PDA

View Full Version : airborne machine shop



aostling
09-15-2007, 11:31 PM
The recent post about the USS Macon and its squadron of five Sparrowhawk fighters makes me wonder about the repair facility inside the dirigible. http://bbs.homeshopmachinist.net/showthread.php?t=25552&highlight=macon

Imagine you were a chief in the 1930s Navy, asked to stock this imaginary on-board machine shop. What would you choose? Light weight, of course, is critical.

What would you select for machine tools? A valve grinder?

IOWOLF
09-16-2007, 07:20 AM
Oh Yea a valve grinder, with all that Hydrogen .

How did we end up with this guy, Just lucky I guess.:rolleyes:

Your Old Dog
09-16-2007, 07:28 AM
A Sawzall
leather gloves
Duct tape
coat hanger
pliers
screwdriver
clean floor to work on
tube of LanacaneTotal expense: $185.00

Tube of leak detector: priceless

Bmyers
09-16-2007, 07:29 AM
IOWolf, Last time i looked, the Navy used Helium.

A.K. Boomer
09-16-2007, 08:17 AM
If I were in charge of the machinery department Id go to Evan and have him build me up an aluminum mill like the one he's got, like weight and should do the trick:)

Doc Nickel
09-16-2007, 08:30 AM
A machine shop would have been considered superfluous on an airship.

Oceangoing ships have them because they often have just one or possibly two engines, and one can't exactly row the ship to shore. The Macon had what, a dozen engines, and the loss of even most of them would not adversely affect the safety of the ship. (Well, assuming it wasn't being fired at. :D)

A zeppelin with no engines is in trouble, yes, but can still land in an emergency by simply venting gas. (Being out over the ocean would be a different matter, of course.)

But suffice it to say that with fairly minimal cargo capacity (by weight, anyway) a machine shop would be largely unneccesary deadweight. The Hindenburg used a great deal of aluminum fixtures, and went to extensive lengths to save weight, such as using simple stretched canvas as cabin and passenger walls.

Now, that said, I could see a small combination machine or 3-in-1, perhaps even special-made with aluminum castings rather than iron, but certainly not much more than that.

Doc.

A.K. Boomer
09-16-2007, 09:04 AM
How many of you guys seen that documentory on the Kee-bird? that was really amazing, there was what i think was a B-24 consolidated liberator that had to be set down in wartime close to the artic or anartic or some cold ass place, it sat for decades frozen half under ice and then a millionaire desided to go free it up and get it home, he had some workhorse of a plane with much tooling, Im pretty sure it had a little machine shop on board, they go through many many pains including flying engines in and out to get rebuilt, it took years because thier window of work time was only a month or two out of the year, His mechanic died due to an illness in the harsh environment, then the day came and they had cleared a runway in the snow, it was a bumpy runway and while the plane was taxying the onboard generator in the back of it spilled fuel and caught on fire, the entire plane burnt to the ground and the ice reclaimed the rebuilt engines and all ------- that show broke my heart, they almost had it and were pressed for weather cond. --- it was either going to sit for another year or they had to rush it --- they rushed it...

rollin45
09-16-2007, 09:21 AM
Not that it makes any difference, but it was a B 29, and you are right about it being a heartbreaker !

rollin'

IOWOLF
09-16-2007, 09:35 AM
IOWolf, Last time i looked, the Navy used Helium.


(With the lowest bow)

I stand corrected !:o

A.K. Boomer
09-16-2007, 09:40 AM
Not that it makes any difference, but it was a B 29, and you are right about it being a heartbreaker !

rollin'


I knew i might have been off on that, something jogs my mind about a split/twin tail in that show and I wonder now if it was the rescue plane or if I just totally slipped a cog:o

Evan
09-16-2007, 10:30 AM
A machine shop would have been considered superfluous on an airship.
Don't count on it.

