Sorting

Sorting is perhaps the most mechanised part of the postal system, a great many letters today are sorted mechanically at some point in their journey. The BPMA collection has examples of some of the most important mechanised sorting equipment. 

Transorma Plate, 1935, accession number: OB1997.0069

This plate is one of the few surviving pieces from the first mechanised sorting machines used in Britain. 

In 1935 the Dutch Transorma Machine was introduced in Brighton. This huge and very noisy machine revolutionised the way mail was processed. It allowed operators to key in details of the destination of the mail. The machine would then automatically sort the letters into boxes for each destination. 

This plate is from the original machine and along with two operator identification (ident) keys is all that physically remains of the Transorma. 

Single Position Letter Sorting Machine (SPLSM), 1959, accession number: 2002-0086

This machine was originally used in Norwich and later in Ipswich. It was in use until 1986. It is an example of the first successful British sorting machines that were first introduced in 1956. These were the next major development in postal mechanisation after the Transorma since the Second World War had interrupted progress.

Letters would appear on a vertical conveyer in front of an operator. He or she would enter a code based on information within the address. The machine would then sort the letter into one of 144 boxes.

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First Generation Coding Desk, 1968, accession number: OB1994.0112

This is an example of the machine that became the first generation of coding desk. This particular one was used at Romford until 1979.

After the introduction of the SPLSM in 1956 improvements were made and the two functions of the SPLSM were separated. 

This machine was introduced in 1968. As with the SPLSM, letters would have been presented vertically to the operator who would key-in a code. 

Instead of sorting the mail immediately into a box like the SPLSM, the machine would print a code made up of phosphor dots onto the envelope. A separate machine would then 'read' the code using UV light and then sort into the relevant box. 

Second Generation Coding Desk, 1975, accession number 2003-0520

This is an example of a second generation of the coding desk and was used from 1975 until 2003 in Twickenham.

This type of desk was introduced in 1975. It was radically different from its predecessors as it was much smaller, easier and more comfortable to operate. 

This machine presented the letter horizontally, from right to left making it much easier for the operators to read the addresses. This led to it being termed the ‘easy view’. 

Like on the earlier machines codes were printed onto the envelopes to be read, electronically, by another machine.

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