The Secret Tunnels of South Heighton

Signals Distribution Office (SDO).  Before & After 2000.

The Signals Distribution Office as found 1994, and after clean up by The Friends (2005)

Plan of the Signals Distribution Office and Annexe post-1943 as described by WRNS veterans.

The Signals Distribution Office was the hub of the Operations Area. Basically it consisted of four telephones, a Lamson Message Tube terminal, a typewriter, and an Ormig Spirit Duplicating Machine. Initially the SDO occupied only the right-hand office; the Cipher Office occupied the left-hand office. However, because the Cipher Office was thought to be inadequate to deal with the traffic that would be generated by the proposed invasion of Normandy, two new Cipher Offices were built in the adjacent long gallery. The SDO  typewriters and duplicating machines were moved next door into the vacated space to create a quieter telephone environment. Lengthy weather forecasts were frequently received from Meteorological Office, and these needed to be copied down, typed up, and distributed both locally and to all the dependant outstations. The PWSS (Port War Signals Station) on Newhaven Fort had to report the details of every vessel leaving or arriving at Newhaven harbour. This could be any Royal Naval vessel, Merchant Naval vessel, or local fishing vessel. It was essential that the plotters were aware of any changes to the friendly shipping in the vicinity at all times. The SDO had to record and report any of these instances to the Plotters. A Typex Cipher machine was also installed in the SDO annexe for the use of the Coders.

Every signal/message that arrived, whether by radio, teleprinter, telephone, dispatch rider or produced locally was sent to the Signals Distribution Office where it was given a reference and its date and time of origin was recorded. It was then sent by messenger to be ciphered or deciphered as necessary, and later returned to the SDO again by messenger, where its progress would be date and time recorded once more. It was then sent by messenger to the radio room or teleprinter room for onward transmission, or if appropriate, sent to the surface by Message Tube to the surface Distribution Office it would either be delivered in the Headquarters Offices 'up top' or handed to a WRNS Dispatch Rider for delivery to any Royal Naval establishment in Sussex that was controlled by HMS Forward - and that could be anywhere from Eastbourne to Littlehampton, and as far north as Burgess Hill.

There was a foul air riser to the surface in the near right-hand corner of the SDO that lead from the W/T Office next door. It was found to contain an empty 65 ft length of 3/4-ins galvanised electrical conduit (see first picture) for no apparent reason. It was later extracted (see second picture) to facilitate soil/chalk removal. Later still, in 2003,work on the surface above this shaft unearthed a 2 ft length of 3/4-ins galvanised electrical conduit with a length of 1/2-ins diameter coaxial cable inside. It is known that radar was used here during the Normandy landings - could this have been the reason for the conduit in the ventilation shaft? The heap of soil/chalk on the flagstones beneath the vent shaft is the product of an over-enthusiastic builder in 1972 who gave up trying to fill a hole when he realised his efforts were in vain!


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All illustrations and text on this site are 1941-2021 Geoffrey Ellis, or The Friends of HMS Forward, or Nick Catford.