1946, Kenworth launched four new model lines of buses, deriving their model designations from the first four letters of the company name. The Model K was a line of small intercity/interurban buses; the Model E, a trolley coach; the Model N, a city transit bus; the Model W, an intercity bus. Subsequently, Kenworth added the Model O one-door transit bus and Model T prototype school bus. Ultimately, the company built trolley buses for just one city – a single order of 50 of model E2 built in 1947–48 for the Portland Traction Company, in Portland, Oregon. Model K, N, W Outwardly similar in appearance, the Model K intercity/interurban and Model W intercity bus differed in function, size, and layout. The Model K was shorter, with a capacity of 25-33 passengers; the longer Model W seated 31-41 passengers. The Model K was equipped with a rear-mounted International Red Diamond RD450 while the Model W used a horizontally-mounted underfloor Hall-Scott 190 engine. The Model N, in its original configuration, was a 36-44 passenger bus; after the design found no takers, the vehicle was downsized in 1947 to a 32-36 passenger bus. After 1947, Kenworth revised its model designations, assigning numerals to its model lines to signify evolutionary variants of each design. Kenworth "Brucks" As production orders for the interurban model Ks and model Ws waned, Kenworth focused its attention on special orders including an order of 10 "Brucks" for Great Northern Railway in Montana, (an earlier version was built for Northern Pacific Transport, but was a split-level coach) and several Highway Post Office coaches. These "special order coaches" were based on the Model T school bus, which entered production in early 1949. The company also test-marketed a small 20-passenger bus known as the Carcoach (only one example was built). 1950s Model T and CT The Model T school bus, which entered production after the last bus was built for Great Northern in April 1949, was an immediate hit with many school bus operators in the Pacific Northwest. The T-126 as it was known, boasted a unique four-pane windshield that offered unheralded forward visibility in any school bus at the time, and was the first school bus ever built to feature a roof escape hatch (now required equipment). Production of the T-126 averaged over 375 buses per year, making it Kenworth's most lucrative bus offering in the company's history up to that time.