April Challenge - Circle

Now this is quite a random blip in answering a challenge to blip something circular - but please bear with me in this....

This blip was taken from a Thames Clipper river bus today of HMS Belfast and the new Shard building going up above London Bridge Station... So why a circle???

Between 1960 and 1961 my Dad was the doctor on HMS Belfast as she returned from the Far East for the final time as the empire drew down as did our Far East Fleet (anyone remember Eden declaring a withdrawal to the west of Suez at about that time? I don't but I have read of it / learned of it in history lesions at school..)

the Belfast (here comes the circle bit) is armed with 12 6inch guns in 4 turrets of 3 guns in each (incidentally used to fire star shells over the Scharnhorst to allow bigger Royal Navy ships to see her at night to then finally sink her in WW2). With these guns the ship can engage targets 360 degrees around her (ie a circle) - clever eh? The range using maximum charge is approx 15 miles - the distance to Wembley or the Potters Bar services on the M25 from the river if anyone is actually interested.....

Random I know, but the blip does therefore involve a circle of sorts!!!