It was used for firing long - range shells in a north - easterly direction across the estuary into shallow mudflats of the Maplin Sands .
The firing point was an ' out ' battery of the experimental establishment at Shoeburyness .
firing point was used for firing long - range shells in a north - easterly direction across the estuary into shallow mudflats of the Maplin Sands .
The firing point was an ' out ' battery of the experimental establishment at Shoeburyness .