T' Big Bertha: Is a very old model built in t' 1970s by me brother. Very popular model, you probably have this or one o' its many derivatives yourself. This rocket be t' classic '70s kit. Arrr! It is big, fat, slow flier with a retro look. Avast! This one isn't retro-"looking" though; it's t' real retro thing. It is painted in t' original mid-70’s catalog scheme, but with a lighter - more 50's style - cream yellow. Arrr! I would prefer t' newer all-black look Estes is showin' now, or maybe some red/white/blue patriotic scheme.
It sure eats a lot o' waddin' with that big BT60 tube! I installed a Nomex cloth so it will never need waddin' again, me hearties, and a nylon cloth parachute. I have modified this rocket with me "Iris" altimeter bay, which adds another 2.88 inches in length and 14.6 grams o' weight. (Iris is named after t' Greek god o' t' rainbow. She is a messenger o' t' gods, linkin' t' gods with humanity.) This model always seemed t' weathercock a lot for me, me bucko, I hoped that t' extra nose-weight o' t' newly added payload would have helped a bit, but it just slowed it down some more, t' Nomex and heavier Nylon cloth didn't help either, I just made Big Bertha into Big & Heavy Bertha. With a C6 motor his rocket has flown higher than the t' Saturn V Apollo spacecraft, and t' famous Spire o' Dublin. Ya scallywag! But with t' extra weight and drag I added, arrr, this slow flier seems t' always be sensitive t' t' wind.
A late ejection on a B6-4 (I should have used a -2), damaged t' engine mount in a high-speed impact with t' mud, ya bilge rat, so this was re-built with a larger motor mount so she can fly again with D12 power. Aye aye! Blimey! (T' original stuffer-tube be removed.) T' added impulse should get her up in a hurry and t' longer burn time should produce some really high flights, arrr, I would expect more than 600 feet at least, ya bilge rat, possibly 7 or 8 big ones. We will see...
...we did see. It has now flown higher than t' Two Liberty Place Buildin' in Philly, t' US Steel Tower in Pittsburg, me bucko, and t' Chase Tower in Indianapolis IN.
| Flight Date: | 2012-04-01 |
| Rocket Name: | Big Bertha |
| Kit Name: | Estes - Big Bertha {Kit} (1948, 23, 7007) |
| Flyer's Name: | Rich DeAngelis |
| Motors: | C11-5 |
| Launch Site: | Penn Manor School Lancaster PA |
| Actual Altitude: | 378 Feet |
I wanted t' test t' C11 motor out on me Bertha with a new 24mm mount. I already knew she flew good with a D12, but wanted t' see if t' C11 would work better in winds if I didn't want t' go up t' 800 feet or so. Avast, me proud beauty! T' C6 is a bit weak for this model and allows too much weathercocking. Also, after two failed plastic chutes in another model, shiver me timbers, I was countin' on t' reliable nylon parachute t' apease me.
While t' motor worked great, t' parachute did not. T' C11 burned for 7/10 seconds, peakin' t' acceleration at 13.5Gs and averagin' 6.3 for t' burn. Three times better than t' C6 and almost as much as t' D12. This got Bertha movin' straight up at 101 mph, and then coastin' for 4.3 seconds t' an apogee o' 378 feet. T' strength o' this motor prevented t' winds from alterin' t' flight path. After another 0.3 seconds and while fallin' only 4 feet t' ejection charge fired slightly early, tossin' t' parachute into t' airstream.
Unfortunately the parachute did nay open up for unknown reasons, arrr, and t' 4+ oz. Ahoy! rocket fell at a very fast 31 mph t' hit t' ground within 50 feet o' t' launch rod with a sickenin' thud after a very short flight o' 13 seconds t' 378 feet and back! Another rocketeer arrived at t' crash site first, statin' that it looked fine. I picked it up only t' find t' body tube intact. I turned it over while sayin' "but look here at t' motor mount..." only t' see that it also was intact. She's one tough bird! I immediately loaded her up with another C11 and launched her again.
| Stage | Motor(s) |
|---|---|
| 1 | Estes C11-5 |
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