Any interesting CATO stories? [Archive]

CTRockets

28th January 2009, 02:49 PM

I think many people her would have a CATO story or two. One where you think everything will go off without a hitch only to ddiscover that 5 feet off the launch pad things go horribly wrong.

My first and only CATO was when I was 11 years old, and I take complete and utter responsibility for what happened. I had built a Big Bertha rocket (the first of many Big Bertha Rockets I have flown) and set it up for launch in a football field behind a local high school. I pressed the launch button and it went about 4 feet and The engine lodged in the middle of the rcket and blew out the side of the rocket which was on fire for a few seconds. I found that I had not glued the motor mount in the Bertha proprly causing it to dislodge and get caught in the middle of the rocket. Needless to say I have learned from that mistake.

Anyone want to share their stories?

Mike

shreadvector

28th January 2009, 02:54 PM

:rolleyes: Here we go again....

Cato is not an acronym. It is simply a slang shorthand abbreviation for catastrophic failure. Discussed endlessly in other threads on the previous TRF and recently on YORF where numerous rolcketry old timers supported this fact and others refused to accept the truth.

http://forums.rocketshoppe.com/showthread.php?t=4411

I would suggest fixing this thread and taking any and all discussion of the beleif in the false acronym over to that thread on YORF. [comment removed w/ consent] :D;)

jadebox

28th January 2009, 05:39 PM

[comment removed w/ consent]

-- Roger

Der Red Max

28th January 2009, 05:46 PM

:rolleyes: Here we go again....

Cato is not an acronym.

Not only that, but he doesn't even describe a Cato. His engine/motor didn't fail, his motor mount failed!

shreadvector

28th January 2009, 05:49 PM

Not only that, but he doesn't even describe a Cato. His engine/motor didn't fail, his motor mount failed!

Well, motors can cato and entire rocket systems can also cato since it is a catastrophic failure. Of course, we are usually using the slang term to identify a failure that has the motor as the root cause.

I'm enjoying a 44 ounce cup of BRAWNDO right now.

http://en.wikipedia.org/wiki/Idiocracy

Der Red Max

28th January 2009, 05:57 PM

Well, motors can cato and entire rocket systems can also cato since it is a catastrophic failure. I stand corrected.
I'm enjoying a 44 ounce cup of BRAWNDO right now. Not bad, but I think a 44 ounce cup of BRANDY might make for a better break.

CTRockets

28th January 2009, 06:01 PM

Sorry, Im new here. Didnt mean to cause any controversy. I should have looked in other forums before posting.

jadebox

28th January 2009, 06:02 PM

Anyone want to share their stories?

I've had a few memorable CATOs that I'd like to forget. :-)

Once, I had a run of bad luck. First, my Shadow clone (http://www.payloadbay.com/article-from-the-ashes-a-shadow-reborn.html) was incinerated on the pad. The motor failed, burning from the top. Not too long after that, another motor failed blowing the head off my Akavish (http://www.payloadbay.com/gallery/v/other/winternationals-2007/2007-01-27+Winternationals+Launch+388.jpg.html).

http://www.payloadbay.com/gallery/d/10317-2/2007-01-27+Winternationals+Launch+388.jpg

The UFO you see flying away is a 1/4" plywood bulkhead that was blown out of the top of the rocket.

Later, our larger "Akavish" also suffered a problem with a motor. In this case, the J motor over-pressurized at ignition shooting off the rear enclosure and firing the motor up through two 1/4" centering rings and the top of the rocket.

http://www.payloadbay.com/gallery/d/25482-2/2008-06-14-00173.jpg

A short video of the event is at:

http://www.payloadbay.com/video-7934.html

-- Roger

Der Red Max

28th January 2009, 06:11 PM

Sorry, Im new here. Didnt mean to cause any controversy. I should have looked in other forums before posting. No need to apologize, that's what forums are for - to learn from others. Some use it to inform, others to disseminate ignorance. You sound as if you're part of those wanting to know what's correct. We need more like you, welcome aboard!

CTRockets

28th January 2009, 06:14 PM

Thanks. I see things as learning experiences. Im glad I found this board. Seems like a great place to learn from others.:)

shreadvector

28th January 2009, 06:24 PM

Cool. We love questions.

And don't forget that when you have a motor malfunction, notify the manufacturer AND the NAR.

