The Thames Trader model range covered weights from 2 to 7 tons, powered by either petrol or diesel engines in four- or six-cylinder guises.

Externally it is very easy to differentiate between Mk1 and Mk2 versions; the Mk1 has the words THAMES TRADER in red on a chrome strip along the bottom of the bonnet opening and the white painted grill between the headlights has a vertical divider with a red circular badge with 4 stars, whereas the Mk2 has just the word THAMES under the bonnet, and TRADER in white letters spaced out between the headlights replacing the divider and badge.

The lighter duty Thames NC was initially fitted only with the four-cylinder petrol or diesel engine, now producing 73 and 70 bhp (54 and 52 kW) respectively.

The first models ranged between 1.5 and 5 long tons (1,520 and 5,080 kg) capacity and replaced the earlier, semi-forward control Thames Trader of the same weights.

London Transport ordered five double decker buses based on the Thames Trader for special duties, taking cyclists through the Dartford Tunnel.