Colt Park lime kiln MYD35163 (c) YDNPA, 2023
This kiln is in excellent condition, inside and out, though the bowl has been infilled for safety reasons and so is not accessible. It stands over 5 metres tall and was built to a design that is not common in this part of the Dales, being rounded rather than square. Round kilns were considered structurally weaker than squared ones. It has a fine, round-arched draw hole opening through which burned lime was drawn to be packed for despatch. The kiln was built like a dry stone wall. The outer shell is made up of courses or rough-cut limestone but this is just the kiln facing. Inside, lining the bowl, were courses of fire-resistant sandstone. In between the facing and the lining is rubble infill. The back of this kiln was cut into bedrock.
Pieces of limestone from the adjacent quarry were barrowed along an earth ramp to be tipped in to the top of the open bowl. First, though, a grate or grill was placed at the bottom with kindling and small pieces of fuel to get the fire going. Then alternate layers of stone and fuel were stacked up until the bowl was full. The fire was allowed to build up to start burning the stone. Kilns like this one were used in one of two ways. It may have been used on a continuous basis: as stone was turned into quicklime it fell to the bottom of the bowl to cool down, while hot air from the fire rose to the upper section of the bowl to dry out fresh stone put in at the top. As lime was removed through the draw hole, fresh stone was added at the top. In this way the kiln could have been in continuous use for many weeks.
An alternative method of working was to use the kiln on an intermittent basis. It was filled, and possibly covered over at the top, and the whole mass was allowed to burn through before cooling and being completed emptied. The whole process then started all over again.
This kiln was probably built in the 19th century to supply lime for agricultural use in the local area. Soils were acidic and could only support low quality grasses. Liming reduced this acidity and made the pastures more productive, boosting farmers’ incomes.
Johnson, David (2002) Limestone Industries of the Yorkshire Dales. Stroud: Tempus