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SAN - SAV MRDI Survey Point 'INDIA'
Robben Island, Western Cape

Date:1986-1988
Type:Military structure
Status:Extant

 


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Coordinates:
33°48'51.18" S 18°21'47.69" E Alt: 3m

The National Monuments Council (NMC) enlisted the help of the South African Navy (SAN) / Suid Afrikaanse Vloot (SAV) in the late 1980's to locate and plot shipwrecks and anything of maritime archaeological interest on the Robben Island coastline. Dr. Janette Deacon represented the NMC on the project and she was assisted by Dr. Bruno Wertz, a marine archaeologist.

The Navy code-named the project 'Operation Sea Eagle' and it took place in the summer months - from 1986 through to 1988. Navy divers were utilised over this period and stayed on Robben Island from Monday through to Friday, returning home for weekends.

The crew of the SAS Protea - a survey vessel of the South African Navy - placed two cardinal points on Robben Island for Operation Sea Eagle. Eugene Ugolini and his SAN / SAV support team then surveyed and installed a total of 52 SAN - SAV MRDI points - from A through to ZZ. They used theodolites from SAS Protea in order to accurately place the MRDI points at suitable positions, following the perimeter road around Robben Island.

MRDI was an acronym for Multi Radio Detection Mk 1. (The 1 became an I to make it easier to pronounce). The MRDI system relied on a triangulation principle using a master and two slave stations, similar to the much longer range Decca and LORAN navigation systems, now replaced by GPS.

The brass discs to identify each of the surveyed MRDI points were made in the workshop at the Chapman Battery, cut from a damaged phosphor-bronze shaft. The hole in the middle of the brass disc was drilled to assist the disc to adhere to the cement sub-structures. The original stamped disc identification markings were done by Alan Pinkney on SAS Protea early in 1986. This particular MRDI point 'INDIA' was affixed to the top of a circular cast in-situ concrete stub column. The witness marks of the original timber form are still clearly visible on the external face of the concrete stub column.

The "sites of interest" discovered by the Navy divers around the coastline of Robben Island were then plotted on a chart with reference to the adjacent surveyed MRDI points.

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Text compiled with assistance from Warrant Officer 1st Class Eugene Ugolini (Ret. Radio and Radar Technician involved in Operation Sea Eagle) and Captain Chris Dooner (Ret.)

Submitted by: William Martinson, July 2019