Here we see Southend Transport Leyland-engined Routemaster 113 on the A13 near Wennington en route for London on a special operation on X1 in connection with the 1989 Southend Bus Rally.
It worked the 0730 to Green Park and 0945 return to Southend (duplicated by a conventional coach, Leopard 505), continuing on to Southchurch Park for the rally. It then operated a shuttle on service 7 between the Park and Southend Bus Station, along with AEC-engined Routemaster 108, Astromega 606 and open top Fleetline 902.

Photo from the Peter Cackett collection, photographer unknown, taken Sunday 4 June 1989, A13, Wennington