The following production schedule provides a list of Great Western serial numbers that were assigned to each year. It should be used as a general guide only.
1953. . . . . . . . . . GW1 - GW1507break;1954. . . . . . . . . . GW150 - GW4500
1955. . . . . . . . . . GW4500 - GW11000
1956. . . . . . . . . . GW11000 - GW11500
1957. . . . . . . . . . 11500 - 15000
1958. . . . . . . . . .15000 - 17000
1959. . . . . . . . . .17000 - 18500
1960. . . . . . . . . .18500 - 20500
1961. . . . . . . . . .GW20500 - GW21500
1963. . . . . . . . . .GW21500 - GW22000