A platform escapement is a self-contained escapement mounted on its own small plate, or platform, usually on top of a clock movement. It contains the balance wheel, hairspring and escapement, and is regulated by a balance rather than a pendulum, so the clock can keep time while being moved or when not standing perfectly level.
Platform escapements are most familiar on carriage clocks, where they are often visible through a glass panel in the top of the case, but they also appear on ship's clocks, drum clocks, travelling clocks and some mantel and wall clocks. The two main types are the cylinder escapement, common on simpler and earlier examples, and the lever escapement, which is more robust and accurate and generally preferred. French makers produced large numbers of platforms in the nineteenth century, often supplied to English and French clockmakers, and finer examples may have bimetallic compensated balances. When buying, a collector checks that the platform is original to the movement, that the balance runs freely without wobble and that the jewels and pivots are sound. Because platforms are delicate, servicing should always be undertaken by a qualified clock restorer.
