Aidan & Holly's amazing year: Llanymynech Lime Kilns

Friday 3 February

Today we went to see the Llanymynech Lime Kilns. We are staying in a house in Shropshire, but the border into Wales is only a mile away so many of the towns have funny names. If you want to say Llanymynech it sounds a bit like this - lanny-man-eck

Lime burning started on Llanymynech Hill in the mid 1700s.

Brick kilns were built to burn limestone cut from the hill above Llanymynech. By lighting fires in the kilns and adding crushed limestone, lime was produced and could be used as fertiliser in the fields. Slaked slime was also used as lime putty for building, as it is soft when first mixed but hardens over time as it absorbs carbon dioxide from the atmosphere and reverts back to hard limestone.

This is the Hoffman Kiln

This is the inside of the kiln

These are entrances to the chambers where the limestone was stacked inside the kiln to burn

a replica of an old cart on the tram track

A Hoffman kiln is a continuous kiln. It is called this because the fire never goes out. The kiln is built with chambers and as the limestone is burnt, the fire is transferred from one chamber to another. The chambers have a damper between them which can be opened up so the fire can move from one chamber to the next. All the chambers in the kiln are connected to a single chimney. When the limestone has been burnt down in one chamber the fire moves into the next one so the burnt chambers can gradually cool down before the lime can be shoveled out and loaded onto wagons.

This is the only Hoffman Kiln in the UK with its chimney still intact. The chimney is about 30 metres high and took the smoke away.

you can see the chimney here

The chambers were filled with chunks of limestone up to the roof. The men were paid for the amount of work they did, so if no limestone came from the quarry then the kiln workers didn't get paid.

After the limestone was burnt, more men had the job of emptying the kiln. It was very hot inside the kiln and it was dangerous work because the powdered lime causes an itchy rash and can burn when it get onto sweaty skin.

Quicklime reacts if it gets wet so the kiln needed a roof to keep everything dry.

Coal was stacked on top of the kiln and was put inside through stoking holes. The fire inside has to reach 900°C to burn the limestone properly.

Coal for the kiln came by horse drawn barge on the Montgomery canal and was poured into the kiln through holes in its roof by the firers.

The limestone came from the quarry above the kiln. The loaded carts came down on tramway tracks laid on an incline plane.

The limestone from the quarry was weighed at the Tally House. There was a weighbridge in front of the tally house and a system of levers and counterbalances allowed a heavy load to be weighed by moving a small weight along a calibrated bar known as a steelyard.

The tallyman recorded the weight of each truck of limestone carried from the quarry and directed it to the kilns, the canal or the railway siding. Teams of quarrymen were paid according to how much stone they delivered. Each truck would contain a 'tally' - a brass token engraved with a team master's special number. Using this the tallyman kept a record of how much each team produced.

This was the tally house

On the hill above the kiln was the limestone quarry. The cut limestone had to be brought down the hill to the kiln on tram tracks in carts.

This is the brake drum house on the English side of the border. 200m along the path was another brake drum house on the Welsh side of the border. A Brakeman controlled the descent of the limestone filled trucks. The heavy stone filled trucks were connected by a cable wound around the brake drum and the other end was connected to an empty truck lower down. The weight of the heavy truck was enough to pull the empty truck back up the hill for re-fillling.

This is the powder house where the explosives were kept for the quarry.