Berengrave & cement

When chalk extraction first started in the Rainham chalk pit, quarrying of the chalk was done by hand. The chalk workers, suspended from the top of the chalk face by a single rope, hewed at the chalk with hammer, pickaxes and levers. As the demand for cement increased, it became necessary to extract chalk in greater and greater quantities. Explosives were then used to bring down the chalk face. The remains of the explosives store can still be seen in the reserve

In the early days of chalk extraction from Rainham chalk pit, the chalk was probably loaded onto horse-drawn wagons to be taken to Rainham Dock for loading onto the barges. There is evidence that at least one steam driven lorry was used to take chalk to the nearby cement works

(Click HERE for examples of steam driven road vehicles)

The other main ingredient of cement is clay. At the Motney Hill cement works the clay used was mud, dug from the bottom of the River Medway by 'Muddies'

At high tide, barges sailed from Rainham Dock into the Medway and, as the tide fell, these were grounded on the mud flats. The Muddies then had the unenviable task of jumping over the side and shovelling this stinking slime into the barge. As the tide again came in, the barges were floated off and sailed back to Rainham Dock for unloading. So much mud was dug from the river in this way that the character of the estuary was changed for ever. The bottom of the river is covered in deep pits which are now filled with soft mud. At one time it was feared that all this mud extraction might change the flow of water in the river which, in turn, could cause silting and prove to be a hazard to navigation

As the quarry was enlarged, a narrow gauge (24 inch) railway system was installed. We do not know how the railway wagons were moved in the early days, but this may also have been by horsepower. By the end of World War I, steam engines were in use, one of which was an ex-American Army 'Baldwin' 4-6-0T. These locomotives were originally built for the US Army to use in the battlefields of Europe, running troops and supplies to-and-from the trenches. They suffered from one major design defect. The two water tanks, which are the rectangular boxes on either side of the boiler, were interconnected. If the engine was left standing on a banked curve, the water drained from the higher tank to the lower. This change in centre-of-gravity could tip the engine off the track

The chalk dug from the pit was first taken to the washmills where heavy harrows broke it up and extracted the flints and other impurities. The wash mills were about 4.5 metres in diameter and about 1.5 metres deep. In its center was a pier to which a horizontal beam was attached and from which vertical blades were suspended. These blades reaching nearly to the bottom of the tank. The beam was made to rotate at a speed of fifteen revolutions a minute and by this means the chalk was broken up. Three men operated the washmill and it was capable of dealing with 40-50 tons of chalk in a ten hour day. Men were paid an additional few shillings a week to remove the flints by hand

The remains of the washmills can still be seen in the reserve

(Click HERE for further information on Rawmills and Washmills)

From the washmills it went to the crushing mill in the cement works where it was ground into a fine powder. This fine chalk powder then went into a tank where it was mixed with the river mud that the Muddies had provided. The mixture, now called 'slurry' was poured in to the top of a rotating kiln. The kilns, of which there were two, are like long tubes, inclined at an angle of 1 in 30 and rotating slowly. Blasting coal dust into the lower end and igniting it produced temperatures of about 1500°C (2700°F). The rotation of the kilns caused the slurry to move slowly along the length of the kiln and the high temperatures removed the water and carbon dioxide content. The dry mixture, known as 'clinker', emerged from the lower end of the kiln. This was then mixed with about 2% of gypsum, to prevent it setting too rapidly when mixed with water, and ground into the fine powder known as Portland cement. This was then stored in large, cylindrical storage tanks, known as 'tower silos', until it needed to be transported

The force of blasting the coal dust into the lower end of the furnace raised clouds of chalk and clay dust, but this was not wasted. Air from the furnace was passed through a filter where sprays of water washed the dust from the air. The dust was then returned to the production process

Barges sailed from Rainham Dock carrying cement, flints and, probably, bricks from the local brick fields. They returned carrying  timber for local industry and fish fertilizer for local agriculture. After the cement works opened in 1912, they also returned with coal dust, for firing the furnaces in the cement works, and staves for making the barrels in which cement was transported at that time