The NAR uses the M.E.S.S. to see if there are any failure trends and identify potential problems with specific motors or production batches. The manufacturers will do the same AND they will replace your defective motor (and sometimes the rocket if it was damaged).

http://www.nar.org/NARmessform.html

http://www.nar.org/2009/01/electronic_rocketeer_january_2.php

MysticalRockets

28th January 2009, 06:43 PM

Don't have any photos, unfortunately.

My first reload. A 29mm F40. I put the delay in wrong. I put the spacer end pointing out instead of in.

Yeah, forward closure failure. Went up about 100 feet and turned into a flaming ruin. Did get the nosecone and one fin back. Got most of the case back too. Just needed another forward closure.

But it looked great. Flaming death. Loved it.

Johnly

28th January 2009, 06:52 PM

I remember a Delta Clipper flight where the D12-0 booster CATOed on the pad, but the upper stage motor lit and the upper half had a nominal flight.

John

REAPER

28th January 2009, 07:10 PM

jadebox

28th January 2009, 07:15 PM

Thanks. I see things as learning experiences. Im glad I found this board. Seems like a great place to learn from others.:)

There are a few [comment removed w/ consent] who will insist otherwise, but you were not wrong to use "CATO" as an acronym. Lots of people use it that way and it's no more or less correct that using "cato." Undoubtably, the use of "cato" pre-dates "CATO," but that doesn't make it more correct.

http://www.google.com/search?hl=en&q=CATO+catastrophe+at+take+off

-- Roger

Der Red Max

28th January 2009, 07:24 PM

but that doesn't make it more correct. "more correct"? - Either something IS correct or it ISN'T.

BsSmith

28th January 2009, 07:35 PM

Back when I was about 9, I was still a little scared of rockets still. My dad had old estes kits, a Seastike D, and an Omega. It was before we knew how to tape the motors together, so the rockets would go up on the first stage and the second stages would never light. We spent tons of time replacing the body tubes after every lawn dart.

About a year later, we had just gotten an estes orange plastic rocket, I forgot the name. It launched on the little 1/4 A's. So we had it on the pad, and it exploded when we tried to launch it. It split in half and a 6" wide fireball flew out of it, went up about 10' and snuffed out in the grass. It must have been the delay charge.

Rich Pitzeruse

28th January 2009, 07:35 PM

I'm not sure what was learned here. But here's my CATO story.

Many moons ago, probably 20 years or so, I flew an Estes V2 on a D12-3. The rocket got about 15' in the air and the motor turned itself into a ball of fire about the size of a basketball. It completely shattered the tailcone and fins. The engine, err, I mean motor (don't want the motor/engine police after me!) had split straight up the side.

I rebuilt it, pieced the tailcone back together and cut new fins for those that were too destroyed, and still have the rocket.

shreadvector

28th January 2009, 07:55 PM

There are a few [comment removed w/ consent] who will insist otherwise, but you were not wrong to use "CATO" as an acronym. Lots of people use it that way and it's no more or less correct that using "cato." Undoubtably, the use of "cato" pre-dates "CATO," but that doesn't make it more correct.

http://www.google.com/search?hl=en&q=CATO+catastrophe+at+take+off

-- Roger

i requested that people take the discussion about the incorrect acronym vs. the correct abbreviation/slang term take it to the original thread on YORF.

Anyone who reads it completely will understand what is correct and what is a set of words made-up to fit a mistaken assumption that a term heard verbally was an acronym.

Rockets do not "take-off". See the YORF thread.

The multiple threads here on TRF are in the old database and not available.

[comment removed w/ consent]

SwingWing

28th January 2009, 08:01 PM

Why would a cato be limited to "take-off"? Can't catastrophy happen anytime?

troj

28th January 2009, 08:02 PM

There are a few [deleted] who will insist otherwise, but you were not wrong to use "CATO" as an acronym. Lots of people use it that way and it's no more or less correct that using "cato." Undoubtably, the use of "cato" pre-dates "CATO," but that doesn't make it more correct.

Because it's common practice doesn't make it "right".

It's no different than writing, "The horse's are pretty". Misuse of the apostrophe when making something plural has become very common, and even mainstream media does it far too often.

That, however, doesn't make it correct.

It's no different than your argument.

-Kevin

jadebox

28th January 2009, 08:22 PM

Because it's common practice doesn't make it "right".

It's no different than writing, "The horse's are pretty". Misuse of the apostrophe when making something plural has become very common, and even mainstream media does it far too often.

That, however, doesn't make it correct.

