Dreamspace Chester-le-Street 23rd July 2006, A Meteorological Investigation by John Greetham, Coates-Greetham, Forensic Meteorologist
The 23rd. July 2006 dawned bright and sunny with the promise of a warm summers day. People flocked to the park in Chester-le-Street during the morning and afternoon enjoying the warm weather with children splashing in the pool without a care in the world. At lunch time many enjoyed a picnic on the grass, many others paid to walk through the Dreamspace structure with music playing and a kaleidoscope of changing colours.
Witness statements called the experience "It's very womb-like and trippy. It's dreamy, a really nice vibe," one said. "Previous visitors have likened the experience of walking through the labyrinth of coloured caverns to standing inside a rainbow fish" (Independent newspaper 25th. July 2006). Air temperatures were of the order of 23 to 25 degrees C. at the three weather stations at about 3.30 p.m.
Dreamspace was a giant plastic structure erected in a park at Chester-le-Street in July 2006. It was about 50 metres by 50 metres. and comprised 5 metre by 5 metre "rooms" and 5 metres high. Each 5 by 5 metre room was a different colour. At about 3.40 p.m. the structure suddenly rose into the air from the east side whilst still being tethered with ropes on the west side, these too gave way as it stretched upwards into the sky. The structure rose clear of the ground and folded over and drifted over the park, coming to rest against a CCTV tower. At the time there were about 30 people inside, two tragically died and the others injured to various degrees.
There was a very early indication that there was a risk of it lifting, hence the ropes tying it down. CCTV was available throughout the day and before the structure was inflated by air blowers, the structure lay flat on the ground. Prior to inflation about 8 a.m. the CCTV showed ripples affecting the structure, yet the CCTV showed almost no wind.
Just prior to it lifting at about 3.30 pm, the sides of structure were sucked in and then out for a matter of minutes rather like a wobbly jelly but with an up and down motion too. At the same time, trees just to the West were being quite vigorously blown about, where before they were almost still. This indicated a flow of quite a strong wind towards the structure. Where there is a strong vertical motion, air is sucked in to replace the rising air. (Sea breezes and tornados are good examples.)
Mr. Agis, the designer was charged with manslaughter and breaking health and safety rules, he pleaded guilty to the latter and not guilty to the former. The case was heard in the Newcastle Crown court.
The meteorologist acting for the prosecution, gave the cause as a fresh to strong wind. The one acting for the defence put the cause down to a strong convection current forming on the top of the structure during a period on bright sunlight and sucking it into the air.
Both experts used the data from three weather stations, Durham, Newcastle Airport and Albemarle, (upper sir sounding station). There were many witness statements and CCTV footage available for examination. Almost all of the witnesses described the wind as being light and only two referred winds stronger than light. (one witness said a light/moderate breeze (BF 2 to 4 ) and one at approx. 3.30 p.m. “A very moderate breeze was blowing across the park. This last witness did not refer to moderate breezes before 3.30 p.m. One witness said the wind was too light to fly a kite. Some of the witnesses said that it became very hot inside Dreamspace.
Mean wind speeds were of the order of seven to eleven knots at 10 metres above the ground from the West. Durham the nearest station, showed 7 to 9 knots. The wind at 1 metre is about 0.8 the wind at 10 metres. This gives mean speeds of 6 to 10 knots at 1 metre. (7 to 11 knots is force 3 to 4 on the Beaufort wind scale, gentle to moderate breeze. However gusts were almost and at times more than double, the mean speed).
An examination of the upper air sounding from Albemarle for 1 p.m. showed an unstable air mass to about 5000 feet and winds of 14 knots at 3000 feet. The surface wind is normally about one third the wind at 3000 feet. That is the wind at 10 metres would have been about 5 knots. In fact, the wind at the surface at 1 p.m. from the ascent, was only 3 knots from the West
There was therefore a disparity between the wind conditions at the stations and the evidence of many of the witnesses, the CCTV coverage and the data from the upper air ascent. However an examination of the topography of the area, showed that the park was sheltered by high ground to the West with the town being on the high ground. Indeed the CCTV coverage showed very little wind all day.
Convection occurs when differential heating is caused by the proximity of hot and cooler areas. In this case the top of the structure would have been much hotter than the surrounding grass in the park all day. At about 3.30 p.m. the cloud was well broken with a long period of bright sunshine. It is possible that the temperature of upper surface of the structure exceeded 35 degrees C.
As part of the report for the defence, the defence expert examined other occasions in a number of countries. Some of these were in much warmer countries and on windier days. On occasions the show was closed for safety reasons due to strong winds. Despite the occasions when it was closed because of strong winds there was no mention of it lifting clear of the ground.
The defence alleged that two of the ropes holding it down had been cut, an act of vandalism if indeed this was the case.
The case went to trial in Newcastle in January 2009 and lasted for a few days. In the event although the prosecution expert gave evidence, the defence expert did not. The jury were undecided and Mr. Agis was found not guilty of manslaughter.
In my experience meteorological evidence is vital in only a few cases, it is always useful where there is doubt concerning the effect of the weather on incidents in both criminal and civil cases. In this case the witness and CCTV evidence was vital whereas the weather station data suggested a rather windy day whereas the CCTV evidence showed very little wind. However the meteorologists were vital in interpreting the evidence from the CCTV and witnesses.
In Penhaligon -V- Cornwall CC, Fatal road traffic accident ) Goodes -V- E. Sussex CC ( House of Lords appeal ), the weather report was important in establishing when ice formed and the likely air and road surface temperatures. The two cases concerned ice on the roads and salting. In a case of rape in a secure mental hospital in London, it was alleged that the victim had identified the attacker by sunlight through the window just about sunrise. The window faced West not East. A site visit was made at which it was discovered that there was a security light just outside the window which would have lit the room up. A case where the weather evidence was totally unnecessary. The case was dropped by the CPS.
John Coates-Greetham has 30 years’ experience as an expert witness. His consultancy was started in 1988 after 37 years in the Meteorological Office as observer, forecaster and head of the legal and insurance enquiry section.
Cases over the last 18 years include, on the civil side, road traffic accidents, storm damage, construction, flooding, personal injury, slipping accidents in the wet and on ice/snow, insurance claims, agricultural matters, public enquiries into building matters, as well as criminal cases requiring forensic meteorology in criminal cases.