I wrote this as an answer in the 'introduce yourself' thread.
Thought it might be of interest here.
I'm a walk sequence machine operator working nights (23.30-7.30) We assume the trial must be over cause we've been told that funding has been withdrawn and the machines now have to be paid for by our own office budget.
'We are trialing 2 French walk sequencing machines.
The mail arrives from the mail centre in batches containing 12-14 walks and are about 5000-6000 letters in size.It then takes up to 45 minutes to sequence the mail (the mail has to be put through 3 times)
Mail is then in walk order which saves an experienced post person about 10 minutes a day.However it also means that anyone can throw in a walk (even managers)
The machines can also walk sort mail,that takes about 10 minutes to do 12-14 walks.
Before the mail can be sequenced it has to go through a mail centre for franking and coding as the sequencing machines can only read the red bar codes.
They're probably not the all singing all dancing machines that they were made out to be.
An engineer told me that Royal Fail intend to buy about 450 more machines to put in bigger delivery offices when they have decided between the French and German versions.'