It's no different than your argument.

-Kevin

There's a large difference between formal writing and information language. Someone made up "cato" recently and someone else made up "CATO." There's nothing that makes one correct and the other incorrect.

-- Roger

shreadvector

28th January 2009, 08:59 PM

I was not and am not "looking for a chance to jump on someone for a perceived wrong".

I am now under the impression that you are intentionally argueing with me because you have some kind of personal problem with me and this impression is based upon the post I am currently responding to as well as the one above where you actually resortet to name-calling (mild, but still insulting).

If I provide information and it happens to be a correction, I provide a full explanation and I do not do so for any reason other than to help people learn the correct information. I definitely do not like the propagation of false information, especially when it is being done intentionally or in spite.

Others seem to have a similar opinion:

http://forums.rocketshoppe.com/showpost.php?p=59692&postcount=40

http://forums.rocketshoppe.com/showpost.php?p=59800&postcount=46

http://forums.rocketshoppe.com/showpost.php?p=59806&postcount=47

http://forums.rocketshoppe.com/showpost.php?p=59854&postcount=49

Even if you have a problem with me personally posting information, what about all the others who posted the above identical information. Some were not as polite as I tried to be.

Maybe they will chime in here as well? Or maybe they respected the request to keep the discussion over on the original thread on YORF?

You started the discussion here. Instead of always looking for a chance to jump on someone for a perceived wrong, please just let it go in the future.

"CATO" is an acronym because people use it as an acronym. Someone coined it and it caught on. Certainly it is a contrived acronym based on "cato." But, acronyms are coined every day and there is no "official clearing house" for them. If you don't choose to use the acronym, that's fine. But, don't criticize others for using it.

The "Take Off" part is, as I explained, irrelevant. The acronym was apparently contrived to fit the letters "CATO" and the definition as "Catastrophe At Take Off" was most likely based on "JATO." Other people have contrived different definitions for CATO including the self-referential one "CATO At Take Off."

Yes, the explicit definitions of the acronym doen't make sense. They don't have to. It's just the result of someone playing with the acronym - something done for fun. Like building rockets.

Now, please drop it and let the discussion return to actual "CATO" or "cato" stories.

-- Roger

RangerStl

28th January 2009, 10:16 PM

jadebox and shredvector and Der_Red_Max:

Please take this disagreement offline. We're getting distracted from the original purpose of the thread which is talking about your engines failing at launch.

Please don't take this argument any farther in public.

Respectfully

RangerStl

MarkII

29th January 2009, 01:00 AM

Sorry, Im new here. Didnt mean to cause any controversy. I should have looked in other forums before posting.
I think that Fred overreacted to your post, reading things into it that you never said. Fred's a good guy, and he makes great contributions to forum discussions, but he's a little touchy about some things. This is obviously one of those sore subjects for him, but that's his problem, not yours. You did absolutely nothing wrong.

OK, let's get back on topic here. I'm interested in the topic of this thread, too, and I'd like to see some more <propulsion device failure> stories. ;)

Mark \\.

H_Rocket

29th January 2009, 02:46 AM

It's more like 10' off the pad, but here's my entry

http://i260.photobucket.com/albums/ii35/al_gloer/cato.jpg

The story?

All the parts in the reload bag are needed.

SwingWing

29th January 2009, 04:00 AM

It's more like 10' off the pad, but here's my entry

Would that be a CATFOTP (catastrophy at ten feet off the pad)???

Sorry Fred:o

MarkM

29th January 2009, 04:32 AM

It's more like 10' off the pad, but here's my entry
Ouch!

How about a Roman Candle? Roger...you probably remember this one at NEFAR in August. Check out the video HERE (http://www.nefar.net/gallery/2008-08/Gator-Smoke-Mark-Morris-I206.wmv)
Forward snap ring let go on a EX motor once motor fully pressurized, then propellant proceded to burn. Fortunately the ebay (with electronics) was perfectly fine. The chute was not salvageable and fin can...well, the video explains it's condition.

PS: Based on the experiences, seems like this is more a HPR thread than LPR,

H_Rocket

29th January 2009, 12:59 PM

Loki I405 in my Sudden Rush - Forgot the forward closure O-ring

This is the flight that spawned the saying

"If this kind of thing bothers you, get a train set"

jflis

29th January 2009, 02:00 PM

My most interesting STORY involved a scratch built cluster that was launched at a CMASS launch. It was a 3 or 4 motor cluster and upon ignition 1-2 of the motors cato'ed. This released one of the motors from the model and off it went...

