The Gent's Waiting Train turret clock movement was a highly successful attempt to get rid of the heavy weights and intrusive weight shafts of conventional mechanical turret clocks. It also avoided the necessity of having to wind the clock at regular intervals. By applying electricity to drive the pendulum directly, even this smallest of the WT movements was capable of driving the hands of four exposed dials of up to six feet (nearly 2 metres) in diameter. The largest clock dials in the world (installed on clock towers in the early 20th century) used Gent's Waiting Train movements in order to achieve sufficient power. The movements were necessarily much larger and heavier than the smallest "WT" movement illustrated here. The ability to handle such heavy loads lay in the clever Hipp Toggle mechanism. (invented by Matheus Hipp in 1838) The Hipp toggle switches on the electric current briefly to the coils of the power electromagnets. But only when the pendulum needs a push to maintain its steady swing. Normally this push may be as little as once per minute. But under heavy loads it can call on up to 30 times more power by getting a push from the power electromagnets as often as every two seconds. This caters for the times when the exposed hands are iced up or a gale is resisting the movement of the hands on the clock dials outside the tower. --------------------------- The complete drive train is as follows: The pendulum is driven by an occasional push from the two large power electromagnets. A hooked lever pivoted near the top of the pendulum draws the 16-toothed escape wheel round one tooth at a time. The escape wheel rotates once in 30 seconds. Rotating the worm fixed behind it on the same shaft. The wormwheel is then rotated once per hour driven by the worm. A "worm" is really a short screwed rod designed to drive the (specially-shaped) fine-toothed wormwheel. The 120-tooth wormwheel drives the first gear of the bevel gear cluster via the shaft to which both are affixed. Each of the vertical bevel wheels can drive the minute hands on an exposed clock dial on the outside of the tower. Drive to the clock hands is via simple universal couplings & lead-off rods. The hour hands are driven by simple 12:1 gears (called motion work) usually fitted just behind the exterior dials. Larger images are available here: http://mysite.wanadoo-members.co.uk/waitingtrain2/index.jhtml