Blancpain, Fifty Fathoms Divers Watch, Horology Deconstructed

High resolution, book format. Deconstruction Series Blancpain The Original Fifty Fathoms Divers Watch by THE NAKED WATCHMAKER Images from www.thenakedwatchmaker.com All texts, photographs and illustrations are Copyright ©2018 The Naked Watchmaker Edition BP1a Formatted for use on mobile telephones, laptops and tablets. All rights to this publication are reserved. It would be appreciated by the author that no part of this book may be reproduced, copied or transmitted in any form or by any means, electronic or mechanical, including photocopy, xerography and videography recording, with out the permission of The Naked Watchmaker. The Original Fifty Fathoms Divers Watch The original Fifty Fathoms carried the trademark “LIP Blancpain”. LIP was a watch retailer in Paris and manufacturer in Besançon. Jean-Jacques Fiechter, Blancpain's CEO from 1950 until 1980, a diver himself, developed the Fifty Fathoms model. On the following pages is an example of the original Fifty Fathoms divers watch which was manufactured in the early 1950’s. Incabloc, ie shock protection for the balance pivots of the balance staff, was developed in the late 1940’s. This was a considerable evolution in practical watchmaking. Prior to Incabloc, when watches received shocks, the balance pivots could be easily broken and the watch would stop. This was such a phenomena that the military would employ watch technicians to repair the watches that were being damaged in action. Antimagnetic/waterproof & shockproof, even automatic, as engraved below were all technological advances of the period and used as strong selling points. This watch was restored & photographed at Blancpain in their restoration workshop. The soft iron cover (cage) protecting the movement from magnetism. The pip, or button in the centre would push against the inner case back holding the movement in place. The fully assembled movement. The under-dial view of the movement. The mainplate is slightly domed as was often the style in the 1940’s to allow a curved dial to be added. The dial, with luminescent indexes printed onto the surface. The original luminescent materials used, specifically for the military due to their norms, were highly radioactive, more-so than for models which were made for the public, as were the hands. The rotor weight. The milled out section below the pivoting point for the rotor creates a spring section in the rotor to allow the rotor to flex avoiding the rotor axel to be broken in case of shocks. Cut aways showing the position of the Swiss lever escapement and part of the automatic winding mechanism. The movement in this sequence of images is being dismantelled for the first time and is not in its final serviced state. The automatic block removed. The intermediate automatic winding wheel removed. The upper crown wheel and ratchet wheel removed. The train bridge removed. The barrel bridge removed. All parts removed except the centre wheel and escapement. The order of disassembly is for photographic purposesonly. When servicing a calibre the order is different,removing the balance and escapement first. Explosion of the calibre excluding the rotor weight. Summary The Fifty Fathoms shown in this book is one of the first to have been made in the early 1950’s. By comparison to the modern version, it is of a far inferior quality both in finishing and technical execution, showing the distance that the contemporary version has evolved. It is, however, a classic example of the beginning of the evolution of the divers watch and represents one of, if not the very first official divers watch to be made in horological history. Despit