...Now, I'm off to the side talking to someone (standing right next to Bill Ralston's table - Bill was the LCO at the time of the launch) keeping my eye on things while chatting about something when I heard the BANG!

I started to turn towards the launch pad when I saw the loose motor, totally stable, and coming right at me...

I instinctively started to turn away from the oncoming motor and tried to drop to the ground when the thing hit me in the temple. Well, the reaction to that was to spin and drop faster and I found myself laying across all of Bill's rockets... ...SMOOSH!

Didn't really hurt, but startled the heck out of me! Needless to say, the owner of the model was very concerned :) And Bill was none too happy... Actually, only a few models got damages and most of that was broken fins.

It was an experience though...

Some cool pictures I've gotten over the years are of this Maxi-Brute Honest John (http://jflis.com/hobbies/rocketry/photos/exploding_rocket_small.jpg) and this Foam Cup Rocket (http://jflis.com/hobbies/rocketry/photos/13-mar-01/styro10a.jpg)

If you think cato's do a lot of damage to *conventional* rockets, try one in a FOAM rocket... Not pretty... LOL

jim

CTRockets

29th January 2009, 02:11 PM

Wow Jim, those pictures are pretty amazing! Regarding your story, did they ever figure out what went wrong? Was it motor failure? I saw my experience as a way for me to learn from My mistake which caused the failure. As evident from my story it wasnt a motor failure but a motor mount failure because of my large oversight.

jadebox

29th January 2009, 04:08 PM

Oh, here's a dramatic video of an Estes D motor failure. It was actually the first "high-speed video" I made.

http://www.payloadbay.com/video-7927.html

-- Roger

jflis

29th January 2009, 10:25 PM

cornyl

30th January 2009, 03:37 AM

This is my design Reckless Abandon. This event took place at the PARA club launch. First stage exploded about 10 feet off the pad. The arrow points to the engine. Fortunately it was enough to ignite the second stage D-12-5 for a nice flight. Landed in deep corn. Was lucky to find it.

MysticalRockets

30th January 2009, 05:26 PM

jadebox

30th January 2009, 05:33 PM

BTW, you can view dozens of photos I've taken of "CATOs and Crunches" at:

http://www.payloadbay.com/gallery/v/other/CATO/

http://www.payloadbay.com/gallery/d/18771-2/2007-09-08+NEFAR+388.jpg (http://www.payloadbay.com/gallery/v/other/CATO/)

-- Roger

Mikus

30th January 2009, 08:35 PM

Sorry, Im new here. Didnt mean to cause any controversy. I should have looked in other forums before posting.

No. Consider it no more than hazing the new guy. You'll get used to ignoring it at some point. :rolleyes:

I once had a Estes E9 spit out the nozzle and my Rubicon just sat there spewing burning goop onto the blast deflector. It was a borrowed pad so I felt so embarrassed and sad although it wasn't really my fault and there was nothing I could have done about it. It didn't help that the owner promply packed up and left just afterwards but oh well, now I pretty much only use my gear. :cool:

Amazingly the plastic nozzles on the underside of the Rubicon didn't melt from the CATO.

Jamski

30th January 2009, 08:42 PM

Oh, here's a dramatic video of an Estes D motor failure. It was actually the first "high-speed video" I made.

http://www.payloadbay.com/video-7927.html

-- Roger
Wow. I had one happen that looked just like that, except mine stuck on the rod. I've got a video of that and as soon as I find it, I'll post it. That's two Eagles gone for me. The first one glided over a highway and got run over. I think I'll try another brand next, maybe a Flat Cat...

I had a SkyWriter pop a B6 a few months ago. Got that on video too; as near as I can figure it blew the nozzle out.

MysticalRockets

30th January 2009, 10:17 PM

Sorry, Im new here. Didnt mean to cause any controversy. I should have looked in other forums before posting.

Don't worry. It's just Fred over-reacting as usual.

Peartree

30th January 2009, 10:27 PM

Now, now, let's not start beating up on Fred either.:)

MarkII

31st January 2009, 01:32 AM

[...]
PS: Based on the experiences, seems like this is more a HPR thread than LPR,
That's because Estes D13's and FSI F motors went OOP long before everyone had their own camcorders! :rolleyes:

Mark \\.

