just been browsing on the web

the Saturn V was made from aluminium, most likely 6061 aluminium alloy?

the nasa site is down thanks to the sanctions on America so I’ve been looking through other stuff

aluminium when cold grows stronger so I’ve read

one thing that has made me think is that they must have somehow designed out the problems that might have come with expansion

uneven expansion would make the frame of the rocket bend like a banana I suspect. concorde used to expand, anyone know where I could look for airframe expansion and how to cure problems with it?

>aluminium when cold grows stronger so I’ve read

That stirs a memory. Cryogenic plants are made from aluminium IIRC.

morrie said:

>aluminium when cold grows stronger so I’ve read

That stirs a memory. Cryogenic plants are made from aluminium IIRC.

Yep. It’s not so much that aluminium gets stronger at low temperatures, just that it retains its ductility better than a lot of other construction metals, whereas steel tends to get rather brittle. However, it depends on the alloy – high nickel steel is still usable at fairly low temps.

OTOH, some metals that aren’t suitable for construction at normal temps become useful at low temps, eg if you make a spring from lead it’s useless at room temp, but it works great at liquid nitrogen temperature.

From http://www.keytometals.com/article23.htm

Aluminum alloys represent a very important class of structural metals for subzero-temperature applications and are used for structural parts for operation at temperatures as low as -270°C.

Below zero, most aluminum alloys show little change in properties; yield and tensile strengths may increase; elongation may decrease slightly; impact strength remains approximately constant. Consequently, aluminum is useful material for many low-temperature applications.

[…]

Retention of toughness also is of major importance for equipment operating at low temperature. Aluminum alloys have no ductile-to-brittle transition;

[…]

Fatigue Strength. Results of axial and flexural fatigue tests at 106 cycles on aluminum alloy specimens at room temperature and at subzero temperatures indicate that, for a fatigue life of 106 cycles, fatigue strength is higher at subzero temperatures than at room temperature for each alloy. This trend is not necessarily valid for the tests at higher stress levels and shorter fatigue lives, but at 106 cycles results are consistent with the effect of subzero temperatures on tensile strength.

PM 2Ring said:

OTOH, some metals that aren’t suitable for construction at normal temps become useful at low temps, eg if you make a spring from lead it’s useless at room temp, but it works great at liquid nitrogen temperature.

Makes one wonder what a super-low temp computer could be built from. Could liquids and gasses be employed as material for hardware?

Don’t forget that a statement like “made of” is very broad; the outer shell, the LOX tank, the LH2 tank, the RP-1 (kerosene) tank, etc.

There are numerous materials used in the construction of the Saturn V.

And of course we have the S-IC stage, the S-II stage, the S-IVB stage, etc. Each was designed according to purpose.

i’m assuming stage 1 had a fuselage made of the same material

i’m wondering how expansion might affect the Saturn V

for example you’d need an equal expansion across the length of it or the Saturn V might bend out of shape mid air

i’m thinking the strings and ribs of the stage 1 held the thing straight regardless of any unequal expansion caused by some sections being cooler than others.

wookiemeister said:

i’m assuming stage 1 had a fuselage made of the same material

To assume makes an ass out of u and me.

Obviousman said:

wookiemeister said:

i’m assuming stage 1 had a fuselage made of the same material

To assume makes an ass out of u and me.

the tanks would be made from something different to be sure

but the frame itself might be made from the same thing all over to keep things simple expansion wise and construction wise

Like I said: to assume….

The stages were made by different contractors. Google is pretty good; look up some sites like Astronautix.com, etc.

Obviousman said:

Like I said: to assume….

The stages were made by different contractors. Google is pretty good; look up some sites like Astronautix.com, etc.

I’ve only ever seen one cutaway of the fuselage and that isn’t that reliable

Astronautix.com

wow, haven’t been to that site for years…had forgot all about it.

A cutaway won’t normally tell you the construction material.

Obviousman said:

A cutaway won’t normally tell you the construction material.

no

I saw something that started talking about 6061 alloy

apparently its an aluminium alloy useful if you need to weld it – which gives some clue about how they might have been putting it together

in the bowling for columbine movie – moore is shown walking around a missile factory for ICBMs

they seem to use a very thin skin of metal – this must be welded onto some underlying frame

I have read somewhere about small missiles being made from aluminium tubes rather than some expensive epoxies

looking through another website it seems aluminium is very strong even with thin walls

the ratio between radius and wall thickness is the deciding factor to how it will bear up under pressure it seems

length / diameter should ideally not exceed 15 or the thing has a tendency to buckle

The Atlas had to be either fuelled or filled with a gas, otherwise it would collapse under its own weight. In fact, some collapsed in flight during early testing; they solved it by the addition of a band around the rocket.

