NPL Water Rocket Challenge 2003

Triggered through Robert Youens announcements in our WR email list, I decided to take part in the Water Rocket Challenge 2003, together with my friend Norbert Pfanner as a co-member of the WRUNG Team (Water Rockets from Ulrich and Norbert, Germany). The event was arranged by the NPL, National Physical Laboratory in Teddington, south of London.

NPL Sports field: an Overview
foreground: landing zone
background: people are gathering around the launch area.

It was the first time that Robert, myself and Charudatta (left to right) met. It was an interesting experience to see the individuals who are behind the often read email adresses.

This is Roberts well and lightly built rocket #1. His launch bay was not too far from a row of trees, behind which his high going rocket, hanging at a big and very light parachute, soon disappeared due to side wind. But the rules did not count the hang time behind the trees ...

Robert's 3rd (experimental) rocket with 2 tube fins. Launch angle was 60° for all teams.

Roberts launcher - state of the art.
I was glad that I could borrow it from him for my own rocket. The launcher I am using is made from copper tubes - it would have been hard to bring over here (aircraft safety restrictions).

This is the rocket I have made shortly before the event. A 2 liter coke bottle, 4 fins from laminated cardboard, paper cone, HDTT chute mechanism.

Details of the HDTT: It was built especially for this event, because any metal parts on the outside of the rocket were not allowed. Tomy timer (green), inertial release system (white). The downwards pointing rocker arm (right side) blocks the excenter of the timer before launch, as shown. The glued in weight (a small nut) on the other side of the arm pulls this side of the arm down when accelerated, freeing the excenter. After launch, the nut is held down by a flat magnet. The hole close to the nut is used to block the rocker arm during chute loading. Above, the horizontal tube with a plunger with its rubber bands.

Left: The rocket after my first launch - a classic lawndart. The rocket went very high, the chute came out too late.

Right top: My second launch (with a new nosecone) went very high again. Not on the animated pic: the chute came out right after apogee with a first puff of talcum. But the chute was dragged behind and DID NOT OPEN until ca.5 meter above the ground - with an elegant glide for a few more seconds. The (zoomed) second puff of talcum when the chute finally opened in the distance can be seen clearly.

This spectacular dive from quite an altitude with the chute opening in the very last moment made the jury give us one of their 3 Special Prizes. That was unexpected, but very pleasing!

I believe that my 1 m diameter chute was too large for my tube size, I had to stuff it in tightly. Due to this, the material (a thin garbage sack) eventually got some static charge.

Here is Dave (also from the list), Charudatta and myself.

Some more team members (from the left):
Åke Ottoson (from Sweden with son and daughter Eleonora), Nicholas Olesen, Robert Youens, Charudatta Phatak, Norbert Pfanner (my team buddy), and myself, Ulrich Hornstein. 

Click here for enlarged view.

Here below I am showing some shots of the Schools Event.

Here below I am showing some shots of the Open Event.

Start of a heavily loaded rocket. Note the 2 water jets: one coming out of the launcher (upwards), and the main one from the rocket, which is going quickly steeper and steeper due to the heavy water load.

- All moving pics in 15x slow motion. -

Dangerous practices: a) Right hand pulls the trigger ring - it is reported that elsewhere a hand has been broken after being hit by the violent water exhaust.
b) Left hand guides the rocket - fingers can be cut severely by the fins!
NEVER DO THAT!

This yellow-red glider was the most elaborate aircraft of the competition and attracted the interest of many. It used a multi-bottle concept with 5 (five) nozzles. After a steep start it was supposed to glide down, guided by RC equipment. However, the maiden flight could not really convince, as far as altitude or flight time were concerned. However, the launch was spectacular. Stuart Rogers made the IMHO best picture of the NPL event (click here).
More pics from him and others on the NPL 2003 gallery page.

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Above and left: Custom made WR powered gliders. One can tell that the builders have a long modelling experience.