Billinghams famous landmark the nitro-chalk tower at ICI. The nitrate silo can be seen in the background. 
Picture Stockton Archive
A Pictorial History of Stockton-on-Tees
Billinghams famous landmark the nitro-chalk tower at ICI. The nitrate silo can be seen in the background.
Nitro Chalk, a good Fertilizer. The Ammonia reacted with the Chalk which was mined, on-site as Anhydrite (anhydrous calcium sulfate) with the Sulphur removed (gypsum). It was a slow release Fertilizer and the Chalk was good for breaking up Clay. ICI used the Sulphur to produce Sulphuric Acid, on-site and, the remainder of the Gypsum to produce Wallboard, ICI wasted very little. Other Nitrate Fertilizer that are produced are high in Nitrate and were popular until it was found that over use was creating a runoff problem into rivers and streams, polluting them with weed that removed the Oxygen and killed fish.
It is of interest that the ICI Beehive Silo’s especially those on the Billingham main site were unique in their structure. They were originally of Italian design and actually floated. Billingham was at one time a boggy area and difficult to build on, those Silo’s when full held many thousands of tons so were built with a large flat base integral with the sides with external ribs to give the strength to the the structure, the whole building being concrete. The end walls were free standing with a steel structure and single brick panels sealed against the elements around the top and down the sides. This allowed the main building to rise and fall as it filled and emptied. It was not a large movement although one year after exceeding dry weather we got a call at maintenance that the static end wall was buckling, the main Silo building had sunk then not lifted so was resting on the fixed wall. We removed some brick panels altered the steel work and replaced and resealed the walls putting back the operating gap. There was a cellar with underground conveyors to remove the stored product, a large inbuilt scraper pulled the product onto this conveyor. There was a brick built conveyor housing on top of the Silo with a lifting tower at one end for filling the Silo, the whole workings being well engineered and lasting a long time. Apart from the moving parts of the conveyors they needed very little maintenance and worked well in keeping the stored products dry and free flowing, a brilliant bit of engineering.
My old Dad John Wealleans worked here in the sixties. (He would have been 108 in October, but died in 1975 aged 72)
My Father, Tony Millward, also worked here for many, many years.
This was the old CCF plant wasn’t it? My dad, George Smith, worked there for many years. I think its part of the Growhow site now, wouldn’t mind working there, bring everything full circle!
Production of Nitro-Chalk started in 1927. By 1930 about 250 tons a day were being produced. The war years saw a dramatic rise in production from 77,000 tons in 1939 increasing to 148,000 tons in 1944.