TS 1478 EN 124 
Standard Name:
Gully tops and manhole tops for vehicular and pedestrian areas. Design requirements, type testing, marking, quality control. Standard Scope: This standard includes gully tops and maintenance manhole elements up to a net clearing of 1000mm (incl. 1000mm) placed in vehicular and/or pedestrian areas.

International Equivalents: 

EN 124: 1994
BD EN 124: 1994 (EQV)
NF P98-311: 1994 (NF EN 124: 1994)
DIN EN 124: 1994 (EQV) - EN 124: 1994

Source: https://www.tse.org.tr