391 – Hydraulic ram from Haslital Berne
This water pump does not require any external energy. It is propelled by the water itself. Thanks to its hammering rhythm, it was given the name “ram”.
Economic Activity
A ram is ideal for homes or stables with no electricity. If there is a stream or pond nearby, all it needs is a gentle gradient, no other energy.
The water from the drive pipe accelerates in the narrower waste valve. Negative pressure causes this to close abruptly. The water now opens the delivery check valve upwards and flows into the pressure vessel. There, the air is compressed, and back pressure closes the delivery check valve. The water now looks to escape the overpressure in the vessel and rises up into the delivery pipe. At the same time, the pressure in the drive pipe drops when the delivery check valve is closed. The waste valve re-opens, and the process starts all over again.
A ram can pump water up to 15 times its height. After being started just once, this pulsing system continues to work as long as water continues to flow. This model is powered at 80 to 150 litres a minute.
Builder/Occupants
The first ram was patented in 1797 in France, with other countries then following suit. In Switzerland, Johann Georg Schlumpf began manufacturing rams from 1885. In 1923, he developed the automatic self-ventilation system. This fills the air cushion in the vessel, enabling rams to run for decades without any maintenance.
This ram is a model from 1923. There is no record of who used it in the past. It was last stored in the Haslital valley. The owner of a barn collection offered it to the museum via the Förderverein Ballenberg.
The Building in the Museum
The ram complements the machinery of the Open-Air Museum. It brings the thumping sound that once reverberated in many mountain landscapes back to life.
It was restored and installed in 2021. The museum does not have a natural stream, so the ram pumps water in an artificial closed circuit.
Ballenberg
Swiss Open-Air Museum
Museumsstrasse 100
CH-3858 Hofstetten bei Brienz
Opening hours Administration
3 November 2025 to 8 April 2026
From Monday to Friday
8.30 am to 11.30 am
1.30 pm to 4.30 pm
Opening hours
9 April to 1 November 2026
10 am to 5 pm daily