The Atlas was the first US ICBM and was also used during the Mercury missions (the orbital flight, John Glenn onwards).

I’ll see what I can dig up regarding the Saturn and the temperature of the skin. They had to use novel approaches because the propellants (LOX, RP-1, LH2) were at very low temperatures but also very different temperatures.

http://www.wired.co.uk/news/archive/2013-04/16/f-1-moon-rocket/viewall
How Nasa brought the monstrous F-1 ‘moon rocket’ engine back to life

have you read about Jeff Bezos that found one of the engines at the bottom of the ocean and has retrieved one

yeah

Material varied from stage to stage but some of the alloys used in he construction of the Saturn V included:

Aluminium alloy 2014 T6, 2219
Beryllium alloy
Magnesium-lithium alloy
Nickel alloy

I was also thinking about it the other day

the frame/ fuselage of the Saturn V

how was the skin attached to the frame, rivets/ spot welding/ continuous weld?

Give me a while; I’ll look it up.

perhaps you’d want the skin made from the same stuff as the frame OR with the same expansion properties

you could have a situation where the skin was expanding or contracting at odds with the frame?

other thoughts buzzing around my head

I was watching an old film about the engines, the nozzles are moved by what looks like hydraulics, they can be moved up,down, side to side

given the power of the motors perhaps it would be possible to make the north south engines move in one plane and the east west engines move in a plane perpendicular to the other two motors

this way you still control the rocket but the engines are easier to control and don’t need the same level of movement making things expensive ie the engines are hinged on a rod like a door

wookiemeister said:

I was also thinking about it the other day

the frame/ fuselage of the Saturn V

how was the skin attached to the frame, rivets/ spot welding/ continuous weld?

Again, it varied. Some areas were riveted (interstage, skirts), some were welded (bulkheads, tank assemblies). For example, the S-IVB stage:

“With the LOX tank at the bottom of the assembly tower and the LH2 cylinder hanging overhead, workmen heated the base of the LH2 tank cylinder, expanding it slightly. Then the heated cylinder was slipped over the LOX tank, creating a close ‘interference fit’. When cool, the LH2 cylinder and LOX tank presented a minimum gap for welding and enhanced the prospects of a high-quality weld with minimum distortion.”
(STAGES TO SATURN, Roger E. Bilstein, University Press of Florida, 2003)

TIG welding was used extensively. An interesting fact was the conditions for welding: often it was done using environmental conditions less than 25C and 50% humidity. Cleanliness was absolutely essential. On the 366,000 cm of welds made on four S-IC stages, porosity accounted for 79% of weld defects followed by cracks at 9%.

I liked a comment about the cleanliness; when dealing with LOX tanks, oil was an absolute no-no. Even the oil left by a worker’s fingerprints could cause an explosion. The surfaces underwent acid baths and hot air drying to remove any trace of it.

Obviousman said:

I liked a comment about the cleanliness; when dealing with LOX tanks, oil was an absolute no-no. Even the oil left by a worker’s fingerprints could cause an explosion. The surfaces underwent acid baths and hot air drying to remove any trace of it.

I’ve been mildly disturbed about the difference between modern and pre-industrial content the film of oil that is inevitably collected by any object within the Terran atmosphere. The difficulty of removing this from space bound objects being the inspiration for the concern.

Riff-in-Thyme said:

I’ve been mildly disturbed about the difference between modern and pre-industrial content the film of oil that is inevitably collected by any object within the Terran atmosphere. The difficulty of removing this from space bound objects being the inspiration for the concern.

WB&D, obviously.

Riff-in-Thyme said:

Obviousman said:

I liked a comment about the cleanliness; when dealing with LOX tanks, oil was an absolute no-no. Even the oil left by a worker’s fingerprints could cause an explosion. The surfaces underwent acid baths and hot air drying to remove any trace of it.

I’ve been mildly disturbed about the difference between modern and pre-industrial content the film of oil that is inevitably collected by any object within the Terran atmosphere. The difficulty of removing this from space bound objects being the inspiration for the concern.

showering used to be more straightforward

Divine Angel said:

Riff-in-Thyme said:

I’ve been mildly disturbed about the difference between modern and pre-industrial content the film of oil that is inevitably collected by any object within the Terran atmosphere. The difficulty of removing this from space bound objects being the inspiration for the concern.

WB&D, obviously.

Is that safe on sensitive skin?

Here is a link to an online PDF version of Stages to Saturn:

http://apollo.josefsipek.net/Documents/StagesToSaturn-Bilstein.pdf

This is the definitive book about how the Saturn V was constructed.

Will check it out

Will check it out

they used a slip joint to hold the tanks in the frame

one way that comes to mind is that if the diameter of an oxidiser tank reduces due to cooling you could have a joint that allows the tank to slide down on a V shape rail, this would hold it in position for launch