Why does a Watch Need a Second Hand?
By: Dyedo Tikio
Tags: Knowledge, Learning, Sharing, Storytelling, Watches

Why does a Watch Need a Second Hand?

A wall clock, desk clock or watch has 3 basic hands. These are the hour, minute and second hands. But when we check time, we only need the hour and minute hands. So what is the second hand appearing on the dial for? Do we let our free time have nothing to do, can we sit and watch time slowly pass in vain?

In fact, the second hand is not so essential on the dial, but not useless either. And the second hand also has a pretty heroic history and a great deal of responsibility, which many of us may not even know.

When did the second hand appear?

The seconds hand is actually a later innovation on modern timepieces, but they have appeared from the 15th century. Although, at the time, the seconds hand was still uncommon. This is partly due to user’s needs and partly due to technology.

The second hand first appeared in the 15th century on pocket watches made in Germany. At that time, the second hand was mainly used for specialized watches, rather than for conventional watches.

With conventional watches, the second hands had no practical effect and were also difficult to manufacture. Until the 17th century, watchmakers added a “4th wheel” to a standard 3-wheel movement, with a rotation period of exactly 1 minute.

Then, this 4th gear is combined with an external gear, responsible for stop time. Since then, it has become simpler for the manufacturers to add an extra dial and second hand to the watch, and also more common.

In the 19th century, the second hand and seconds sub dial became popular. It was not until the 20th century that the second hand was introduced into the center, on the same axis and dial as the minute and hour hands. However, the second hand was still considered only a subset of the powertrain inside the watch.

It wasn’t until 1948, that Zen’s Cal’s watch. 133 marked the shuffle in the arrangement of the gears, to set the second hand as the center of the movement. Previous “indirect” seconds hand caused their movement to vibrate on the dial. The minute hand wheel previously located in the center was shifted outward and became the minute hand indirectly, and the vibrations of the minute hand were ignored due to its relatively slow movement.

Why does a watch need a second hand?

First, a watch is not required to have a second hand and it can still function properly, accurately displaying the time. In fact, there are still a lot of watches today that do not have a second hand.

The meaning of the second hand stems from the need to accurately measure time. That is why most chronographs (chronographs feature) have a large central second hand and a sub-dial to show the seconds that are running normally.

During war, the second hand stop feature is also very important. “Stop seconds” or “Hacking” became a popular feature after the US military asked for A-11 watches during World War II.

Soldiers often cannot communicate directly with each other, but need to coordinate their actions correctly. A second hand that can be stopped for synchronization is crucial when performing a task.

While it seems simple enough, this hacking effect requires technical components that a typical watch doesn’t have. The manufacturer must add a lever or brake to prevent the movement of the main wheel, when pulling the crown, the entire movement of the watch will stop. However, until now, this feature has become very popular and is available on almost all types of wristwatches.