In 1967/8, Charles Roberts Ltd built a batch of chemical tankers for Tank Rentals Ltd, with a through vacuum pipe, to TOPS code TTB. They were later refurbished and reclassified TTA. Both ICI Mond and Associated Octel used them to transport liquid chlorine. These tankers were built with smaller diameter barrels than the more common petrochemical tankers of the same TOPS code, and were painted white with an orange band to denote their hazardous contents.
This kit was originally based around a Farish TTA wagon, which was used as a chassis donor. A moulded brick bund wall is included, which allowed the unused tank to be used for a static depot fuel tank as a scenic accessory. Since the Farish wagon became unavailable, the kit is now supplied with a Peco chassis.
The body is moulded in self-coloured plastic so that minimal painting is required. Etched brass accessories are included. A comprehensive sheet of decals is included covering early and late ICI chlorine, Associated Octel and Hays chlorine, ICI sodium hypochlorite and caustic soda, plus two other variants for sulphuric acid and molas