MarkII

31st January 2009, 01:41 AM

Who has a great [propulsion device failure] story that involves a black powder [propulsion device]? With pictures, if possible. :D

EDIT: D'oh! I should have read further along in the thread!

I hesitate to report this, but I have yet to personally experience the dreaded "c--o." Keep in mind though, that I don't launch all that often, and so I'm probably a few hundred to a few thousand launches behind the rest of you. :eek:

Mark \\.

FatBoy

31st January 2009, 02:21 AM

...I hesitate to report this, but I have yet to personally experience the dreaded "c--o."...

I'm with you Mark. I haven't had a Cato yet either (knock on wood filler). I know it will happen some day, and I hope it is the day I remember to bring the camcorder.

..."If this kind of thing bothers you, get a train set"...

H_Rocket.... That is a fabulous saying! I hope you have it on a t-shirt!

Peartree

31st January 2009, 02:37 AM

It didn't happen to me and I don't have pictures but I saw the nozzle blow out of an Estes 'E' in a Mean Machine. It lifted maybe an inch on the pad and the biggest column of flame (on a LPR rocket) I've ever seen poured out, then smoke, the poof. When the smoke cleared the rocket sat undamaged right where it started. Of course it crashed twice later in the day. That rocket just had bad mojo.

jflis

31st January 2009, 02:54 AM

OH! OH! I just remembered another cato story...

Happened at NARAM last year (yeah, the BIG five-oh event)...

It was during the imagination celebration. I had a UFFO outfitted for 24mm with an E9 in it. Under each of 12 cups there was a pleat folded streamer, 12 different colors. For those of you familiar with the "St. Louis Arch" event, this was more of a "NARAM Rainbow" type of thing.

I've done this before and it is SPECTACULAR. To keep the thing as secret as possible leading up to the event, I kept it inside a cardboard fence all around the launcher, so you couldn't see the UFFO. The intent (as it worked before) was that this thing would leap out of the box, trailing a rainbow of color for 100 or so feet into the air.

To add to the suspense, I gave a short memorial to my friend Glenn Avalear who had recently passed away.

You could cut the tension with a knife as we reached zero in the count down!

Blew the nozzle.... Just a bunch of smoke rising out of the cake shaped box... ...then flames... The dreadful part was when they had to walk over and take the fire extinguisher to the mess...

ick...

MarkII

31st January 2009, 09:30 AM

an·ti·cli·max (\-ˈklī-ˌmaks\) noun 1710:

1: an event, period, or outcome that is strikingly less important or dramatic than expected (Example: http://www.rocketryforum.com/showpost.php?p=4713&postcount=47 )

:D :D :D

(Dictionary citation with apologies to the Merriam-Webster Online Dictionary (http://www.merriam-webster.com/dictionary/anticlimax))

Mark \\.

quickburst

31st January 2009, 02:40 PM

I guess any catastrophic failure can be described as a CATO or cato or whatever you choose to call it. It's not in Webster (as we define it) so I guess the user has exclusive right to define it as he pleases.

Anyway, I'm sure some of you have used the Pro38 motors? I have seen this happen three times. The rocketeer opens the package and inserts the reload into the rocket. Carries it out to the pad, countdown ends and the entire rocket goes up in flames.

Pretty cool but hard on the rocket, know what I mean?

It seems that these two rocketeers (both experienced High Power fliers) forgot to place the reload in the casing prior to loading the motor in the rocket.

We created "The Hall Of Flame" and enter the name of each rocketeer that made this mistake.

MysticalRockets

31st January 2009, 04:21 PM

One I forgot about. (Don't know how I could, but...)

Was flying some small stuff at a local baseball field. Had a reporter doing an article there. Put an A10-3T in an Estes Gauchito (always loved that little thing).

Spits the nozzle.

Melts a hole through the blast deflector. The rocket burned.

I was so embarrassed. I was glad they didn't use that pic. Would have been interesting to explain that one to the rec department.

luke strawwalker

1st February 2009, 03:43 AM

No. Consider it no more than hazing the new guy. You'll get used to ignoring it at some point. :rolleyes:

I once had a Estes E9 spit out the nozzle and my Rubicon just sat there spewing burning goop onto the blast deflector. It was a borrowed pad so I felt so embarrassed and sad although it wasn't really my fault and there was nothing I could have done about it. It didn't help that the owner promply packed up and left just afterwards but oh well, now I pretty much only use my gear. :cool:

Amazingly the plastic nozzles on the underside of the Rubicon didn't melt from the CATO.

