How to...Process and Package Salt

After the salt blocks had reached the warehouse it was processed and packaged in a number of ways. Some of the processes were manual whilst others used a variety of 'Heath Robinson' machines to process the salt.

The Crushing Machine

The crushing machine was originally located in the warehouse of Stove House 2 at the north of the site. It was powered by a steam engine that sat on a brick base outside the stove house. The steam engine in turn was powered by steam from the boiler in the Engine House/ Brine Tank. It probably dates to around c. 1900 when Stove House 2 was built.

The crushing machine was moved to Stove House 4 when it was rebuilt in 1956. Henry Thompson the final owner and manager of the works recalled in 2009 how he dismantled and rebuilt the crushing machine in its new location.

Power

When it was rebuilt it was powered by an electric motor sat on a stand east of the crushing machine. This powered a series of two belts and wheels.  A large flywheel mounted on the northern side allowed the motion of the belts to be continued. All the mechanisms within the work were powered from this individual mechanism.

Cogs

A series of cogs powered the internal mechanism. These were a 30 cog, 28 cog, 74 cog gears on the northern side (see north elevation) and two series of 28 cog gears on the southern side (see south elevation).  This powered the internal crushing mechanism.

Bucket Lift

A belt ran to an upper wheel on the southern side that powered the chain lift that raised the salt buckets on the western side. These brought blocks of salt from the flue level of the stove house and deposited them automatically in the central crushing mechanism.

The Crushing Mechanism

The upper part had two large toothed/ hooked barrels that turned towards each other crushing the blocks of salt. The lower mechanism had paddles that separated the crushed salt into four individual chute. The salt ran down the chutes and was bagged at the bottom.

Why was the salt crushed?

Two sorts of salt were produced in the work. Fine and Coarse Salt (see salt science). It was the blocks of fine salt that were placed in the buckets and crushed. 

Some salt was sold as blocks whilst others were crushed. This was part of the marketing of the salt. Some salt was sold in small blocks like loaves of bread and were not crushed. This type of block salt was common throughout the 19^th and early 20^th century. It continued to be popular in the later 20^th century in the Cheshire region where housewives continued to prefer the block salt. These blocks were cut up by a series of saw blades (see the cutting machines below).

The blocks allowed salt to be preserved for longer in damp households. Salt hardens when it is in damp air and granular salt will usually harden into a block. If the salt was bought in block form a small amount could be removed and used as and when needed. This was usually crushed using a rolling pin.

The blocks would also be crushed to provide ready-made granular salt. The salt produced in blocks from the fine pans would be suitable for the table and would often be sold in sacks ready for repacking as table salt.

The salt that was sold to Africa known as Lagos Salt was crushed prior to sale. It was not the block salt produced in the fine pans but was salt from the warehouses that were crushed from its hardened state prior to sale.

The Cutting Machines – The Packing Area

The cutting machines used large circular saws to cut the block salt into smaller blocks that were sold in packets (like loafs of bread). This was the traditional way salt was sold since the 19^th century. It was then crushed in the house using a rolling pin or mortar and pestle. This practice survived into the 20^th century in Cheshire into the 1970s when local housewives preferred to buy their salt in blocks.

 A further modern crushing machine was located in the Packing Area. This was powered by two electric motors with opposing ridged barrels. The salt fell onto a small conveyor belt and passed through the wall to Stove House 4 where it was sorted through the hopper in Crushing Machine 2.