London Underground coaching stock London Underground coaching stock In 1989, the first 'Steam on the Met' event took place, and London Underground, hired British Rail coaching stock for the excursions. It was found that it was actually cheaper to buy the coaches instead of hiring them. Thus, London Underground has acquired numerous former British Rail coaching stock for these special excursion trains on the Metropolitan line, usually hauled by either steam locomotives, or the preserved electric locomotive No. 12 "Sarah Siddons". The fleet consisted of several Mark 1 and Mark 2 vehicles, and eight former British Rail Class 438 electrical multiple unit trailer set
Medium-capacity rail system requisite ridership due to network inadequacies (e.g. single-tracking) or changing demographics. In contrast with most light rail systems, an MCS usually (though not always) runs on a fully grade separated exclusive right-of-way. In some cases, the distance between stations is much longer than typically found on heavy rail networks. An MCS may also be suitable for branch line connections to another mode of a heavy-capacity transportation system, such as an airport or a main route of a metro network. The definition of a medium-capacity system varies due to its non-standardization. Inconsistencies in international definitions are even reflected within individual countries.