Yeah, Dave (dwmzmm) nearly lost his FSI Maverick out at Needville last year when he and I were doing some test launches and his E9 spit the nozzle out... it burned and smoked furiously and caught one of his fins on fire, but it wasn't too bad and I think he's since fixed it...

My rod tipped D12-D12 staged Maniac that cruise missiled into the south pasture a few minutes later... THAT was unfixable... OL JR :)

MarkII

1st February 2009, 05:21 AM

jeff_in_AZ

1st February 2009, 06:37 AM

I can add a few LPR experiences. The first
photo below is from an Estes Gnome launching on a
1/2A3-4T. Evidently the clay nozzle cracked, you can see
the vectored thrust in the photo. It barely cleared the
launch rod, then gave up and dropped to the ground.
The video's kinda funny, I had my camcorder set up
on a tripod and you see me run into the picture and
stamp out the grass fire. When I inspected the motor
afterward there was no clay nozzle present anymore.
The rocket was ok and flew again that day.

The second photo is from an Estes Blue Ninja launching
on an E9-4. When I built the rocket, I made the motor mount
so that it could use a D or an E engine. This was the first
flight on an E for the rocket and for myself. Same story
as above, the nozzle cracked and the rocket never left the
launch pad, although this time it didn't start a grass fire.
The fin can melted from the heat, though, and the bottom section
of the rocket was totaled. Later I realized that I had used
the wrong size igniter plug for the motor - I had used the
larger white plug that goes with a D12 engine and not the
smaller black plug that goes with the C11 and E9 motors.
I also realized that if I had followed the instructions
and placed the rocket 8" above the blast deflector,
the fins might have not melted. Ah well, live and learn.
I chalked it up to experience and headed to the hobby store.

jeff

jadebox

1st February 2009, 06:56 PM

Anyway, I'm sure some of you have used the Pro38 motors? I have seen this happen three times. The rocketeer opens the package and inserts the reload into the rocket. Carries it out to the pad, countdown ends and the entire rocket goes up in flames.

We don't miss a chance to remind our friend, Robb, about the time he did that. I have a series of stills I took as Robb's rocket sat on the pad, engulfed in flames. But, for some reason, I can't find the photos right now. When I find them, I'll post a link.

-- Roger

SwingWing

1st February 2009, 07:18 PM

I'm kind of curious to find out whether or not black powder propulsion device failures occur more often with rocket fliers who live in hot climates. Perhaps the propulsion devices that they keep on hand are more likely to undergo extreme temperature cycling? (Or else may be it is just that they launch more often...) :confused:

I live in a relatively cool climate, and so my BP propulsion devices are not exposed to high ambient temperatures during storage. That could possibly be a factor in why I don't seem to get those failures. Maybe?

Mark \\.

Of the four odd catos I have had, two of them were at winter launches. The motor/engines were stored at reasonable temps, but obviously cooled significantly when installed.
I would think that the northern climates have as big or bigger temp swings than the southern climates, but proper storage is still the key.

Handeman

1st February 2009, 07:37 PM

I've never had what I would call a cato, I did have a B6 erode the nozzle enough the ejection charge blew out the bottom and only popped the nose cone off, but I wouldn't call that a cato.

I've seen several. One of the more memorable was a Mean Machine that blew the nozzle. It sat on the Estes pad, without a blast deflector, I don't know why, and burned away. About the time the motor quite burning, the plastic pad had melted enough that the rocket fell over. It laid there a couple of seconds before the ejection charge popped the nose cone off.

MarkII

2nd February 2009, 04:12 AM

Of the four odd catos I have had, two of them were at winter launches. The motor/engines were stored at reasonable temps, but obviously cooled significantly when installed.
I would think that the northern climates have as big or bigger temp swings than the southern climates, but proper storage is still the key.
It was my understanding that temperature cycling between cold and moderate temps wasn't associated with more catastrophic failures of BP engines, but that temperature cycling between moderate and very hot temperatures (such as leaving a box of engines in a hot garage or storage shed for a couple of weeks) definitely was. I don't do much launching in the winter, and the summers here don't get all that hot, at least compared to parts of the country where there are a lot of rocket clubs and a lot of rocket launches. (You know where I mean...) Also, as I understand it, the temperature variations that BP engines experienced during storage were critical, not the air temp at the time of launch. I would imagine that rocketeers who live above the snow line store their engines indoors or in a heated building during the winter, where they are not exposed to cold temperatures for any extended period. (That's certainly what I do. It does get rather cool in my basement during those weeks of sub-zero temps every January, though.) I was just wondering if there was any anecdotal evidence that the incidence of catastrophic BP motor failures might have some relationship to variations in the local climates where the rocket flier lived (and where he or she presumably stored his or her BP motors/engines). There may actually be no reliable way to answer the question without performing a formal statistical analysis of available data or even without conducting a carefully controlled study. But I thought that I would go ahead and ask anyway. ;)

Mark \\.

