THE SEARCH FOR BRENTON’S BEACON :

The first record referring to the alleged “Brenton’s Beacon” was found as an annotation “Beacon erected by Commissioner Sir J.B” on the back of a painting done by Mary Brenton in 1818. Mary was the sister of Sir Jaheel Brenton who was the Naval Commissioner at the time. No later paintings or sketches show this beacon nor could any written records be found referring to it and its purpose.
The beacon was discussed with someone whose hobby was “collecting beacons” and he was of the opinion that there was never a beacon in the position shown and that probably the prominent rock shown in Fig 1 below was interpreted as being the beacon.

 

 

Fig 1 Aerial View of rocks on the mountain slope above SAN Barracks

Looking in the direction of the beacon from a position close to where Mary Brenton must have been when she painted the scene, the rocks are not visible and could not have been mistaken as a beacon. There are no other prominent features on the skyline, see Fig 2 below.

Fig 2. A view from the approximate site of the 1816 painting.

Searches of old maps turned up nothing until the map below was discovered (Fig 4).
The map is in poor shape and difficult to reproduce on a much smaller scale. On examination it can be seen that there is a line extending from Roman Rock through Noah’s Ark Rock to a point on the mountainside. There is also a line extending from the Martello Tower to the same point on the mountainside. At this intersection there is a drawing of a beacon having a shape very similar to that shown in Mary Brenton’s painting
(Fig 3). It was concluded that this was probably where Sir Jaheel Brenton had erected his beacon. The map was not dated but included the standard compass rose printed on all charts.

Fig 3 Expanded view of old map showing shape of beacon

Fig4. The first map found showing a beacon on the mountainside

An attempt was made to date the map by using the Magnetic Deviation shown on the original compass rose. The map was sent to the Magnetic Observatory in Hermanus together with a modern compass rose showing the current magnetic deviation for False Bay. The compass rose is shown below (Fig 5).

Fig 5 Compass Rose with old map version insert

The results received back from the Observatory are as follows:

Magnetic deviation on Old Map (Approx 1810) 27 Degrees West
Current deviation (2007) 24 Degrees 54Minutes West
Year – Declination (West)
(Information Supplied by Hermanus Magnetic Observatory)

1808 -26.9072                           1820 -27.7982
1810 -27.1080                           1822 -27.8757
1812 -27.2919                           1824 -27.9580
1814 -27.4549                           1826 -28.0476
1816 -27.5946                           1828 -28.136
1818 -27.7086
This information then dates the map to circa 1810 but Sir Jahleel Brenton only arrived in 1815. The discrepancy is probably due to inaccuracy in the magnetic deviation or that the base map was drawn earlier; there is only a difference of about 0.5 degrees.

Using the information at hand it was possible to plot the angles and lines shown on the old map, after compensating for the changeover time of the magnetic deviation, to arrive at the approximate position of the beacon on a modern map. As will be discussed later this puts Brenton’s Beacon in a similar position to later beacons that were used to help navigators to avoid the dangerous Whittle Rock shoal in False Bay.

Whittle Rock
During the course of a survey of False Bay in 1797 Lieutenant Daniel Whittle, commander of H. M. Brig EUPHROSYNE, reported the discovery of a very dangerous rock and Admiral Pringle stated that “I ordered a buoy to be laid down near it, the rock is of small dimensions, but extremely dangerous, being directly in the fairway coming into Simon’s Bay.” The beacon had a black vane on it which was some 20ft above sea level. Within a year the beacon was washed away in a gale; the rope cable of the day could not stand up to the continuous chafing. Although it was replaced by various kinds of floating beacons, all of them were washed away.
A report was compiled in 1810 by Mr J. Goodridge in which he stated:
“The only marks for a guide were the Commandants house (at the time this was Oatlands at the top of Cruywagen Road) on with a deep cavity in the land at the Waterfall above the Military Barracks – and a rock close at the back of the Commandant’s House, painted white with a red cross (See Fig 6), on with small white rock in the water close to the land and about half a mile without the said house.”
There are a number of rocks off Oatlands Point that could have been used.
The faded remains of the red cross on a white rock can still be seen above the Waterfall. It was maintained for many years by young men who were in training at the South African Naval Diving School but sadly this seems to have fallen away.

Fig 6 Red cross on a white background

This information confirms that in 1810 there was no beacon on the slopes of Simon’s Berg that could be related to Whittle Rock and probably no beacon at all. Brenton’s beacon must then have been erected between 1815 and 1818.
A report shows that in 1864 two beacons were erected on land; the one, triangular in shape and thirty five feet high, white with a red band in the centre was placed on a flat-topped rock near Oatlands Point, the other with a white staff and ball, on the shoulder of the hill south of Simon’s Berg. For 80 years these beacons remained the only indication of the position of the rock. Fig 7 below is of a map dated 1883 and shows what must have been the position of the staff and ball beacon.

