Tower clock

Tower clock

Tower clock

The digital tour in the Saarland Clock Museum was made possible by the support of:


The first written mention of a clock in literature can be found in the "Divine Comedy" (approx. 1320) by Dante Alighieri (1265 - 1321):

How, well arranged, the wheels of clocks do -
the last one seems to fly in a hurry
the first seems to be resting when you look at it.
So set in motion differently
every circle, as it turned out,
fast or sluggish, I appreciated his wealth.
On like clockwork that wakes us up to the hour
where the bride of God rises from the bed,
to say hello to the groom that he loves her.
That now pulls one cog, drives another.
To be, Tintin ‘ringing in such a lovely way,
that joyful the spirit of love swells.

The clockwork that the infernal poet marveled at was probably ticking in the Church of Santo Eustorgio in Milan. In 1309 it was given an "iron clock". (Drawing from 1461 of the Astrarium by Giovanni de Dondi (1364) as an example of a clock from the 14th century)


The mechanical wheel clock, invented at the end of the 13th century, as a tower clock, initially had the task of showing the tower guard the passage of the hours so that he could strike the appropriate time on a bell. We find their establishment in Italy: 1307 in Orvieto, 1336 in Milan or 1344 in Padua. The oldest surviving cathedrals are found in Salisbury 1386 and Wells 1392 in England. They had weight drive and striking mechanism. Soon, when the clock was not yet common knowledge, they could also use a dial facing the public to show the time.

From the 14th century onwards, these clocks with their striking mechanisms were also used in many communities to indicate the opening and closing of city gates, the beginning and end of market times, as well as council and court sessions. Many of these clocks also had very elaborate astronomical or astrological indications as well as automatic figure machines, also known as Jacquemarts. Examples: 1352 Strasbourg Cathedral, 1356 the Nuremberg Men’s Run, the Ulm City Hall Clock, the Bern Clock Tower, etc.


The first tower clocks still had balance beams and verge escapements and only from the 17th century pendulums. Heavy stones and later weights on ropes were used as propulsion. They had to be raised either daily, every three days, or later every 8 days. At first this was done with handwheels, later with cranks. It was not until the 1930s that electric motors were used for winding. Over time, the works were improved and made smaller or even equipped with synchronous motors. Today these clocks usually only have clocks that are accurate to the second or are radio-controlled.

On the next page you will find the video of a tower clock from approx. 1530:


The tower clock (approx. 1530) with balance escapement was rebuilt around 1750 (modernized to anchor escapement and seconds pendulum) and dismantled again in 2012. After the dismantling, the clock has balance escapement again with weights, spindle and steering wheel on the original armature shaft, all parts are made of forged iron. The cycle time for a full oscillation is 4 seconds. The clock is built on a very old oak frame - this is possibly the original console of the clock - and has an iron frame (forged flat iron). The movement and the hourly striking mechanism are of the old head-to-head design with forged and filed iron wheels and hollow drives (lantern drive) and square forged iron shafts. The elevator runs via a crank and a sliding hollow drive (coupling) on ​​a spur gear connected to the wooden cable drum. The striking mechanism has an internally toothed lock disc with a large wind vane. The escape wheel has 28 teeth, the drive 72 teeth, the intermediate gear on the left 63 teeth, the winding via spur gear has an external winding shaft. A pointer mechanism does not exist, it is a pure striking mechanism clock. During the restoration, the weights were added according to old sandstone patterns.

Temporal hours

Since in the early days of wheel clocks only the hours of day from sunrise to sunset (the working time) were of interest, it had to be taken into account that the twelve hours of the day were of different lengths. The weights on the balance beams were moved either inwards (faster - winter) or outwards (slower - summer) depending on the season.

As astronomers became more and more precise in determining the highest point of the sun - as opposed to sunrise and sunset - the day was eventually set at 24 hours and midday at 12 o'clock.

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