This is the Russian K7, circa 1930:
http://vts.bc.ca/pics2/k7.jpg


This was the first aircraft design allowing mechanics in-flight access to running engines.
http://www.pilotfriend.com/photo_albums/potty/8.htm

I am quite sure they would have had some sort of maintenance support on such an airship as the Macon.

reality checker
09-16-2007, 12:28 PM
I know this is kind of thread hijack but... I saw the The Kee-Bird documentry and it is the saddest thing I have ever seen. I can sit thru something like ole yeller or where the red fern grows with no real emotion. To see an effort as over the top as the men involved in that project gave (including the death of one of the principle people) and to have it end so badly because of a small problem killed me.

A strap over the loose component could have made the effort sucessful.

They got it on film, the airplane being consumed by fire and being a total loss was so shocking to me that I dwelled on it for some time. I tried to talk to people I work with, but either they did not see it or thought it was no big deal.

I knew that a certian few others must have been hit by it as hard as I was, I guess those people live here. There should have been a warning in the beginning like CAUTION IF YOU ARE SENSITIVE TO DESTRUCTION OF FINE MACHINERY AFTER MONUMENTAL EFFORT TO SAVE IT DO NOT WATCH THIS DOCUMENTRY

Your Old Dog
09-16-2007, 12:57 PM
I know this is an odd turn on the direction of this thread but here goes.

I also felt is was a sad affair. But it offered a redeeming quality in television as having the ability to do "real" reality programming and not the hyped op crap of "they only got 7 days to build this ___________ before it has to be displayed, they ran out of coffee, will they be able to get it done in time?"

It was a sad story to be sure but he we are talking all about it. That's not a bad memorial to the fellow who died and his crew who worked so hard and failed due to a time and a bad decision.

IOWOLF
09-16-2007, 02:37 PM
To make a good thread out of a bad one.

Wasn't there a similar event in Iceland or Greenland, But more successful ?

Doc Nickel
09-16-2007, 05:18 PM
Don't count on it.

I am quite sure they would have had some sort of maintenance support on such an airship as the Macon.

-I don't doubt it in the least. On the Hindenburg, each engine had a full-time mechanic (or perhaps each pair of engines?) and was easily accessible from the central walkways. Supposedly passengers were shown them as part of an in-flight tour.

And one presumes that, if the engines had mechanics in regular attendance, that they had a supply of parts and tools with which to perform maintnence.

However, there's a difference between a decent, well-stocked toolbox full of hand tools, and a roomful of machine tools; the former would probably see regular use, the latter would likely be rarely used, and would thus be largely unnecessary dead weight.

Ditto your example- yes, the engines might have been accessible, and able to be worked on in-flight, but it's still an airplane. They're not going to carry around even a small mill and lathe "just in case".

Doc.

bigbill04
09-17-2007, 01:27 PM
"Wasn't there a similar event in Iceland or Greenland, But more successful?"[/QUOTE] Quote from IOWOLF

IOWOLF. I remember seeing two stories on cable tv about retrieving a P38 and a B29 from the North. I did a very quick Google search and came up with a couple of results:

http://www.eaa.org/communications/eaanews/pr/050510_glacier_girl.html
This is the one about the P38.which has now been totally restored and flying.

http://www.blockbuster.com/catalog/movieDetails/142511#readMore
This is about the Nova show that showed the entire operation including the plane's burning on takeoff. I actually cried when I watched that.

These two planes are the rarest of the rare. You would think that there would have been a lot more around since so many were made. Later. Bill Senko

Weston Bye
09-17-2007, 02:10 PM
Not an airborne machine shop, but Floyd Yoder (worked years for my Grandad) was disinclined to bail out of the bomber when a landing gear failed to lower. He was a mechanic on board, and rather than bail out he opened a panel and crawled out into the wing with a hand pump, connected up to the landing gear and manually pumped the gear down and locked. Landed safely.

The movie Flyboys has a short scene where the crew of a German WW1 bomber was adding oil to the engine in flight. Hollywood?
The flying scenes were fun to watch, but the planes were not authentic - no rotary engines.

pcarpenter
09-17-2007, 04:23 PM
I would choose a parachute:D

Yeah....I can see it now...."Hey...we're going down! Quick! Machine us a replacement part" Ahhhhh haaaahaaa haaa....my sides hurt. :D Its an AIRship...but the comparison to a real ship is a bit of a stretch. Oceangoing vessels may be gone for weeks or months at a time with no contact with land. You can replace most of the mechanical parts from within the ship...or send out a diver. By definition you can't do that with a blimp.

