509 (Tynemouth) Coast Regiment RA (TA) was formed from a part of Tynemouth Heavy Regiment RA (TA), in July 1940. RHQ was placed in suspended animation in April 1944 and the batteries went to 508 Coast Regiment RA (TA). 509 (Tynemouth) Coast Regiment RA (TA) was reconstituted in January 1947 as 405 (Tynemouth) Heavy Anti-Aircraft Regiment RA (TA).
Illustrations of the formation badges under which a unit served or supported are given. This is no guarantee that the unit used this formations badge.
| Jul 40 | Formed from part of Tynemouth Heavy Regiment | Sunderland, Tyne & Wear, UK | |
| Jul 40 |  |
Northern Command | Sunderland, Tyne & Wear, UK |
| May 42 |  |
9 Corps | Sunderland, Tyne & Wear, UK |
| Dec 42 | Sunderland Fire Command | Sunderland, Tyne & Wear, UK | |
| Apr 44 | Suspended animation |
Batteries
| Jul 40 | A, B |
| Dec 40 | A, B, 312, 314 |
| Apr 41 | 264 (Roker), 265 (Barrons), 312 (Whitburn), 314 (Seaham) |
| Jun 42 | 264, 312, 314, 397 |
Equipment
| 2 x 6 inch Mk VII Guns | Seaham | 314 Battery |
| 2 x 6 inch Mk VII Guns | Whitburn | 312 Battery |
| 2 x 12 pdr Guns | Barrons | 265 Battery |