Fig 7 1883 Map showing position of Upper Whittle Rock Beacon

Drawings or photographs of this staff and ball beacon could not be found but we know that this beacon was later changed to a diamond shape as can be seen in Fig 8 below.

Fig 8 Triangular Beacon on the ridge below Simon’s Berg

The seaward beacon situated on the flat rock at Oatlands Point is shown in Fig 9 below.

Fig 9 Whittle Rock Transit Beacon
The difficulties of accessing this beacon for maintenance purposes resulted in its being moved to a position on the shore more easily accessible. The new position is shown in Fig 10 below.

Fig 10 The beacon relocated to the foreshore

This beacon was later replaced with a pole type and it and the remains of the footing of the wooden beacon can be seen in Fig 11 below.

Fig 11 The replacement Transit Beacon

As a result of the repositioning of this beacon, the position of that on the ridge below Simon’s Berg had to be moved to compensate for the change in angle of the transit beacon. The map in Fig 12 shows the new position. It should be noted that this beacon lies on a line that runs from Roman Rock through Noah’s Ark, the same line shown on the 1810 map.

Fig 12 New Position of upper beacon

Photographs of the upper beacon are shown in Fig 13 below

Fig 13 A side view and face view of the last upper beacon

During World War ll a lofty light and bell buoy was moored close to the rock. The bell now stands in the courtyard of the Simon’s Town Museum (Fig 14).

Fig 14 The Whittle Rock Bell at Simon’s Town Museum

With the advent of modern navigation systems the beacons were no longer required and the upper beacon was cut down by the Parks Board. The remains of this beacon can still be seen on the mountainside. (Fig 15).

Fig 15 Remains of upper Whittle Rock Transit Beacon

Using the information set out above an effort was made to correlate the various beacon positions to try and establish where Brenton’s Beacon was and what its purpose was. Fig 16 below shows a line drawn from Whittle Rock to the white rock above the Waterfall. It can be seen that this line passes through Oatlands and thus is confirmation of the original recorded navigation aid.

Fig 16 Original marks for the position of Whittle Rock.

Using the data compiled from the first map showing the mountainside beacon, its position was plotted, together with that of Brenton’s Beacon on Google Earth Map, as shown in Fig 17.
These positions are approximate as an ordinary magnetic compass was used to take bearings from the site of the lower beacon and angles on the original map were measured with a protractor.
It can be seen that the alleged “Brenton’s Beacon” was within a radius of about 30 metres of the lower beacon position, the foundations for which still exist.

Fig 17 – Estimated position of Brenton’s Beacon.

After gathering as much information as possible, a search was carried out on the mountainside to try to find any remains of Brenton’s Beacon but there is a gap of some 46 years between when it is believed that Brenton’s Beacon was erected and the reports of the erection of beacons in 1864. The original beacon could have disappeared at any time during this period and the likelihood of finding anything was slim. The last upper beacon was easy to find as it was still erect not so long ago and the remains are clearly visible as shown in Fig 15. The search was then directed to the vicinity of the estimated position of the lower beacon and its base was found where expected. This is shown in Fig 18. Starting from this point a search was conducted in a circle of about 50 metre radius but nothing of significance was found. Unfortunately when Noah’s Ark Battery was constructed an observation post and gun director position plus accommodation was built very close to the site of the lower building together with an access road that passes near where Brenton’s Beacon might have been so any evidence could have been destroyed.

Fig 18 Base of lower mountain beacon

The figure below shows three lines from the various marks extending out towards Whittle Rock. The red (upper)line is from the white painted rock above the Waterfall passing through Oatlands Farm. The green (middle) line is from the lower mountain beacon passing through the beacon on the rock off Oatlands Point and the yellow (lower) line is from the upper mountain beacon passing through the onshore beacon at Oatlands Point.

Fig 19 showing the lines through the various marks

The final figure, Figure 20, shows how the lines converge at the position of whittle rock together with a line through the beacons at Buffels Bay.

Figure 20 – Lines converging on Whittle Rock

Using GPS positioning of the various marks and plotting information on a large-scale chart would probably provide more accuracy but from the information set out in the above there is little doubt that Brenton’s Beacon did exist and that its purpose was to aid in establishing a safe course to steer to avoid Whittle Rock.