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Home / Features / Tripoli Oklahoma: The V2 flew and was recovered!
Tripoli Oklahoma: The V2 flew and was recovered! Print E-mail PDF
Project Review by Darrell D. Mobley   
Tuesday, July 28, 1998

This is the story about a rocketry club with a can-do attitude who was looking to do things in a big way. Tripoli Oklahoma tells the story about the largest V2 constructed to date by hobby enthusiasts.


The V2 idea was conceived during our December, 1996 monthly meeting.  After the demise of the DC3, we needed another mascot and went looking in the junk pile for inspiration.

We came upon an airplane tip tank. Since it looked so much like a V2, we just had to use it for the mold and started the group project known as Shamu, the Killer V2.

In January we began building the beast starting with 2 layers of 6 ounce fiberglass covered with foam strips and another 2 layers of fiberglass.

We built the two halves on the tip tank mold, then dry fit them together and decided that it wasn't quite long enough. So, we cut each half and added another two foot section of body.

The fins and centering rings were cut from aircraft fiberglass phenolic honeycomb sheeting, also found in the surplus pile.

The leading edges of the fins were made from fiberglass and foam in a mold made from bent aluminum.

The one inch tubular nylon parachute strap was secured to the body with a surplus seatbelt.

The Friday night before Sooner Boomer 14, we built the motors for the V2.

The core motor was an AeroTech M1939 with a ten second delay in a Dr. Rockets case. The propellant was donated by Ross of Magnum Hobbies fame. The case also was borrowed from Ross.

We also used two AeroTech K550's, one case and propellant was from Prefect Tracy Dungan, the other propellant was from Greg Trosper with the case from Sam Birchett, as well as two AeroTech K1100's, one case and propellant was from Sam, the other was a Dr. Rockets case and we do not know who donated this.

With Tracy reading the instructions, I built the M1939 motor and one of the K motors. Sam, Tracy, and Wade Wolf built the other K motors. Tracy's was the only one that did not light, so we wonder what he will use it for.

That evening also was memorable for the awesome sunset that not only lit up the western sky but also lit up the clouds in the eastern sky.

Saturday morning came early and we were treated to another atmospheric anomaly: an awe inspiring, very bright and colorful double rainbow. We took this as a very good omen and started launch activities by installing the motors.

The K motors fit the 54mm motor tubes but the M motor was really tight, so a couple hours were spent sanding the inside of the tube so that it would fit.

We finally stood the rocket up, using gravity and 2X4's to help the M motor go the final 6 inches.

The ejection charge on the M motor was increased by adding an extra tube to the end of the ejection well. This charge ended up being a bit too much.

With the motors installed, we checked the CG and CP and found that we needed more nose weight. Dave Berezowski, our newest member, was running VCP on his laptop to provide the CP calculations.

We looked for nose weight material and finally added a five pound crankshaft retainer into the nose tube with paper packing material for padding and a bolt through the tube to hold it in place.

The main chute had 30 shrouds of 330 pound test nylon rope and fifty feet of 3000 pound test tubular nylon for the shock cord.

A four foot Stroud chute was used as a pilot chute that would be pulled out by the nosecone and would pull out the main chute. The Stroud chute was attached to the nosecone with 400 pound test nylon rope.

The V2 ended up being 14 feet in length and 22 inches in diameter. It weighed 115 pounds without the motors, and the loaded motor weight was another 32 pounds. An internal launch lug ran the entire length of the V2 and a one inch launch rod that was 20 feet long was used to initially guide the rocket.

We rolled the V2 out to pad 99 Saturday afternoon but did not launch it due to the winds and the ostrich situation. Rolling it back into the hanger caused the nosecone retainer tabs to break off and they had to be fixed before we launched.

Sunday morning came much too quickly for us. We went over the V2 again, rechecking all systems, and fixing the nosecone retainer tabs.

The V2 was rolled out, igniter installed in the M motor and thermalite installed in the K motors that would be airstarted from the main motor exhaust.

Lots of pictures were taken and an interview was given to the Enid, OK newspaper by yours truly.

As we shutdown the normal launch activities for lunch, the V2 recovery team went into action. The trailer and four Tripoli, OK members left to be in the recovery area.

We were blessed by a nearby passing thunderstorm that caused the winds to die for 30 minutes. We launched the rocket in 2 MPH winds, igniting the M motor and the two K1100 motors on the pad.

As it passed an estimated 2000 feet, one of the K550 motors lit and caused the rocket to take a slight arcing trajectory away from the crowd toward the recovery area.

One of the K550 motors never lit and it may have been that the thermalite was pulled out or that motor was just harder to light.

The ejection charge went off after the ten second delay had burned and with a muffled boom, pushed the nosecone off the V2, shattered the motor tube, and blew some of the fin fillets off of the rocket.

The ejection charge had done its job but had caused some fixable damage to the rocket.

The nosecone pulled out the Stroud chute and broke the 400 pound retaining rope. This caused the nosecone to drop freely into the plowed dirt recovery field where it suffered a large dent. The Stroud chute lasted long enough before it stripped its shroud lines to pull out the main 28 foot chute. The main chute gracefully opened and gently lowered the V2 to the recovery field.

The rocket landed 100 feet from the road and the main chute slowly deflated, collapsing in the zero MPH wind. The recovery team's job was much simplified by the absence of wind, we had visions of the rocket being dragged across the dirt and us having to man handle the chute to get it to collapse.

The rocket was loaded on the trailer and returned to the hanger for flight analysis and more photos.

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