"Damon Hill" wrote in message
31...

Take a good look at how the Russian N-1 moon rocket handled it.
The lines, and there were many more of them, were all external.

I'd rather not look at the N-1 - too much of mess :-)

Mr Jim wrote:

I'd rather not look at the N-1 - too much of mess :-)


Makes a fascinating model though, all girders and bumps; looks like some
sort of Marxist lighthouse more than a rocket:
http://www.ninfinger.org/~sven/models/realspace/n1.html

Pat