Peartree

2nd February 2009, 12:19 PM

I can't speak to most of your post, but temperature cycling would be an issue for any motors that got stored away in someone's attic (or parents attic) or garage when they were out of rocketry for a time. Then you get temperature cycling from cold winter temps to locked car hot summer temps...

SwingWing

2nd February 2009, 02:14 PM

It was my understanding that temperature cycling between cold and moderate temps wasn't associated with more catastrophic failures of BP engines, but that temperature cycling between moderate and very hot temperatures (such as leaving a box of engines in a hot garage or storage shed for a couple of weeks) definitely was. I don't do much launching in the winter, and the summers here don't get all that hot, at least compared to parts of the country where there are a lot of rocket clubs and a lot of rocket launches. (You know where I mean...) Also, as I understand it, the temperature variations that BP engines experienced during storage were critical, not the air temp at the time of launch. I would imagine that rocketeers who live above the snow line store their engines indoors or in a heated building during the winter, where they are not exposed to cold temperatures for any extended period. (That's certainly what I do. It does get rather cool in my basement during those weeks of sub-zero temps every January, though.) I was just wondering if there was any anecdotal evidence that the incidence of catastrophic BP motor failures might have some relationship to variations in the local climates where the rocket flier lived (and where he or she presumably stored his or her BP motors/engines). There may actually be no reliable way to answer the question without performing a formal statistical analysis of available data or even without conducting a carefully controlled study. But I thought that I would go ahead and ask anyway. ;)

Mark \\.
IMHO temperature cycling doesn't just mean getting hot. Cold means shrinkage (did I just say that?):eek: and that can cause the pulling away of the propellant slug from the casing, and cracks in the grain.

shreadvector

2nd February 2009, 02:29 PM

I wish that sticky thread from the previous life of TRF was still here. here is some info on BP motor failures:

init 6

2nd February 2009, 07:01 PM

here's my favourite cato (wasn't he the guy in OJ Simpson's house?)

When a K1440 exceeds the speed of plywood

http://www.youtube.com/watch?v=LN1DIk2oyMw

RocketT.Coyote

3rd February 2009, 04:42 AM

An A8-3 exploded and destroyed my Estes Sandpiper on it's maiden flight in the mid-1980s.
An A10-3T damaged my Boyce Aerospace Saturn V when the propellant grain blew. On it's first flight attempt, a C6-3 Catoed in my Space Camel BG.
During a demo, a C6-3 CATO in my 1:70 scale Apollo Little Joe scratch-built split the solid balsa cone and shredded the LES in the Summer of 1996. On it's maiden flight, a D12 Cato scorched the insides of a TLP Hawk and blistered the paint.
This past Labor Day weekend a D12 blew it's nozzle and propellant grain, damaging my Dynastar Firefox SHX.
:eek:

MarkII

3rd February 2009, 07:49 AM

IMHO temperature cycling doesn't just mean getting hot. Cold means shrinkage (did I just say that?):eek: and that can cause the pulling away of the propellant slug from the casing, and cracks in the grain.

I wish that sticky thread from the previous life of TRF was still here. here is some info on BP motor failures:
OK, I see. All of the stuff I had seen about temperature cycling up until now on various forums, mailing lists, etc. had only talked about the negative effects of cycling the motors in and out of high temps. These are the first references that I have seen to cold cycling. Thanks for the info. I'm surprised that a black powder propellant slug that is highly compressed and has been pressed into a thickly wound paper casing under high pressure can actually contract that much due to exposure to cold temperatures. Any idea of how long the duration of the exposure and how cold the temperature would need to be to produce this effect? If there was some moisture in the propellant, wouldn't that cause the slug to expand rather than contract, if the motors were stored in temperatures that were significantly lower than 32° F for a prolonged period?

