The LMS did not make great use of articulated sets, largely due to the disparate needs of the operating divisions, some of which had rather severe weight restrictions. Three types were introduced which were assembled as three different pairings. This diagram is for the BTO+TO pair. The others are for a TO+TO to D1966 and a TO+CO to D1967, both of which are available as COMET MODELS M66S for sides only, or M66K for the full kit. They were useful coaches which operated in high density and excursion traffic as well as express passenger workings. Their appearance was distinctive not only by their being articulated but also because they rode on centrally trussed underframes.