Fuel and fire for the olympic hand-torch

By Åse Dragland
Foto: Jens Søraa

Professor Bjørn Magnussen at The Norwegian Institute of Technology holds a flame that never fizzles -the hand torch for the 1994 Winter Olympic Games at Lillehammer.

An Olympic flame that fizzles out is perhaps one of the worst media nightmares for the organizers of any Olympic Games.

Researchers from the Norwegian Institute of Technology (NTH) and chemists in the Norwegian oil company Statoil, have therefore been given the task of ensuring that the fuel and combustion technology for the olympic hand-torch are the best Norway has to offer.

It was in May 1993 that Statoil Norway, the main sponsor of the 1994 Winter Olympics, contacted NTH researchers in the Department of Thermodynamics. Because of the torch´s unique design, technical expertise and innovative thinking were needed to get it to work properly. A burner had to be placed inside the aluminum shield which covers the upper part of the torch. The flame is meant to come out through the hole on the backside of the torch shield, and to be visually appealing while being stable and in no danger of going out. Did the burner, for example, have to be specially secured? What could be done to insure that the torch wasn´t too heavy?

Long before this, the outcome of the design competition had established the appearance of the torch. The firm Paal J. Kahrs Architects Ltd. who won the competition, had deliberated over both the form and the choice of material. The torch should spark associations with humanity´s conquest of fire: as a branch is drawn out of the fire, the upper end ignites like a beacon. The long and resilient shape should allow it to be carried like a Birchleg ski pole thus evoking thoughts of Norwegian history. The birch handle and a polished aluminum shield allow parallels to be drawn with modern Norwegian industry and technology.

When chemists at Statoil Norway Ltd were contacted at the end of 1991 about developing a fuel that would tolerate Norwegian weather conditions, the production engineering department began a comprehensive study of the quality of crude oil and refining techniques. After extensive testing and many unsuccessful attempts, the chemists found a satisfactory blend of oil.

"The basic framework was already decided when we came into the picture. We had very little leeway, both with regard to weight and space", says NTH Professor Bjørn F. Magnussen. The laboratory immediately began preliminary experiments to test the wick system and find out how fast the new oil was consumed. When the torch holder and the shield were sent to Trondheim in June, the tests became more realistic.

The number of aspects that had to be considered was incredible. The torch weighed over one kilo, and would be carried by people as young as fifteen years old. Safety factors were therefore a major consideration: what if the flame came too close to the body or face? Furthermore, the flame had to withstand rain and snow and endure winds up to 80 km/hr besides being able to burn for 35-40 minutes from one leg of the relay to the next.

One of the greatest challenges the researchers met resulted from the fact that the oil supply was heated intensely by the flame. The pressure build-up forced the oil out of the wick system. The researchers had to find a way to keep the oil from leaking and dripping down the torch or from converting to the gaseous phase.

"We eventually managed to solve this problem by developing an adjustable wick system and by running small tubes through the top of the torch that allowed the vapourized gas to escape," says Magnussen with a well-deserved sense of satisfaction. "Now the gas is part of the flame itself and creates a superb visual effect on top of the torch."

It´s one thing for the torch to burn satisfactorily inside in the laboratory; how it behaves outside when being held by the runner and when the oil reserve is shaken while the wind and weather affect the flame, is another story. Torgeir Magnussen, the professor´s son, has voluntarily acted as a "test runner" for the olympic torch for the duration of the experiments.

"We can now say that on the basis of what we were given to work with, we´ve found the best technical solution," comments Bjørn Magnusson. "Of course we would have liked to have had more time to work on the problem. For example, we would have wanted to test the torch under the same climatic conditions that it will be used, but it would have been too time consuming to go to the mountains or Svalbard to find winter conditions."

Then what must be done before the torch is ready?

"We would still like to test the wind stability, and the wind tunnel at NTH could be used for these experiments. Additional operational tests would also help to optimize the torch´s performance under various wind and weather conditions. Up until the relay begins on the 27th of November, small modifications can be made - even after the torch is put into production," says Magnusson.