A trapezoidal concrete wireless mast stay wire anchor 15B for mast 15, for the 1923 antenna extension array, which used 400’ steel lattice masts to support the inverted-L antenna. Three such anchors per mast were used for single-height staying. Each anchor featured an iron attachment point for turnbuckle tensioners and two iron loops either side. It measures 3.5m long by 2.6m wide at the base.

Source: Rowlands, J., Marconi's Carnarvon Station 1912-1939: a journey into early commercial wireless in north Wales' Second Edition, 2023.

RCAHMW, 2023.