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. Ahoy! It is big, fat, matey, slow flier with a retro look. Blimey! 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, 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. Aye aye! She is a messenger o' t' gods, arrr, linkin' t' gods with humanity.) This model always seemed t' weathercock a lot for me, 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. Well, blow me down! But with t' extra weight and drag I added, 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, so this was re-built with a larger motor mount so she can fly again with D12 power. Blimey! (T' original stuffer-tube was removed.) T' added impulse should get her up in a hurry and t' longer burn time should produce some really high flights, I would expect more than 600 feet at least, arrr, possibly 7 or 8 big ones. We will see...
...we did see. Begad! It has now flown higher than t' Two Liberty Place Buildin' in Philly, t' US Steel Tower in Pittsburg, me hearties, and t' Chase Tower in Indianapolis IN.
| Flight Date: | 2012-03-18 |
| Rocket Name: | Big Bertha |
| Kit Name: | Estes - Big Bertha {Kit} (1948, 23, 7007) |
| Flyer's Name: | Rich DeAngelis |
| Motors: | D12-5 |
| Launch Site: | Penn Manor School Lancaster PA |
| Actual Altitude: | 852 Feet |
T' best flight I ever had with t' slightly Bigger Bertha. Flies great on a D12, much better than t' C6! Acceleration peaked at 15.7Gs, matey, averagin' 4.7Gs for t' 2.3 second burn. Arrr! With little wind it sped straight up at 171 mph and coasted for 4.3 seconds. Ya scallywag! T' delay was a bit short at 4.1 seconds and it ejected at 821 feet, 2/10 seconds later it apogeed at 852 feet - a record for this model.
A D12-7 might be a bit better. Aye aye! It descended under a good chute at 9 mph. Avast, me proud beauty! Total flight time was 1 minute and 6.1 seconds. It landed within 200 feet o' t' launch pad. Complete success!
| Stage | Motor(s) |
|---|---|
| 1 | Estes D12-5 |
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