47607 - The 3F tank was introduced first in 1957, this model had plastic centre drivers which proved unreliable under heavy usage, breakages were common. Triang soon introduced metal centre drivers to overcome the problem, correspondingly plastic centre wheeled versions are becoming rare, so may actually become collectable.
This version in plain black remained in production from 1957 to 1963 approx. The chassis showed minor modifications & development over the years. The original brass screw/nut under the motor to clamp the frames to the rear weight was dropped and screws into the rear weight were used. Couplings changed from the original lightweight versions to the standard beefed up unit, common to all stock after 1958. Suppressors also changed over the years from orange or green round items to the red & then white more familiar log type. Motor pole pieces were recessed on later models, doing away with the longer brass screws & nuts.
The introduction of the lined 4171 3F tank version occurred in 1962, this loco showed chassis modifications at the front to take the RT 520 smoke unit & also featured a side screw fitting. Not many 'smokers' were manufactured, the high initial cost proving the stumbling block, the standard Jinty was 32/6 to the smoking versions 48/2.(A prairie tank was the same price). Most lined versions were therefore not fitted with the smoke unit, it remained in production from 1962 to 1967. The curious number arose due to the lack of room to fit the correct 5 digits so 4 were used instead!.
A brief history of the Castle class will follow shortly.