Yeah...I think the repair shop was probably a roll of duct tape and some silk for patches etc.:D

Paul

Doc Nickel
09-18-2007, 12:58 AM
You can replace most of the mechanical parts from within the ship...or send out a diver. By definition you can't do that with a blimp.

-A blimp, no. But you can in a Zeppelin.

The Zeppelins were a rigid framework and tensioned, but not sealed, skin, that contained seperate gasbags. A blimp is basically all gasbag that the gondola is hung from.

The primary passenger accomodations on the Hindenburg were actually inside the body of the ship- the "gondola" hanging below was basically just the control cabin/cockpit.

You could walk the length of the ship in one of two walkways- a centered "axial" one, and one at the "belly", from which you could reach any of the engines, the cargo holds, and all the passenger accomodations.

In fact, the book I have on it notes each trip involved twelve mechanics; one rode in each engine gondola, in shifts, for the entire trip. (Four engines, three shifts a day.) The article suggests they throttled the engines manually, taking direction from an annunciator, rather than the engines being controlled directly from the control cockpit.

Theoretically, each engine could almost certainly be shut down individually (more likely in pairs) for anything more than routine maintnence, and the Hindenburg had a pretty phenomenal cargo capacity (the last flight carried thirteen tons of mail alone) but they also spent a great deal of effort making the entire craft as light as possible.

The book- it's actually an illustrated book for older kids- shows quite a few interior photos, and almost every spar or strut, including those of some chairs, is drilled or punched to reduce weight. Walls, as I said earlier, are often not much more than stretched canvas.

So they could, indeed, have carried machine tools, if necessary- they did have a custom-made, reduced-size, aluminum-bodied Baby Grand piano that weighed under 400lb, but it was left off for transoceanic flights. But again, I wager they'd have been seen as superfluous and wasted dead weight.

Doc.

aostling
09-18-2007, 01:58 AM
So they could, indeed, have carried machine tools, if necessary- they did have a custom-made, reduced-size, aluminum-bodied Baby Grand piano that weighed under 400lb, but it was left off for transoceanic flights. But again, I wager they'd have been seen as superfluous and wasted dead weight.
Doc.

Doc,

You've hit on the theme I was hoping this thread would inspire: the problem of excess weight in our machine tools. BadDog just shifted his new Wilton drill press, and plans on shifting it regularly. A peripatetic (wandering?) lifestyle is the lot of many of us, and it is a royal pain to have to shift 800 pounds if the same tool could have been built at 500 pounds and retained all of its effectiveness. That is the challenge.

Doc Nickel
09-18-2007, 02:50 AM
Well, in most cases, weight is directly connected to rigidity, and rigidity is directly related to accuracy.

Bigger, stronger castings also allow bigger depth-of-cuts, and so on.

It's a trade-off; yes, you can make a fairly lightweight machine that gets most of it's support from triangulated braces rather than large castings, but it simply will not have the same rigidity or vibration dampening, and will be forced to take smaller, lighter cuts.

That costs more time, among other things.

I made some stainless parts that required a 5/8" through-hole in 2-1/2" of 1" round 304. With my little 10" Logan, I had to step-drill in at least five, maybe six steps. Borrowing a larger 15" Colchester, I was able to do it in three- spot drill, bore with a 3/16", then bore to 5/8" in one pass. Horsepower aside, I don't think the chuck or tailstock on the Logan could have taken that abuse.

And really, machine tools aren't supposed to be moved. They can be, and are, and some have even been designed specifically to haul around, but really, they're meant to be installed in a workspace, bolted to the floor, and then spend the next twenty years making chips.

A 500-pound drill press is no easier to move than an 800-pound drill press. It'll really only be a difference in how deep a crater it makes if you knock it over.

Besides which, if his is a 20" 800-pound drill press, a 500-pound drill press would simply be a 15" or 16" version of the same machine. My Griz mill weighs 2,000 pounds. If I wanted a 700-pound mill, I'd have a mill-drill.

You're not going to get a 500-pound 9x39" R-8 2HP mill that has any real rigidity, that's just the way things work.

Doc.