Oval Partnership Briefing Note
A consultation event was held on the 23rd May 2011 at Ashmole Hall to discuss the options and the NLE in general.
The picture on the right shows the surface structure above the ventilation shaft at Vauxhall Station. This is a very dated design
Underground lines require such ventilation shafts to help remove air and dust and keep the tunnels cool
The London Air Quality Network pollution monitoring station is a few metres behind. Pollution at this site is more than double the European recommended levels (Annual mean PM10 level is 52 micro grams per cubic metre compared with a recommended level of 20. The contribution of the vent shaft to this is not specified. However, it is noted that cleaning the shaft causes spikes in the readings.
The proposed ventilation shaft in the Claylands/Trigon Road area will also serve as an emergency and maintenance access point to the two underground tunnels below which will be joined by a cross tunnel. The main shaft will be some 15 metres in diameter and 30 metres deep. The visible structure above ground will be smaller than this but larger than the surfae structure for a basic ventilation shaft. The three NLE options for locating the vent shaft are:
(1) On Claylands Green
(2) On the site of adjacent private houses
(3) On the site of garages at the rear
as pictured below.