Wristwatch Essentials: What is a Manual Wind Movement?

In a mechanical watch the two methods of delivering power to the mainspring are automatic or manual wind. Both are effective methods of powering your watch and maintaining accurate time keeping. However, with manual wind movements being first on the scene, what is a manual wind movement and how is it different from an automatic?

Before we explore the manual wind in detail, it should be noted that neither manual or automatic is considered better or more preferable over the other. The choice of movement from brands is often decided based on several factors such as the watch type, complications, watch size, and many other elements. There is also little impact on cost or desirability when it comes to automatic or manual wind. Brands like Patek Philippe, Richard Mille and Vacheron Constantin use both in their product line ups. For example, Patek’s Nautilus 5726 with an annual calendar complication, uses an automatic calibre. Whereas the Patek Grand Complications 5470P monopusher chronograph uses a manual winding calibre.

The difference between an automatic and manual wind movement can simply be explained as the way in which they provide power to the mainspring. The mainspring is the petrol tank of your watch, it’s where all the energy is stored ready to be deployed through the gears and motion works in order to make the hands move. The ability to store energy requires the mainspring to be wound or coiled. As the spring is wound tighter it holds more energy, which it will release as it unwinds. Think of those wind-up toys you had as kids, the more you wound them up the further they would travel across the living room carpet.

As the name suggests manual wind requires the wearer to manually add power to the mainspring. Most commonly by winding the crown. The easiest way to visually differentiate a manual wind from an automatic is the exclusion of a rotor. A manual calibre doesn’t require a rotor of any sort as the movement can only be powered through winding.

In order to add power to your movement you will typically rotate the crown clockwise and this causes the mainspring to coil. A key feature of a manual wind watch is that they can only wind the mainspring by rotating in a single direction. This is because the winding stem, which is the metal pin that connects the crown to the movement, tightens the mainsping when turned in a given direction. Wind the crown in the reverse direction and nothing will happen. Essentially, the winding stem won’t engage with the winding mechanism connected to the mainspring. Think of it like cycling the pedals backwards on a bicycle, the bike doesn’t start moving backwards, the pedals simply rotate freely.

With manual wind watches you need to be adding power at regular intervals to ensure the mainspring has enough energy to continue to operate the watch day after day. Because of this requirement to regularly add power, these movements are not common in dive watches which have a screw down crown to make them water tight. Instead they are better served for watches that are more at home away from water. How about on the moon? Omega’s Speedmaster Profession is arguably the most recognisable manual wind watch on the scene today. With the current generation of Speedmaster it is recommended that you wind the watch every 24 hours. This requires the wearer to complete 20 – 40 turns of the crown to achieve full power.

Different manual wind calibres will require a different number of rotations and winding intervals. One of the most extreme versions can be found in the A. Lange & Söhne Lange 31. The Lange 31 movement has a 31-day power reserve thanks in large part to not one, but two mainsprings. Each mainspring is approximately ten times longer than a standard mainspring. Winding these springs could be such a time consuming and cumbersome task that the Lange 31 comes with a unique winding key to speed up the process.

Many other watches have also defied convention when it comes to manual winding. Some by removing the crown all together. Perhaps the most extreme of these is the MB&F HM11. The watch itself looks like something out of Star Wars, and the way you wind the watch is by rotating the entire case. Rotate the case through 360 degrees 10 times and the watch will be fully powered. Alternatively, a single 90 degree rotation will give you 72 minutes of power.

In the early days of manual watches the biggest issue was with over winding. Once the mainspring is fully coiled if you continue to turn you are likely to do some serious damage to the winding mechanism and mainspring itself. This could be a big problem and a hefty repair bill. So, how would you know if the mainspring is fully wound or if you should keep winding?

The addition of a power reserve indicator, first introduced in a production watch by Jaeger LeCoultre in 1948, is one solution of particular importance for manual wind movements. The visual representation of mainspring power, as you’ll find on the H. Moser Endeavour Perpetual Calendar, clearly shows when you’re full. As an added safety feature many modern manual wind watches have a stopping mechanism that lets the user ‘feel’ when the mainspring has reached capacity.

The most common stopping mechanism uses a small hook inside the mainspring barrel. This hook catches the end of the mainspring to prevent it winding any further. The wearer will feel the crown hit a point of resistance whereby it doesn’t want to turn any more. This is the signal to stop winding, you’re at max power. In modern watches it’s quite difficult to overwind your manual movement unless you ignore and push past the point of resistance.

Manual Wind Movement Pros and Cons

Manual wind movements have both positives and negatives. If you enjoy the mechanical art of a watch movement and want to be involved in its operation then manual winding might be your preferred calibre.