Mark \\.

shreadvector

3rd February 2009, 02:08 PM

OK, I see. All of the stuff I had seen about temperature cycling up until now on various forums, mailing lists, etc. had only talked about the negative effects of cycling the motors in and out of high temps. These are the first references that I have seen to cold cycling. Thanks for the info. I'm surprised that a black powder propellant slug that is highly compressed and has been pressed into a thickly wound paper casing under high pressure can actually contract that much due to exposure to cold temperatures. Any idea of how long the duration of the exposure and how cold the temperature would need to be to produce this effect? If there was some moisture in the propellant, wouldn't that cause the slug to expand rather than contract, if the motors were stored in temperatures that were significantly lower than 32° F for a prolonged period?

Mark \\. (file://\\.)

Too many questions to answer - especially without handy copies of the R&D reports I and the others have written on this subject. I will answer a few that I know I have the facts on:

Humidity: I soaked D12-5 motors in 100% relative humidity for quite a while (OK, I can't remember if it was 2 weeks or a month) by suspending them on a rack above a bunch of water inside a plastic garbage can. Some were static tested immediately after removal and others were placed into a container with dessicant to dry them (another 2 or 4 weeks)
and then static tested. The thrust time curves of the humidity soaked motors exhibited lower thrust with longer burn time and the delay times were WAYYYY long. Same total impulse. No catos. IIRC, after drying, the performance returned to normal or nearly normal, but I'm not sure I recall correctly.

I don't think the average motor will absord enough moisture in normal conditions to be able to form ice crystals inside that can cause expansion and cracking. I think the moisture in an average motor is pretty low and is not concentrated enough to form large crystals. I don;t know if anyone looked at this in an R&D report, but it could be interesting.

pyrovette20

4th February 2009, 12:19 PM

I had an Estes space shuttle Challenger with a C6 cato about 2 months before the real Challenger blew up. Premanition maybe,wierd yes. But it happened.

Pem Tech

1st May 2009, 12:32 AM

While not as spectacular as some of the other CATO's in this thread, this is one of the few I have experienced.

Right before NSL2007 I was rushing to get the Space Ark Jr. into production, should have known better than to put such a purdy paint job on it.
Lift off on a D12-3 of unknown age.
Well, an attempted lift off...

http://pembertontechnologies.com/images/SAJCATO_4506.jpg

And a fraction of a second later here she is completing loop-de-loop.

http://pembertontechnologies.com/images/SAJ_4507.jpg

The rocket was a total loss, charred to a crisp.

Chrisn

1st May 2009, 02:14 AM

Who cares what a Cato is, this thread is about CATOs, catastrophes at take off, not the shorthand catastrophic failure. 2 completely different things.

Its not like EMRR is the oxford dictionary or anything, why is this always bought up?

RangerStl

1st May 2009, 05:17 AM

Before anyone gets too uptight.. Chrisn please note the dates on these posts. Since January many things have been discussed and things have been left alone since then. I think we had all come to the agreement that many opinions exist and it really wasn't worth arguing over, especially since launching personal barbs at individuals is distracting and not permitted under our rules.

I think that agreement should stand and we should instead all mourn the loss of Layne's Space Ark. :(

Cue "Taps".

Chrisn

1st May 2009, 05:42 AM

Before anyone gets too uptight.. Chrisn please note the dates on these posts. Since January many things have been discussed and things have been left alone since then. I think we had all come to the agreement that many opinions exist and it really wasn't worth arguing over, especially since launching personal barbs at individuals is distracting and not permitted under our rules.

It was a simple statement voicing my opinion on the matter, nothing more nothing less. Maybe I could have replied to this in January, if it didn't take until last week or whenever for my account to be manually approved

Rocketcrab

1st May 2009, 01:47 PM

Back in 1988, when I was getting "back into" rocketry as a BAR, I bought and eagerly built the then-new Estes Jupiter-C model. It was released as part of the 30th anniversary of the launch of the first US satellite, Explorer-1. I put all kinds if time into that model - I even filled in the body tube sprals for the fist time! Man, I was proud of that build. It flew for the fisrt and last time in December of that year. I loaded up a C5-3 motor, which gave that model a great boost....she arc'd over...and...straight into the frozen ground, completely pulverizing the satellite and "bucket". The reason? The ejection charge never went off. The cap was still present. I was informed I'd suffered a CATO - never happened to me before. For some dumba$$ reason, I never returned the remnants to Estes for replacement. :bang: