Sunderland sound mirror

The Grade II-listed 15′ mirror is documented and photographed on the City of Sunderland website.

[Front view of the Sunderland mirror]
© Copyright (2002) City of Sunderland Council, used with permission.

 

[Front view of the mirror]
Photo: Paul Grantham June 2003

The front of the mirror is inclined at approximately 11 degrees to the vertical.  The rear wall is 5.8 m long, and 4 m high, and the flanking walls are 3.9 m long. 

[Front and side view of the mirror]
Photo: Paul Grantham June 2003

In June 2003 the mirror, although clearly visible, was lost amidst deep brambles and nettles, and partially obscured by elder tees.

[Plaque on the end of the mirror]
Photo: Paul Grantham June 2003

There is a plaque on the north side of the mirror explaining what it is.

City of Sunderland

COASTAL WATCH
MIRROR
This convex [sic. It is concave] dish detected
German Zeppelins sent to
bomb north – east ports.
Their course could be judged
from engine sounds focussed
onto a receiver, giving
15 minutes warning for

anti – aircraft defences
to be directed
onto them.

World War I Defences

[Rear view of the Sunderland mirror]
Photo: Paul Grantham June 2003

The City of Sunderland website notes that it is thought that the Tees/Tyne early warning system dates to the last two years of the [first world] war.  This mirror faces east and was positioned to cover the approaches to the Tyne and Wear estuaries.  There were probably other mirrors as part of the Tyne and Wear defensive chain but the location of these is currently unknown. Does anyone know more about these possible mirrors? If you do, please let me know.

The sound collection equipment at Sunderland might have been slightly different to at the other mirrors: The reflected sound was detected by a microphone placed in front of the dish and then transmitted to the headphones of the operator who sat in a trench to the front.  The location of the operators trench is currently unknown.  It has been suggested that at this mirror the microphone was secured in front of the dish by wires attached to the side walls,  so allowing it to be variably positioned.  This differs from other mirrors in the north east where the microphone was fixed on a metal post in front of the dish. 

Location

The mirror stands on a gently sloping hillside, 2 km from the coast at Newcastle Road, Fulwell. The Sunderland website has a map showing where it is, on Namey Hill, 570 m north of Carley Hill Cricket Ground (Grid reference NZ38945960).

It is alongside the bridleway about 200 metres west of the Sunderland to South Shields road. Access and parking can be found down the unmade road which starts a short distance north of the Fulwell Windmill.