This is a branch of modern postal history which is concerned with how the postal process is affected by use of machines. Because it demands a lot of data obtained from letters and other media which go through the posts it tends, mainly, to be philatelists / stamp collectors who switch to collecting the whole envelope, packet etc. who follow this interest. A UK society exists which is dedicated to the study of this topic called the Postal Mechanisation Study Circle, which issues a monthly Newsletter and a quarterly journal, has meetings and arranges visits to see equipment. There are also societies in Germany, France and Holland/Belgium which specialise in their own area but all the societies have a world-wide interest. I am also a member of my local philatelic society which caters for all aspects of the hobby.
So what data is obtained from these collected items? The earliest attempts to mechanise the posts were the development of machines to cancel ( deface ) stamps and to mark quality of service ( QOS ) information such as the date, time and place of handling. The famous earliest machine was developed by Pearson and Hill in 1857 but there have been hundreds since. As these machine postmarks were recognisably different from hand postmarks this immediately put information about the use of the machines onto the letters. Other landmarks were:
The use of 'postcodes' in the form of the compass district codes for London.
The introduction of meter machines in 1922.
The earliest successful sorting machines - the Transorma - first used in 1931 in Rotterdam in Holland and in Brighton, UK from 1935 to 1968. Transorma machines were also used in Argentina, Belgium, Brazil, Canada, Germany, Phillipines, Sweden, USA and Venezuela and were used in 5 other Dutch sorting offices.
Use of a simplified national postal address code originated in Germany in 1941, trialled in Norwich, UK in the late 1950s and widely introduced in UK from the mid 1960s onwards. These are usually in the form of a 3 - 6 digit number but some countries use alphanumeric codes (including UK, Canada, Nederland).
The early British direct sorting machines - the experimental 6PLSM used at Mountpleasant 1952 - 55 and the SPLSMs used in the 1950s and 60s at various sorting offices eg. Southampton and Norwich.
The successful 2nd generation direct sorting machines developed in many countries in the 1950/60s. As well as in the UK, machines were developed in Germany, France, Belgium, East Germany and USA. The most successful were the Bell (BTMC) machines built in Antwerp Belgium and the Burroughs machine built in Detroit USA (based on the Bell design).
The first Automatic seggregating and letter facing machines (ALFs) trialled in Southampton in the 1950s using first graphite lines then phosphor lines on the stamps to allow the machine to detect position and class of posting. Other detection methods are optical contrast, fluorescent bars or inks, perforation patterns (used in Switzerland). Seggregators divide mixed mail into machine-handleable envelopes and mail that needs manual handling. eg. packets small parcels, thick or large envelopes etc.
The first indirect coding / sorting system using an address code printed on the letter as phosphor bars by one machine then sorted on a separate machine that can read the code. Engineering trials were carried out in 1959 and on live mail from 1960 at Luton sorting office, UK. Further trials were carried out at Norwich sorting office between 1966 and 1975 on code printing systems, Post-coding and bar coding systems and Video coding. Indirect sorting was also developed independently in Germany, France, Belgium, Holland and the USA using fluor bars/spots, magnetic ink bars, optical contrast bars etc.and is now the most common system in use.
The first use of optical character recognition ( OCR ) to read addresses at Brussels Girocentre around 1967. These machines could only read pre-addressed envelopes with the numerical postal code in a special font called OCR-A.
The introduction of simple OCR readers for handwritten codes in boxes used widely in Japan and the East and in USSR.
The first successful OCR address reader / coder system for normal typed or printed addresses used at Wiesbaden sorting office in Germany from early 1978 onwards.
The development of remote Video coding in conjunction with the OCR system to allow a flexible mixture of machine and manual recognition and sorting.
the development of the use of normal product marking bar codes during the 1970s for tracking registered and insured goods. Now widely used for accounting purposes and routing data indication.
The latest machines in the UK are Integrated Mail Processors - IMPs. These combine automatic seggregating and facing, OCR address reading, evaluation of stamps (class), printing of postmarks and presorting.
Most of these machines mark the mail in a recognisable way giving the collector something to search for and sort, giving the curious plenty to study, the cataloguer plent to list, the lover of puzzles plenty to unravel!.
Phosphor dot codes: My particular interest has been in the coding systems used to print a machine-readable address on letters especially by the British postal system over the years since the first indirect sorting system at Luton. Including this system there have been 5 different outward encoding systems used employing the 14 dot format plus an inward system. Recently a new system has been introduced which uses the same number values as the old system but a highly complex encoding using the four-state bar system. If anyone has any interest in this topic (somewhat arcane I admit) I have available a 200 page book BRITISH LETTER SORTING CODES covering a substantial range of the known data. Data is available (not in the book) on foreign coding systems but these are generally much simpler than the UK system and can be described in a few lines.